WI Earlier invention of use of fins to stabilize smooth-bore cannon projectiles

[Alfred Montestruc]

In the 1960s smooth-bore tank guns were reintroduced by the USSR where some clever engineer figured out one could use fins to stabilize a projectile and have less loss of muzzle velocity.

http://en.wikipedia.org/wiki/Smoothbore

" To reliably penetrate the thick armor of modern armored vehicles, a very long, thin kinetic-energy projectile is required. The longer the projectile is in relation to its diameter, the higher the spin rate must be to provide stability. Practical rifling can only stabilize projectiles of a limited length-to-diameter ratio, and these modern rounds are simply too long. These rounds are instead formed into a dart shape, using fins for stabilization. With the fins for stability, rifling is no longer needed, and in fact the spin imparted by rifling would degrade the accuracy of a finned projectile. The first tank with a smoothbore gun was the Soviet T-62, introduced into service in 1961; today all main battle tanks except the British Challenger 2 and Indian Arjun MBT use smoothbore guns. The Russian navy conducted experiments with large-caliber smoothbore naval guns, which were halted by budget cuts."

This is a matter of thinking the problem through, not of high technology. This innovation could have been introduced at any time after the invention of rifling. Using sub-caliber armor piercing shot with a sabot and fin stabilization would have a huge advantage in armor penetration

For sake of discussion, suppose this was thought of by the German Navy prior to WWI and kept a deep dark secret, and numerous German battleships and battle-cruisers are given smooth-bore main guns with APFSDS (Armor Piercing Fin Stabilized Discarding Sabot) ammo for them.

Without question, German heavy naval units with such weapons could roll over British heavy units of similar size. One hit from a hypothetical German 11" APFSDS round would be worth several from a British standard 12" AP round, at much longer ranges.

Again for the sake of argument, the German navy puts to sea shortly after the outbreak of hostilities in 1914 and trounces the RN inflicting very heavy losses, and forcing a retreat where the RN clearly no longer dominates the North Sea or Atlantic.

Now what?

[Don Phillipson]

Post by Alfred Montestruc
In the 1960s smooth-bore tank guns were reintroduced by the USSR where
some
clever engineer figured out one could use fins to stabilize a projectile
and have less
loss of muzzle velocity.
http://en.wikipedia.org/wiki/Smoothbore
. . .
suppose . . . numerous German battleships and battle-cruisers are given
smooth-bore main guns with APFSDS (Armor Piercing Fin Stabilized
Discarding Sabot) ammo for them.
. . .
the German navy puts to sea shortly after
the outbreak of hostilities in 1914 and trounces the RN inflicting very
heavy
losses, and forcing a retreat where the RN clearly no longer dominates
the North Sea or Atlantic.

1. The metallurgical science necessary to build such a missile
had not yet been discovered by WW1.

2. Hitting the target was the main problem of naval gunnery (and
German ships shot more accurately than British ones in 1916.) Other
factors include the rate of fire (speed at reloading).

3. No navy commander introduces a new weapon in "numerous"
ships. Trials take months or years, and existing weapons are
not discarded until the new one has been proved better.

4. A superior weapon does not alter the geography, that
RN ports are much better placed to blockade NW Europe than
KM ports are to launch a campaign against RN fleets.

[Alfred Montestruc]

Alfred Montestruc" <monte wrote in message
news:9968b8c9-3b30-4ca5-a82d-5de

Post by Alfred Montestruc
In the 1960s smooth-bore tank guns were reintroduced by the USSR where
some
clever engineer figured out one could use fins to stabilize a projectile
and have less
loss of muzzle velocity.
http://en.wikipedia.org/wiki/Smoothbore
. . .
suppose . . . numerous German battleships and battle-cruisers are given
smooth-bore main guns with APFSDS (Armor Piercing Fin Stabilized
Discarding Sabot) ammo for them.
. . .
the German navy puts to sea shortly after
the outbreak of hostilities in 1914 and trounces the RN inflicting very
heavy
losses, and forcing a retreat where the RN clearly no longer dominates
the North Sea or Atlantic.

1. The metallurgical science necessary to build such a missile
had not yet been discovered by WW1.

That would not be correct. Metallurgy has almost nothing to do with this. Please explain what EXACTLY you think the metallurgy could affect?


Metallurgy of the gun barrel? No way, the pressures would be the same or less, if you think that you are showing a lack of understanding of what is going on.

Metallurgy of the projectile? It can be made of the same material you make a gun barrel of, so that will not fly either.

Metallurgy of the Sabot? No, that is generally made of lighter metals such as Aluminum which was in common use by that time.

The metallurgy argument is one often used by people who have no clue about a technical subject. The only case I know of where it was true was on gas turbines, and you needed a small amount of either Molybdenum or Tungsten to mix with your steel & nickle to make the turbine blades not creep and crack under high temperatures. Gun metallurgy was stable and well established well before WWI.

2. Hitting the target was the main problem of naval gunnery (and
German ships shot more accurately than British ones in 1916.) Other
factors include the rate of fire (speed at reloading).

Penetration of armor at any given range is also a major issue. If my projectile will punch right through your ship's very thickest armor, at ranges where your gun cannot punch through most of my ship's armor, you are up the proverbial creek without a paddle. Aside from that, an APFSDS round has a much higher velocity and so flatter trajectory than a standard APHE round, so drop is less and so you have less of a correction to make.

It is a well proven fact that APFSDS ammo will punch through much thicker armor than the same gun firing standard AP at the same range and that it has a much flatter trajectory. If secrecy is kept, the British will not know till the German battleships open fire and start blowing up British ships at "impossible" ranges, and nearly all the hits do far more damage than expected, and the British ships would have to run a long gauntlet of fire to close to ranges they could hurt the German ships at.

3. No navy commander introduces a new weapon in "numerous"
ships. Trials take months or years, and existing weapons are
not discarded until the new one has been proved better.

They do keep developed weapons secret as long as they can. The Germans might have done first concept designs and production of prototypes in the 1890's, then proving ground tests, then introduced them in quantity to large battleships and battle-cruisers and so on, so again this is not pertinent.

4. A superior weapon does not alter the geography, that
RN ports are much better placed to blockade NW Europe than
KM ports are to launch a campaign against RN fleets.

No, but it can render the Geography largely irreverent, if the British fleet could not run the Germans away from anywhere the high seas fleet wanted to go, then they are pretty much useless.

--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

[Don Phillipson]

Post by Don Phillipson
1. The metallurgical science necessary to build such a missile
had not yet been discovered by WW1.
That would not be correct. Metallurgy has almost nothing to do with
this.
Please explain what EXACTLY you think the metallurgy could affect?

The task is to build missile fins strong enough to survive firing
and the flight to target without damage, and an expendable sabot
that would not damage the gun barrel while protecting the missile
fins. I believe mass production of such devices was beyond the
horizon of munitions factories in WW1.

Post by Don Phillipson
2. Hitting the target was the main problem of naval gunnery (and
German ships shot more accurately than British ones in 1916.) Other
factors include the rate of fire (speed at reloading).
Penetration of armor at any given range is also a major issue. If my
projectile will punch right through your ship's very thickest armor, at
ranges where your gun cannot punch through most of my ship's armor,
you are up the proverbial creek without a paddle. . . .
It is a well proven fact that APFSDS ammo will punch through much
thicker armor than the same gun firing standard AP at the same range
and that it has a much flatter trajectory.

Big battleship guns use "plunging fire" (shells lobbed in a high
ballistic arc) to penetrate targets at ranges up to 15 or 18 km.
The flat trajectory of fin-stabilized shells inhibits their use at
this range besides preventing "plunging fire."

Modern smooth-bore artillery such as https://en.wikipedia.org/wiki/T-62
is designed for ranges up to 4 km. This would be useless for
battleships. It is no good deploying a weapon guaranteed fatal
at 4 km. if you can be cannonaded to bits at 14 km. range, before
you get close enough to use it.

The present (short) range of NRP guns supports my suggestion the
metals technology of 1914 would not have permitted
development of 15-km. NRP guns during WW1
--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

[Alfred Montestruc]

Post by Don Phillipson

Post by Don Phillipson
1. The metallurgical science necessary to build such a missile
had not yet been discovered by WW1.
That would not be correct. Metallurgy has almost nothing to do with
this.
Please explain what EXACTLY you think the metallurgy could affect?

The task is to build missile fins strong enough to survive firing
and the flight to target without damage, and an expendable sabot
that would not damage the gun barrel while protecting the missile
fins. I believe mass production of such devices was beyond the
horizon of munitions factories in WW1.

The missile fins can be forged as part of the projectile, one can set up a hydraulic forge die to do this at temperature. After the missile blank is forged into shape it is quenched and tempered. If you wanted to get fancy you would use a steel with 0.2% carbon or less and carburize the sharpened tip, and protect the rest from carburization, quench and temper at ~ 400 F , that will give you a missile with a tip hardness of ~ 58 Rockwell C. Carburization of steel predates the industrial revolution so that is old technology. So does forging. Forging using hydraulic or steam rams and dies rather than hammers is a 19th century innovation.

The Sabot is designed to fall apart after leaving the gun muzzle so if we have three symmetrical fins we make a five part part sabot. A base plate/gas seal, three identical fill-in segments that take up the space between missile and bore, and a weak slender ring that wraps the front of the sabot to the projectile, but is only strong enough to allow it to be loaded. All of the sabot parts can be Aluminum, a very few experiments need be run to determine the ring part geometry so it is strong enough, but not too strong.

Inside the gun, the base plate, and three segments of sabot together with the missile will be held together by the pressure behind the base and gun barrel. As the group leaves the muzzle the ring should have already snapped and the three segments and base plate will fall off the missile.

Post by Don Phillipson

Post by Don Phillipson
2. Hitting the target was the main problem of naval gunnery (and
German ships shot more accurately than British ones in 1916.) Other
factors include the rate of fire (speed at reloading).
Penetration of armor at any given range is also a major issue. If my
projectile will punch right through your ship's very thickest armor, at
ranges where your gun cannot punch through most of my ship's armor,
you are up the proverbial creek without a paddle. . . .
It is a well proven fact that APFSDS ammo will punch through much
thicker armor than the same gun firing standard AP at the same range
and that it has a much flatter trajectory.

Big battleship guns use "plunging fire" (shells lobbed in a high
ballistic arc) to penetrate targets at ranges up to 15 or 18 km.
The flat trajectory of fin-stabilized shells inhibits their use at
this range besides preventing "plunging fire."

That would be incorrect. The angles would be a bit different, but you would still get plunging projectiles at long range so it would still work. In fact a flatter trajectory makes hit probability higher. If you plunge at 45 degrees the angular width/footprint of the target is smaller than if you plunge 25 degrees, and your velocity is a lot higher so it will penetrate thicker armor.

Post by Don Phillipson
Modern smooth-bore artillery such as https://en.wikipedia.org/wiki/T-62
is designed for ranges up to 4 km.

That is a tank gun with a 115 mm bore = 4.527" bore gun. We are talking naval gunnery, that would be a small gun for a WWI destroyer, let alone a battleship. Smaller guns have intrinsically shorter ranges due to something called the cube square law.

http://en.wikipedia.org/wiki/Square-cube_law

Bottom line a smaller bore gun will have a much shorter range than a larger bore gun all else held equal. So a 0.30 caliber rifle with a muzzle velocity exactly equal to a 4.527" gun with an exact scale projectiles, both being exact scale replicas of each other, made of the same material is going to slow down much much faster than the projectile from a 4.527" gun.

The drag area of your rifle projectile divided by the volume and so weight or mass of the projectile will be 15.1 times higher than that of the cannon. The same effect happens when you compare larger to smaller cannon. A typical 30 caliber rifle has a practical range of maybe 400 meters. The velocity of the projectile has dropped a lot by 400 meters. It could still kill an unarmored man, but the kinetic energy of the bullet has dropped to 53% of the starting energy. As an armor piercing projectile it would be pretty useless at that range, so the ratio of effective ranges between a 30 caliber rifle and 4.527" gun would be larger than 10:1

http://gundata.org/blog/post/30-06-ballistics-chart/


Your numbers, are no good in the first place as you are starting with a tank gun, not a naval gun. It is not reasonable to compare the 11" German naval gun with the rinkidink little 4.527" gun as far as range goes.

The ratio of the ratio of drag area to projectile mass of the 11" to the 4.527" would be 2.43, so the projectile from the 11" gun would obviously shoot many times further and much harder than from a 4.527" gun as the projectiles will lose speed more slowly.

Post by Don Phillipson
This would be useless for
battleships. It is no good deploying a weapon guaranteed fatal
at 4 km. if you can be cannonaded to bits at 14 km. range, before
you get close enough to use it.

This sounds like you seriously do not have any idea of the physics of guns or projectiles. The APFSDS rounds work by being very long with fins on the end and so for their mass, they have very, very low drag. They typically will have an L/d (Length divided by diameter) ratio much larger than 15, while a typical standard naval AP round might be as short as a 3:1 L/d.

Again dragging up the fundamental ratio of drag area divided by volume, for a projectile of equal diameter, and an L/D of 3, set next to one with an L/D of 15 the drag area to volume (which pinch hits for mass) is 5 times larger, so that short projectile slows down much faster.


The tank guns you are talking about are small bore weapons and the maximum practical range of a tank gun is the maximum practical range at which you can spot another tank, and penetrate it's heaviest armor. The range will jump up a lot as you go from a small bore weapon to a really big bore gun.

If an 11" naval gun has a range with a 18.1+ km range, which it does, with an ~ 3 L/d APHE projectile, the range will be a lot LONGER with a APFSDS round out of the same gun. Why? because the coefficent of drag (Cd) on a long narrow aerodynamic streamlined finned shape is much lower than on a short bullet like shape such as a short cylinder. Even more important, the drag area*Cd/mass of a streamlined and finned shape is much smaller than the drag area*Cd/mass of a short cylinder.


http://en.wikipedia.org/wiki/28_cm_SK_C/34_naval_gun
http://en.wikipedia.org/wiki/28_cm_SK_L/50_gun
http://en.wikipedia.org/wiki/28_cm_K_L/40_%22Kurf%C3%BCrst%22
http://en.wikipedia.org/wiki/Drag_coefficient

Say for the sake of argument 2 11" gun shells fired, both with a muzzle velocity of 715 m/s both with a weight of 240 kg at the start counting both the missile and sabot in that weight. The Cd of the standard shell will be 1.15, the area is pi*(283mm)^2=62901mm^2 so Cd*Area/mass= 301 mm^2/kg. Then assume the sabot weighs in at 96kg, the projectile weighs in at 144 kg, and has a diameter of 125mm and length of 1330 mm. That makes it's Cd*drag area/mass=3.42 about 1/88 of that of the standard shell. That projectile is going to travel a lot further a lot faster with the same initial speed, and will have much more ability to penetrate armor at much longer ranges.

Post by Don Phillipson
The present (short) range of NRP guns supports my suggestion the
metals technology of 1914 would not have permitted
development of 15-km. NRP guns during WW1
--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

Look Don, no hard feelings, but you clearly do not know enough about the physics of guns or projectiles to have an intelligent discussion on the subject, that bit about thinking that the effective range of a 115 mm gun is going to have much effect on the range of a 283 mm gun makes that really clear. So does that nonsense about metallurgy.

FYI - the sabots on modern tank guns are made from carbon fiber composite materials, not metal, so you don't know what you are talking about on that -- again, that implies to me that you might be able to get away with using some wood in your sabot on a big gun. Not all by any means, but some, you would still need a metal base-plate..

http://en.wikipedia.org/wiki/M829#Variants.23M829A2

You clearly do not want to talk about the military and political implications, which is what I was interested in, so I am not going to reply to more claims to the effect that it would not work.

You don't have the technical chops to have an intelligent discussion on the subject so, I will not bother.

I have a graduate degree in engineering and have published academic papers in design engineering. I was interested in the military and political fallout, not debating someone who thinks it could not work, who clearly does not know the subject well enough to have an intelligent opinion on that matter.

You have a right to believe whatever you want, that does not make it an educated intelligent opinion.

[Don Phillipson]

Post by Alfred Montestruc
no hard feelings, but you clearly do not know enough about the physics of
guns
or projectiles to have an intelligent discussion on the subject,
You clearly do not want to talk about the military and political
implications,
which is what I was interested in, so I am not going to reply to more
claims
to the effect that it would not work.
You don't have the technical chops to have an intelligent discussion on
the
subject so, I will not bother.
. . .I was interested in the military and political fallout,
not debating someone who thinks it could not work

This makes the OP's argument look like:
1. Non Rotating Projectiles were in 1914 feasible weapons.
2. German industry had the capacity to produce enough NRP
battleship guns (say 11-inch = 300 kg. shell weight) to equip
a significant number of ships before 1914.
3. The Kriegsmarine would have approved (say 1910-1914)
development of NRP guns and would have approved their
installation on at least some warships by 1914, i.e. replacing
guns of known effectiveness with which crews had trained.
This is a significant change of policy -- as was Tirpitz's
reorganization of the KM from a coastal fleet to a "blue
water" fleet.
4. Introduction of the new weapon would be successfully
secret in ways Dreadnought battleships never were.

Germany commissioned 11-inch Dreadnoughts from 1904
and the RN could count them (31 in 1914) and inspect most
either in port or at periodical RN and KM formal regattas.
If half these ships were withdrawn from service for some
unannounced reason (to be re-equipped with NRP guns)
we must suppose the RN would not notice, or else might
notice but would be unable to find out the reason.

This argument looks at least as interesting as the
supposition that a miracle weapon destroyed half
Jellicoe's fleet in 1914, with later "military and political fallout."

[The Old Man]

Germany commissioned 11-inch Dreadnoughts from 1904 and the RN could count
them (31 in 1914) and inspect most either in port or at periodical RN and KM
formal regattas.
If half these ships were withdrawn from service for some unannounced reason
(to be re-equipped with NRP guns) we must suppose the RN would not notice,

? or else might notice but would be unable to find out the reason.

This argument looks at least as interesting as the supposition that a miracle
weapon destroyed half Jellicoe's fleet in 1914, with later "military and
political fallout."

German naval intelligence (I'm assuming that there WAS some) might spread rumors that the affected ships were brought back to harbor owing to "malfunctioning engines", or "aiming control problems with their big guns" (the British WOULD have spies keeping an eye on the shipyards after all) to somewhat assuage their fears. Misinformation is the key.

Regards,
John Braungart

[Alfred Montestruc]

Post by The Old Man

Germany commissioned 11-inch Dreadnoughts from 1904 and the RN could count
them (31 in 1914) and inspect most either in port or at periodical RN and KM
formal regattas.
If half these ships were withdrawn from service for some unannounced reason
(to be re-equipped with NRP guns) we must suppose the RN would not notice,

? or else might notice but would be unable to find out the reason.

This argument looks at least as interesting as the supposition that a miracle
weapon destroyed half Jellicoe's fleet in 1914, with later "military and
political fallout."

German naval intelligence (I'm assuming that there WAS some) might spread rumors that the affected ships were brought back to harbor owing to "malfunctioning engines", or "aiming control problems with their big guns" (the British WOULD have spies keeping an eye on the shipyards after all) to somewhat assuage their fears. Misinformation is the key.

Yes lots of disinformation. As I said, attempting to hide the smooth-bore guns is not likely to work, but hiding the exact nature of the APFSDS ammo probably could work with lots of disinformation, and fake super AP ammo that in fact does not work all that well.

Post by The Old Man
Regards,
John Braungart

[h***@gmail.com]

Post by Alfred Montestruc

Post by The Old Man

Germany commissioned 11-inch Dreadnoughts from 1904 and the RN could count
them (31 in 1914) and inspect most either in port or at periodical RN and KM
formal regattas.
If half these ships were withdrawn from service for some unannounced reason
(to be re-equipped with NRP guns) we must suppose the RN would not notice,

? or else might notice but would be unable to find out the reason.

This argument looks at least as interesting as the supposition that a miracle
weapon destroyed half Jellicoe's fleet in 1914, with later "military and
political fallout."

German naval intelligence (I'm assuming that there WAS some) might spread rumors that the affected ships were brought back to harbor owing to "malfunctioning engines", or "aiming control problems with their big guns" (the British WOULD have spies keeping an eye on the shipyards after all) to somewhat assuage their fears. Misinformation is the key.

Yes lots of disinformation. As I said, attempting to hide the smooth-bore guns is not likely to work, but hiding the exact nature of the APFSDS ammo probably could work with lots of disinformation, and fake super AP ammo that in fact does not work all that well.

Post by The Old Man
Regards,
John Braungart

What if, rather than around WWI, someone came up with the idea much earlier (say, 1700 odd). When smooth bores were the rule.

The idea of fins to stabilise a missile was hardly new (think, arrows). The guns were already smooth bore. The only 'eureka' idea was the sabot.

This would very possibly lead also to a much earlier adoption of the percussion fuse and explosive shells. The problem with shells in round shot is a reliable fuse, given that one cannot know which part of the ball will hit the target. With a stabilised 'dart' projectile, no such problem.

Could the idea have significantly affected 18th century warfare ? I'm assuming the metallurgy issue could be dealt with, I don't really see it as a biggie (The sabots could even be made of wood!)

[Alfred Montestruc]

Post by h***@gmail.com

Post by Alfred Montestruc

Post by The Old Man

Germany commissioned 11-inch Dreadnoughts from 1904 and the RN could count
them (31 in 1914) and inspect most either in port or at periodical RN and KM
formal regattas.
If half these ships were withdrawn from service for some unannounced reason
(to be re-equipped with NRP guns) we must suppose the RN would not notice,

? or else might notice but would be unable to find out the reason.

This argument looks at least as interesting as the supposition that a miracle
weapon destroyed half Jellicoe's fleet in 1914, with later "military and
political fallout."

German naval intelligence (I'm assuming that there WAS some) might spread rumors that the affected ships were brought back to harbor owing to "malfunctioning engines", or "aiming control problems with their big guns" (the British WOULD have spies keeping an eye on the shipyards after all) to somewhat assuage their fears. Misinformation is the key.

Yes lots of disinformation. As I said, attempting to hide the smooth-bore guns is not likely to work, but hiding the exact nature of the APFSDS ammo probably could work with lots of disinformation, and fake super AP ammo that in fact does not work all that well.

Post by The Old Man
Regards,
John Braungart

What if, rather than around WWI, someone came up with the idea much earlier (say, 1700 odd). When smooth bores were the rule.

Exactly.

Post by h***@gmail.com
The idea of fins to stabilise a missile was hardly new (think, arrows). The guns were already smooth bore. The only 'eureka' idea was the sabot.

Which was also known and used for grape shot, and for cannon balls to aid in sealing in propellent gass, so less leaked.

http://en.wikipedia.org/wiki/Sabot

Post by h***@gmail.com
This would very possibly lead also to a much earlier adoption of the percussion fuse and explosive shells. The problem with shells in round shot is a reliable fuse, given that one cannot know which part of the ball will hit the target. With a stabilised 'dart' projectile, no such problem.

But the percussion cap was not invented till the early 19th century, but with "arrow shot" that might provide incentive for an earlier introduction of it.

OTL the percussion cap was invented by a duck hunter tired of rain ruining his shots either by wetting the powder in his flintlock shotgun pan, or by the delay from the trigger pull and hammer fall, till the gun fired. Forsyth thought that the animals were dodging his fire on hearing the hammerfall.

http://en.wikipedia.org/wiki/Percussion_cap

http://en.wikipedia.org/wiki/Alexander_John_Forsyth

Post by h***@gmail.com
Could the idea have significantly affected 18th century warfare ? I'm assuming the metallurgy issue could be dealt with, I don't really see it as a biggie (The sabots could even be made of wood!)

The metallurgy issue is non-existent. Absolutely this would change 18th century warfare. This dramatically makes cannon accuracy, range and power grow before you add explosive sub-caliber munitions. Ok I am starting up my program again and assume that we have a 12 pounder field gun again and my previous example.

http://www.civilwarartillery.com/

(on the left hand side of the link pulldown technical information then shot tables)

So a common 12 pounder cannon has a bore of 4.62" and a typical shot diameter of 4.52". Commonly wadding or a wooden sabot. Imagine a three finned cast iron arrow 2" diameter about 10" long. It would weigh about 8 lb.

If you go back to the civil war artillery site and go to technical information then range tables, then scroll down to 12 pounder field gun with 5 degree elevation, and 2.5 lbs of black powder (maximum recommended) you get a range of 1663 yards. I set up a program using a spherical projectile drag coefficient of 0.48, and the mass of the ball (5.64 kg ~ 12lb) the size and mass of the projectile and back-solved for the muzzle velocity. I get 480 meters per second at the muzzle and an impact velocity of 98 meters per second, and a plunging angle of 22.9 degrees while the up angle was 5 degrees.

I use the same program for an arrow with a launch velocity of 480 meters per second 50 mm in diameter, up angle of 5 degrees, and weighing 8 lb, with a streamlined body drag coefficient of 0.04. The range where the arrow hits the ground is now 4217 yards with an impact velocity of 430 meters per second, with a plunging angle of 5.55 degrees on an up angle of 5 degrees.

So now let us use a 2.75" subcaliber round that weighs 10 lbs and has about the same rough length. With a muzzle velocity of 480 m/s and a 5 degree up angle, I get an impact range of 4258 yards and impact velocity of 438 m/s, plunging fire angle of 5.46 degrees. Again, the range went way up figure 3 lb black powder with a 75% reliable impact fuse. The best way to rig the percussion primer is a pin in the back between the fins that hits the primer on impact. That way the pin cannot hit on firing as it is being accelerated forward, on impact it is decelerated so the pin will fly forward and hit the primer.

That would tear up wooden sailing ships something fierce.

Like I said, much longer range, much more effective cannon, shore batteries would be much much more effective.

[Alfred Montestruc]

Post by Don Phillipson

Post by Alfred Montestruc
no hard feelings, but you clearly do not know enough about the physics of
guns
or projectiles to have an intelligent discussion on the subject,
You clearly do not want to talk about the military and political
implications,
which is what I was interested in, so I am not going to reply to more
claims
to the effect that it would not work.
You don't have the technical chops to have an intelligent discussion on
the
subject so, I will not bother.
. . .I was interested in the military and political fallout,
not debating someone who thinks it could not work

1. Non Rotating Projectiles were in 1914 feasible weapons.

Correct,

Post by Don Phillipson
2. German industry had the capacity to produce enough NRP
battleship guns (say 11-inch = 300 kg. shell weight) to equip
a significant number of ships before 1914.

Since they did equip nearly all German BB and BC class vessels with 11" rifles, and providing a non-rifled variations REDUCES the work load in original manufacture, that would in fact be 100% correct. Furthermore removal of rifling is just not that hard. Yes you must pull the gun from the BB and ream out the rifling, and that means you will have a slightly larger caliber. Big deal, you need additional projectiles anyway.

Post by Don Phillipson
3. The Kriegsmarine would have approved (say 1910-1914)
development of NRP guns

Probably earlier I suggested a time frame of the 1890s for preliminary testing.

Post by Don Phillipson
and would have approved their
installation on at least some warships by 1914, i.e. replacing
guns of known effectiveness with which crews had trained.
This is a significant change of policy -- as was Tirpitz's
reorganization of the KM from a coastal fleet to a "blue
water" fleet.
4. Introduction of the new weapon would be successfully
secret in ways Dreadnought battleships never were.

The guns need not be secret. You can construct a disinformation campaign to go with this that hides the sub-caliber APFSDS munitions which is the critical technology.

You have several fake secrets that are used as a bodyguard of lies to protect the APFSDS munitions.

For example the British will swallow no problem that the smooth-bore guns will produce higher velocities, and so better energy and penetration of at the same range, a less than 10% improvement, that is basic physics.

The Germans have a "secret" mechanism for deploying fins on standard full caliber AP rounds that make the rounds as or more accurate than standard AP rounds and they hit harder. The "secret mechanism" is the great secret, and German intelligence creates a number of fake traitors to sell several different mechanisms to British intelligence, ones that work badly.

Start rumors that the real secret is a fantastical lubricant painted on the tips of German AP rounds that allows much greater penetration, but cannot tolerate spin, and so on.

Then German intelligence spreads disinformation of serious problems with deployment of this smooth-bore AP round fins, such that it is not that reliable, these are badly hushed up. Rumors of corruption in high places that Krupp is paying fantastic bribes to Naval and Government officials to continue the program. Rumors that the Kaiser is unconcerned so long as on paper he has a large fleet with high military capability. Have the Kaiser make public statements backing the smooth-bore guns as a great modern weapons system that the British cannot equal, blah, blah.

As with Sun Tzu, lots of disinformation, you cannot practically hide the smooth-bore guns.


However, you can practically hide the APFSDS ammo, by having the ammo look like a more or less standard AP round with fake deploy-able fins for "show" rounds, and tell sailors the fins are inside the round, and pop out on real ones after being fired. Make the Sabot cover the whole of the sub-caliber projectile so that the nature of the projectile does not show in stored or handled ammo.


Sailors and officers on the ships that use the weapons need not know the details of how the weapon works. They have strict orders never to try to disassemble the rounds and to never ever let a round fall into anyone's hands but authorized personnel, and never fire such a round other than when authorized which is only at authorized firing ranges. The officers and crew are shown by demonstration what the weapon does to armored targets.

They are also instructed that dis-assembly of these rounds, or allowing such rounds to fall in to unauthorized hands is treason and will be punished as such. That what they do not know, they cannot betray.

Manufacturing of the rounds is done in secret by a small team, and information is kept as compartmentalized as possible.

The German naval staff who know the real performance of the weapon, but not how it works, is tasked with coming up with strategies for attacking the British fleet under three assumptions

1) That the British do not expect the effects you can achieve but only think it will be marginally superior standard AP rounds.

2) For after they have a clear idea of the real effects,

3) For a case were German disinformation has successfully been planted that the smooth-bore AP ammo is unreliable and the German fleet must close to very close ranges to have any chances of winning.

On the first battle adapt your strategy to either 1 or 3 depending on how the Brits act, then open fire when all your ships are well in range but the British are not, do not let them close, or retreat far, and tear them to pieces.

Post by Don Phillipson
Germany commissioned 11-inch Dreadnoughts from 1904
and the RN could count them (31 in 1914) and inspect most
either in port or at periodical RN and KM formal regattas.
If half these ships were withdrawn from service for some
unannounced reason (to be re-equipped with NRP guns)
we must suppose the RN would not notice, or else might
notice but would be unable to find out the reason.

Sure, the Germans announce the Smooth-bore guns, and all the disinformation I mentioned above.

The real test data of the ammo is kept a close secret, as is how it works.

Post by Don Phillipson
This argument looks at least as interesting as the
supposition that a miracle weapon destroyed half
Jellicoe's fleet in 1914, with later "military and political fallout."

What argument?

Post by Don Phillipson
--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

[Don Phillipson]

Post by Alfred Montestruc
The Germans have a "secret" mechanism for deploying fins on standard
full caliber AP rounds that make the rounds as or more accurate . . .
Sailors and officers on the ships that use the weapons need not know the
details of how the weapon works. They have strict orders never to try to
disassemble the rounds . .
They are also instructed that dis-assembly of these rounds, or allowing
such rounds to fall in to unauthorized hands is treason and will be
punished
as such. That what they do not know, they cannot betray. . . .
The German naval staff who know the real performance of the weapon,
but not how it works, is tasked with coming up with strategies for
attacking
the British fleet

The first invitation was to discuss the "fallout" of such a miracle weapon.
WW1 warships went to the ends of the earth (e.g. Coronel) equipped
to repair independently whatever damage either battle or the weather
might cause: but we now have to suppose they do so with a new weapon
they are allowed to launch but neither understand nor repair.

Since the KM's actual weapons of 1914 seemed to work rather well
(cf. Aboukir, Cressy and Hogue) we may wonder what all the fuss
is about.

[Alfred Montestruc]

Post by Don Phillipson

Post by Alfred Montestruc
The Germans have a "secret" mechanism for deploying fins on standard
full caliber AP rounds that make the rounds as or more accurate . . .
Sailors and officers on the ships that use the weapons need not know the
details of how the weapon works. They have strict orders never to try to
disassemble the rounds . .
They are also instructed that dis-assembly of these rounds, or allowing
such rounds to fall in to unauthorized hands is treason and will be
punished
as such. That what they do not know, they cannot betray. . . .
The German naval staff who know the real performance of the weapon,
but not how it works, is tasked with coming up with strategies for
attacking
the British fleet

The first invitation was to discuss the "fallout" of such a miracle weapon.
WW1 warships went to the ends of the earth (e.g. Coronel) equipped
to repair independently whatever damage either battle or the weather
might cause: but we now have to suppose they do so with a new weapon
they are allowed to launch but neither understand nor repair.
Since the KM's actual weapons of 1914 seemed to work rather well
(cf. Aboukir, Cressy and Hogue) we may wonder what all the fuss
is about.
--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

Repair ammunition? Really?

[unknown]

Post by Alfred Montestruc
Metallurgy of the Sabot? No, that is generally made of lighter
metals such as Aluminum which was in common use by that time.

Aluminium alloys were very much a problem before WW1. Have you any idea
what is involved in designing and building gun mounts for capital ships.

[Alfred Montestruc]

Post by unknown

Post by Alfred Montestruc
Metallurgy of the Sabot? No, that is generally made of lighter
metals such as Aluminum which was in common use by that time.

Aluminium alloys were very much a problem before WW1.

Not really.

http://en.wikipedia.org/wiki/Aluminium#Hall-Heroult_process:_availability_of_cheap_aluminium_metal
--------------quote---------------

Hall-Heroult process: availability of cheap aluminium metal

Charles Martin Hall of Ohio in the U.S. and Paul Héroult of France independently developed the Hall-Héroult electrolytic process that facilitated large-scale production of metallic aluminium. This process remains in use today.[59] In 1888 with the financial backing of Alfred E. Hunt, the Pittsburgh Reduction Company started, today it is known as Alcoa. Héroult's process was in production by 1889 in Switzerland at Aluminium Industrie, now Alcan, and at British Aluminium, now Luxfer Group and Alcoa, by 1896 in Scotland.[60]

By 1895, the metal was being used as a building material as far away as Sydney, Australia in the dome of the Chief Secretary's Building.

---end quote----------

Have you any idea

Post by unknown
what is involved in designing and building gun mounts for capital ships.

What does that have to do with the price of Scotch in Texas???

I was speaking of using aluminum in the Sabot of the ammunition, not on the gun. For the Sabot it could be cast, and could be pretty much as cast.

[unknown]

Post by Alfred Montestruc
By 1895, the metal was being used as a building material as far
away as Sydney, Australia in the dome of the Chief Secretary's
Building.

I said alloys allumininium is not used pure in anything except cans.
Definitely not in sabots. As for mountings the length and diameter of the
shell is limited by the hoists. Also the mounts took as long to design
and build as the ships. When the Lion class was suspended work was
continued on their mounts in case construction was resumed. Germany had
one firm that could build these mounts Britain had three which still
limited constuction.

[Alfred Montestruc]

Post by unknown

Post by Alfred Montestruc
By 1895, the metal was being used as a building material as far
away as Sydney, Australia in the dome of the Chief Secretary's
Building.

I said alloys allumininium is not used pure in anything except cans.

No you didn't and so what?

Post by unknown
Definitely not in sabots.

DUH! It is a what if!!!!

How many degrees in mechanical engineering do you have?

Post by unknown
As for mountings the length and diameter of the
shell is limited by the hoists.

The diameter of the shell that you put in the gun is EXACTLY the same as those used OTL by the Germans in their 11" naval rifles. The overall length of the shell could stay the same.

Do you have any clue as to the nature of the concept of APFSDS is?

Do you not understand the term sub-caliber munition?

The PROJECTILE can have an L/D of 15, while the assembled SHELL will have an OD of ~11" and length not longer than the maximum allowed. Say for the sake of argument that this maximum is 3.5 L/D=38.5". How can this be done? Because the diameter of the PROJECTILE is much less than 11". If we use a projectile diameter of 2.566" we can have an L/D of 15 on the projectile and have the OA length less than 38.5". The sabot fits around the projectile to form the shape of a shell of 11" OD. Get it now?

Post by unknown
Also the mounts took as long to design

So what, we are not changing the gun design other than subtracting the rifling. The gun becomes a smooth-bore. Otherwise identical to the existing 11" German Naval gun,

Post by unknown
and build as the ships. When the Lion class was suspended work was
continued on their mounts in case construction was resumed. Germany had
one firm that could build these mounts Britain had three which still
limited constuction.

Removing the rifling step from the manufacturing process will slow things down???

[unknown]

Post by Alfred Montestruc
Removing the rifling step from the manufacturing process will slow things down???

It won't speed anything up the barrel is the easiest thing to construct.
As I understand things you are proposing to fire long rod solid shot.
What makes you think that will do significantly more damage or even hit
at longer range than conventional weapons. Ships have a lot more empty
space than tanks.

[Alfred Montestruc]

Post by unknown

Post by Alfred Montestruc
Removing the rifling step from the manufacturing process will slow things down???

It won't speed anything up the barrel is the easiest thing to construct.
As I understand things you are proposing to fire long rod solid shot.
What makes you think that will do significantly more damage or even hit
at longer range than conventional weapons. Ships have a lot more empty
space than tanks.

Physics.

Fluid dynamics specifically, A long slender rod with fins on the back will have enormously less loss of speed by drag than a "bullet" or ball shape all else held equal. As in I did some calculations and find that with the same starting muzzle a long slender projectile of the same mass as a bullet shaped projectile, will fly many times further, and hit at a much higher velocity.

http://en.wikipedia.org/wiki/Drag_coefficient

drag coefficient of a sphere = .47

drag coefficient of a cone = 0.50

drag coefficient of a streamlined body= 0.04

Specific results compared a round solid iron 12 lb cannon ball moving at 480 m/s at the muzzle on a 5 degree up angle to an 8lb iron dart with fins, with the same muzzle velocity and same up angle. The dart has a diameter of 50 mm and length of ~250 mm, the cannon ball has a diameter of 114.8 mm. The sabot for the dart is wood.

Both projectiles assumed fired from the same smooth-bore 12 lb muzzle loading cannon. I looked up the range of a 12 lb ball shot with a 5 degree up angle and solved for the muzzle velocity to calibrate.

http://en.wikipedia.org/wiki/Sabot

Wood and paper mâché - were commonly used for sabot for cannons, but for smaller cannon balls and grapeshot, not iron darts, no reason in principle why it would not work however.

Given the initial conditions my calculations indicate the following.

The ball comes back level (altitude wise) with the firing gun in 1663 yards downrange at a velocity of 98 meters/second.

The dart comes back to the same level at a range of 3737 yards, with a velocity of 343 m/s.

The impact energy of the dart is 7.69 times that of the ball shot.

Obviously it would penetrate a lot more armor at 3737 yards than the ball would at 1663 yards, because it has a lot more energy.

Energy of motion can cause lots of sparks and can even start fires if the energy of motion is high enough. Modern APFSDS rounds have zero explosives, and more reliably set tanks on fire, or cause them to explode, than high explosive shaped charge shells.

Lots of flammable and explosive materials existed on warships of the WWI era, even coal fires could be quite dangerous, let alone the tendency of British battle-cruisers to blow up when hit in the turret by ordinary German AP rounds, with sabot rounds making Swiss cheese of their armor it would get worse fast.

If the German ships can start shooting at the British at ~ double their effective range, more accurately with less drop (more accurate because the drop is less), and pretty much the British armor is useless against the German projectiles, they are in a world of hurt.

You don't believe my calculations, fine do your own. You don't know how? Not my problem.

FYI I hold two degrees in mechanical engineering and work for a living at it.

[unknown]

Post by Alfred Montestruc
FYI I hold two degrees in mechanical engineering and work for a living at it.

That means you know something about engineering, it says nothing about
your knowledge of pre-WW1 metallurgy or WW1 fire control. The RN fitted
10ft range finders because average North Sea visibility is 10 miles. Fire
control depended on visibility as was proved at Jutland.

[Dean]

Post by unknown

Post by Alfred Montestruc
FYI I hold two degrees in mechanical engineering and work for a living at it.

That means you know something about engineering, it says nothing about
your knowledge of pre-WW1 metallurgy or WW1 fire control. The RN fitted
10ft range finders because average North Sea visibility is 10 miles. Fire
control depended on visibility as was proved at Jutland.

The whole discussion is reminiscent of "Steam-punk". This is what I like to refer to as retro-sci-fi. The plain fact is that weapons technology tends to advance through use. The idea of smooth-bore discarding sabot naval guns in WW1 fits right into this category. The technology did not exist at the time for this to happen. Even if it did, targeting technology did not exist either.

[Alfred Montestruc]

Post by Dean

Post by unknown

Post by Alfred Montestruc
FYI I hold two degrees in mechanical engineering and work for a living at it.

That means you know something about engineering, it says nothing about
your knowledge of pre-WW1 metallurgy or WW1 fire control. The RN fitted
10ft range finders because average North Sea visibility is 10 miles. Fire
control depended on visibility as was proved at Jutland.

The whole discussion is reminiscent of "Steam-punk". This is what I like to refer to as retro-sci-fi. The plain fact is that weapons technology tends to advance through use. The idea of smooth-bore discarding sabot naval guns in WW1 fits right into this category.
The technology did not exist at the time for this to happen

BS -- absolute complete and total BS. You have no idea what you are talking about.

The technology to do it existed since the first smooth-bore cannons were built, this could have been introduced at any time from the 15th century on, and perhaps before. Nothing even hard about the materials, or fabrication methods, they just did not think of it.

Post by Dean
Even if it did, targeting technology did not exist either.

Nonsense.

[The Old Man]

Post by Alfred Montestruc

Post by Dean

Post by unknown

Post by Alfred Montestruc
FYI I hold two degrees in mechanical engineering and work for a living at it.

That means you know something about engineering, it says nothing about
your knowledge of pre-WW1 metallurgy or WW1 fire control. The RN fitted
10ft range finders because average North Sea visibility is 10 miles. Fire
control depended on visibility as was proved at Jutland.

The whole discussion is reminiscent of "Steam-punk". This is what I like to refer to as retro-sci-fi. The plain fact is that weapons technology tends to advance through use. The idea of smooth-bore discarding sabot naval guns in WW1 fits right into this category.
The technology did not exist at the time for this to happen

BS -- absolute complete and total BS. You have no idea what you are talking about.
The technology to do it existed since the first smooth-bore cannons were built, this could have been introduced at any time from the 15th century on, and perhaps before. Nothing even hard about the materials, or fabrication methods, they just did not think of it.

Post by Dean
Even if it did, targeting technology did not exist either.

Nonsense.

What Al is describing IS nothing new. Doing a Google search, I found a photo of an "Arrow_fireing_cannon1" (Loading Image...%3Bhttp%253A%252F%252Fen.wikipedia.org%252Fwiki%252FEnglish_cannon%3B1792%3B1200) (sorry for the length of thne link) that dates to 1331, so he's correct - it was possible to do this. The question is why didn't they?

Regards,
John Braungart

[Alfred Montestruc]

Post by The Old Man

Post by Alfred Montestruc

Post by Dean

Post by unknown

Post by Alfred Montestruc
FYI I hold two degrees in mechanical engineering and work for a
living at it.

That means you know something about engineering, it says nothing about
your knowledge of pre-WW1 metallurgy or WW1 fire control. The RN fitted
10ft range finders because average North Sea visibility is 10 miles. Fire
control depended on visibility as was proved at Jutland.

The whole discussion is reminiscent of "Steam-punk". This is what I like to refer to as retro-sci-fi. The plain fact is that weapons technology tends to advance through use. The idea of smooth-bore discarding sabot naval guns in WW1 fits right into this category.
The technology did not exist at the time for this to happen

BS -- absolute complete and total BS. You have no idea what you are talking about.
The technology to do it existed since the first smooth-bore cannons were built, this could have been introduced at any time from the 15th century on, and perhaps before. Nothing even hard about the materials, or fabrication methods, they just did not think of it.

Post by Dean
Even if it did, targeting technology did not exist either.

Nonsense.

What Al is describing IS nothing new. Doing a Google search, I found a photo of an "Arrow_fireing_cannon1" (https://www.google.com/search?q=Arrows+fired+from+cannon&rlz=1C1LDJZ_enUS500US509&espv=2&biw=1120&bih=617&tbm=isch&imgil=fHf1_7K7a6RRlM%253A%253BoSl-OhqI4VMlyM%253Bhttp%25253A%25252F%25252Fen.wikipedia.org%25252Fwiki%25252FEnglish_cannon&source=iu&pf=m&fir=fHf1_7K7a6RRlM%253A%252CoSl-OhqI4VMlyM%252C_&usg=__V5YlaCPO2BNcI_teTBoq5snbFSg%3D&dpr=1.5&ved=0CEoQyjc&ei=-OOvVKm-A8qlNrOngBg#imgdii=_&imgrc=fHf1_7K7a6RRlM%253A%3BoSl-OhqI4VMlyM%3Bhttp%253A%252F%252Fupload.wikimedia.org%252Fwikipedia%252Fcommons%252Fe%252Fe9%252FArrow_fireing_cannon1.jpg%3Bhttp%253A%252F%252Fen.wikipedia.org%252Fwiki%252FEnglish_cannon%3B1792%3B1200) (sorry for the length of thne link) that dates to 1331, so he's correct - it was possible to do this. The question is why didn't they?
Regards,
John Braungart

A cast iron "arrow" with a sabot is new. What you showed is not that.

[Alfred Montestruc]

Post by unknown

Post by Alfred Montestruc
FYI I hold two degrees in mechanical engineering and work for a living at it.

That means you know something about engineering, it says nothing about
your knowledge of pre-WW1 metallurgy

That would be incorrect, it means I understand metallurgy a lot better than the typical person and that I can read, so I did look up and present encyclopedia articled for you to check. If you don't understand them, that is not my problem.

Post by unknown
or WW1 fire control. The RN fitted
10ft range finders because average North Sea visibility is 10 miles.

Cite it. In any case average means jack squat on a clear day, a sane naval planning group would opt for far better fire control so they could dominate in the event of clear weather. If the actual average visibility of a battleship, from a battleship on the north sea is 10 miles (17600 yards.

If a typical battleship has crow's nest mast height of 100' the distance to the horizon is 12.3 miles away, while the other fellows crow's nest would be visible 24.6 miles away assuming both are 100 foot high, and the weather is clear. If 150 feet, the horizon is 15 miles away and the height the crows nest of another BB with a 150 high crows nest would be visible over the horizon at 30 miles (52,800 yards). Spherical trig, or you can cheat use this website.

http://www.ringbell.co.uk/info/hdist.htm

So what?

I do not need your BB to be hull up on the horizon from my BB's crow's nest to shoot at you by direct line of sight.

I can be firing at the tops of your smoke stacks or masts. I could even be firing at your smoke.

Then their are such things as destroyers and light cruisers, who can be much closer to your BB, than my BB is but still be able to see both, and can send blinker signals to my BB telling me where you are, and your speed and course, and can relay whether my shots are over, short, left or right and by how much. Doing that is just math, math that naval officers did a lot of in those days using tables and slide rules, and plotting paper.



Fire

Post by unknown
control depended on visibility as was proved at Jutland.

To shoot someone on your side who can communicate with you in close to real time, who has a range finder and who knows how to spot for artillery has to be able to see the target, and communicate with the fire control officer of the ship with the heavy guns, yes. That can be by Morse code on a blinker light.

[unknown]

Post by Alfred Montestruc
That would be incorrect, it means I understand metallurgy a lot
better than the typical person

It means nothing of the sort. Assuming you are telling the truth about
your qualifications. I find it hard to believe either course included a
history of metallurgy.

Post by Alfred Montestruc
I do not need your BB to be hull up on the horizon from my BB's
crow's nest to shoot at you by direct line of sight.

Wrong see any gunnery treatise. The USN tried air spotting using radio
and could not get it too work. By the way citing a article that says
aluminium was used as a roofing material proofs it was as useful as lead.
I believe the first Tay Bridge, the Tacoma Narrows bridge and the
Millennium Bridge in London were all designed by professional engineers.

[The Old Man]

Post by unknown

Post by Alfred Montestruc
That would be incorrect, it means I understand metallurgy a lot
better than the typical person

It means nothing of the sort. Assuming you are telling the truth about
your qualifications. I find it hard to believe either course included a
history of metallurgy.

Post by Alfred Montestruc
I do not need your BB to be hull up on the horizon from my BB's
crow's nest to shoot at you by direct line of sight.

Wrong see any gunnery treatise. The USN tried air spotting using radio
and could not get it too work. By the way citing a article that says
aluminium was used as a roofing material proofs it was as useful as lead.
I believe the first Tay Bridge, the Tacoma Narrows bridge and the
Millennium Bridge in London were all designed by professional engineers.

Professional Engineers built the Titanic, an amateur built the Ark...
Professional Engineers also built the Tacoma Narrows Bridge in 1940.
As I used to tell my boss, a P.E., "you have a license, but you aren't God."

Regards,
John Braungart

[Alfred Montestruc]

Post by The Old Man

Post by unknown

Post by Alfred Montestruc
That would be incorrect, it means I understand metallurgy a lot
better than the typical person

It means nothing of the sort. Assuming you are telling the truth about
your qualifications. I find it hard to believe either course included a
history of metallurgy.

Post by Alfred Montestruc
I do not need your BB to be hull up on the horizon from my BB's
crow's nest to shoot at you by direct line of sight.

Wrong see any gunnery treatise. The USN tried air spotting using radio
and could not get it too work. By the way citing a article that says
aluminium was used as a roofing material proofs it was as useful as lead.
I believe the first Tay Bridge, the Tacoma Narrows bridge and the
Millennium Bridge in London were all designed by professional engineers.

Professional Engineers built the Titanic, an amateur built the Ark...
Professional Engineers also built the Tacoma Narrows Bridge in 1940.
As I used to tell my boss, a P.E., "you have a license, but you aren't God."
Regards,
John Braungart

The Titanic sunk because the Captain screwed the pooch. He had no business steaming that fast at night in waters where he has reports of icebergs.

The Tacoma narrows bridge involved a lot of very special, very unusual circumstances, and the fact that to that time no bridge, even very big long ones, had ever had resonance issues with wind.

I have never claimed to be god, I am claiming that you guys are ignoring the physics, which FYI is what caused the bridge you bring up to fall.

A long slender cast iron, or steel rod with fins of the same material on the back end will fly many, many times further given the same muzzle velocity than will a ball or a bullet shaped projectile of roughly the same mass. It will keep it's kinetic energy much better as well. If you think that is controversial or wrong, all I can say is you are ignorant.

The technical issue is shooting this projectile from a much larger bore (than the projectile diameter or fin diameter) gun. That requires a much less dense material to be used as a sabot, to prevent the projectile from hitting the tube and to seal the gas in while accelerating downrange. If you look on the below site you can see that sabots have been used in cannon for many centuries.

http://en.wikipedia.org/wiki/Sabot

The combination of a sabot with a solid metal arrow shot such as I describe that fits wholly within the tube was first thought of in the USSR in the 1950s. The USSR design used a "ring sabot" While modern western designs use a spindle type sabot.

What I am proposing is that at some point well before WWI, possibly in the great age of sail, someone figures out how to make a long rod arrow shot with metal fins using a sabot, probably of the type called a base sabot in the above website, out of wood, or if late in the 19th or early 20th century using aluminum.

What is your technical basis to claim it would not work. Metallurgy is BS, we do not need high strength aluminum. As cast would do just fine. Oak wood would probably be good enough for the 11" naval guns I spoke of.

[The Old Man]

Post by Alfred Montestruc

Post by The Old Man

Post by unknown

Post by Alfred Montestruc
That would be incorrect, it means I understand metallurgy a lot
better than the typical person

It means nothing of the sort. Assuming you are telling the truth about
your qualifications. I find it hard to believe either course included a
history of metallurgy.

Post by Alfred Montestruc
I do not need your BB to be hull up on the horizon from my BB's
crow's nest to shoot at you by direct line of sight.

Wrong see any gunnery treatise. The USN tried air spotting using radio
and could not get it too work. By the way citing a article that says
aluminium was used as a roofing material proofs it was as useful as lead.
I believe the first Tay Bridge, the Tacoma Narrows bridge and the
Millennium Bridge in London were all designed by professional engineers.

Professional Engineers built the Titanic, an amateur built the Ark...
Professional Engineers also built the Tacoma Narrows Bridge in 1940.
As I used to tell my boss, a P.E., "you have a license, but you aren't God."

The Titanic sunk because the Captain screwed the pooch. He had no business steaming that fast at night in waters where he has reports of icebergs.
The Tacoma narrows bridge involved a lot of very special, very unusual circumstances, and the fact that to that time no bridge, even very big long ones, had ever had resonance issues with wind.
I have never claimed to be god, I am claiming that you guys are ignoring the physics, which FYI is what caused the bridge you bring up to fall.
A long slender cast iron, or steel rod with fins of the same material on the back end will fly many, many times further given the same muzzle velocity than will a ball or a bullet shaped projectile of roughly the same mass. It will keep it's kinetic energy much better as well. If you think that is controversial or wrong, all I can say is you are ignorant.
The technical issue is shooting this projectile from a much larger bore (than the projectile diameter or fin diameter) gun. That requires a much less dense material to be used as a sabot, to prevent the projectile from hitting the tube and to seal the gas in while accelerating downrange. If you look on the below site you can see that sabots have been used in cannon for many centuries.
http://en.wikipedia.org/wiki/Sabot
The combination of a sabot with a solid metal arrow shot such as I describe that fits wholly within the tube was first thought of in the USSR in the 1950s. The USSR design used a "ring sabot" While modern western designs use a spindle type sabot.
What I am proposing is that at some point well before WWI, possibly in the great age of sail, someone figures out how to make a long rod arrow shot with metal fins using a sabot, probably of the type called a base sabot in the above website, out of wood, or if late in the 19th or early 20th century using aluminum.
What is your technical basis to claim it would not work. Metallurgy is BS, we do not need high strength aluminum. As cast would do just fine. Oak wood would probably be good enough for the 11" naval guns I spoke of.

Al - Several points, first my comment about P.E.s and God refered to my boss, who had a definate Messiahic Complex because HE had his license. ("Hey, who's the professional here?")
2) I agree about the Titanic, Capt. Smith shouldn't have tried to break the record; all he did was break his boat. But reports recently seen online indicate that the steel used was too high in sulphur content (substandard); that ship is ice-cold water was essentially like sailing in a milk bottle. Hit something and cracks appear.
3) As for the Tacoma bridge, it was a case of someone not checking their math, bridges of that type have had resonance tests done well before 1940. The formula are in thne older Sealy Books (of which we used a full set).
As to the comment in thne other posting, all I was pointing out was that cannon-fired arrows are nothing new, all you'd have to do is modernize an ancient idea to work with shipboard main guns.
Anyway, these comments were aimed at Ken, not you, so I'll butt out now.

Have a nice night,
John Braungart

[Alfred Montestruc]

Post by The Old Man

Post by Alfred Montestruc

Post by The Old Man

Post by unknown

Post by Alfred Montestruc
That would be incorrect, it means I understand metallurgy a lot
better than the typical person

It means nothing of the sort. Assuming you are telling the truth about
your qualifications. I find it hard to believe either course included a
history of metallurgy.

Post by Alfred Montestruc
I do not need your BB to be hull up on the horizon from my BB's
crow's nest to shoot at you by direct line of sight.

Wrong see any gunnery treatise. The USN tried air spotting using radio
and could not get it too work. By the way citing a article that says
aluminium was used as a roofing material proofs it was as useful as lead.
I believe the first Tay Bridge, the Tacoma Narrows bridge and the
Millennium Bridge in London were all designed by professional engineers.

Professional Engineers built the Titanic, an amateur built the Ark...
Professional Engineers also built the Tacoma Narrows Bridge in 1940.
As I used to tell my boss, a P.E., "you have a license, but you aren't God."

The Titanic sunk because the Captain screwed the pooch. He had no business steaming that fast at night in waters where he has reports of icebergs.
The Tacoma narrows bridge involved a lot of very special, very unusual circumstances, and the fact that to that time no bridge, even very big long ones, had ever had resonance issues with wind.
I have never claimed to be god, I am claiming that you guys are ignoring the physics, which FYI is what caused the bridge you bring up to fall.
A long slender cast iron, or steel rod with fins of the same material on the back end will fly many, many times further given the same muzzle velocity than will a ball or a bullet shaped projectile of roughly the same mass. It will keep it's kinetic energy much better as well. If you think that is controversial or wrong, all I can say is you are ignorant.
The technical issue is shooting this projectile from a much larger bore (than the projectile diameter or fin diameter) gun. That requires a much less dense material to be used as a sabot, to prevent the projectile from hitting the tube and to seal the gas in while accelerating downrange. If you look on the below site you can see that sabots have been used in cannon for many centuries.
http://en.wikipedia.org/wiki/Sabot
The combination of a sabot with a solid metal arrow shot such as I describe that fits wholly within the tube was first thought of in the USSR in the 1950s. The USSR design used a "ring sabot" While modern western designs use a spindle type sabot.
What I am proposing is that at some point well before WWI, possibly in the great age of sail, someone figures out how to make a long rod arrow shot with metal fins using a sabot, probably of the type called a base sabot in the above website, out of wood, or if late in the 19th or early 20th century using aluminum.
What is your technical basis to claim it would not work. Metallurgy is BS, we do not need high strength aluminum. As cast would do just fine. Oak wood would probably be good enough for the 11" naval guns I spoke of.

Al - Several points, first my comment about P.E.s and God refered to my boss, who had a definate Messiahic Complex because HE had his license. ("Hey, who's the professional here?")
2) I agree about the Titanic, Capt. Smith shouldn't have tried to break the record; all he did was break his boat. But reports recently seen online indicate that the steel used was too high in sulphur content (substandard); that ship is ice-cold water was essentially like sailing in a milk bottle. Hit something and cracks appear.
3) As for the Tacoma bridge, it was a case of someone not checking their math, bridges of that type have had resonance tests done well before 1940. The formula are in thne older Sealy Books (of which we used a full set).
As to the comment in thne other posting, all I was pointing out was that cannon-fired arrows are nothing new, all you'd have to do is modernize an ancient idea to work with shipboard main guns.
Anyway, these comments were aimed at Ken, not you, so I'll butt out now.
Have a nice night,
John Braungart

Cannon fired arrows are indeed not new, they came into existence about the same time cannons did. But a long tube smooth-bore cannon with an all metal sub-caliber arrow projectile fired with a light-weight sabot, that was invented in the 1950s in the USSR.

I am not asking you to butt out. I am wanting to have a conversation about the military and political implications. Ken is getting on my very last nerve with his ignoramus attacks to the effect of "I told Wilbur and I told Orville and now I'm telling you that contraption will never fly!"

[The Horny Goat]

On Fri, 9 Jan 2015 13:38:39 -0800 (PST), Alfred Montestruc

Post by Alfred Montestruc
The Titanic sunk because the Captain screwed the pooch. He had no business steaming that fast at night in waters where he has reports of icebergs.

Perhaps - but how many ships were lost to icebergs before 1912? I know
how many were lost to icebergs since then - ONE - and that was in 1943
when the International Iceberg Patrol was suspended as U-boats were
more feared than icebergs...

Post by Alfred Montestruc
The Tacoma narrows bridge involved a lot of very special, very unusual circumstances, and the fact that to that time no bridge, even very big long ones, had ever had resonance issues with wind.

I think pretty much every high school physics student since then has
seen the newsreel though! In retrospect it should have been obvious
that the side panels should have let air through - at the time not so
much.

Post by Alfred Montestruc
The combination of a sabot with a solid metal arrow shot such as I describe that fits wholly within the tube was first thought of in the USSR in the 1950s. The USSR design used a "ring sabot" While modern western designs use a spindle type sabot.

I believe you on the dates - but is there any technical reason why it
couldn't have been thought of 10-20 years earlier? (e.g. in time to be
developed for 1939-45) I'm not aware of any postwar advance in this
area that would have prevented earlier development of the concept
(anymore than I'm not aware of any particular engineering reason why
the modern concept of freight containers couldn't have been developed
40-50 years earlier)

[Alfred Montestruc]

Post by The Horny Goat

Post by Alfred Montestruc
The Titanic sunk because the Captain screwed the pooch. He had no business steaming that fast at night in waters where he has reports of icebergs.

Perhaps - but how many ships were lost to icebergs before 1912? I know
how many were lost to icebergs since then - ONE - and that was in 1943
when the International Iceberg Patrol was suspended as U-boats were
more feared than icebergs...

Post by Alfred Montestruc
The Tacoma narrows bridge involved a lot of very special, very unusual circumstances, and the fact that to that time no bridge, even very big long ones, had ever had resonance issues with wind.

I think pretty much every high school physics student since then has
seen the newsreel though! In retrospect it should have been obvious
that the side panels should have let air through - at the time not so
much.

Post by Alfred Montestruc
The combination of a sabot with a solid metal arrow shot such as I describe that fits wholly within the tube was first thought of in the USSR in the 1950s. The USSR design used a "ring sabot" While modern western designs use a spindle type sabot.

I believe you on the dates - but is there any technical reason why it
couldn't have been thought of 10-20 years earlier? (e.g. in time to be
developed for 1939-45) I'm not aware of any postwar advance in this
area that would have prevented earlier development of the concept

Absolutely none, which it my point you could have seen it introduced at anytime from shortly after the invention of longish tube smooth-bore cannons in the 1300's till 1950s when someone finally did not only think of it, he persuaded someone to build it. For example the Germans in the 1930s could have figured this out and built smooth-bore, high velocity anti-tank guns designed to do this. That would negate the advantage the USSR had in heavier tanks, but it would have been copied rapidly by the soviets.

Net result, probably stale-mate in tank vs anti-tank causing Germany to lose as OTL.

Post by The Horny Goat
(anymore than I'm not aware of any particular engineering reason why
the modern concept of freight containers couldn't have been developed
40-50 years earlier)

FYI - the first introduction of the basic idea of the freight container was in the 1960s by Friede and Goldman a naval architecture firm. Specifically by Jerome Goldman. What they invented first was called the LASH concept, (lighter aboard ship) where the ship would be designed to carry large numbers of identical barges that could be stacked on the ship and lifted off by a system of cranes on the ship, much as later container ships did.

http://en.wikipedia.org/wiki/Lighter_aboard_ship

http://www.google.com/patents/US3273527

I worked for F&G for a period. From the history of the company I understood, the point of the LASH concept was to get around longshoreman's unions. As you need not pull up to a dock to load and unload. You just deploy the lighters and have the tugboats move them to the customer direct, and collect refilled lighters with new cargo, never having paid a dime to the longshoremen.

[The Old Man]

Post by Alfred Montestruc

Post by The Horny Goat
I believe you on the dates - but is there any technical reason why it
couldn't have been thought of 10-20 years earlier? (e.g. in time to be
developed for 1939-45) I'm not aware of any postwar advance in this
area that would have prevented earlier development of the concept

Absolutely none, which it my point you could have seen it introduced
at anytime from shortly after the invention of longish tube smooth-bore
cannons in the 1300's till 1950s when someone finally did not only think
of it, he persuaded someone to build it. For example the Germans in the
1930s could have figured this out and built smooth-bore, high velocity
anti-tank guns designed to do this. That would negate the advantage the
USSR had in heavier tanks, but it would have been copied rapidly by the
soviets.

Okay, here's a question for you on this topic. The Germans developed a shaped charge with their Mistel bombcraft. Could a scaled-down version of this charge work, either for the tank rounds mentioned above OR the naval rounds that started this thread?
Honest question.

Regards,
John Braungart

[Alfred Montestruc]

Post by The Old Man

Post by Alfred Montestruc

Post by The Horny Goat
I believe you on the dates - but is there any technical reason why it
couldn't have been thought of 10-20 years earlier? (e.g. in time to be
developed for 1939-45) I'm not aware of any postwar advance in this
area that would have prevented earlier development of the concept

Absolutely none, which it my point you could have seen it introduced
at anytime from shortly after the invention of longish tube smooth-bore
cannons in the 1300's till 1950s when someone finally did not only think
of it, he persuaded someone to build it. For example the Germans in the
1930s could have figured this out and built smooth-bore, high velocity
anti-tank guns designed to do this. That would negate the advantage the
USSR had in heavier tanks, but it would have been copied rapidly by the
soviets.

Okay, here's a question for you on this topic. The Germans developed a shaped charge with their Mistel bombcraft. Could a scaled-down version of this charge work, either for the tank rounds mentioned above OR the naval rounds that started this thread?
Honest question.
Regards,
John Braungart

I think you mean this?

http://en.wikipedia.org/wiki/Mistel


Earliest recorded mention of use of shaped charges was in 1792 by a German mining engineer for use in mines. As he did not have high explosives only black powder it did not work. First successful use was also in Germany in 1883, using nitrocellulose.

Tanks and anti-tank guns in WWII used shaped charge rounds in OTL, both sides. US Army called them HEAT (high explosive anti tank) shells. Infantry anti-tank weapons such as the US Bazooka, the British PIAT and the German Panzerfaust all used shaped charges. They are not generally as effective as sabot rounds fired from a full sized cannon, but they could kill tanks. Note, nobody had APDS ammo at this time.

http://en.wikipedia.org/wiki/Shaped_charge

http://en.wikipedia.org/wiki/Panzerfaust


The Germans in WWII also developed a precursor to a sabot round that used a tungsten or tungsten-carbide penetration rod in the center of a lighter alloy shell. The light alloy jacket stayed on the rod till it hit the tank. Problem with this is it has the same air drag as a normal AP round. This was called HVAP by the US Army and called APCR by the Brits.

http://en.wikipedia.org/wiki/Shell_%28projectile%29#Armour-piercing.2C_composite_rigid

Air drag would mean the HVAP is a pretty short range weapon, APFSDS fired from a smooth-bore is a very long range, accurate armor killer ammo.

[unknown]

Post by Alfred Montestruc
Note, nobody had APDS ammo at this time.

Wrong, nobody had long rod ammo then The British produce APDS shot for
the 6pdr and the 17pdr. Smooth bore weapons were probably introduced
because spinning the projectile degraded HEAT performance Britain which
used HESH stayed with rifled guns. Sabot use was not confined to AT guns,
it was proposed as a means of extending the range of heavy artillery and
reducing time of flight of AA weapons.

[Alfred Montestruc]

Post by unknown

Post by Alfred Montestruc
Note, nobody had APDS ammo at this time.

Wrong, nobody had long rod ammo then The British produce APDS shot for
the 6pdr and the 17pdr.

Ok my bad, but these were not introduced in large quantity during a phase of the war when it could have been decisive,had the French deployed it in quantity in 1940 the results might have been different. APDS of the spin type was invented in France.

http://en.wikipedia.org/wiki/Armour-piercing_discarding_sabot

"APDS was developed by engineers working for the French Edgar Brandt company, and was fielded in two calibers (75 mm/57 mm for the Mle1897/33 75 mm anti-tank cannon, 37 mm/25 mm for several 37 mm gun types) just before the French-German armistice of 1940.[1] The Edgar Brandt engineers, having been evacuated to the United Kingdom, joined ongoing APDS development efforts there, culminating in significant improvements to the concept and its realization.The APDS projectile type was further developed in the United Kingdom between 1941-1944 by Permutter and Coppock, two designers with the Armaments Research Department. In mid-1944 the APDS projectile was first introduced into service for the UK's QF 6 pdr anti-tank gun and later in September 1944 for the 17 pdr anti-tank gun.[2]"

None of these involved fin stabilized long rod projectiles. Also the article seems to miss the point that on penetration the length and mass of the penetration rod matters a lot. They also miss the point that a long rod that is spin stabilized is extremely unstable in flight, and on impact. Any spinning object is more stable spinning about a larger mass moment of inertia axis, than a short mass moment of inertia axis.

The mass moment of inertia of a solid body about any axis through it's centroid is an integration of the infinitesimal mass of an element times the distance from the axis squared. In effect this means a long rod will "prefer" to spin end over end rather than about it's axis. If it starts spinning about it's axis, anything that perturbs that, like brushing up against a water droplet in flight, or hitting an armored target, will tend to shift it from spinning around it's axis to end over end. APDS rods without fins were limited to a maximum l/d of ~ 7 - no such limit with a fin stabilized rod.

Post by unknown
Smooth bore weapons were probably introduced
because spinning the projectile degraded HEAT performance Britain which
used HESH stayed with rifled guns.

Smooth bore guns for APFSDS were introduced by the USSR in 1955 in an anti-tank gun design, the first tank using a smooth-bore gun firing APFSDS ammo was the T62.


http://en.wikipedia.org/wiki/T-12_antitank_gun
http://en.wikipedia.org/wiki/T-62

Post by unknown
Sabot use was not confined to AT guns,
it was proposed as a means of extending the range of heavy artillery and
reducing time of flight of AA weapons.

All true - which proves my point that this could have been introduced at any time after smooth-bore long tube cannons were invented. You need to have a gun with at least a bore length of several (5?) L/D for this to be practical.

[Paul J. Adam]

Post by The Old Man
Okay, here's a question for you on this topic. The Germans developed
a shaped charge with their Mistel bombcraft. Could a scaled-down
version of this charge work, either for the tank rounds mentioned
above OR the naval rounds that started this thread? Honest question.

Shaped charges were fairly widespread by the end of WW2, primarily as
antitank weapons (PIAT, Bazooka, Panzerfaust et al). They saw some use
in guns, usually for low-velocity howitzers to give them a last-ditch
anti-tank capability, but spinning the projectile disrupts the jet
formation and so they're less effective than an unspun projectile. (The
HEAT rounds fired by tank guns are fin-stabilised, avoiding the issue)

One problem with adapting them - or long-rod, fin-stabilised penetrator
shot - for antiship use, is that a tank is densely packed with
vulnerable, flammable and/or explosive stuff, a ship rather less so: a
HEAT jet defeating a tank's armour is likely to be then hitting
something sensitive, while on a ship there's some considerable
additional distance and additional obstacles to go before anything
really touchy (e.g. magazines) are reached: the ship's structure forms
very effective composite armour to keep the projectile or jet, and any
spalling, away from anything it would seriously harm.

[The Horny Goat]

On Sat, 10 Jan 2015 11:33:33 -0800 (PST), Alfred Montestruc

Post by Alfred Montestruc

Post by The Horny Goat
I believe you on the dates - but is there any technical reason why it
couldn't have been thought of 10-20 years earlier? (e.g. in time to be
developed for 1939-45) I'm not aware of any postwar advance in this
area that would have prevented earlier development of the concept

Absolutely none, which it my point you could have seen it introduced at anytime from shortly after the invention of longish tube smooth-bore cannons in the 1300's till 1950s when someone finally did not only think of it, he persuaded someone to build it. For example the Germans in the 1930s could have figured this out and built smooth-bore, high velocity anti-tank guns designed to do this. That would negate the advantage the USSR had in heavier tanks, but it would have been copied rapidly by the soviets.

If Russia is going to lose the war they are going to lose it in 1941
or >possibly< 1942. In the summer of 1941 the main German armor-killer
was the Luftwaffe - the early model PzKwIII/IV of early 1941 just
wasn't up to killing the heavier Russian armor of that year. That
changed later but not in the first year of the eastern campaign.

No question the sabot is a huge force multiplier for the Germans if
available in time for June 1941 - though I have long felt that even if
Moscow were taken it was unlikely to be held through the winter and
with the greatest of respect, I don't see OKW really having thought
through a winter campaign until too late - they expected victory in
1941.

What that victory might have entailed is anybody's guess - we hear a
lot about the "Archangel-Astrakhan line" but to me that makes as much
sense as Hitler saying in April 1940 that he was driving for what
became the boundary of Vichy France and declaring victory when he got
there. (Queue "They're Coming To Take Me Away Hee Hee Ha Ha" here)

Post by Alfred Montestruc
Net result, probably stale-mate in tank vs anti-tank causing Germany to lose as OTL.

Mty person opinion is that if this had been available to the Germans
it would be available to the Russians in 1942 since Russian
manufacturig was somewhat in a state of chaos in the first 3-4 months
of their war. They did a great job later but up to Sept-Oct 1941 not
so much.

How much extra damage the Panzers could do is an open question but I
am skeptical this is a war winner for them. The main problem with
German armor in 1941 was that it kept getting shifted back and forth -
and that's not a probably of gunnery!

Post by Alfred Montestruc

Post by The Horny Goat
(anymore than I'm not aware of any particular engineering reason why
the modern concept of freight containers couldn't have been developed
40-50 years earlier)

FYI - the first introduction of the basic idea of the freight container was in the 1960s by Friede and Goldman a naval architecture firm. Specifically by Jerome Goldman. What they invented first was called the LASH concept, (lighter aboard ship) where the ship would be designed to carry large numbers of identical barges that could be stacked on the ship and lifted off by a system of cranes on the ship, much as later container ships did.
http://en.wikipedia.org/wiki/Lighter_aboard_ship
http://www.google.com/patents/US3273527
I worked for F&G for a period. From the history of the company I understood, the point of the LASH concept was to get around longshoreman's unions. As you need not pull up to a dock to load and unload. You just deploy the lighters and have the tugboats move them to the customer direct, and collect refilled lighters with new cargo, never having paid a dime to the longshoremen.

Are you seriously suggesting an even more militant ILWU (International
Longshoreman's Worker Union) would have accelerated the development of
container type shipping??!?

[Alfred Montestruc]

Post by The Horny Goat
On Sat, 10 Jan 2015 11:33:33 -0800 (PST), Alfred Montestruc

Post by Alfred Montestruc

Post by The Horny Goat
I believe you on the dates - but is there any technical reason why it
couldn't have been thought of 10-20 years earlier? (e.g. in time to be
developed for 1939-45) I'm not aware of any postwar advance in this
area that would have prevented earlier development of the concept

Absolutely none, which it my point you could have seen it introduced at anytime from shortly after the invention of longish tube smooth-bore cannons in the 1300's till 1950s when someone finally did not only think of it, he persuaded someone to build it. For example the Germans in the 1930s could have figured this out and built smooth-bore, high velocity anti-tank guns designed to do this. That would negate the advantage the USSR had in heavier tanks, but it would have been copied rapidly by the soviets.

If Russia is going to lose the war they are going to lose it in 1941
or >possibly< 1942. In the summer of 1941 the main German armor-killer
was the Luftwaffe - the early model PzKwIII/IV of early 1941 just
wasn't up to killing the heavier Russian armor of that year. That
changed later but not in the first year of the eastern campaign.

Ok - so the Germans roll back the Russians further. Moscow falls in say late October 1941.

That recalls a much earlier post of mine in 2007.

https://groups.google.com/forum/#!searchin/soc.history.what-if/montestruc$20stalin$20boards$20the$20train/soc.history.what-if/6ASvCPpvicY/ihLXDyrC7oMJ

The MSNBC link no longer exists, but the bottom line is Stalin almost panics and boards his train headed for the far east on 15 April '41.

The problem is that Moscow is not just the capital, it is also the central rail hub in the western USSR. If the Germans take and hold Moscow, the USSR is enormously weaker, logistically they cannot get supplied from south of Moscow to north of Moscow by rail and visa-versa for a very, very long distance east.

The Germans are very well aware of this, their planning is largely based on this fact. They take Moscow, they will hold onto it like Unka Scrooge holds onto his first dime.

Post by The Horny Goat
No question the sabot is a huge force multiplier for the Germans if
available in time for June 1941 - though I have long felt that even if
Moscow were taken it was unlikely to be held through the winter and
with the greatest of respect, I don't see OKW really having thought
through a winter campaign until too late - they expected victory in
1941.
What that victory might have entailed is anybody's guess - we hear a
lot about the "Archangel-Astrakhan line" but to me that makes as much
sense as Hitler saying in April 1940 that he was driving for what
became the boundary of Vichy France and declaring victory when he got
there. (Queue "They're Coming To Take Me Away Hee Hee Ha Ha" here)

No wrong, you are not looking at the maps of the period. No north-south rail lines east of Moscow for a long, long way. None at all that get to Archangel. Moscow falls (and stays fallen), Archangel will fall by siege, as they can only get supplied by sea and no Russian reinforcements. Do you see the USA or the UK shoveling men by the hundreds of thousands into that arctic blast furnace of a battle? I don't.

Post by The Horny Goat

Post by Alfred Montestruc
Net result, probably stale-mate in tank vs anti-tank causing Germany to lose as OTL.

Mty person opinion is that if this had been available to the Germans
it would be available to the Russians in 1942 since Russian
manufacturig was somewhat in a state of chaos in the first 3-4 months
of their war. They did a great job later but up to Sept-Oct 1941 not
so much.
How much extra damage the Panzers could do is an open question but I
am skeptical this is a war winner for them. The main problem with
German armor in 1941 was that it kept getting shifted back and forth -
and that's not a probably of gunnery!

Very true. But it might shorten the armor vs armor battles they do fight and reduce German losses, and badly hurt red army moral, and boost panzer crew confidence. All of those will help.

Post by The Horny Goat

Post by Alfred Montestruc

Post by The Horny Goat
(anymore than I'm not aware of any particular engineering reason why
the modern concept of freight containers couldn't have been developed
40-50 years earlier)

FYI - the first introduction of the basic idea of the freight container was in the 1960s by Friede and Goldman a naval architecture firm. Specifically by Jerome Goldman. What they invented first was called the LASH concept, (lighter aboard ship) where the ship would be designed to carry large numbers of identical barges that could be stacked on the ship and lifted off by a system of cranes on the ship, much as later container ships did.
http://en.wikipedia.org/wiki/Lighter_aboard_ship
http://www.google.com/patents/US3273527
I worked for F&G for a period. From the history of the company I understood, the point of the LASH concept was to get around longshoreman's unions. As you need not pull up to a dock to load and unload. You just deploy the lighters and have the tugboats move them to the customer direct, and collect refilled lighters with new cargo, never having paid a dime to the longshoremen.

Are you seriously suggesting an even more militant ILWU (International
Longshoreman's Worker Union) would have accelerated the development of
container type shipping??!?

Humm, , possible, not sure. But Mr. Goldman was a Regular US Naval officer during WWII with his training in naval architecture, he started the firm with the much older Mr. Friede (who was a former white Russian naval officer) after WWII in New Orleans, they had an office downtown by the quarter. They would not get into that business till after WWII, and this was Goldman's idea. He was a very smart businessman who knew how to see business opportunities and had a good feel for when the market would bust, and so when to bug out of a market. He saw the bottom would fall out of the drilling rig market in the early eighties and avoided losing his shirt as so many others did.

He saw in the '60s that he could create the ability for shipping companies to cut out the longshoremen, and so want to buy ships using his patents.

So if it was before WWII it would not be Goldman.

[The Horny Goat]

On Sat, 10 Jan 2015 20:38:26 -0800 (PST), Alfred Montestruc

Post by Alfred Montestruc

Post by The Horny Goat
If Russia is going to lose the war they are going to lose it in 1941
or >possibly< 1942. In the summer of 1941 the main German armor-killer
was the Luftwaffe - the early model PzKwIII/IV of early 1941 just
wasn't up to killing the heavier Russian armor of that year. That
changed later but not in the first year of the eastern campaign.

Ok - so the Germans roll back the Russians further. Moscow falls in say late October 1941.

That's by no means guaranteed even if the Panzers are not diverted to
help close the Kiev Pocket. For one thing it means 300-600,000 extra
Russian troops facing them in the winter of 1941-42 - on the other
hand when the panzers were sent south it did pretty much make the
battle for Moscow a primarily infantry affair on the German side.

Post by Alfred Montestruc
That recalls a much earlier post of mine in 2007.
https://groups.google.com/forum/#!searchin/soc.history.what-if/montestruc$20stalin$20boards$20the$20train/soc.history.what-if/6ASvCPpvicY/ihLXDyrC7oMJ
The MSNBC link no longer exists, but the bottom line is Stalin almost panics and boards his train headed for the far east on 15 April '41.
The problem is that Moscow is not just the capital, it is also the central rail hub in the western USSR. If the Germans take and hold Moscow, the USSR is enormously weaker, logistically they cannot get supplied from south of Moscow to north of Moscow by rail and visa-versa for a very, very long distance east.
The Germans are very well aware of this, their planning is largely based on this fact. They take Moscow, they will hold onto it like Unka Scrooge holds onto his first dime.

I fully understand your argument about the Russian rail net in 1941.
And as we discussed 7 years ago, the operative words in your argument
are "and hold"

Post by Alfred Montestruc
No wrong, you are not looking at the maps of the period. No north-south rail lines east of Moscow for a long, long way. None at all that get to Archangel. Moscow falls (and stays fallen), Archangel will fall by siege, as they can only get supplied by sea and no Russian reinforcements. Do you see the USA or the UK shoveling men by the hundreds of thousands into that arctic blast furnace of a battle? I don't.

I agree with you that a German seizure of Moscow in 1941 means Soviet
defeat in 1942 if they are able to hold it through the winter - for
exactly the reasons you say. My reference to Archangel was strictly in
reference to the so-called German Archangel-Astrakhan stop line which
was said to be the objective of the German 1941 campaign.

My point is that while I do think a German capture of Moscow was
possible in 1941, holding through the winter it was far more dubious.

Post by Alfred Montestruc
Very true. But it might shorten the armor vs armor battles they do fight and reduce German losses, and badly hurt red army moral, and boost panzer crew confidence. All of those will help.

The whole point in my argument was that in 1941 (which was a very
different set of conditions than later) the main killer of Russian
tanks was air power not German gunnery. Your suggestion might or might
not change that.

If we're talking about a 1941 German attack on Moscow the problem was
not that German tank guns were inadequate - it was that the tanks had
been sentence south and were thus nowhere near Moscow.

My personal view is that "Germany rolled a lot of sixes in 1941" but
made a very bad long-term decision in moving the tanks south to cement
their win in the Kiev battle. For one thing, the Kiev pocket was
largely decided by the time the Army Group Center tanks got there and
on the other it is highly likely Soviet losses would have been nearly
as high without them.

Quite apart from anything else, diverting the armor in 1941 put a LOT
of wear and tear on the German tanks that cost them heavily come
winter.

Post by Alfred Montestruc

Post by The Horny Goat

Post by Alfred Montestruc
FYI - the first introduction of the basic idea of the freight container was in the 1960s by Friede and Goldman a naval architecture firm. Specifically by Jerome Goldman. What they invented first was called the LASH concept, (lighter aboard ship) where the ship would be designed to carry large numbers of identical barges that could be stacked on the ship and lifted off by a system of cranes on the ship, much as later container ships did.
http://en.wikipedia.org/wiki/Lighter_aboard_ship
http://www.google.com/patents/US3273527
I worked for F&G for a period. From the history of the company I understood, the point of the LASH concept was to get around longshoreman's unions. As you need not pull up to a dock to load and unload. You just deploy the lighters and have the tugboats move them to the customer direct, and collect refilled lighters with new cargo, never having paid a dime to the longshoremen.

Are you seriously suggesting an even more militant ILWU (International
Longshoreman's Worker Union) would have accelerated the development of
container type shipping??!?

Humm, , possible, not sure. But Mr. Goldman was a Regular US Naval officer during WWII with his training in naval architecture, he started the firm with the much older Mr. Friede (who was a former white Russian naval officer) after WWII in New Orleans, they had an office downtown by the quarter. They would not get into that business till after WWII, and this was Goldman's idea. He was a very smart businessman who knew how to see business opportunities and had a good feel for when the market would bust, and so when to bug out of a market. He saw the bottom would fall out of the drilling rig market in the early eighties and avoided losing his shirt as so many others did.
He saw in the '60s that he could create the ability for shipping companies to cut out the longshoremen, and so want to buy ships using his patents.
So if it was before WWII it would not be Goldman.

I accept that - my original question was whether there was anything
technological that prevented earlier development of shipping
containers. Given the shipping containers of today I'm doubtful.

Now, maximizing efficiency of US -> Europe/Africa shipping was a high
US priority pretty much from the planning stages of Torch all the way
to the end of 1944 (particularly during the breakout phase of July -
September) so given the superb job done in moving supplies to Europe
in 1944 one wonders how much better they could have done. (My guess is
not much since other than the failure to capture the approaches to
Antwerp and thus render the port usable by September 1944 they did do
an incredible job)

[Rich Rostrom]

Post by The Horny Goat
The whole point in my argument was that in 1941
(which was a very different set of conditions than
later) the main killer of Russian tanks was air
power not German gunnery.

I very much doubt that. None of the German ground
attack planes were particularly well-equipped to
bust tanks. And there are endless accounts of
German tanks and AT guns bagging a dozen Soviet
tanks in a single day. And the Germans had very
good AT guns.

The most comparable case was the battle of Normandy
and subsequent breakout and pursuit - Caen, Mortain,
Falaise. It's often said that Allied airpower took
out the panzers. But the British sent out teams to
survey the battlefields afterwards. and determine
how many German tanks were destroyed in each way.

They found that very few German tanks were actually
killed by air attack. Some were killed by AT fire
from AFVs or towed guns. Some ran out of fuel and
were abandoned (air attack _was_ effective against
fuel bowsers and other soft-skinned vehicles).
Many were _abandoned_ under air attack - after a
few near misses, the crews bailed out and walked
away rather then risk getting "brewed up". But
only a few were actually _killed_ by planes.

The Allies had _hordes_ of aircraft in action in
Normandy and after, and faced negligible German
air opposition; I doubt very much if the Germans
in 1941 were better off.

[Malcom "Mal" Reynolds]

Post by Alfred Montestruc

Post by The Horny Goat
No question the sabot is a huge force multiplier for the Germans if
available in time for June 1941 - though I have long felt that even if
Moscow were taken it was unlikely to be held through the winter and
with the greatest of respect, I don't see OKW really having thought
through a winter campaign until too late - they expected victory in
1941.
What that victory might have entailed is anybody's guess - we hear a
lot about the "Archangel-Astrakhan line" but to me that makes as much
sense as Hitler saying in April 1940 that he was driving for what
became the boundary of Vichy France and declaring victory when he got
there. (Queue "They're Coming To Take Me Away Hee Hee Ha Ha" here)

No wrong, you are not looking at the maps of the period. No north-south rail
lines east of Moscow for a long, long way. None at all that get to
Archangel. Moscow falls (and stays fallen), Archangel will fall by siege, as
they can only get supplied by sea and no Russian reinforcements. Do you see
the USA or the UK shoveling men by the hundreds of thousands into that arctic
blast furnace of a battle? I don't.

The Germans were exceedingly good at repairing damage to their rail
lines and bridges, could not the Soviets simply have built another rail
line east of Moscow?

[Alfred Montestruc]

Post by Malcom "Mal" Reynolds

Post by Alfred Montestruc

Post by The Horny Goat
No question the sabot is a huge force multiplier for the Germans if
available in time for June 1941 - though I have long felt that even if
Moscow were taken it was unlikely to be held through the winter and
with the greatest of respect, I don't see OKW really having thought
through a winter campaign until too late - they expected victory in
1941.
What that victory might have entailed is anybody's guess - we hear a
lot about the "Archangel-Astrakhan line" but to me that makes as much
sense as Hitler saying in April 1940 that he was driving for what
became the boundary of Vichy France and declaring victory when he got
there. (Queue "They're Coming To Take Me Away Hee Hee Ha Ha" here)

No wrong, you are not looking at the maps of the period. No north-south rail
lines east of Moscow for a long, long way. None at all that get to
Archangel. Moscow falls (and stays fallen), Archangel will fall by siege, as
they can only get supplied by sea and no Russian reinforcements. Do you see
the USA or the UK shoveling men by the hundreds of thousands into that arctic
blast furnace of a battle? I don't.

The Germans were exceedingly good at repairing damage to their rail
lines and bridges, could not the Soviets simply have built another rail
line east of Moscow?

Not in time to do any good. Building a railroad is normally a multi-year long task generally and throwing more human bodies at the problem is not going to help that much.

http://en.wikipedia.org/wiki/First_Transcontinental_Railroad

It took from 1863 till 1869 building from both ends covering 3069 kilometers of the US far west. Now you propose to build from say Novgorod 322 km east of Moscow to Archangel 5845 km away over arctic and subarctic wilderness and over mountains, and it needs to be done in 6 months or the war is lost?

The Russians do not have significantly better methods than used by the USA in the 1860s. They did not have heavy construction earth moving machines in quantity. So this is going to get done by large numbers of men with idiot sticks.

Throwing too many men at it makes the problem worse, now you have food and fuel logistics issues, if the crew freezes to death no km of railroad get built.

See the point? This would be a many year long project regardless.

[Alfred Montestruc]

Post by Alfred Montestruc
the advantage the USSR had in heavier tanks, but it would have been
copied rapidly by the soviets.

The Germans produced composite non -rigid and composite rigid shot but
both of those required tungsten cores and Germany had a tungsten
shortage.
If Arrow shot was so good why was it abandoned in favour of stone shot
which required a skilled man to make?

Arrow shot w/o a sabot and a longish smooth-bore gun tube is no good. It is the combination of three things, a long tube smooth-bore cannon, a sabot that will keep the arrow centered in the tube, and seals the propellent gas in the tube while firing, and a fin stabilized rod strong enough to make a useful projectile.

All three are required in one package that works well. Stuffing an arrow into a pot with gunpowder so it will fly out does not win the prize.

[Alfred Montestruc]

Post by unknown

Post by Alfred Montestruc
That would be incorrect, it means I understand metallurgy a lot
better than the typical person

It means nothing of the sort. Assuming you are telling the truth about
your qualifications.

http://www.biblos.pk.edu.pl/files/File/STC/2011/ASMEMechanicalDesign.pdf

http://mechanicaldesign.asmedigitalcollection.asme.org/article.aspx?articleid=1449619


Oh yes the ASME and I are in a conspiracy to pretend I have qualifications I do not so we can make Kenneth Young look like a fool.

Obviously that is more important that my day job, and the reason for the ASME to exist. Yawn, right sure.

Post by unknown
I find it hard to believe either course included a
history of metallurgy.

Does not need to. It means I know what basic materials are needed for the device to work, and I can read an encyclopedia as to the history of making aluminum.

Post by unknown

Post by Alfred Montestruc
I do not need your BB to be hull up on the horizon from my BB's
crow's nest to shoot at you by direct line of sight.

Wrong see any gunnery treatise.

You clearly do not understand what I said. You do not understand what hull up on the horizon means. If I can see your smoke stack tops, I can get your range from a stereo optic range finder, and I have a direct LOS to your ship, and from the positioning of the mast and stacks I can figure out your course, by taking several range and bearing readings, in a row, I can plot your course, so yes obviously if my guns have the range I can fire on you.


Here I will cite a discussion of the mathematics.

http://en.wikipedia.org/wiki/Mathematical_discussion_of_rangekeeping

"In addition to ship-board target observations, rangekeepers could also take input from spotting aircraft or even manned balloons tethered to the own ship. These spotting platforms could be launched and recovered from large warships, like battleships. In general, target observations made by shipboard instruments were preferred for targets at ranges of less than 20,000 yards [11.36 standard miles] and aircraft observations were preferred for longer range targets.[8] After World War II, helicopters became available and the need to conduct the dangerous operations of launching and recovering spotting aircraft or balloons was eliminated (see Iowa-class battleship for a brief discussion)."

Imagine the curvature of the earth. A man at the crows nest of a ship can see the smoke stacks of another ship much farther than you could from the deck.

Post by unknown
The USN tried air spotting using radio
and could not get it too work.

Citation? When? Show some effing evidence. I have cited numerous links to actual evidence, including the above that cites that that is EXACTLY what the USN did in WWII. Put up or shut up.

I know for a fact that indirect bombardment using naval gunfire with spotters and radio by the USN has been used, very effectively.

Post by unknown
By the way citing a article that says
aluminium was used as a roofing material proofs it was as useful as lead.

So what? The Sabot does not need high strength, it needs to take up space between the projectile and the gun tube wall till the projectile leaves the barrel. Lead would work, but would be too heavy. Aluminum is a better choice as it has low density. One might be able to use wood. Modern tank sabot use carbon fiber composites, but probably do so to minimize weight so as much as possible energy goes into the projectile, not the sabot. If you looked at the article about them I posted earlier you can see that sabots made for the US Army are very slender and highly shaped, as in optimized designs with absolutely minimal weight.

Probably you could use wood for a sabot on a modern tank round, it would just cost a moderate % of the kinetic energy of the projectile.

Post by unknown
I believe the first Tay Bridge, the Tacoma Narrows bridge and the
Millennium Bridge in London were all designed by professional engineers.

That makes you qualified to have an opinion? I don't think so.

You cite no EVIDENCE at all, I have repeatedly cited lots of evidence.

What is your issue? That you did not think of it? Is it that you get your jollies taking a crap on other people's ideas that you are not even capable of understanding?

You live to pretend to being able to intelligently discuss ideas that it is blindingly obvious to an educated person you are just not qualified to discuss?

Is this starting to offend you? You started being rude to me quite some time ago, and now my patience with you is exhausted. You refuse to engage in the basic issue, which is what the political and military effects would have been, and still you post pig-ignorant comments pretending to knowledge you don't have.

Why?

[The Horny Goat]

On Fri, 9 Jan 2015 12:40:30 -0800 (PST), Alfred Montestruc

Post by Alfred Montestruc
Probably you could use wood for a sabot on a modern tank round, it would just cost a moderate % of the kinetic energy of the projectile.

Isn't the whole point of a sabot to be as light weight as possible
while being strong enough not to break apart before it has done its
job? Seems to me if the sabot is heavier than necessary isn't all
you're doing either using a bigger charge than you need to or having a
lower shell speed (i.e. kinetic energy) than you might?

Or have I missed something here? (I assume the above is simplistic
enough to have missed one or more important factors...)

[Alfred Montestruc]

Post by The Horny Goat
On Fri, 9 Jan 2015 12:40:30 -0800 (PST), Alfred Montestruc
<montestru

Post by Alfred Montestruc
Probably you could use wood for a sabot on a modern tank round, it would just cost a moderate % of the kinetic energy of the projectile.

Isn't the whole point of a sabot to be as light weight as possible
while being strong enough not to break apart before it has done its
job?

Pretty much, but you are perhaps not seeing the point that the advantage of a sabot round concept over a standard AP round is enormous.

Going back over the numbers from the 12 pounder smooth-bore I spoke of earlyer. Muzzle velocity 482 m/s weight of cannon ball 12.45 lb =5.64 kg range 1663 yards. Impact energy 27.1 kJoules. Muzzle energy 655.9 kJ (big difference huh?)

So we make the ASSUMPTION -- probably wrong -- that the sabot plus the projectile weighs exactly the same as the cannon ball so the muzzle energy will be the same (from Newtonion kinetic energy KE=0.5*m*v*v)so we need not argue about details of the efficiencies of burning gunpowder being converted to KE. Same mass being shoved down the same tube by same mass of gunpowder burning, so the speed at the exit will be the same.

We choose a shape of 50 mm diameter x 250 mm long for the projectile and figure ~ +10% for fins, -10% for taper in nose and net wash- wind up with 3.53 kg ~ 8 lb(about 2/3 of the ball weight, and figure the rest of the 12.45 lb is sabot.

Probably we could make the weight of the sabot less. But that means 2/3 of the muzzle energy of the gun goes to the projectile. Then we do the ballistic + drag calculations with the same muzzle velocity and up angle and we get that the projectile comes back to earth at 3737 yards moving at 343 m/s with 208.7 kJoules, so the energy of impact is many times that of the ball and is a good % of the original muzzle energy.

Set that 208.7 kJ at 3737 yards next to the 27.1 kJ of the cannon ball at 1663 yards, and a small percentage gain from making the sabot a little lighter is just not that big a deal.

So yeah, if I make the sabot 33% lighter, I add maybe 6% to the muzzle speed of the projectile, I will gain maybe 12% more impact energy. Big whoop!

But in OTL after the USSR introduced the sabot round, the USA was playing catch up with the USSR, so we went all out and made slightly better sabot rounds than they did.

But mainly we went to a bigger gun (125 mm while the USSR started with 115mm) and had better fire control computers and gyro-stabilization so our tank guns were more accurate. The USSR introduction of the Sabot round was a technical leap that got them a huge initial advantage for a short while till we copied their method and improved on it.

Same thing would happen if this were introduced earlier in naval guns, it would give the nation that invented it first, a large technical advantage for a few years at most, and then would change naval tactics a lot. Just as tank tactics changed significantly with the intro of sabot rounds.

My point was suppose Germany came up with it first before WWI and kept it secret till introduced on the battlefield in significant numbers.

My take, it would break the RN, and probably win the war for Germany early. Very different history after that.

Post by The Horny Goat
Seems to me if the sabot is heavier than necessary isn't all
you're doing either using a bigger charge than you need to or having a
lower shell speed (i.e. kinetic energy) than you might?

The actual sabot projectile is almost always lighter than the original AP round would be. If you make the sabot+projectile weigh exactly the same as the old AP round you will have the same muzzle velocity, with the same powder charge. If you made it lighter then you get a higher velocity.

If you make the powder charge larger and keep the mass the same you increase the bore pressure, which gets you higher velocity, but you must worry about the gun blowing up.

The theoretical calculations for that are messy and mathematically hard, which is why I avoid them. In reality you always prove it by experiment, then back off the higher propellent loads as you do have such a thing as fatigue cracking of gun barrels, which need not happen the first time you shoot with that high a charge, or even with that high a charge. You can damage the barrel w/o it being obvious and it may fail with a standard charge ten or 100 shots later.

As above discussed yes you have a point, but it is not as big a deal as you may think.

Post by The Horny Goat
Or have I missed something here? (I assume the above is simplistic
enough to have missed one or more important factors...)

[unknown]

Post by Alfred Montestruc
If you made it lighter then you get a higher velocity.

Shame all naval gun designers preferred heavier shells and lower velocity.
Hence the increase in gun size from 12 to 16 inches and the US producing
heavier AP for existing guns.

[Alfred Montestruc]

Post by unknown

Post by Alfred Montestruc
If you made it lighter then you get a higher velocity.

Shame all naval gun designers preferred heavier shells and lower velocity.
Hence the increase in gun size from 12 to 16 inches and the US producing
heavier AP for existing guns.

Why?

[John Dallman]

Post by unknown
Shame all naval gun designers preferred heavier shells and lower
velocity. Hence the increase in gun size from 12 to 16 inches and
the US producing heavier AP for existing guns.

Why?

Heavier shells lose velocity with range more slowly, and also penetrate
better at the same velocity as lighter ones.

It's also easier to make heavy shells stable as they go up the gun barrel:
they can have a longer parallel-sided section, which means they don't
wobble as much in the barrel and leave it with their axis more nearly
parallel to the trajectory. A light shell with a long parallel body needs
a relatively blunt nose, which imposes a lot of aerodynamic drag and
means it slows down quickly.

Another point was barrel whip. Large gun barrels inevitably droop under
gravity, and straighten as a shell goes up them, which introduces more
dispersion into the trajectory. Making the barrels more rigid costs a lot
of weight, which meant there was a practical limit to barrel length of
about 50 calibres.

Finally, barrel wear. The life of a gun barrel was only 200-300 shots
before wear reduced accuracy so much that it needed relining. Since
nobody liked the idea of sending a ship into battle when it would start
losing accuracy part-way through its ammo loadout, the practical life was
the actual life minus the number of shells per gun in a full load of ammo.
Increasing velocity increases barrel wear very rapidly.

John

[Alfred Montestruc]

Post by John Dallman

Post by unknown
Shame all naval gun designers preferred heavier shells and lower
velocity. Hence the increase in gun size from 12 to 16 inches and
the US producing heavier AP for existing guns.

Why?

Heavier shells lose velocity with range more slowly, and also penetrate
better at the same velocity as lighter ones.

Yes I know, that is not the why I am asking, why should it be "shame on".

Post by John Dallman
they can have a longer parallel-sided section, which means they don't
wobble as much in the barrel and leave it with their axis more nearly
parallel to the trajectory. A light shell with a long parallel body needs
a relatively blunt nose, which imposes a lot of aerodynamic drag and
means it slows down quickly.
Another point was barrel whip. Large gun barrels inevitably droop under
gravity, and straighten as a shell goes up them, which introduces more
dispersion into the trajectory. Making the barrels more rigid costs a lot
of weight, which meant there was a practical limit to barrel length of
about 50 calibres.

Except that the Germans were quite successful with L70 anti-tank gun designs during WWII both 75 L70 and 99 L70 and the modern German made 120 mm smooth-bore used on the M1 Abrams is IIRC an L55,

http://en.wikipedia.org/wiki/Rheinmetall_120_mm_gun

Post by John Dallman
Finally, barrel wear. The life of a gun barrel was only 200-300 shots
before wear reduced accuracy so much that it needed relining.

Perhaps on some types of guns, not on small-arms, and I doubt it on smaller cannon of relatively low pressure and velocity.

Post by John Dallman
Since
nobody liked the idea of sending a ship into battle when it would start
losing accuracy part-way through its ammo loadout, the practical life was
the actual life minus the number of shells per gun in a full load of ammo.
Increasing velocity increases barrel wear very rapidly.

Barrel wear drops a lot if it is not rifled, all else held equal, and one can make sabots slightly larger so they can seal better on a worn barrel.

[Dean]

Post by Alfred Montestruc

Post by John Dallman

Post by unknown
Shame all naval gun designers preferred heavier shells and lower
velocity. Hence the increase in gun size from 12 to 16 inches and
the US producing heavier AP for existing guns.

Why?

Heavier shells lose velocity with range more slowly, and also penetrate
better at the same velocity as lighter ones.

Yes I know, that is not the why I am asking, why should it be "shame on".

Post by John Dallman
they can have a longer parallel-sided section, which means they don't
wobble as much in the barrel and leave it with their axis more nearly
parallel to the trajectory. A light shell with a long parallel body needs
a relatively blunt nose, which imposes a lot of aerodynamic drag and
means it slows down quickly.
Another point was barrel whip. Large gun barrels inevitably droop under
gravity, and straighten as a shell goes up them, which introduces more
dispersion into the trajectory. Making the barrels more rigid costs a lot
of weight, which meant there was a practical limit to barrel length of
about 50 calibres.

Except that the Germans were quite successful with L70 anti-tank gun designs during WWII both 75 L70 and 99 L70 and the modern German made 120 mm smooth-bore used on the M1 Abrams is IIRC an L55,
http://en.wikipedia.org/wiki/Rheinmetall_120_mm_gun

Post by John Dallman
Finally, barrel wear. The life of a gun barrel was only 200-300 shots
before wear reduced accuracy so much that it needed relining.

Perhaps on some types of guns, not on small-arms, and I doubt it on smaller cannon of relatively low pressure and velocity.

Post by John Dallman
Since
nobody liked the idea of sending a ship into battle when it would start
losing accuracy part-way through its ammo loadout, the practical life was
the actual life minus the number of shells per gun in a full load of ammo.
Increasing velocity increases barrel wear very rapidly.

Barrel wear drops a lot if it is not rifled, all else held equal, and one can make sabots slightly larger so they can seal better on a worn barrel.

All of this discussion would be simplified if a little googling had been done:
http://en.wikipedia.org/wiki/Paixhans_gun

[Alfred Montestruc]

Post by Dean

Post by Alfred Montestruc

Post by John Dallman

Post by unknown
Shame all naval gun designers preferred heavier shells and lower
velocity. Hence the increase in gun size from 12 to 16 inches and
the US producing heavier AP for existing guns.

Why?

Heavier shells lose velocity with range more slowly, and also penetrate
better at the same velocity as lighter ones.

Yes I know, that is not the why I am asking, why should it be "shame on".

Post by John Dallman
they can have a longer parallel-sided section, which means they don't
wobble as much in the barrel and leave it with their axis more nearly
parallel to the trajectory. A light shell with a long parallel body needs
a relatively blunt nose, which imposes a lot of aerodynamic drag and
means it slows down quickly.
Another point was barrel whip. Large gun barrels inevitably droop under
gravity, and straighten as a shell goes up them, which introduces more
dispersion into the trajectory. Making the barrels more rigid costs a lot
of weight, which meant there was a practical limit to barrel length of
about 50 calibres.

Except that the Germans were quite successful with L70 anti-tank gun designs during WWII both 75 L70 and 99 L70 and the modern German made 120 mm smooth-bore used on the M1 Abrams is IIRC an L55,
http://en.wikipedia.org/wiki/Rheinmetall_120_mm_gun

Post by John Dallman
Finally, barrel wear. The life of a gun barrel was only 200-300 shots
before wear reduced accuracy so much that it needed relining.

Perhaps on some types of guns, not on small-arms, and I doubt it on smaller cannon of relatively low pressure and velocity.

Post by John Dallman
Since
nobody liked the idea of sending a ship into battle when it would start
losing accuracy part-way through its ammo loadout, the practical life was
the actual life minus the number of shells per gun in a full load of ammo.
Increasing velocity increases barrel wear very rapidly.

Barrel wear drops a lot if it is not rifled, all else held equal, and one can make sabots slightly larger so they can seal better on a worn barrel.

http://en.wikipedia.org/wiki/Paixhans_gun

Yes but this does not have arrow shot and sabots had been around a long time.

[Paul J. Adam]

Post by unknown

Post by Alfred Montestruc
If you made it lighter then you get a higher velocity.

Shame all naval gun designers preferred heavier shells and lower velocity.
Hence the increase in gun size from 12 to 16 inches and the US producing
heavier AP for existing guns.

Why?

Improved penetration performance (both from greater energy density, and
because you're getting more plunging fire onto the deck, rather than
horizontal fire into the armour belt), less barrel wear, greater
consistency (and hence accuracy).

The US increased the shell weight of the 16" AP round from 2240lb to
2700lb and considerably increased its performance as a result, for example.

[Bradipus]

Post by Alfred Montestruc
If a typical battleship has crow's nest mast height of 100'
the distance to the horizon is 12.3 miles away, while the
other fellows crow's nest would be visible 24.6 miles away
assuming both are 100 foot high, and the weather is clear.
If 150 feet, the horizon is 15 miles away and the height the
crows nest of another BB with a 150 high crows nest would be
visible over the horizon at 30 miles (52,800 yards).
Spherical trig, or you can cheat use this website.
http://www.ringbell.co.uk/info/hdist.htm
So what?
I do not need your BB to be hull up on the horizon from my
BB's crow's nest to shoot at you by direct line of sight.
I can be firing at the tops of your smoke stacks or masts.  I
could even be firing at your smoke.

Doesn't fire control need to see plumes of projectiles near the
target to assess corrections?

Are those plumes 100 ft high?

[Alfred Montestruc]

Post by Bradipus

Post by Alfred Montestruc
If a typical battleship has crow's nest mast height of 100'
the distance to the horizon is 12.3 miles away, while the
other fellows crow's nest would be visible 24.6 miles away
assuming both are 100 foot high, and the weather is clear.
If 150 feet, the horizon is 15 miles away and the height the
crows nest of another BB with a 150 high crows nest would be
visible over the horizon at 30 miles (52,800 yards).
Spherical trig, or you can cheat use this website.
http://www.ringbell.co.uk/info/hdist.htm
So what?
I do not need your BB to be hull up on the horizon from my
BB's crow's nest to shoot at you by direct line of sight.
I can be firing at the tops of your smoke stacks or masts.  I
could even be firing at your smoke.

Doesn't fire control need to see plumes of projectiles near the
target to assess corrections?

To correct, they need at least an observer who can see them and report back. Ideal would be fire control able to see them

Post by Bradipus
Are those plumes 100 ft high?

http://www.criticalpast.com/video/65675066432_Russian-Campaign_deck-gun-on-ship_Russian-vessel-shelled_German-Navy-officers-watch

The splashes in this film looked a lot taller than the ships. I suspect that an 11" gun projectile impact energy being as high as it is will make a huge splash.

Post by Bradipus
--
Bradipus

[Paul J. Adam]

Post by Alfred Montestruc

1. The metallurgical science necessary to build such a missile had
not yet been discovered by WW1.

That would not be correct. Metallurgy has almost nothing to do with
this. Please explain what EXACTLY you think the metallurgy could
affect?

If you fire a steel long-rod penetrator at useful velocities, it'll
simply shatter on impact: hence why AP shell adopted caps of softer
metal to prevent that effect even on full-bore projectiles.

In APFSFS rounds to date, only tungsten or uranium have worked so far
(steel is only used for training rounds to cut costs, one claimed reason
Iraqi tanks in 1991 did so poorly was that they were firing steel rounds
which completely failed against US and UK armour).

[Alfred Montestruc]

Post by Paul J. Adam

Post by Alfred Montestruc

1. The metallurgical science necessary to build such a missile had
not yet been discovered by WW1.

That would not be correct. Metallurgy has almost nothing to do with
this. Please explain what EXACTLY you think the metallurgy could
affect?

If you fire a steel long-rod penetrator at useful velocities, it'll

Citation evidence, as in back this statement up with some evidence.

Post by Paul J. Adam
hence why AP shell adopted caps of softer
metal to prevent that effect even on full-bore projectiles.

False.

http://en.wikipedia.org/wiki/Armor-piercing_shot_and_shell

Quote the citation:
"An armor-piercing shell must withstand the shock of punching through armor plating. Shells designed for this purpose have a greatly strengthened case with a specially hardened and shaped nose, and a much smaller bursting charge. Some smaller-caliber AP shells have an inert filling, or incendiary charge in place of the HE bursting charge."

Their is a thin soft steel windscreen that is there ONLY to reduce drag in the air. See the article.

Post by Paul J. Adam
In APFSFS rounds to date, only tungsten or uranium have worked so far

Citation? Evidence??

http://en.wikipedia.org/wiki/Kinetic_energy_penetrator

--------------------Quote the site---------------------------

The principle of the kinetic energy penetrator is that it uses its kinetic energy, which is a function of its mass and velocity, to force its way through armor. If the armor is defeated, the heat and spalling (particle spray) generated by the penetrator going through the armor, and the pressure wave that would develop, ideally destroys the target.[1]

The modern kinetic energy weapon maximizes the stress (kinetic energy divided by impact area) delivered to the target by:

* maximizing the mass - that is, using the densest metals practical, which is one of the reasons depleted uranium or tungsten carbide is often used - and muzzle velocity of the projectile, as kinetic energy scales with the mass m and the square of the velocity v of the projectile. ke=m*v*v/2

* minimizing the width, since if the projectile does not tumble, it will hit the target face first; as most modern projectiles have circular cross-sectional areas, their impact area will scale with the square of the radius r (the impact area being A= pi*r^2

This has led to the current designs which resemble a long metal arrow.
-----------------------END QUOTE----------------------

I agree 100% that a denser material is better, not because it is stronger, but because it is denser, more mass per unit volume. In point of fact:

http://en.wikipedia.org/wiki/Tungsten
Quote site :


"A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as a metal in 1783. Its important ores include wolframite and scheelite. The free element is remarkable for its robustness, especially the fact that it has the highest melting point of all the elements. Also remarkable is its high density of 19.3 times that of water, comparable to that of uranium and gold, and much higher (about 1.7 times) than that of lead.[4] Polycrystalline tungsten is an intrinsically brittle[5][6] and hard material due to its weak grain boundaries, making it difficult to work. However, pure single-crystalline tungsten is more ductile, and can be cut with a hard-steel hacksaw.[7]"

http://en.wikipedia.org/wiki/Uranium

--------------quote---------------------
The major application of uranium in the military sector is in high-density penetrators. This ammunition consists of depleted uranium (DU) alloyed with 1–2% other elements. At high impact speed, the density, hardness, and pyrophoricity of the projectile enable destruction of heavily armored targets.
-----------------end quote------------------------

pyrophoricity means flammable, very flammable. Specifically

http://en.wikipedia.org/wiki/Pyrophoricity

"A pyrophoric substance (from Greek πυροφόρος, pyrophoros, "fire-bearing") ignites spontaneously in air at or below 55°C (130°F).[1] Examples are iron sulfide and many reactive metals including uranium, when powdered or thinly sliced. Pyrophoric materials are often water-reactive as well and will ignite when they contact water or humid air. They can be handled safely in atmospheres of argon or (with a few exceptions) nitrogen. Most pyrophoric fires should be extinguished with a Class D fire extinguisher for burning metals."

In fact all of these materials are a lot more brittle than a well selected steel alloy. Steel can have excellent ductility, stretching well over 20% of the original length before fracture. The steel penetration rod fracturing is simply not an issue, density is.

Post by Paul J. Adam
(steel is only used for training rounds to cut costs, one claimed reason
Iraqi tanks in 1991 did so poorly was that they were firing steel rounds
which completely failed against US and UK armour).

Evidence? Citation?

You seem very lazy, as in unwilling to look things up and check your facts.

Post by Paul J. Adam
--
He thinks too much, such men are dangerous.

Men who think without checking their facts can be quite dangerous, to their friends, and themselves.

[Paul J. Adam]

Post by Alfred Montestruc

Post by Paul J. Adam
If you fire a steel long-rod penetrator at useful velocities, it'll

Citation evidence, as in back this statement up with some evidence.

Chapter 9, "Kinetic Energy Attack of Armour", from "Ammunition for the
Land Battle" published by the Royal Military College of Science,
Shrivenham.

Post by Alfred Montestruc

Post by Paul J. Adam
hence why AP shell adopted caps of softer
metal to prevent that effect even on full-bore projectiles.

False.

Entirely true, and a very basic point in AP projectile development.

Post by Alfred Montestruc
http://en.wikipedia.org/wiki/Armor-piercing_shot_and_shell
"An armor-piercing shell must withstand the shock of punching through armor plating. Shells designed for this purpose have a greatly strengthened case with a specially hardened and shaped nose, and a much smaller bursting charge. Some smaller-caliber AP shells have an inert filling, or incendiary charge in place of the HE bursting charge."
Their is a thin soft steel windscreen that is there ONLY to reduce drag in the air. See the article.

You mean the article that says " Another change was the introduction of
a soft metal cap over the point of the shell – so called "Makarov tips"
invented by Russian admiral Stepan Makarov. This "cap" increased
penetration by cushioning some of the impact shock and preventing the
armor-piercing point from being damaged before it struck the armor face,
or the body of the shell from shattering. It could also help penetration
from an oblique angle by keeping the point from deflecting away from the
armor face."

And shortly thereafter, in the WW2 section, "Due to the increase in
armor thickness during the conflict, the projectiles’ size and impact
velocity had to be increased to ensure perforation. At these higher
velocities, the hardened tip of the shot or shell has to be protected
from the initial impact shock, or risk shattering. To raise the impact
velocity and stop the shattering, they were initially fitted with soft
steel penetrating caps. The best performance penetrating caps were not
very aerodynamic, so an additional ballistic cap was later fitted to
reduce drag. The resulting projectile types were named armor-piercing
capped (APC) and armor-piercing capped ballistic capped (APCBC).

Early WWII-era uncapped AP projectiles fired from high-velocity guns
were able to penetrate about twice their caliber at close range (100 m).
At longer ranges (500-1,000 m), this dropped 1.5–1.1 calibers due to the
poor ballistic shape and higher drag of the smaller-diameter early
projectiles. Later in the conflict, APCBC fired at close range (100 m)
from large-caliber, high-velocity guns (75–128 mm) were able to
penetrate a much greater thickness of armor in relation to their caliber
(2.5 times) and also a greater thickness (2–1.75 times) at longer ranges
(1,500–2,000 m)."


Did you fail to read the article, or did you fail to understand it?

[Alfred Montestruc]

Post by Paul J. Adam

Post by Alfred Montestruc

Post by Paul J. Adam
If you fire a steel long-rod penetrator at useful velocities, it'll

Citation evidence, as in back this statement up with some evidence.

Chapter 9, "Kinetic Energy Attack of Armour", from "Ammunition for the
Land Battle" published by the Royal Military College of Science,
Shrivenham.

You mean the book by P. Cortney-Green? printed 1991 Y/N

Post by Paul J. Adam

Post by Alfred Montestruc

Post by Paul J. Adam
hence why AP shell adopted caps of softer
metal to prevent that effect even on full-bore projectiles.

False.

Entirely true, and a very basic point in AP projectile development.

You are quite mistaken and clearly ignorant of the physics involved. I doubt you understand the differences between the terms hard, brittle strong, and tough, which all have very specific definitions.

For a component to shatter because of a large release of kinetic energy (impact)it mainly needs to be brittle which is the opposite of tough. Toughness in a material is defined by how much energy it can absorb per unit volume before fracture.

http://en.wikipedia.org/wiki/Toughness

Having a soft metal cap, or to be more precise a tough metal cap will not help much and in fact wastes energy on deforming the tough cap rather than punching through the armor. What you want is a very hard relatively sharp impact surface area that is part of a solid part made of very tough base material. Going back to the original reference:

http://en.wikipedia.org/wiki/Armor-piercing_shot_and_shell

" The first solution to this problem was effected by Major Sir W. Palliser, who, with the Palliser shot, invented a method of hardening the head of the pointed cast-iron shot.[a] By casting the projectile point downwards and forming the head in an iron mold, the hot metal was suddenly chilled and became intensely hard (resistant to deformation through a Martensite phase transformation), while the remainder of the mold, being formed of sand, allowed the metal to cool slowly and the body of the shot to be made tough (resistant to shattering)."

Problem -- cast iron is an intrinsically low toughness material. Cast steel is also compared to forged or hot rolled steel has low toughness. Toughness is often measured in terms of % elongation, how many percent of the original length of a test bar can you stretch the test bar before fracture.

I am not faulting either party (Palliser or Makarov) no doubt the cap had some helpful effect on penetration, probably on the order of few percent at most, and the Palliser design was clearly better than a round cast iron ball, however that does not get you to being able to claim that "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact"

1) Steel long rod penetrators of reasonable toughness don't historically "shatter on impact" see the reference.

http://fofanov.armor.kiev.ua/Tanks/ARM/apfsds/ammo.html

They do not penetrate as well as tungsten or uranium rod, but they do work.


Also many people, not just the soviets used tungsten carbide for perpetrators, which is a much less tough material than a good grade of steel.

http://www-materials.eng.cam.ac.uk/mpsite/interactive_charts/strength-toughness/basic.html

http://youtu.be/yy9R5QHURzw

If a seven year old kid can shatter a tungsten carbide ring,and you know damn well she could not do that to a steel ring, and various people used tungsten carbide perpetrators in kinetic energy tank rounds, your statement is bunk.

The issue that makes uranium or tungsten carbide better for a sabot round is DENSITY getting more mass packed into a smaller volume so the air drag is less and the mass behind a small hard penetration point is large and has a lot of kinetic energy per square area of armor attacked. As in (mv^2)/r^2 where r is the radius of the penetration point.

Post by Paul J. Adam

Post by Alfred Montestruc
http://en.wikipedia.org/wiki/Armor-piercing_shot_and_shell
"An armor-piercing shell must withstand the shock of punching through armor plating. Shells designed for this purpose have a greatly strengthened case with a specially hardened and shaped nose, and a much smaller bursting charge. Some smaller-caliber AP shells have an inert filling, or incendiary charge in place of the HE bursting charge."
Their is a thin soft steel windscreen that is there ONLY to reduce drag in the air. See the article.

You mean the article that says " Another change was the introduction of
a soft metal cap over the point of the shell - so called "Makarov tips"
invented by Russian admiral Stepan Makarov. This "cap" increased
penetration by cushioning some of the impact shock and preventing the
armor-piercing point from being damaged before it struck the armor face,

You left off a whole lot of technical discussion before that.

Post by Paul J. Adam
or the body of the shell from shattering. It could also help penetration
from an oblique angle by keeping the point from deflecting away from the
armor face."
And shortly thereafter, in the WW2 section, "Due to the increase in
armor thickness during the conflict, the projectiles' size and impact
velocity had to be increased to ensure perforation.

No one was trying to use the APFSDS concept, same old scale up, not thinking, brute force.


At these higher

Post by Paul J. Adam
velocities, the hardened tip of the shot or shell has to be protected
from the initial impact shock, or risk shattering. To raise the impact
velocity and stop the shattering, they were initially fitted with soft
steel penetrating caps. The best performance penetrating caps were not
very aerodynamic, so an additional ballistic cap was later fitted to
reduce drag. The resulting projectile types were named armor-piercing
capped (APC) and armor-piercing capped ballistic capped (APCBC).
Early WWII-era uncapped AP projectiles fired from high-velocity guns
were able to penetrate about twice their caliber at close range (100 m).
At longer ranges (500-1,000 m), this dropped 1.5-1.1 calibers due to the
poor ballistic shape and higher drag of the smaller-diameter early
projectiles. Later in the conflict, APCBC fired at close range (100 m)
from large-caliber, high-velocity guns (75-128 mm) were able to
penetrate a much greater thickness of armor in relation to their caliber
(2.5 times) and also a greater thickness (2-1.75 times) at longer ranges
(1,500-2,000 m)."
Did you fail to read the article, or did you fail to understand it?

More like you failed to understand.


Your claim that "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact" is totally refuted as the soviets used them with success. They do not do as well as a tungsten carbide tipped or uranium tipped projectile, but no mention of 'shatter on impact", and they do work.


I did not claim the soft cap idea was never used, I asked you to cite it.

[Paul J. Adam]

On Saturday, January 17, 2015 at 9:49:00 AM UTC-6, Paul.J.Adam

Post by Paul J. Adam
Chapter 9, "Kinetic Energy Attack of Armour", from "Ammunition for
the Land Battle" published by the Royal Military College of
Science, Shrivenham.

You mean the book by P. Cortney-Green? printed 1991 Y/N

Correct, as a starting point.

Post by Paul J. Adam
Entirely true, and a very basic point in AP projectile
development.

You are quite mistaken and clearly ignorant of the physics involved.

Unfortunately, I am neither mistaken nor ignorant - your limited
comprehension is your problem rather than mine.

I doubt you understand the differences between the terms hard,
brittle strong, and tough, which all have very specific definitions.

Your doubts are amusing but irrelevant, since I've been able to
demonstrate my understanding of those terms and their definitions to
several academic and professional bodies over the years.

I'll accept their judgement over yours, since yours has so often been...
amusing.

Having a soft metal cap, or to be more precise a tough metal cap will
not help much and in fact wastes energy on deforming the tough cap
rather than punching through the armor.

Makes you wonder why anyone ever bothered putting caps on AP shot, since
you've proved to your own satisfaction that it's entirely useless to so so.

For steel penetrators, the cap pushed the striking velocity where
deformation, fracture, or (depending on geometry, metallurgy and heat
treatment) shatter of an AP shot's hardened tip upwards, usefully
increasing its piercing performance. This still hit a practical limit,
hence the introduction of APCR and then APDS rounds using tungsten-alloy
penetrators

Courtney-Green on APCR shot: "Tungsten alloy was the densest and hardest
material available, and this became the standard material for the
manufacture of sub-calibre penetrators. Steel was still used for making
the full-calibre shot in order to provide the large cross-sectional area
required in the gun. At the target *the steel outer core would shatter*
(my emphasis) after making the initial indentation in the armour".

I am not faulting either party (Palliser or Makarov) no doubt the cap
had some helpful effect on penetration, probably on the order of few
percent at most, and the Palliser design was clearly better than a
round cast iron ball, however that does not get you to being able to
claim that "If you fire a steel long-rod penetrator at useful
velocities, it'll simply shatter on impact"

Then please give the designation of the APFSDS round in either UK or US
service that employs a steel penetrator.

Steel is used in this application only for training purposes due to the
very poor performance. Combat experience in 1991, where Iraqi tanks were
firing steel training rounds with dismal results, amply confirm that.

A key issue in achieving high performance with a long-rod penetrator is
velocity: at sufficiently high striking velocities, the interaction
between projectile and armour moves into a hydrodynamic regime where the
materials flow as if liquid, although remaining solid. (Interestingly,
the liner in a shaped charge uses the same effect, flowing like liquid
while remaining solid): once in this regime (but not before),
penetration depth becomes a function of the length of the penetrator.

Using a steel penetrator causes several problems. Firstly, the much
lower sectional density means it loses energy more rapidly and thus
falls below the velocity required for hydrodynamic penetration earlier.
This is an issue even at tank combat ranges: it's a showstopper for
1914-vintange naval combat.

Secondly, the lower mass of the projectile means that it's more prone to
yawing on impact (similar forces applying, for a given penetration of
armour, but less mass and therefore more acceleration). This massively
increases the stresses on the penetrator, making it far more likely to
break up rather than remain intact to defeat the armour or be consumed
trying. It can be persuaded to perform on the proof range, but fails in
combat.


Or for the short, short version, "Steel projectiles could not withstand
the stresses of very high velocity impact on armour plate, and so it was
necessary to find better materials". (Courtney-Green, p. 114). Hence the
development of APCR, then APDS rounds.

1) Steel long rod penetrators of reasonable toughness don't
historically "shatter on impact" see the reference.
http://fofanov.armor.kiev.ua/Tanks/ARM/apfsds/ammo.html

They break up rather than penetrating uswfully, which is the key point -
as the statement "The penetrator is made of maraging steel so has a
rather modest penetration potential. This, as well as unsatisfactory
performance on slanted impacts, delegated the round to practice and
trials use" confirms - it didn't even impress in proving firings, let
alone combat.

They do not penetrate as well as tungsten or uranium rod, but they do work.

If they work, why aren't they used on anything more robust than target
screens? (Or to conserve target hulks, by scoring hits with little
damage to the target)

Post by Paul J. Adam
You mean the article that says " Another change was the
introduction of a soft metal cap over the point of the shell - so
called "Makarov tips" invented by Russian admiral Stepan Makarov.
This "cap" increased penetration by cushioning some of the impact
shock and preventing the armor-piercing point from being damaged
before it struck the armor face,

You left off a whole lot of technical discussion before that.

Which explained, in reasonable Wikipedia fashion, why steel penetrators
found themselves requiring soft metal caps (later covered by ballistic
windshields) to improve penetation, hence the transition in both naval
and anti-tank guns from AP, to APC, to APCBC - the very tradition you
seem to insist didn't happen and provided no improvement.

Even your website describes the 3BM-17 projectile as being "A
low-technology version of 3BM-15 that had no W-C slug, but had a more
developed armor-piercing cap to offset reduction in penetration.
Presumably limited to export and training use." Why bother with a cap to
try to offet the reduced performance? (And note that this confirms the
3MB-17 isn't hitting in the hydrodynamic regime, where the cap would be
an irrelevance)

Post by Paul J. Adam
And shortly thereafter, in the WW2 section, "Due to the increase
in armor thickness during the conflict, the projectiles' size and
impact velocity had to be increased to ensure perforation.

No one was trying to use the APFSDS concept, same old scale up, not thinking, brute force.

Without the combination of extreme velocity and tungsten or DU
penetrators, there's very little point.

Even experiments like the squeezebore guns, which achieved very high
velocity at the cost of high manufacturing cost and rapid barrel wear,
required tungsten penetrators to avoid projectile shatter on impact.

Of course, simply because the penetrator shatters doesn't mean it
becomes completely harmless: it simply performs poorly and is unlikely
to be useful in combat except on lightly-protected targets (which would
be better engaged with HE/HESH/HEAT depending on nation anyway). Hence,
again, their relegation to training ranges as inexpensive practice rounds.

Post by Paul J. Adam
Early WWII-era uncapped AP projectiles fired from high-velocity
guns were able to penetrate about twice their caliber at close
range (100 m). At longer ranges (500-1,000 m), this dropped 1.5-1.1
calibers due to the poor ballistic shape and higher drag of the
smaller-diameter early projectiles. Later in the conflict, APCBC
fired at close range (100 m) from large-caliber, high-velocity guns
(75-128 mm) were able to penetrate a much greater thickness of
armor in relation to their caliber (2.5 times) and also a greater
thickness (2-1.75 times) at longer ranges (1,500-2,000 m)."
Did you fail to read the article, or did you fail to understand it?

More like you failed to understand.

Since you're insisting that steel works perfectly well as a material for
APFSDS projectiles and they are widely and effectively used, while this
is utterly at variance with both the science and the practical
experience, I admit to a certain incomprehension.

Long-rod penetrators in steel are hard to get to the target with the
velocity required for hydrodynamic penetration, and are much more prone
to failure on impact. If you have evidence to the contrary - not a web
site that diplomatically describes performance as "limited" - then
please, try to provide it.

Your claim that "If you fire a steel long-rod penetrator at useful
velocities, it'll simply shatter on impact" is totally refuted as the
soviets used them with success.

The Soviets didn't actually use them, they delicately referred to them
being limited to "training and export".

When they were used as a desperation measure by the Iraqis, they failed
to achieve a single penetration, breaking up on impact.

If you call that "success" what do they have to do to be classed as
failures? Circle back and hit the tank that fired them?

I did not claim the soft cap idea was never used, I asked you to cite it.

Which I did, pointing to the description of how they provided a 25-50%
improvement in effectiveness *from the very same reference* you said
proved they didn't exist and weren't effective.


So, who's using and developing steel APFSDS for anything other than
training purposes these days?

[Alfred Montestruc]

On Monday, January 19, 2015 at 1:52:44 PM UTC-6, Paul.J.Adam wrote:
---snip rubbish----------

Post by Paul J. Adam
When they were used as a desperation measure by the Iraqis, they failed
to achieve a single penetration, breaking up on impact.

Which is neither here nor there, nor have you proved they broke up on impact. You said "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact" --that is not the same as "fail to penetrate" the best tank armor in the world at this time which was designed 20 + years after those specific weapons were in the field.

Yes a uranium or tungsten carbide rod will penetrate better as it is denser, so effing what? That is not the point.

The point is you said "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact"

Which is stupid ridiculous and wrong.

Post by Paul J. Adam
If you call that "success" what do they have to do to be classed as
failures? Circle back and hit the tank that fired them?

Post by Alfred Montestruc
I did not claim the soft cap idea was never used, I asked you to cite it.

Which I did, pointing to the description of how they provided a 25-50%
improvement in effectiveness *from the very same reference* you said
proved they didn't exist and weren't effective.

No it does not say 25 to 50% it does not state any percentage and the shattering has to do with poor material quality of effing CAST IRON SHOT, made in the late 19th century more than 100 years ago, not forged steel.

Post by Paul J. Adam
So, who's using and developing steel APFSDS for anything other than
training purposes these days?

"These days" do not matter.

We started this discussion about WWI warships using steel APFSDS as a hypothetical, the question is not whether "these days" it is the best shot to use.

The question is would it have been of significant advantage at the time in WWI.

Tungsten carbide use in shot was 20 odd years in the future to 1914, Uranium use in AP ammo more than 40 years away.

The question is would a good grade of forged steel available in ~1910 made into shot put on an APFSDS mode penetrate better than standard cast steel AP shot of WWI. Obviously it would be better given the use by the USSR, now you should have shut the eff up about this ages ago and moved on to the political and military impacts.

You dredging all this kaka up is moving the goal posts so you can pretend you are "winning", which you are not.

Nor am I winning, you are wasting my time with kaka, when what I want is an intelligent discussion which clearly you are unable to have. All you succeed at in being annoying and making yourself look really effing stupid and childish.


What matters is you were flatly wrong in stating that "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact" and I proved it and you know it. Any claim otherwise is just you lying, and we both know it.

Now ta-ta and eff off.

Post by Paul J. Adam
--
He thinks too much, such men are dangerous.

You are an entirely disarmed man then, you think not ad all.

[Dean]

Post by Alfred Montestruc
---snip rubbish----------

Post by Paul J. Adam
When they were used as a desperation measure by the Iraqis, they failed
to achieve a single penetration, breaking up on impact.

Which is neither here nor there, nor have you proved they broke up on impact. You said "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact" --that is not the same as "fail to penetrate" the best tank armor in the world at this time which was designed 20 + years after those specific weapons were in the field.
Yes a uranium or tungsten carbide rod will penetrate better as it is denser, so effing what? That is not the point.
The point is you said "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact"
Which is stupid ridiculous and wrong.

Post by Paul J. Adam
If you call that "success" what do they have to do to be classed as
failures? Circle back and hit the tank that fired them?

Post by Alfred Montestruc
I did not claim the soft cap idea was never used, I asked you to cite it.

Which I did, pointing to the description of how they provided a 25-50%
improvement in effectiveness *from the very same reference* you said
proved they didn't exist and weren't effective.

No it does not say 25 to 50% it does not state any percentage and the shattering has to do with poor material quality of effing CAST IRON SHOT, made in the late 19th century more than 100 years ago, not forged steel.

Post by Paul J. Adam
So, who's using and developing steel APFSDS for anything other than
training purposes these days?

"These days" do not matter.
We started this discussion about WWI warships using steel APFSDS as a hypothetical, the question is not whether "these days" it is the best shot to use.
The question is would it have been of significant advantage at the time in WWI.
Tungsten carbide use in shot was 20 odd years in the future to 1914, Uranium use in AP ammo more than 40 years away.
The question is would a good grade of forged steel available in ~1910 made into shot put on an APFSDS mode penetrate better than standard cast steel AP shot of WWI. Obviously it would be better given the use by the USSR, now you should have shut the eff up about this ages ago and moved on to the political and military impacts.
You dredging all this kaka up is moving the goal posts so you can pretend you are "winning", which you are not.
Nor am I winning, you are wasting my time with kaka, when what I want is an intelligent discussion which clearly you are unable to have. All you succeed at in being annoying and making yourself look really effing stupid and childish.
What matters is you were flatly wrong in stating that "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact" and I proved it and you know it. Any claim otherwise is just you lying, and we both know it.
Now ta-ta and eff off.

Post by Paul J. Adam
--
He thinks too much, such men are dangerous.

You are an entirely disarmed man then, you think not ad all.

Wow, Paul just handed your ass to you and all you can do is resort to insults? All you reply with are "it doesn't matter", "you're wrong" and such which is not much of a rebuttal.

Can you cite a steel penetrator that works?

[Alfred Montestruc]

Post by Dean

Post by Alfred Montestruc
---snip rubbish----------

Post by Paul J. Adam
When they were used as a desperation measure by the Iraqis, they failed
to achieve a single penetration, breaking up on impact.

Which is neither here nor there, nor have you proved they broke up on impact. You said "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact" --that is not the same as "fail to penetrate" the best tank armor in the world at this time which was designed 20 + years after those specific weapons were in the field.
Yes a uranium or tungsten carbide rod will penetrate better as it is denser, so effing what? That is not the point.
The point is you said "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact"
Which is stupid ridiculous and wrong.

Post by Paul J. Adam
If you call that "success" what do they have to do to be classed as
failures? Circle back and hit the tank that fired them?

Post by Alfred Montestruc
I did not claim the soft cap idea was never used, I asked you to cite it.

Which I did, pointing to the description of how they provided a 25-50%
improvement in effectiveness *from the very same reference* you said
proved they didn't exist and weren't effective.

No it does not say 25 to 50% it does not state any percentage and the shattering has to do with poor material quality of effing CAST IRON SHOT, made in the late 19th century more than 100 years ago, not forged steel.

Post by Paul J. Adam
So, who's using and developing steel APFSDS for anything other than
training purposes these days?

"These days" do not matter.
We started this discussion about WWI warships using steel APFSDS as a hypothetical, the question is not whether "these days" it is the best shot to use.
The question is would it have been of significant advantage at the time in WWI.
Tungsten carbide use in shot was 20 odd years in the future to 1914, Uranium use in AP ammo more than 40 years away.
The question is would a good grade of forged steel available in ~1910 made into shot put on an APFSDS mode penetrate better than standard cast steel AP shot of WWI. Obviously it would be better given the use by the USSR, now you should have shut the eff up about this ages ago and moved on to the political and military impacts.
You dredging all this kaka up is moving the goal posts so you can pretend you are "winning", which you are not.
Nor am I winning, you are wasting my time with kaka, when what I want is an intelligent discussion which clearly you are unable to have. All you succeed at in being annoying and making yourself look really effing stupid and childish.
What matters is you were flatly wrong in stating that "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact" and I proved it and you know it. Any claim otherwise is just you lying, and we both know it.
Now ta-ta and eff off.

Post by Paul J. Adam
--
He thinks too much, such men are dangerous.

You are an entirely disarmed man then, you think not ad all.

Wow, Paul just handed your ass to you and all you can do is resort to insults? All you reply with are "it doesn't matter", "you're wrong" and such which is not much of a rebuttal.
Can you cite a steel penetrator that works?

I did -- moron -- read the effing thread

[Alfred Montestruc]

Post by Dean

Post by Alfred Montestruc
---snip rubbish----------

Post by Paul J. Adam
When they were used as a desperation measure by the Iraqis, they failed
to achieve a single penetration, breaking up on impact.

Which is neither here nor there, nor have you proved they broke up on impact. You said "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact" --that is not the same as "fail to penetrate" the best tank armor in the world at this time which was designed 20 + years after those specific weapons were in the field.
Yes a uranium or tungsten carbide rod will penetrate better as it is denser, so effing what? That is not the point.
The point is you said "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact"
Which is stupid ridiculous and wrong.

Post by Paul J. Adam
If you call that "success" what do they have to do to be classed as
failures? Circle back and hit the tank that fired them?

Post by Alfred Montestruc
I did not claim the soft cap idea was never used, I asked you to cite it.

Which I did, pointing to the description of how they provided a 25-50%
improvement in effectiveness *from the very same reference* you said
proved they didn't exist and weren't effective.

No it does not say 25 to 50% it does not state any percentage and the shattering has to do with poor material quality of effing CAST IRON SHOT, made in the late 19th century more than 100 years ago, not forged steel.

Post by Paul J. Adam
So, who's using and developing steel APFSDS for anything other than
training purposes these days?

"These days" do not matter.
We started this discussion about WWI warships using steel APFSDS as a hypothetical, the question is not whether "these days" it is the best shot to use.
The question is would it have been of significant advantage at the time in WWI.
Tungsten carbide use in shot was 20 odd years in the future to 1914, Uranium use in AP ammo more than 40 years away.
The question is would a good grade of forged steel available in ~1910 made into shot put on an APFSDS mode penetrate better than standard cast steel AP shot of WWI. Obviously it would be better given the use by the USSR, now you should have shut the eff up about this ages ago and moved on to the political and military impacts.
You dredging all this kaka up is moving the goal posts so you can pretend you are "winning", which you are not.
Nor am I winning, you are wasting my time with kaka, when what I want is an intelligent discussion which clearly you are unable to have. All you succeed at in being annoying and making yourself look really effing stupid and childish.
What matters is you were flatly wrong in stating that "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact" and I proved it and you know it. Any claim otherwise is just you lying, and we both know it.
Now ta-ta and eff off.

Post by Paul J. Adam
--
He thinks too much, such men are dangerous.

You are an entirely disarmed man then, you think not ad all.

Wow, Paul just handed your ass to you and all you can do is resort to insults? All you reply with are "it doesn't matter", "you're wrong" and such which is not much of a rebuttal.
Can you cite a steel penetrator that works?

Here moron.

Steel long rod penetrators of reasonable toughness don't historically 1"shatter on impact" see the reference.

http://fofanov.armor.kiev.ua/Tanks/ARM/apfsds/ammo.html

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&ved=0CDEQFjAD&url=http%3A%2F%2Fmilitaryrussia.ru%2Fforum%2Fdownload%2Ffile.php%3Fid%3D17600&ei=fJDAVMKOJcOfggSU_oCoAg&usg=AFQjCNHN4mTymvDKhxdC5jOjm3ecsQGgEg&sig2=yhlj29CN9D2aag8zpD8ytQ&bvm=bv.83829542,d.eXY&cad=rja

LOOK ON PAGE 29 THE PURE STEEL SHOT 3BVM-3 APFSDS ROUND HAS A PENETRATION RATING OF 290 MM 2000 METERS DOWNRANGE FROM THE GUN. THIS PROJECTILE WAS INTRODUCED IN 1962, 290 MM (11.42") PENETRATION IS NOTHING TO SNEEZE AT

They do not penetrate as well as tungsten or uranium rod, which rounds from an APFSDS-DU type penetration can exceed 600 mm, but they do work.

If such a small projectile fired from a rinkidink 115mm (4.52") gun can punch through 11.42" of armor, imagine the penetration of an 11" (280 mm) naval gun with a steel APFSDS round. 12" armor belt (300 mm) was a lot in those days, as much or more than most British Battleships had.

[Dean]

Post by Alfred Montestruc

Post by Dean

Post by Alfred Montestruc
---snip rubbish----------

Post by Paul J. Adam
When they were used as a desperation measure by the Iraqis, they failed
to achieve a single penetration, breaking up on impact.

Which is neither here nor there, nor have you proved they broke up on impact. You said "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact" --that is not the same as "fail to penetrate" the best tank armor in the world at this time which was designed 20 + years after those specific weapons were in the field.
Yes a uranium or tungsten carbide rod will penetrate better as it is denser, so effing what? That is not the point.
The point is you said "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact"
Which is stupid ridiculous and wrong.

Post by Paul J. Adam
If you call that "success" what do they have to do to be classed as
failures? Circle back and hit the tank that fired them?

Post by Alfred Montestruc
I did not claim the soft cap idea was never used, I asked you to cite it.

Which I did, pointing to the description of how they provided a 25-50%
improvement in effectiveness *from the very same reference* you said
proved they didn't exist and weren't effective.

No it does not say 25 to 50% it does not state any percentage and the shattering has to do with poor material quality of effing CAST IRON SHOT, made in the late 19th century more than 100 years ago, not forged steel.

Post by Paul J. Adam
So, who's using and developing steel APFSDS for anything other than
training purposes these days?

"These days" do not matter.
We started this discussion about WWI warships using steel APFSDS as a hypothetical, the question is not whether "these days" it is the best shot to use.
The question is would it have been of significant advantage at the time in WWI.
Tungsten carbide use in shot was 20 odd years in the future to 1914, Uranium use in AP ammo more than 40 years away.
The question is would a good grade of forged steel available in ~1910 made into shot put on an APFSDS mode penetrate better than standard cast steel AP shot of WWI. Obviously it would be better given the use by the USSR, now you should have shut the eff up about this ages ago and moved on to the political and military impacts.
You dredging all this kaka up is moving the goal posts so you can pretend you are "winning", which you are not.
Nor am I winning, you are wasting my time with kaka, when what I want is an intelligent discussion which clearly you are unable to have. All you succeed at in being annoying and making yourself look really effing stupid and childish.
What matters is you were flatly wrong in stating that "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact" and I proved it and you know it. Any claim otherwise is just you lying, and we both know it.
Now ta-ta and eff off.

Post by Paul J. Adam
--
He thinks too much, such men are dangerous.

You are an entirely disarmed man then, you think not ad all.

Wow, Paul just handed your ass to you and all you can do is resort to insults? All you reply with are "it doesn't matter", "you're wrong" and such which is not much of a rebuttal.
Can you cite a steel penetrator that works?

Here moron.
Steel long rod penetrators of reasonable toughness don't historically 1"shatter on impact" see the reference.
http://fofanov.armor.kiev.ua/Tanks/ARM/apfsds/ammo.html
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&ved=0CDEQFjAD&url=http%3A%2F%2Fmilitaryrussia.ru%2Fforum%2Fdownload%2Ffile.php%3Fid%3D17600&ei=fJDAVMKOJcOfggSU_oCoAg&usg=AFQjCNHN4mTymvDKhxdC5jOjm3ecsQGgEg&sig2=yhlj29CN9D2aag8zpD8ytQ&bvm=bv.83829542,d.eXY&cad=rja
LOOK ON PAGE 29 THE PURE STEEL SHOT 3BVM-3 APFSDS ROUND HAS A PENETRATION RATING OF 290 MM 2000 METERS DOWNRANGE FROM THE GUN. THIS PROJECTILE WAS INTRODUCED IN 1962, 290 MM (11.42") PENETRATION IS NOTHING TO SNEEZE AT
They do not penetrate as well as tungsten or uranium rod, which rounds from an APFSDS-DU type penetration can exceed 600 mm, but they do work.
If such a small projectile fired from a rinkidink 115mm (4.52") gun can punch through 11.42" of armor, imagine the penetration of an 11" (280 mm) naval gun with a steel APFSDS round. 12" armor belt (300 mm) was a lot in those days, as much or more than most British Battleships had.

Continued insults. How mature of you. I saw this in the first link YOU provided: "The penetrator is made of maraging steel so has a rather modest penetration potential. This, as well as unsatisfactory performance on slanted impacts, delegated the round to practice and trials use".

[Alfred Montestruc]

Post by Dean

Post by Alfred Montestruc

Post by Dean

Post by Alfred Montestruc
---snip rubbish----------

Post by Paul J. Adam
When they were used as a desperation measure by the Iraqis, they failed
to achieve a single penetration, breaking up on impact.

Which is neither here nor there, nor have you proved they broke up on impact. You said "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact" --that is not the same as "fail to penetrate" the best tank armor in the world at this time which was designed 20 + years after those specific weapons were in the field.
Yes a uranium or tungsten carbide rod will penetrate better as it is denser, so effing what? That is not the point.
The point is you said "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact"
Which is stupid ridiculous and wrong.

Post by Paul J. Adam
If you call that "success" what do they have to do to be classed as
failures? Circle back and hit the tank that fired them?

Post by Alfred Montestruc
I did not claim the soft cap idea was never used, I asked you to cite
it.

Which I did, pointing to the description of how they provided a 25-50%
improvement in effectiveness *from the very same reference* you said
proved they didn't exist and weren't effective.

No it does not say 25 to 50% it does not state any percentage and the shattering has to do with poor material quality of effing CAST IRON SHOT, made in the late 19th century more than 100 years ago, not forged steel.

Post by Paul J. Adam
So, who's using and developing steel APFSDS for anything other than
training purposes these days?

"These days" do not matter.
We started this discussion about WWI warships using steel APFSDS as a hypothetical, the question is not whether "these days" it is the best shot to use.
The question is would it have been of significant advantage at the time in WWI.
Tungsten carbide use in shot was 20 odd years in the future to 1914, Uranium use in AP ammo more than 40 years away.
The question is would a good grade of forged steel available in ~1910 made into shot put on an APFSDS mode penetrate better than standard cast steel AP shot of WWI. Obviously it would be better given the use by the USSR, now you should have shut the eff up about this ages ago and moved on to the political and military impacts.
You dredging all this kaka up is moving the goal posts so you can pretend you are "winning", which you are not.
Nor am I winning, you are wasting my time with kaka, when what I want is an intelligent discussion which clearly you are unable to have. All you succeed at in being annoying and making yourself look really effing stupid and childish.
What matters is you were flatly wrong in stating that "If you fire a steel long-rod penetrator at useful velocities, it'll simply shatter on impact" and I proved it and you know it. Any claim otherwise is just you lying, and we both know it.
Now ta-ta and eff off.

Post by Paul J. Adam
--
He thinks too much, such men are dangerous.

You are an entirely disarmed man then, you think not ad all.

Wow, Paul just handed your ass to you and all you can do is resort to insults? All you reply with are "it doesn't matter", "you're wrong" and such which is not much of a rebuttal.
Can you cite a steel penetrator that works?

Here moron.
Steel long rod penetrators of reasonable toughness don't historically 1"shatter on impact" see the reference.
http://fofanov.armor.kiev.ua/Tanks/ARM/apfsds/ammo.html
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&ved=0CDEQFjAD&url=http%3A%2F%2Fmilitaryrussia.ru%2Fforum%2Fdownload%2Ffile.php%3Fid%3D17600&ei=fJDAVMKOJcOfggSU_oCoAg&usg=AFQjCNHN4mTymvDKhxdC5jOjm3ecsQGgEg&sig2=yhlj29CN9D2aag8zpD8ytQ&bvm=bv.83829542,d.eXY&cad=rja
LOOK ON PAGE 29 THE PURE STEEL SHOT 3BVM-3 APFSDS ROUND HAS A PENETRATION RATING OF 290 MM 2000 METERS DOWNRANGE FROM THE GUN. THIS PROJECTILE WAS INTRODUCED IN 1962, 290 MM (11.42") PENETRATION IS NOTHING TO SNEEZE AT
They do not penetrate as well as tungsten or uranium rod, which rounds from an APFSDS-DU type penetration can exceed 600 mm, but they do work.
If such a small projectile fired from a rinkidink 115mm (4.52") gun can punch through 11.42" of armor, imagine the penetration of an 11" (280 mm) naval gun with a steel APFSDS round. 12" armor belt (300 mm) was a lot in those days, as much or more than most British Battleships had.

Continued insults. How mature of you.

Far more mature than your refusal to read or think, and continued behavior like bozo the clown, you deserve a sharp rap across the knuckles for being this dense.

Post by Dean
I saw this in the first link YOU provided: "The penetrator is made of maraging steel so has a rather modest penetration potential.

As opposed to Depleted Uranium (DU) core or Tungsten Carbide ammo, sure, which is what the writer is comparing it to for discussion of modern tanks.

APFSDS ammo was introduced in the mid 1950's with steel rods as you should be able to gather by the references I have provided, and able to penetrate any THEN EXISTING (mid 1950's) tank armor (~290mm) at ranges of ~ 2000 meters. That is far better than most anti-tank ammo of that (mid 1950's) period.

The point of the WI was the introduction of APFSDS ammo on naval guns by the Germans in WWI, some 40-50 years prior to this. NOTHING impossible about it, the only changes are geometric, all the materials issues were already solved.

Post by Dean
This, as well as unsatisfactory performance on slanted impacts, delegated the round to practice and trials use".

So what? Again set next to tungsten carbide or DU, it does not make it better than the AP used by WWI era battleships.

[Paul J. Adam]

Post by Alfred Montestruc

Post by Dean
Wow, Paul just handed your ass to you and all you can do is resort
to insults? All you reply with are "it doesn't matter", "you're
wrong" and such which is not much of a rebuttal.
Can you cite a steel penetrator that works?

Here moron.
Steel long rod penetrators of reasonable toughness don't historically
1"shatter on impact" see the reference.

Actually they do, which is why they aren't used.

The Royal Military College of Science's "Attack of Armour" again,

+++++
If the penetrator should break up on striking, its chances of
penetrating are better than those of a comparable spun round, since with
the unspun round the fragments tend to hold together and so retain
enough concentrated kinetic energy to defeat the remaining armour. The
fragments from a spun penetrator tend to disperse under centrifugal forces.
+++++

However, this is primarily an effect on proof firings at normal impact:
once the penetrator fails during an oblique impact (and steel is much
more prone to doing so than tungsten or DU) the yaw accelerations
induced scatter the fragments and deny effective penetration.

Which, curiously enough, is why only the Soviets attempted steel LRPs
and even they abandoned them for operational use (they're good for
training, though, because they do much less damage to the target hulks)

Post by Alfred Montestruc
LOOK ON PAGE 29 THE PURE STEEL SHOT 3BVM-3 APFSDS ROUND HAS A
PENETRATION RATING OF 290 MM 2000 METERS DOWNRANGE FROM THE GUN.
THIS PROJECTILE WAS INTRODUCED IN 1962, 290 MM (11.42") PENETRATION
IS NOTHING TO SNEEZE AT

Amazing: this is less than the 1948 20pdr (83mm) gun on the Centurion
could achieve (and against steeply angled targets too) Over a decade of
progress and it's becoming *less* effective?

And of course it has to be a normal impact, otherwise the penetration
drops to nearly zero - while the 20pdr was tested against sloped armour
at 30 degrees, which effectively doubled the path length.

Post by Alfred Montestruc
If such a small projectile fired from a rinkidink 115mm (4.52") gun
can punch through 11.42" of armor, imagine the penetration of an 11"
(280 mm) naval gun with a steel APFSDS round.

At two thousand metres? When, at Jutland, did the battleships trade fire
at such short range?

And a steel long-rod from a 115mm gun, defeating 300mm of RHA at normal
impact... amazing. The German 128mm PaK 44, with a full-bore capped
steel shot, would defeat 150mm of armour at that range... angled at 30
degrees, which meant an actual piercing performance of 300mm (and the
steel long-rod would simply scar the surface at any significant slope of
target).




Why not use long-rod penetrators in the 1910s? Several reasons.

APFSDS is reliant for its effect on extreme velocity: which wasn't
achievable in any practical gun until the 1950s, and then only at the
muzzle. By 1945 we were testing the 32pdr AT gun which, using APDS, was
clocking about 1,250 metres a second of muzzle velocity: still too slow
to benefit from a long-rod penetrator of any material. (It would,
though, also have matched or beaten the Soviet 115mm with steel APFSDS
for armour penetration)

Oddly enough, you lose velocity over range (hence the use of chemical
energy rounds like HEAT or HESH, and for the Soviets gun-launched guided
missiles, for longer-range engagements) so even if you can achieve the
muzzle velocity, at practical battleship fighting range you're out of
the hypersonic regime where a long-rod penetrator offers any gain over
full-calibre capped AP shell. Hence, no performance gain from long-rod
penetrators even if you make them out of tungsten or uranium, and steel
looks even more pointless.

Steel long-rods, breaking up on impact, can at least have some effect on
a normal impact (ninety degrees to the target), typically two-thirds of
APCBC shot, a bit less than APDS and half that of a decent tungsten
APFSDS. However, a combination of penetrator shatter and impact yaw
means that a steel long-rod loses that effectiveness with only ten to
fifteen degrees of angle off normal impact.

Let's not even consider the behind-armour effects required: it's not
enough to merely poke a hole in the belt, there's an essential "in order
to..." which involves wreaking sufficient damage to machinery or
magazines to disable, disarm or destroy the target ship. (Hence why HEAT
projectiles are also of seriously limited utility)

Or for the short version: using steel in a long-rod penetrator produces
*less* penetrative effect than a well-designed full-calibre steel round
of similar calibre: which is why the Soviets dropped it like a hot
potato and switched to something that works.

[Alfred Montestruc]

Post by Paul J. Adam

Post by Alfred Montestruc

Post by Dean
Wow, Paul just handed your ass to you and all you can do is resort
to insults? All you reply with are "it doesn't matter", "you're
wrong" and such which is not much of a rebuttal.
Can you cite a steel penetrator that works?

Here moron.
Steel long rod penetrators of reasonable toughness don't historically
1"shatter on impact" see the reference.

Actually they do, which is why they aren't used.
The Royal Military College of Science's "Attack of Armour" again,
+++++
If the penetrator should break up on striking, its chances of
penetrating are better than those of a comparable spun round, since with
the unspun round the fragments tend to hold together and so retain
enough concentrated kinetic energy to defeat the remaining armour. The
fragments from a spun penetrator tend to disperse under centrifugal forces.
+++++
once the penetrator fails during an oblique impact (and steel is much
more prone to doing so than tungsten or DU) the yaw accelerations
induced scatter the fragments and deny effective penetration.
Which, curiously enough, is why only the Soviets attempted steel LRPs
and even they abandoned them for operational use (they're good for
training, though, because they do much less damage to the target hulks)

Post by Alfred Montestruc
LOOK ON PAGE 29 THE PURE STEEL SHOT 3BVM-3 APFSDS ROUND HAS A
PENETRATION RATING OF 290 MM 2000 METERS DOWNRANGE FROM THE GUN.
THIS PROJECTILE WAS INTRODUCED IN 1962, 290 MM (11.42") PENETRATION
IS NOTHING TO SNEEZE AT

Amazing: this is less than the 1948 20pdr (83mm) gun on the Centurion
could achieve (and against steeply angled targets too) Over a decade of
progress and it's becoming *less* effective?
And of course it has to be a normal impact, otherwise the penetration
drops to nearly zero - while the 20pdr was tested against sloped armour
at 30 degrees, which effectively doubled the path length.

Post by Alfred Montestruc
If such a small projectile fired from a rinkidink 115mm (4.52") gun
can punch through 11.42" of armor, imagine the penetration of an 11"
(280 mm) naval gun with a steel APFSDS round.

At two thousand metres? When, at Jutland, did the battleships trade fire
at such short range?

Ever hear of air drag? How about the cube square law?

The mass of the same type geometry projectile fired from a much larger caliber gun will be proportional to the cube of the bore.

The air drag will be proportional to the square of the bore diameter. So if both guns fire solid shot, with the same L/D and the same basic geometry and are fired at exactly the same up angle with the same muzzle velocity, and neither one hits an aircraft or some other obstruction, the larger gun will shoot further. By rough calculation an 11" gun would shoot close to 3 times further than a 4.52" gun, and the projectile would impact at about double the velocity.

APFSDS ammo would have much lower air drag, which is one of the main points of using it. So an 11" gun firing

Post by Paul J. Adam
And a steel long-rod from a 115mm gun, defeating 300mm of RHA at normal
impact... amazing. The German 128mm PaK 44, with a full-bore capped
steel shot, would defeat 150mm of armour at that range

2000 meters really? ~ half the penetration of a gun of 89% the bore but using a APFSDS round and APFSDS with steel is ineffective, sure.

Post by Paul J. Adam
... angled at 30
degrees, which meant an actual piercing performance of 300mm

Nope -- straight through dimension is 173.2 mm by 150/cos(30).

By this:

http://www.combinedfleet.com/formula.htm

Using Thompson methods for calculation of armor penetration I get that 150mm at 30 degrees slope gives 230 mm at 0 degrees slope, and that 290 mm at 0 degrees gives 217mm at 30 degrees slope. This was the method used by the US Navy in wwII


(and the

Post by Paul J. Adam
steel long-rod would simply scar the surface at any significant slope of
target).
Why not use long-rod penetrators in the 1910s? Several reasons.

Nope -- your massive ignorance showing. APFSDS ammo has much lower air drag, so it KEEPS a larger fraction of the muzzle energy much longer the muzzle velocities are not enormously larger, and where larger they are larger because the projectile + sabot is lighter than a conventional AP round.

<>which wasn't

Post by Paul J. Adam
achievable in any practical gun until the 1950s,

Using the thompson method and krupp method described above I get that 11" gun firing solid AP weighing 447 kg with a muzzle velocity of 800 m/s (possible in 1900) shot at 10,000 meters will hit moving at 199 m/s and punch through 129 mm of armor flat, and 58.9 mm of deck armor as it is plunging in at an angle of 42 degrees and is fired at an up angle of 19.2 degrees to throw it that far.

Now same gun, same muzzle velocity but an APFSDS round with 1/2.5 the diameter and an L/D of 15, gives a projectile weight of 128 kg, and length of 1.67 meters, and only needs 5.05 degrees of up angle to throw 10,000 meters, and is moving at 621 m/s on impact and by the krupp method will penetrate 439 mm flat, and by thompson method will penetrate 412 mm at a slope of 14.2 which is the plunging angle of this shot on side plate.

So that will punch through a British BB's main belt armor at 10,000 meters no problem at all, at all.

Once I found the USN Navy and krupp method calculation I can calibrate them off hard data that I have already looked up including Navy data and APFSDS data.

Post by Paul J. Adam
and then only at the
muzzle. By 1945 we were testing the 32pdr AT gun which, using APDS, was
clocking about 1,250 metres a second of muzzle velocity: still too slow
to benefit from a long-rod penetrator of any material.

No no no, the issue is a long rod cannot be stabilized by spin, it will tumble, it is not that you need some magic velocity to make it work. The problem is bozos like you were the "it can't be done" idiots, not thinking through the physics.

Fin stabilization works fine at lower velocities and the long rod penetrator works fine at lower velocities, see a pike!!



---------snip more Paul rubbish

[Paul J. Adam]

Post by Alfred Montestruc

Post by Paul J. Adam
At two thousand metres? When, at Jutland, did the battleships trade
fire at such short range?

Ever hear of air drag? How about the cube square law?

Yep. Also heard of wave drag and a few other issues. I've even worked on
problems of "push this through a resisting medium a lot faster and see
what happens... oh, not as simple as it seems".

Post by Alfred Montestruc
The mass of the same type geometry projectile fired from a much
larger caliber gun will be proportional to the cube of the bore.
The air drag will be proportional to the square of the bore diameter.
So if both guns fire solid shot, with the same L/D and the same basic
geometry and are fired at exactly the same up angle with the same
muzzle velocity, and neither one hits an aircraft or some other
obstruction, the larger gun will shoot further. By rough calculation
an 11" gun would shoot close to 3 times further than a 4.52" gun, and
the projectile would impact at about double the velocity.

So, your maximum battle range for a 11" gun firing APFSDS will be about
three times the maximum effective range of a 115mm gun firing APFSDS.

Amazing, two to three miles. When did the battle lines at Jutland ever
get that close?

Post by Alfred Montestruc
APFSDS ammo would have much lower air drag, which is one of the main
points of using it.

No, it doesn't, not in its effective region (above 1400 metres per
second or so) - fluid drag is proportional to velocity cubed, remember?
A German SK L/40 naval gun has a muzzle velocity of 820 metres per
second, but to make a long-rod penetrator effective you want to fire it
at over twice that: so you've got *eight times* the drag force acting,
and the fact that you've got a L/D of ten instead of five isn't going to
sustain that velocity over dreadnought fighting distances.

Also, you've got much more wetted area and fin area, which further ups
your drag (and for gunnery purposes makes you much more susceptible to
crosswind, since the projectile will weathercock)

For someone who claims to be an engineering expert, you don't actually
understand your subject very well, Al.

Post by Alfred Montestruc

Post by Paul J. Adam
And a steel long-rod from a 115mm gun, defeating 300mm of RHA at
normal impact... amazing. The German 128mm PaK 44, with a full-bore
capped steel shot, would defeat 150mm of armour at that range

2000 meters really? ~ half the penetration of a gun of 89% the bore
but using a APFSDS round and APFSDS with steel is ineffective, sure.

200mm of *steeply armoured* plate, while steel APFSDS glaces off at
anything off normal impact.

One will penetrate effectively in combat conditions (and did), one
produces reasonable results in a piercing trial but proved useless in
action. Not exactly a dramatic step forward, is it?

Post by Alfred Montestruc

Post by Paul J. Adam
... angled at 30 degrees, which meant an actual piercing
performance of 300mm

Nope -- straight through dimension is 173.2 mm by 150/cos(30).

*sin* 30. The Germans were worried about steeply inclined plates,
because even the Sherman had a decent glacis slope and also very few
combat shots were at normal impact.

Post by Alfred Montestruc

Post by Paul J. Adam
Why not use long-rod penetrators in the 1910s? Several reasons.

Nope -- your massive ignorance showing.

I'm not responsible for your incomprehension, Al.

APFSDS ammo has much lower

Post by Alfred Montestruc
air drag,

No, it doesn't. It's got higher form drag. Fins, remember?

Post by Alfred Montestruc
so it KEEPS a larger fraction of the muzzle energy much
longer the muzzle velocities are not enormously larger,

If the muzzle velocity isn't larger, there's no benefit in using a
long-rod penetrator because you're not able to exploit the hydrodynamic
piercing regime.

"At these high velocities [above ~1400m/s] both the projectile and the
target armour are subjected to a hydrodynamic regime in which the
materials flow as if they were liquids, although they do not change
their state. The metal at the leading end of the penetrator and the
armour in contact with it both flow away from the point of contact, so
that the armour is penetrated and the mass of the projectile is
progressively used up as it passes through the armour until there is
insufficient mass for the process to continue. Penetration is therefore
proportional to the length of the penetrator." [Courtney-Green]

*That* is the regime where L/D becomes critical, where long-rod
penetrators become effective, and where getting a L/D over seven
requires fin stabilisation. If you're firing steel at lower velocities,
you just shatter on the armour and hope the energy transfer's enough to
cause local failure of the plate.

Seriously, Al, if you don't understand either aerodynamics or armour
penetration, you're going to struggle to avoid looking like a
belligerent idiot.

Post by Alfred Montestruc
<>which wasn't

Post by Paul J. Adam
achievable in any practical gun until the 1950s,

Using the thompson method and krupp method described above I get
that 11" gun firing solid AP weighing 447 kg with a muzzle velocity
of 800 m/s (possible in 1900) shot at 10,000 meters will hit moving
at 199 m/s and punch through 129 mm of armor flat, and 58.9 mm of
deck armor as it is plunging in at an angle of 42 degrees and is
fired at an up angle of 19.2 degrees to throw it that far.

And yet a *real* 11" gun, firing a 300kg AP round with a muzzle velocity
of 910 metres per second, had a striking velocity at 10,000 metres of
three times your calculations (611 metres per second) and an angle of
fall of six degrees.

http://www.navweaps.com/Weapons/WNGER_11-52_skc28.htm

It appears that the real world seems somewhat resistant to your
calculations.

Post by Alfred Montestruc
Now same gun, same muzzle velocity but an APFSDS round with 1/2.5 the
diameter and an L/D of 15, gives a projectile weight of 128 kg, and
length of 1.67 meters, and only needs 5.05 degrees of up angle to
throw 10,000 meters, and is moving at 621 m/s on impact

In other words, you've calculated a way to achieve the same striking
velocity with a 128kg projectile in theory, that was achieved in reality
with a 300kg projectile.

Amazing.

Post by Alfred Montestruc
Once I found the USN Navy and krupp method calculation I can
calibrate them off hard data that I have already looked up including
Navy data and APFSDS data.

Did you actually bother with the trivially tedious step of checking your
calculations against real-world data?

Post by Alfred Montestruc

Post by Paul J. Adam
and then only at the muzzle. By 1945 we were testing the 32pdr AT
gun which, using APDS, was clocking about 1,250 metres a second of
muzzle velocity: still too slow to benefit from a long-rod
penetrator of any material.

No no no, the issue is a long rod cannot be stabilized by spin, it
will tumble, it is not that you need some magic velocity to make it
work.

I'm sure you're adequately convinced that's true.

Now, who makes long-rod penetrators with muzzle velocities of ~900
metres per second? Nobody. To take advantage of the benefits of
increasing L/D ratio, you need to get into the hydrodynamic regime.

Post by Alfred Montestruc
The problem is bozos like you were the "it can't be done"
idiots, not thinking through the physics.

There's no technical reason a 1916 naval rifle couldn't be equipped with
a saboted, finned penetrating dart (and a slipping driving band).

There's just no point - until you bring in the high velocity and the
improved penetrator materials, it produces no advantage in penetration
and greatly reduces the behind-armour effects.

[Alfred Montestruc]

Post by Paul J. Adam

Post by Alfred Montestruc

Post by Paul J. Adam
At two thousand metres? When, at Jutland, did the battleships trade
fire at such short range?

Ever hear of air drag? How about the cube square law?

Yep. Also heard of wave drag and a few other issues. I've even worked on
problems of "push this through a resisting medium a lot faster and see
what happens... oh, not as simple as it seems".

Simple or easy you need to have some vague semblance of an understanding of physics to work the problem, which it seems you do not.

Post by Paul J. Adam

Post by Alfred Montestruc
The mass of the same type geometry projectile fired from a much
larger caliber gun will be proportional to the cube of the bore.
The air drag will be proportional to the square of the bore diameter.
So if both guns fire solid shot, with the same L/D and the same basic
geometry and are fired at exactly the same up angle with the same
muzzle velocity, and neither one hits an aircraft or some other
obstruction, the larger gun will shoot further. By rough calculation
an 11" gun would shoot close to 3 times further than a 4.52" gun, and
the projectile would impact at about double the velocity.

So, your maximum battle range for a 11" gun firing APFSDS will be about
three times the maximum effective range of a 115mm gun firing APFSDS.
Amazing, two to three miles.

2 miles is ~ 3.2 km
3 miles is ~ 4.8 km

Does not follow, per the US Military the effective range of APFSDS rounds (in terms of capability to do a lot of damage, and still be moving really fast, not necessarily in accurate ability to hit) is a whole lot more than that.

http://www.dtic.mil/dtic/tr/fulltext/u2/a224217.pdf

See page 11, an 120 mm M829 APFSDU round has a muzzle velocity of ~ 1650 m/s and at 14 km downrange is still trucking along at over 800 m/s, that is FYI range data, not calculation, but it agrees with my calculations.

You might also note that M791 APDS ammo from tiny 25mm gun has a muzzle velocity of ~1390 m/s at at 3km downrange it is still moving at over 900 m/s.

Post by Paul J. Adam
When did the battle lines at Jutland ever
get that close?

Did not, you are playing move the goal post again and showing your ignorance.

Post by Paul J. Adam

Post by Alfred Montestruc
APFSDS ammo would have much lower air drag, which is one of the main
points of using it.

No, it doesn't,

Yes it does, else you would not see linear decline in projectile velocity over distance as hard data from the US army shows on page 11 in the above. If it were proportional to V^3 as you idiotically maintain the graph would be clearly non-linear with very rapid initial decline and the slope getting more gentle as speed dropped. The slope is linear over many kilometers.

Post by Paul J. Adam
not in its effective region (above 1400 metres per
second or so) - fluid drag is proportional to velocity cubed, remember?

Wrong, stupidly, , , astonishingly stupidly wrong.

I am going to drag this up every time you make another post on this group about a technical subject. As in "That this is the opinion of Paul J. Adam AKA bozo the clown thinks that " fluid drag is proportional to velocity cubed"

The basic drag equation is : Drag in consistent units of force (D)

D=Cd*A*rho*V*V/2

In other words, proportional to several terms of which velocity squared, not cubed is one

where V= velocity, rho is the fluid density, A is a characteristic area of the object, and Cd is a sort of constant that depends on geometry of the object, Reynolds number, and Mach number.

http://en.wikipedia.org/wiki/Drag_coefficient

See under definition of Cd or the coefficient of drag.

Post by Paul J. Adam
A German SK L/40 naval gun has a muzzle velocity of 820 metres per
second, but to make a long-rod penetrator effective you want to fire it

You are pulling that out of your arse. I have already proven that an APFSDS round (one made of steel) fired from the exact same gun, at exactly the same muzzle velocity can at long range penetrate far more armor at long range than a standard AP round made for the same gun.

Post by Paul J. Adam
so you've got *eight times* the drag force acting,

No,

1 - first off you are pulling the velocity requirement out of your arse, it simply is not required at all to get good results at long range.

2 - Second off drag is proportional to velocity squared, not cubed, so if the rest of your idiotic assumptions were right, which they are not, it would be 4x the drag force, not 8 and your assumptions are as usual dead wrong.

3 - This is really the important point that you are missing, the characteristic drag area of the object is most closely associated with the frontal projected area. So for a standard AP round that area is reasonably accurate to represent as A=pi*D*D/4, where D is for all intents and purposes the bore diameter. Now if you look at the below website I present again:


http://en.wikipedia.org/wiki/Drag_coefficient

From that site:

"The reference area depends on what type of drag coefficient is being measured. For automobiles and many other objects, the reference area is the projected frontal area of the vehicle. This may not necessarily be the cross sectional area of the vehicle, depending on where the cross section is taken. For example, for a sphere A = \pi r^2\, (note this is not the surface area = \!\ 4 \pi r^2).

For airfoils, the reference area is the planform area. Since this tends to be a rather large area compared to the projected frontal area, the resulting drag coefficients tend to be low: much lower than for a car with the same drag and frontal area, and at the same speed.

Airships and some bodies of revolution use the volumetric drag coefficient, in which the reference area is the square of the cube root of the airship volume (volume to the two-thirds power). Submerged streamlined bodies use the wetted surface area.

Two objects having the same reference area moving at the same speed through a fluid will experience a drag force proportional to their respective drag coefficients. Coefficients for unstreamlined objects can be 1 or more, for streamlined objects much less."


End quote, simple objects like a simple geometry AP projectile, you can just use the bore area and that is close enough.

An APFSDS projectile is best represented as a "body of revolution" where you calculate the characteristic drag area of the projectile using the volume of the projectile to the 2/3 power. That is what I did in my math model, the paper produced by the US Army agrees in general with that sort of approach in terms of results they get.

So A standard AP round will have a drag area * Cd much larger than the drag area *Cd of the APFSDS projectile, In the case of the 11" gun I did before the ratio was over 8, this is backed up by experimental science as I pointed out in the UD Army paper "Projectile Supersonic Drag Characteristics".

What matters is the effective drag area which is the characteristic area * Cd, and the mass and speed of the projectile. Where the effective drag area is small, and the mass is larger, the projectile will keep it's velocity longer.

Post by Paul J. Adam
Also, you've got much more wetted area and fin area,

I allowed for that. As I said I used the method of volume^(2/3)to get the characteristic area. I first assume the volume is a simple cylinder, then note that I am going to have a conic taper on the nose (the impact point) and some taper toward the tail, that material is budgeted for the fins.


FYI taking the data from the paper Army paper and looking at the Cd they came up with they are basing it on pi*d*d/4 of the penetrator rod. Doing it that way I get the same ballpart (~ 0.3 Cd at high mach numbers) as they if I do it by the volume method I get ~ 0.07, this is from the same drag you can calculate yourself from the paper.

Post by Paul J. Adam
which further ups
your drag (and for gunnery purposes makes you much more susceptible to
crosswind, since the projectile will weathercock)

OMG !! weathercock !! the projectile moving at 600 m/s + has to worry about a hurricane force wind of 30 odd m/s maybe, a reasonable side wind of maybe 1-2 m/s so what! Adjust for windage, but in the opposite since as with spin stabilize projectiles as that is what happens with arrows.

Post by Paul J. Adam
For someone who claims to be an engineering expert, you don't actually
understand your subject very well, Al.

Look who is talking!! Mr. Paul J. Adam AKA bozo the clown thinks that " fluid drag is proportional to velocity cubed"

Post by Paul J. Adam

Post by Alfred Montestruc

Post by Paul J. Adam
And a steel long-rod from a 115mm gun, defeating 300mm of RHA at
normal impact... amazing. The German 128mm PaK 44, with a full-bore
capped steel shot, would defeat 150mm of armour at that range

2000 meters really? ~ half the penetration of a gun of 89% the bore
but using a APFSDS round and APFSDS with steel is ineffective, sure.

200mm of *steeply armoured* plate, while steel APFSDS glaces off at
anything off normal impact.

You said 30 degrees which is not steep.

Post by Paul J. Adam
One will penetrate effectively in combat conditions (and did), one
produces reasonable results in a piercing trial but proved useless in
action. Not exactly a dramatic step forward, is it?

Post by Alfred Montestruc

Post by Paul J. Adam
... angled at 30 degrees, which meant an actual piercing
performance of 300mm

Nope -- straight through dimension is 173.2 mm by 150/cos(30).

*sin* 30.

No Paul J. Adam AKA bozo the clown who thinks that " fluid drag is proportional to velocity cubed" it is cos (30).

Post by Paul J. Adam

Post by Alfred Montestruc

Post by Paul J. Adam
Why not use long-rod penetrators in the 1910s? Several reasons.

Nope -- your massive ignorance showing.

I'm not responsible for your incomprehension, Al.

And I am not for yours Mr. Paul J. Adam AKA bozo the clown thinks that " fluid drag is proportional to velocity cubed"

Post by Paul J. Adam
APFSDS ammo has much lower

Post by Alfred Montestruc
air drag,

No, it doesn't. It's got higher form drag. Fins, remember?

Wrong, that is not what the technical papers with experimental evidence shows.

Post by Paul J. Adam

Post by Alfred Montestruc
so it KEEPS a larger fraction of the muzzle energy much
longer the muzzle velocities are not enormously larger,

If the muzzle velocity isn't larger, there's no benefit in using a
long-rod penetrator because you're not able to exploit the hydrodynamic
piercing regime.

That is not what the Armor penetration paper calculations say. What matters according to them is velocity and projectile mass/ the the cube of the diameter of the of projectile impact and inclination, with some effects of material properties of both armor and projectile.

http://www.combinedfleet.com/formula.htm

All of them have major factors to the effect of V & (W/D^3). So the velocity and mass of the projectile divided by the cube of the penetrator diameter are major players. So a smaller diameter penetrator with large mass divided by the cube of the penetrator diameter is and the same velocity is going to punch through more than the same mass at a much larger diameter.

But then I am thinking you can actually visualize math and I have no evidence of that.

Post by Paul J. Adam
"At these high velocities [above ~1400m/s] both the projectile and the
target armour are subjected to a hydrodynamic regime in which the
materials flow as if they were liquids, although they do not change
their state. The metal at the leading end of the penetrator and the
armour in contact with it both flow away from the point of contact, so
that the armour is penetrated and the mass of the projectile is
progressively used up as it passes through the armour until there is
insufficient mass for the process to continue. Penetration is therefore
proportional to the length of the penetrator." [Courtney-Green]

Me thinks you either quote the man out of context, or that he is a moron like you.

Post by Paul J. Adam
*That* is the regime where L/D becomes critical, where long-rod
penetrators become effective, and where getting a L/D over seven
requires fin stabilisation. If you're firing steel at lower velocities,
you just shatter on the armour and hope the energy transfer's enough to
cause local failure of the plate.
Seriously, Al, if you don't understand either aerodynamics or armour
penetration, you're going to struggle to avoid looking like a
belligerent idiot.

Said Mr. Paul J. Adam AKA bozo the clown who thinks that "fluid drag is proportional to velocity cubed".

Post by Paul J. Adam

Post by Alfred Montestruc
<>which wasn't

Post by Paul J. Adam
achievable in any practical gun until the 1950s,

Using the thompson method and krupp method described above I get
that 11" gun firing solid AP weighing 447 kg with a muzzle velocity
of 800 m/s (possible in 1900) shot at 10,000 meters will hit moving
at 199 m/s and punch through 129 mm of armor flat, and 58.9 mm of
deck armor as it is plunging in at an angle of 42 degrees and is
fired at an up angle of 19.2 degrees to throw it that far.

And yet a *real* 11" gun, firing a 300kg AP round with a muzzle velocity
of 910 metres per second, had a striking velocity at 10,000 metres of
three times your calculations (611 metres per second) and an angle of
fall of six degrees.
http://www.navweaps.com/Weapons/WNGER_11-52_skc28.htm

So nice of you to provide some hard data to adjust my Cd with hard numbers.

I had not allowed for reduction in density of air at high altitude which will make a significant difference and had not allowed for Cd not being really constant but rather dependent on Mach & Reynolds numbers.

The assumptions I made in my model tend to favor standard projectiles, as I had not inflicted the effect that Cd gets really very large around Mach 1, which will strongly affect long range gunfire with standard AP, slowing them down faster, while the APFSDS round will stay in the high Mach numbers longer due to it's small effective drag area, so will drop below ~ Mach 2 to 2.5 much later than the standard AP rounds.

Mach 1 at 20 C is 343.2M/S, so Mach 2.5 is 858 m/s, and Cd gets really large near Mach 1. So as your projectile approaches Mach 1 from above it slows much faster than a simple V ^2 law would imply.

Also, and this is important, a gun tube muzzle velocity is strongly dependent on the projectile mass being pushed by the expanding gases. If the APFSDS projectile + sabot is much lighter than a standard AP round, and you use the same powder charge as with a standard AP round, you will get a significantly higher velocity. The velocity increase can be estimated by assuming the same kinetic energy of everything leaving the muzzle with both rounds.

In fact the peak pressure with the same powder charge will be less, because the lighter load will have moved further down the bore (because it is less massive) when maximum pressure of the charge is reached, so it has more volume to expand in. In fact you surely bump up the powder charge a bit and get an even higher velocity with the same peak pressure.

Be that as it may, you need to get over yourself, you can do research on the internet and find documents -- bully for you.

You do not have a significant level of understanding of basic classical physics. You are in way over your head and clearly have no clue what you are talking about.

[Paul J. Adam]

On Saturday, January 24, 2015 at 5:16:15 AM UTC-6, Paul.J.Adam

Post by Paul J. Adam
Yep. Also heard of wave drag and a few other issues. I've even
worked on problems of "push this through a resisting medium a lot
faster and see what happens... oh, not as simple as it seems".

Simple or easy you need to have some vague semblance of an
understanding of physics to work the problem, which it seems you do
not.

Well, I understand the difference between form and skin drag, which you
seem determined to ignore, and I'm aware that drag forces rise as the
square of velocity through the resisting medium (another point that
seems to escape you)

Perhaps the problem is that you know a lot less about this than you
think, and bluster is failing to make up the gap?

Post by Paul J. Adam
So, your maximum battle range for a 11" gun firing APFSDS will be
about three times the maximum effective range of a 115mm gun firing
APFSDS.
Amazing, two to three miles.

2 miles is ~ 3.2 km 3 miles is ~ 4.8 km
Does not follow,

Really? Who's getting lethal hits with APFSDS at over three kilometres?
Ever?

The generally accepted longest-range tank-vs-tank hit was by a British
Challenger 1 in 1991, during OP GRANBY (Desert Saber to the US) - a
little over five kilometres. Using HESH, not APDFSDS, because the
tankies understand how much performance drops off by that range.

per the US Military the effective range of APFSDS

rounds (in terms of capability to do a lot of damage, and still be
moving really fast, not necessarily in accurate ability to hit) is a
whole lot more than that.

Not "really fast" in APFSDS terms. Long rod penetrators need to be in a
very high velocity regime to be effective, though tungsten and DU are
less affected by this than steel. The graph at

http://www.longrods.ch/optv.php

is worth a look as to why nobody bothers with steel APFSDS - you can't
get it moving fast enough to achieve its theoretical performance and it
loses what penetration capability it can achieve, rather too fast for
comfort as the velocity drops.

Post by Paul J. Adam
When did the battle lines at Jutland ever get that close?

Did not, you are playing move the goal post again and showing your ignorance.

No, I'm asking you for some evidence to support your rather hysterical
rantings.

You're claiming that using steel APFSDS rounds from battleship guns -
such as at Jutland - would have had a dramatic effect on the outcome,
apparently being far more effective, lethal, deadly et cetera. Why is
exploring that claim "moving the goalposts"?

What range is this APFSDS-armed battlewagon fighting at? What targets is
she shooting at, and what effect is she expecting to achieve that's
better than the APCBC and HE ammunition available at the time?

Post by Paul J. Adam
not in its effective region (above 1400 metres per second or so) -
fluid drag is proportional to velocity cubed, remember?

Wrong, stupidly, , , astonishingly stupidly wrong.

Actually, that's the first thing you've got right in a long time.
*Power* to maintain velocity is velocity-cubed, drag force is velocity
squared.

Post by Paul J. Adam
A German SK L/40 naval gun has a muzzle velocity of 820 metres per
second, but to make a long-rod penetrator effective you want to

You are pulling that out of your arse.

No, I'm pulling it from the equations at

http://www.longrods.ch/perfcalc.php

I have already proven that
an APFSDS round (one made of steel) fired from the exact same gun, at
exactly the same muzzle velocity can at long range penetrate far more
armor at long range than a standard AP round made for the same gun.

Using a 120mm L/44 tank gun as a reference (because its performance with
APFSDS is well understood) and a steel penetrator, you might get 650mm
of penetration of RHA, at an impact velocity of 2,400 metres per second,
which isn't a bad performance until you discover the impossibility of
achieving that impact velocity with any conventional gun design.

The practical upper limit of ~1700m/s at the muzzle gets you a little
over 550mm of penetration... at the muzzle.

Slow the projectile down to 1,000 metres per second *at impact* (not at
the muzzle) and penetration drops to 200mm of RHA... which is less than
a PaK 44 128mm gun, with APCBC, could achieve in 1944.

So no, I'm afraid that until you can generate a *lot* more impact
velocity, there's no advantage and serious disadvantages in using a
steel long-rod penetrator in reality.

3 - This is really the important point that you are missing, the
characteristic drag area of the object is most closely associated
with the frontal projected area.

Unless it's a long, slim finned object, where profile drag reduces in
significance and skin drag predominates.

Post by Paul J. Adam
which further ups your drag (and for gunnery purposes makes you
much more susceptible to crosswind, since the projectile will
weathercock)

OMG !! weathercock !! the projectile moving at 600 m/s + has to
worry about a hurricane force wind of 30 odd m/s maybe, a reasonable
side wind of maybe 1-2 m/s so what!

Where are you getting such light winds from? Ship movement alone gets
you 10 or more at combat speeds.

Adjust for windage, but in the
opposite since as with spin stabilize projectiles as that is what
happens with arrows.

And arrows are notorious for their accuracy at many kilometres? Unguided
fin stabilised rockets replaced rifled artillery for destructive fire
(as opposed to area neutralisation)? This is additional, unpredicted
error into a system you insisted would be far more capable and precise.
It can be resolved and corrected - but not instantly, requiring a lot of
firing trials to generate the necessary corrections (no ballistic
computers back then) and there needs to be a point of significantly
improved performance to make it worthwhile.

Sticking your fingers in your ears and shutting your eyes only means
you're ignoring the problem, it doesn't solve the problem.

Post by Paul J. Adam
No, it doesn't. It's got higher form drag. Fins, remember?

Wrong, that is not what the technical papers with experimental
evidence shows.

So, just to make it really clear, your contention is that stabilising
fins have no effect whatsoever on drag, because... because... well,
because you'd rather they didn't?

How, then, do they actually work?

Post by Paul J. Adam
If the muzzle velocity isn't larger, there's no benefit in using a
long-rod penetrator because you're not able to exploit the
hydrodynamic piercing regime.

That is not what the Armor penetration paper calculations say.

That may be because you're using calculations intended for full-bore
spun projectiles (which imposed an automatic limit on the L/D of the
shot or shell) and neglecting details like the structural strength of
the penetrator.

What
matters according to them is velocity and projectile mass/ the the
cube of the diameter of the of projectile impact and inclination,
with some effects of material properties of both armor and
projectile.
http://www.combinedfleet.com/formula.htm

Did you miss the caveat that the formula was derived for cases where

+++++
The projectiles assumed in these tests are usually between 1 and 3.5
calibers long (ignoring the projectile's windscreen, if any)
+++++

when you tried to assess performance for a long-rod penetrator?

Did you also miss the warning that

+++++
Oblique impact was ignored by most of the earlier of these formulae
because the projectiles were not very well designed for handling the
sideways forces caused by such impacts and had considerable variation in
penetration ability from test to test due to projectile deformation and
breakage in various unpredictable ways.
+++++

which is back to the problem that steel APFSDS performed little better
than APDS even at normal impact, and broke up on impact on sloped armour?

All of them have major factors to the effect of V & (W/D^3). So the
velocity and mass of the projectile divided by the cube of the
penetrator diameter are major players. So a smaller diameter
penetrator with large mass divided by the cube of the penetrator
diameter is and the same velocity is going to punch through more than
the same mass at a much larger diameter.

...unless it shatters on impact, whereupon its effect is greatly reduced.

Firstly, steel penetrators shatter on impact at velocities somewhat
below 800m/s, hence the use of capped shot to delay shatter. (You've
declared the irrelevance of the hydrodynamic regime where APFSDS
*actually* works, so we may as well ignore that)

Secondly, achieving the theoretical penetration by extending projectile
length brings problems like barrelling and buckling. The critical load
on a long, slim column - like an APFSDS penetrator - is inversely
proportional to the square of the length, as a clever fellow called
Euler worked out some time ago. Double the length of your penetrator and
you've got four times the buckling load; and if the penetrator buckles,
its effectiveness is greatly reduced.

And any obliquity with a long-rod at these sub-hydrodynamic velocities
further complicates your performance:-

+++++
...projectiles that impact plates at above their biting angle will have
their noses pushed strongly away from the plate, so they will rotate in
the direction parallel to the plate face and try to push through the
plate sideways, which causes a considerable increase in the required
energy to penetrate due to the larger hole needed and the loss of
concentrated impact force on the plate at the point of initial impact as
the nose skids sideways on the plate surface.
+++++

For a conventional AP shot or shell you'll get some piercing performance
as the shell crashes through sideways, or is stopped by the armour. A
long-rod penetrator in this situation is, fairly obviously, rather less
effective - all the advantages of L/D ratio depend on it *not* yawing,
even before you get into it breaking up under the bending moments.

Post by Paul J. Adam
"At these high velocities [above ~1400m/s] both the projectile and
the target armour are subjected to a hydrodynamic regime in which
the materials flow as if they were liquids, although they do not
change their state. The metal at the leading end of the penetrator
and the armour in contact with it both flow away from the point of
contact, so that the armour is penetrated and the mass of the
projectile is progressively used up as it passes through the armour
until there is insufficient mass for the process to continue.
Penetration is therefore proportional to the length of the
penetrator." [Courtney-Green]

Me thinks you either quote the man out of context, or that he is a moron like you.

Or, a third option, you're simply unable to understand that a formula
for full-bore shot, L/D of three or less, fired at muzzle velocities of
~900 metres per second, doesn't read across to long-rod penetrators
fired at twice that velocity.

If you need it described in pictures, there's a nice animation of
hydrodynamic penetration at

http://www.longrods.ch/bilder/Simulation.wmv

You could also try the Journal of Battlefield Technology, Vol 1 #3:-

+++++
Hydrodynamic penetration is a complex mechanism which begins to appear
when the strike velocity exceeds a critical value, typically about
1,150m/s for current penetrators against rolled homogenous armour (RHA)
targets. Full hydrodynamic behaviour does not occur until the strike
velocity reaches several kilometres per second, such as occurs with
shaped charge munitions. At strike velocities less than about
1,150 m/s penetration of metal armour occurs mainly through the
mechanism of plastic deformation.

A typical penetrator achieves a strike velocity around 1,500m/s to
1,700m/s, depending on range, and therefore target effects generally
exhibit both hydrodynamic behaviour and plastic deformation. A number of
models of varying degrees of complexity have been developed to predict
long rod penetrator performance. A common feature that emerges from
these models is the importance of a high strike velocity to exploit more
fully the hydrodynamic penetration mechanism.
+++++

This is well-established, widely-published fact, Al, it's nobody's fault
but yours if you're unable or unwilling to understand it.

Rambling about how you took a 1930s formula for penetration of armour by
full-bore shot in the plastic deformation regime of impact velocity and
got results for long-rod penetrators, is about as useful as claiming
that simply by swapping the Lycoming engine for a Rolls-Royce Griffon, a
Cessna 172 can break the sound barrier in level flight.

Also, and this is important, a gun tube muzzle velocity is strongly
dependent on the projectile mass being pushed by the expanding gases.
If the APFSDS projectile + sabot is much lighter than a standard AP
round, and you use the same powder charge as with a standard AP
round, you will get a significantly higher velocity.

Amazing. Somebody should have noticed this decades ago... a lighter
projectile means a higher muzzle velocity.

Who would ever have imagined such a thing to be possible?

The velocity
increase can be estimated by assuming the same kinetic energy of
everything leaving the muzzle with both rounds.

Life is rarely that simple.

In fact the peak pressure with the same powder charge will be less,
because the lighter load will have moved further down the bore
(because it is less massive) when maximum pressure of the charge is
reached, so it has more volume to expand in.

Correct: and because the projectile is leaving the gun sooner (because
of its higher velocity) less of the charge energy is able to be
transferred to it. The lower chamber pressure also reduces the burn
rate, further reducing efficiency. Interior ballistics is a large and
complicated subject.

In fact you surely bump
up the powder charge a bit and get an even higher velocity with the
same peak pressure.

Enlarging the charge will only give you more muzzle flash: you need to
speed up the propellant burn rate to change the pressure/time curve
significantly for the much lighter projectile.

Achieving the required muzzle velocities for long-rod penetrators in the
real world didn't just require piling in more cordite, or changing the
grain shape: typically, the charge for an APFSDS projectile is a
half-and-half mix of triple-base propellant (nitrocellulose,
nitroglycerine and nitroguanidine) and RDX explosive, as a way to
generate the very high energies and rapid burn rate required: with
consequent effects on chamber pressure and barrel wear.

You do not have a significant level of understanding of basic
classical physics.

Unfortunately, your assertion does not truth create.

You are in way over your head and clearly have no
clue what you are talking about.

Your incomprehension is your problem, not mine.

[John Dallman]

Post by Paul J. Adam
What range is this APFSDS-armed battlewagon fighting at? What
targets is she shooting at, and what effect is she expecting to
achieve that's better than the APCBC and HE ammunition available at
the time?

Incidentally, attempting to close the range at Jutland isn't really
practical. Neither side had enough of a speed advantage to force a rapid
range reduction, and the actual battle ranges were close to being a
matter of consensus. Nobody wanted to get too close, because they knew
well that they were vulnerable to the conventional shells of the period
at close range.

If a ship was badly hit she might turn away, and the other side was
generally happy with that, since it improved the odds for them.

John

[Alfred Montestruc]

Post by John Dallman

Post by Paul J. Adam
What range is this APFSDS-armed battlewagon fighting at? What
targets is she shooting at, and what effect is she expecting to
achieve that's better than the APCBC and HE ammunition available at
the time?

Incidentally, attempting to close the range at Jutland isn't really
practical. Neither side had enough of a speed advantage to force a rapid
range reduction, and the actual battle ranges were close to being a
matter of consensus. Nobody wanted to get too close, because they knew
well that they were vulnerable to the conventional shells of the period
at close range.
If a ship was badly hit she might turn away, and the other side was
generally happy with that, since it improved the odds for them.
John

Yes we both know that, he is being a horse's behind

[Dean]

Post by Alfred Montestruc

Post by John Dallman

Post by Paul J. Adam
What range is this APFSDS-armed battlewagon fighting at? What
targets is she shooting at, and what effect is she expecting to
achieve that's better than the APCBC and HE ammunition available at
the time?

Incidentally, attempting to close the range at Jutland isn't really
practical. Neither side had enough of a speed advantage to force a rapid
range reduction, and the actual battle ranges were close to being a
matter of consensus. Nobody wanted to get too close, because they knew
well that they were vulnerable to the conventional shells of the period
at close range.
If a ship was badly hit she might turn away, and the other side was
generally happy with that, since it improved the odds for them.
John

Yes we both know that, he is being a horse's behind

And yet Paul is providing a counter-argument without resorting to insults as you are. I think everyone here knows what that means.

[unknown]

Post by Paul J. Adam
Really? Who's getting lethal hits with APFSDS at over three
kilometres? Ever?

He seems unaware of the pratical limits of Naval fire control and cuts
and pastes part of web pages without giving the original author credit.
By the way I would like to clarify that performance against RHA is
largely irrelevant as BB armour was either Krupp cemented or high tensile
steel. Second as BB had torpedoes the range was going to be held to a
minimum of around 10,000 yards with a maximum determined by visibility.

[Paul J. Adam]

Post by unknown
By the way I would like to clarify that performance against RHA is
largely irrelevant as BB armour was either Krupp cemented or high tensile
steel.

That's not a critical issue if you're using long-rod penetrators
properly, in the hydrodynamic regime: it's a matter of relative
densities, and surface hardness doesn't have a major impact - certainly
nowhere near as significant as against AP shell striking at plastic
deformation velocities (i.e. where the guns of the time worked)

It does seriously affect steel LRPs that strike at below the critical
velocity (around 1150 metres per second) but that's a different set of
problems.

[Alfred Montestruc]

Post by Paul J. Adam

Post by Alfred Montestruc

Post by Paul J. Adam
Yep. Also heard of wave drag and a few other issues. I've even
worked on problems of "push this through a resisting medium a lot
faster and see what happens... oh, not as simple as it seems".

Simple or easy you need to have some vague semblance of an
understanding of physics to work the problem, which it seems you do
not.

Well, I understand the difference between form and skin drag, which you
seem determined to ignore, and I'm aware that drag forces rise as the
square of velocity through the resisting medium (another point that
seems to escape you)
Perhaps the problem is that you know a lot less about this than you
think, and bluster is failing to make up the gap?

Post by Alfred Montestruc

Post by Paul J. Adam
So, your maximum battle range for a 11" gun firing APFSDS will be
about three times the maximum effective range of a 115mm gun firing
APFSDS.
Amazing, two to three miles.

2 miles is ~ 3.2 km 3 miles is ~ 4.8 km
Does not follow,

Really? Who's getting lethal hits with APFSDS at over three kilometres?
Ever?

Numbskull did you not see the paper I posted??


http://www.dtic.mil/dtic/tr/fulltext/u2/a224217.pdf

While the aiming system on tanks may or may not be able to hit a target at 10 km downrange the projectile is moving at ~1050 m/s, at 6 km it is still moving at ~ 1300 m/s.

Aside from that A British Tank in Gulf War I killed a Iraqi tank at over 5 km.

http://en.wikipedia.org/wiki/Challenger_1

Given they use the same gun an M1 should be able to as well.

Post by Paul J. Adam
The generally accepted longest-range tank-vs-tank hit was by a British
Challenger 1 in 1991, during OP GRANBY (Desert Saber to the US) - a
little over five kilometres. Using HESH, not APDFSDS, because the
tankies understand how much performance drops off by that range.

Said Mr. Paul J. Adam AKA bozo the clown who thinks that "fluid drag is proportional to velocity cubed".


No they used A DU round, sorry nitwit.

http://www.bbc.co.uk/dna/hub/html/A888753

Quote the effing BBC--- "The longest range for a confirmed kill in Desert Storm was a Challenger 1 engaging a tank at 5.1km using a DU sabot round."

Seriously, when are you going to shut the eff up about this, you lost, a long time ago.

Post by Paul J. Adam
per the US Military the effective range of APFSDS

Post by Alfred Montestruc
rounds (in terms of capability to do a lot of damage, and still be
moving really fast, not necessarily in accurate ability to hit) is a
whole lot more than that.

Not "really fast" in APFSDS terms. Long rod penetrators need to be in a
very high velocity regime to be effective, though tungsten and DU are
less affected by this than steel. The graph at
http://www.longrods.ch/optv.php

Well Mr. Paul J. Adam AKA bozo the clown who thinks that "fluid drag is proportional to velocity cubed". If you bother to look at that site critically one would not be so quick to believe it.

1) It says all the rods are uniformly L/D=30 which means these are not test results as nobody makes sabot rounds that long in practice.

2) It says all the rods have a uniform kinetic energy of 10 MJ, which means they cannot have the same mass, as the only thing that is now allowed to vary as now the L/D and energy are constrained so all that is left to make the kinetic energy equation balance is "M", that means the rod diameters are variable. As in KE=m*v*v/2, must be, no wiggle room at all.

I get that for ALL of them to have a 10 MJ the mass at 1000 m/s = 20 kg, at 1100 m/s it is 16.52 kg, and so on till at 1800 m/s the mass is 6.17 kg.

http://www.longrods.ch/givgun.php

If you look at this nonsense he is showing on another page DU rounds having significantly different results from what he reports in the first link. I calculate using the density of uranium than the DU result he gives on the first for 1450 m/s will have a diameter of 27 mm and the first site gives a penetration for that 27mm x 833 mm rod as under 700 mm @ 1450 m/s the second gives over 740 mm at the same speed and size.

Then he has penetration and ballistics pages that are also nonsense. Why is this some wargame site you like?

This is not for real, it is a wargamer site, it would not be accessible if it had real solid militarily useful info.

Furthermore nobody now makes a DU round over 850 mm long, yet the numbers this guy throws about are for DU rods over 1 meter long if you do the math and can look up the density of the materials.

My take, this is a nut job fanboi site.

Post by Paul J. Adam
is worth a look as to why nobody bothers with steel APFSDS - you can't
get it moving fast enough to achieve its theoretical performance

The maximum penetration for some given material idea of his is kark.

Post by Paul J. Adam
and it
loses what penetration capability it can achieve, rather too fast for
comfort as the velocity drops.

Post by Alfred Montestruc

Post by Paul J. Adam
When did the battle lines at Jutland ever get that close?

Did not, you are playing move the goal post again and showing your ignorance.

No, I'm asking you for some evidence to support your rather hysterical
rantings.

Said Mr. Paul J. Adam AKA bozo the clown who thinks that "fluid drag is proportional to velocity cubed". Hysterical ?? That is you.

Physics nitwit, is what backs me.

Post by Paul J. Adam
You're claiming that using steel APFSDS rounds from battleship guns -
such as at Jutland - would have had a dramatic effect on the outcome,
apparently being far more effective, lethal, deadly et cetera. Why is
exploring that claim "moving the goalposts"?

You are not honestly exploring the idea, you are attacking it without regard for reason.

Basic physics of projectile flight show that a long slender shape with fins will travel farther without tumbling than a short stubby shape. Arrows from prehistory on fly far set next to sling stones.

Yes there is such a thing as surface friction, but it is small set next to drag from the frontal area. If that were not true submarines and torpedoes would look like balls, they don't they are long and slender.

Surface drag in air is less than surface drag in water (because the viscosity is a lot lower, so the optimum shape for low drag in air will be longer and narrower than in water.


http://en.wikipedia.org/wiki/Drag_coefficient

See the figure near the bottom on the right hand side titled "Trade-off relationship between pressure drag and friction drag" you will note that as L/D or in this case D/L changes surface friction changes in importance with respect to pressure drag. one can find an optimal L/d ratio for a given Reynolds number or Mach number in the fluid to minimize drag and in air it is blindingly obvious from airliners, and fighter jets and so on, that short stubby shapes are not optimal.

Post by Paul J. Adam
What range is this APFSDS-armed battlewagon fighting at?

Obviously as long as practical.

Post by Paul J. Adam
What targets is
she shooting at, and what effect is she expecting to achieve that's
better than the APCBC and HE ammunition available at the time?

The APFSDS will first off have much less drag than an equivalent sized AP round, that means the trajectory is flatter, and so less need to elevate, so in principle it is easier to aim. Also as it loses less speed, it takes less time to hit the target.

Calculating for the energy you gave a reference of 4.5 degrees up angle for 10,000 meters range and a muzzle velocity of 910 m/s for an 11" gun. Time of flight of 14.5 seconds

With the same muzzle energy a sabot round with 1/2.5 the diameter made of steel with an l/d of 15 I get a muzzle velocity of 1218 m/s, an impact velocity 815 m/s and up angle of only 1.9 degrees and time of flight of just over 8.2 seconds. By the Krupp equation this will punch through 618 mm flat, and that is close enough to true. As the British heavies have ~ 300 mm of belt armor this will get through to magazines.

The bottom line is ALL the German heavies will have guns and ammo that good or better.


The German fleet had, they had an awful lot of Battleships, Battle cruisers and dreadnought era warships with 11" guns, some with as few as 4, but this was the most common heavy gun in the German fleet. If you make those guns a lot more accurate and harder hitting at longer range, this will turn the tide, if they can keep the development secret while the deploy it.

Post by Paul J. Adam

Post by Alfred Montestruc

Post by Paul J. Adam
not in its effective region (above 1400 metres per second or so) -
fluid drag is proportional to velocity cubed, remember?

Wrong, stupidly, , , astonishingly stupidly wrong.

Actually, that's the first thing you've got right in a long time.
*Power* to maintain velocity is velocity-cubed, drag force is velocity
squared.

Said Mr. Paul J. Adam AKA bozo the clown who thinks that "fluid drag is proportional to velocity cubed".

Post by Paul J. Adam

Post by Alfred Montestruc

Post by Paul J. Adam
A German SK L/40 naval gun has a muzzle velocity of 820 metres per
second, but to make a long-rod penetrator effective you want to

You are pulling that out of your arse.

No, I'm pulling it from the equations at
http://www.longrods.ch/perfcalc.php

This is not a reliable site.

Post by Paul J. Adam

Post by Alfred Montestruc
I have already proven that
an APFSDS round (one made of steel) fired from the exact same gun, at
exactly the same muzzle velocity can at long range penetrate far more
armor at long range than a standard AP round made for the same gun.

Using a 120mm L/44 tank gun as a reference (because its performance with
APFSDS is well understood) and a steel penetrator, you might get 650mm
of penetration of RHA, at an impact velocity of 2,400 metres per second,
which isn't a bad performance until you discover the impossibility of
achieving that impact velocity with any conventional gun design.

You did not study his site, that was with 10 MJ of energy on all projectiles. So if my energy is a lot more than that, as in fired from an 11" gun which you gave the reference to, has a muzzle velocity of 910 m/s, that is 124 MJ, the site you reference is yammering about 10 MJ,

I have more than 12 times that as muzzle energy. On impact I have 42.9 MJ, more than 4 times that energy.

Do you really think that I am going to limited by what you, Mr. Paul J. Adam AKA bozo the clown who thinks that "fluid drag is proportional to velocity cubed", is fool enough to interpret without even reading what that fanboi website says?

It said 10 MJ energy, so I got 42.9 MJ of energy, so magically you think 300 mm of BS Plate than is not even at 250 HBN than he gives as a minimum, fyi = 250 HBN plate has a tensile strength of about 120 ksi, which means quenched and tempered plate which WWI era armor plate was not. The plate on WWI era battleships was at more like ~ 160 HBN maybe 80 ksi tensile strength, maybe, and it is mostly crap steel set next to modern armor.

[Paul J. Adam]

Post by Alfred Montestruc

Post by Paul J. Adam
Really? Who's getting lethal hits with APFSDS at over three
kilometres? Ever?

Numbskull did you not see the paper I posted??

Yes, I saw the paper you posted. Nowhere in there, is a successful hit
mentioned.

Post by Alfred Montestruc
Aside from that A British Tank in Gulf War I killed a Iraqi tank at over 5 km.
http://en.wikipedia.org/wiki/Challenger_1

Unfortunately, Wiki is - as has been known to happen - wrong. The
engagement was correct, by a tank from the Royal Scots Dragoon Guards,
but the ammunition used was HESH.

Post by Alfred Montestruc
Quote the effing BBC--- "The longest range for a confirmed kill in
Desert Storm was a Challenger 1 engaging a tank at 5.1km using a DU
sabot round."

Except that we fired no DU rounds during Granby, as was stated later
in Parliament.

About twelve per tank were available, in case the T-72s proved to be
tougher than expected, but all the fin rounds fired by UK tanks during
Granby were CHARM1 tungsten. (The DU CHARM3 didn't enter service until
the successor Challenger 2).

Politics, don't you love it?

(This is one of those myths as persistent as HMS Sheffield's "aluminium
superstructure" - I've been aboard most of the 42s, including Sheffield
herself back in 1978, and their structures were all-steel - yet the myth
still gets held forth as truth)

Post by Alfred Montestruc
Seriously, when are you going to shut the eff up about this, you lost, a long time ago.

Of course, Al, and black is white, up is down, and the clerestories to
the south north are transparent as barricadoes.

Post by Alfred Montestruc

Post by Paul J. Adam
Not "really fast" in APFSDS terms. Long rod penetrators need to be
in a very high velocity regime to be effective, though tungsten and
DU are less affected by this than steel. The graph at
http://www.longrods.ch/optv.php

Well Mr. Paul J. Adam AKA bozo the clown who thinks that "fluid drag
is proportional to velocity cubed". If you bother to look at that
site critically one would not be so quick to believe it.

Meaning "Al doesn't like what it says".

After all, the author works at the Defence Technology and Procurement
Agency, Ballistics Division, CH-3602 Thun, Switzerland - obviously knows
nothing at all about defence or technology if the Swiss are letting him
present at international symposia.

Still, perhaps other authors agree with Al. Let's try Grabarek C L,
"Penetration of Armour by Steel and High Density Penetrators",
BRL-MR-2134. 1971, presented at the 4th International Symposium on
Ba-llistics at Monterey, CA, USA.

"The velocity range covered was about 1000m/s to 1800m/s. It was found
that below a certain critical velocity Vc the penetration scaled with
the diameter d rather than the length 1 of the rod. Above this velocity,
for the velocity range of the experiments, the penetration varied almost
linearly with the velocity." [For tungsten alloy Grabarek finds the
critical velocity is 850 metres per second, for steel it's 1150m/s]

Oh... more fan boy stuff, presumably.

Post by Alfred Montestruc
1) It says all the rods are uniformly L/D=30 which means these are
not test results as nobody makes sabot rounds that long in practice.

Test penetrators of at least up to L/D 150 have been fired - that's the
glory of testing. Turning them into practical ammunition is a different
beast altogether, but research into "what works" and "what doesn't" is
useful to find out whether it's worth chasing one attribute over another.

You can also use technologies like light gas guns to generate utterly
implausible velocities of 5000-6000 metres per second, if you go into
the bunkers at Aberdeen or Fort Halstead.

Post by Alfred Montestruc
2) It says all the rods have a uniform kinetic energy of 10 MJ, which
means they cannot have the same mass, as the only thing that is now
allowed to vary as now the L/D and energy are constrained so all that
is left to make the kinetic energy equation balance is "M", that
means the rod diameters are variable. As in KE=m*v*v/2, must be, no
wiggle room at all.

Was this to supposed to make sense?

Vary the diameter (and hence length) to keep the mass the same, keep the
energy the same (since you're using the same gun, chamber,
propellant...) and the velocity remains constant. Simples. Your
penetrators keep the same aspect ratio, mass and velocity, only diameter
and length varying (though remaining in ratio)

Post by Alfred Montestruc

Post by Paul J. Adam
is worth a look as to why nobody bothers with steel APFSDS - you
can't get it moving fast enough to achieve its theoretical
performance

The maximum penetration for some given material idea of his is kark.

Agrees with Grabarek, who was well regarded in the field.

Also ties in with Oxlee, who produced "Penetrative Performance of FSAPDS
Shot Against Single Plates" while working at the Royal Armament Research
and Development Establishment.

It does seem that the published body of work disagrees with you, Al -
you've got some serious fame and fortune coming when you prove all those
ballisticians were wrong for over half a century.

Post by Alfred Montestruc

Post by Paul J. Adam
No, I'm asking you for some evidence to support your rather
hysterical rantings.

Physics nitwit, is what backs me.

Really? All I'm seeing is someone who's got a 1930s formula and no
comprehension of actual real-world reality.

Try Hohler V and Stilp A J, "Penetration of steel and high density rods
in steel and high density rods in semi-infinite steel targets",
presented at the Proceedings of 3rd International Symposium on
Ballistics, Karlsruhe 1977.

Or even Tate A, "Further results in the theory of long rod
Penetration", Journal of Mech Phys 'Solids, no. 17 (1969).

Curiously, there' over half a century of published research in this
area, which - for some strange reason - agrees with me instead of you.

Is this yet another of those cases where the entire world is wrong and
only you are right?

Post by Alfred Montestruc

Post by Paul J. Adam
You're claiming that using steel APFSDS rounds from battleship guns
- such as at Jutland - would have had a dramatic effect on the
outcome, apparently being far more effective, lethal, deadly et
cetera. Why is exploring that claim "moving the goalposts"?

You are not honestly exploring the idea, you are attacking it without regard for reason.

Why is pointing out the proven engineering problems "attacking it"? This
has to offer some tangible benefit.

Post by Alfred Montestruc
Basic physics of projectile flight show that a long slender shape
with fins will travel farther without tumbling than a short stubby
shape. Arrows from prehistory on fly far set next to sling stones.

Were they travelling at four or five times the speed of sound? Appealing
to "common sense" by comparing caveman weapons, is hardly relevant to
penetration of battleship armour.

Post by Alfred Montestruc
Yes there is such a thing as surface friction, but it is small set
next to drag from the frontal area. If that were not true
submarines and torpedoes would look like balls, they don't they are
long and slender.

It's highly velocity dependent. I thought you knew all about this?
Aren't you aware of different flow behaviours at different velocities?

Why does an airliner have a bluff nose, but a supersonic fighter is
pointed? Why does an airliner carry its engines in underwing pods, but
nothing supersonic's done that since the B-58? Because different speeds
produce different impacts of different types of drag.

Post by Alfred Montestruc

Post by Paul J. Adam
What range is this APFSDS-armed battlewagon fighting at?

Obviously as long as practical.

Which is going to be a serious problem, since you need to achieve impact
velocities of well over 1,100 metres per second (not muzzle velocity,
impact velocity) for steel long-rods to offer any detectable advantage
in penetration assuming you can avoid yaw, buckle or shatter on impact.

Grabarek confirmed the critical velocity for hydrodynamic penetration
using tungsten alloy was 850 metres per second, while for steel it's
1150m/s: below that speed the penetration scaled with the diameter,
rather than the length, of the penetrator.

Achieving hits with impact velocity of over 1,150m/s at a 10,000 yard
fighting range using 1916 gun technology is... well, perhaps there's a
reason that regime wasn't explored for a few more decades.

Post by Alfred Montestruc

Post by Paul J. Adam
What targets is she shooting at, and what effect is she expecting
to achieve that's better than the APCBC and HE ammunition available
at the time?

The APFSDS will first off have much less drag than an equivalent
sized AP round, that means the trajectory is flatter, and so less
need to elevate, so in principle it is easier to aim. Also as it
loses less speed, it takes less time to hit the target.

And if it penetrates, it'll achieve very little effect on the target
ship, since it's a spray of fragments passing over the top of the
magazines and machinery spaces instead of descending into them and then
detonating an explosive payload.

Getting through the armour is a means to an end: the intent is to stop
the ship from fighting, moving, and (if you hit it well enough) floating.

Post by Alfred Montestruc
With the same muzzle energy a sabot round with 1/2.5 the diameter
made of steel with an l/d of 15 I get a muzzle velocity of 1218 m/s,
an impact velocity 815 m/s and up angle of only 1.9 degrees and time
of flight of just over 8.2 seconds. By the Krupp equation this will
punch through 618 mm flat, and that is close enough to true.

Unfortunately, you won't achieve that level of penetration with a steel
long-rod penetrator striking at 815 metres per second: you're well below
the hydrodynamic limit, and the penetrator will either buckle or shatter
on 300mm armour.

Permutter L and Garratt A J, "The Development of Metal APDS Projectiles
for the QF 20pr Guns Including a New Theoretical Approach to the Design
of Piercing Projectiles", ARE Report 5/49, 1949 applies:-

+++++
Using the Milne formula, the energy necessary to produce a hole in a
given plate varies as d^1.57 where d is the shot calibre.

If the core mass is M and the mass of the other components is m and if
we assume shot energy is constant for a given gun, the ratio of the
kinetic energy of the core to that of the shot will be M/(M+m). If the
cored shot is to be superior to the solid shot M/(M+m)>l/r^(1.57), where
r is the ratio of the solid shot diameter to that of the core.

Experience shows that this condition cannot be satisfied with an
adequate margin, if the core is of steel, unless the steel core is made
very long. Further, the core cannot be made very long, both because it
would break up during angle attack and because it would tend to shatter.
+++++

Remember, the Krupp equation is for AP shell of L/D 3-4 at most,
striking well below the hydrodynamic limiting velocity for steel: it
takes no account of factors like yaw, buckling, barrelling or shatter,
which you dismiss out of hand yet which have always been major concerns.

Try Tate A, "Further results in the theory of long rod penetration",
Journal of Mech Phys Solids, no. 17 (1969).

+++++
Armour steel targets were struck by steel rods. The penetration (p) was
found to follow the form of

p/l = k(V)(Dp/Dt)^0.5

p = Penetration
l = Projectile length
V = Impact velocity
Dp, Dt = Densities of projectile and target respectively
k = Function describing effects of impact velocity

For the steel projectile and target the function k(V) is essentially
zero below about 500m/s, rises steeply in the region 1 to 3km/s and
reaches a limiting value of 1.2 to 1.3 between 3 and 4km/s. Again it was
found that above a certain critical angle 'trenching' occurs, and the
rod appears to collapse and form a long shallow crater.
+++++

...which, again, is why nobody uses steel APFSDS - it does moderately
well on a test range at normal impact if you throw it fast enough, but
it loses performance dramatically at lower velocities, and at oblique
impact it yaws, breaks up and fails to penetrate.

Post by Alfred Montestruc

Post by Paul J. Adam
No, I'm pulling it from the equations at
http://www.longrods.ch/perfcalc.php

This is not a reliable site.

Well, I'm sure Mr Odermatt is just *crushed* that you think so.

Since he lists the following publications:-

Penetration Limits of Conventional Large Caliber Anti Tank Guns
Kinetic Energy Projectiles, 13th International Symposium on Ballistics,
Stockholm, 1992

Post-perforation Length and Velocity of KE Projectiles with single
oblique Plates, 15th International Symposium on Ballistics, Jerusalem, 1995

Minimum Impact Energy for KE-Penetrators in RHA-Targets, European Forum
on Ballistics and Projectiles, St. Louis (F), 2000

Kinetic Energy Projectiles: Development History, State of the Art,
Trends, 19th International Symposium on Ballistics, Interlaken (CH), 2001

perhaps you can enlighten us on why the Swiss were stupid enough to pay
him for his expertise, and your... interesting grasp on penetration
mechanics (based as it is on a formula dating from the 1870s) is right
instead?

Post by Alfred Montestruc

Post by Paul J. Adam
Using a 120mm L/44 tank gun as a reference (because its performance
with APFSDS is well understood) and a steel penetrator, you might
get 650mm of penetration of RHA, at an impact velocity of 2,400
metres per second, which isn't a bad performance until you discover
the impossibility of achieving that impact velocity with any
conventional gun design.

You did not study his site, that was with 10 MJ of energy on all
projectiles.

Constant energy from the same gun and charge - a perfectly reasonable
assumption for comparing extremes of available performance.

Post by Alfred Montestruc
So if my energy is a lot more than that, as in fired
from an 11" gun which you gave the reference to, has a muzzle
velocity of 910 m/s,

So, well below the critical velocity where long-rod penetrators become
useful.

Post by Alfred Montestruc
I have more than 12 times that as muzzle energy. On impact I have
42.9 MJ, more than 4 times that energy.

A 1944-vintage PaK 44 delivers more energy than modern 120mm APFSDS, yet
penetrates about 20% as much armour at similar fighting ranges, so I'm
not really seeing the point.

Energy assists with penetrating armour but it's far, far more
complicated than simply adding extra megajoules.


For example, consider the following from Tate "A Review of the Post
World War II Military Approach to the Terminal Ballistics of KE
Projectiles" - produced by the Defence Research Agency at Fort Halstead
in June 1994. (Report ID DRA/DWS/WX5/TR9471/1)

Writing about the 1930s investigation into enhanced velocity for
anti-armour weapons, and especially Janecek's proposal for a "squeeze
bore" adaptor for the two-pound AT gun. Initial efforts using steel
projectiles failed to impress:-

+++++
The shot was of reduced weight and therefore of inferior performance at
oblique attack; there was also a critical upper velocity at which the
shot broke up, therefore much metallurgical work would be required.

All this was to change dramatically when it was decided to compare the
performance of steel cored versus WC cored shot for the Janecek or, as
it was now called, the Littlejohn adapted gun. At a trial fired at
Melton Mowbray on 12.3.42 it was shown that the WC cored shot would
defeat a 100mm RH plate at normal, 20 degrees and 30 degrees obliquity
and at a striking velocity (SV) equivalent to 100 to 200 yards. It also
defeated an 81mm plate at normal and raised a smooth bulge at 30 degrees
obliquity at an SV equivalent to 900 to 1000 yards. The steel cored shot
was unsatisfactory at both 200 and 1000 yards. As noted in the OB Q 471
of 30.3.42, which reported on the trial, the "results are so
revolutionary that it is suggested immediate consideration be given to
developing the round as it now stands"."
+++++

[Paul J. Adam]

Post by Paul J. Adam
Except that we fired no DU rounds during Granby, as was stated later
in Parliament.

A quick correction - no DU rounds fired *in combat*. Fewer than a
hundred were fired before the conflict stage in proving trials and
accuracy checks, to ensure that the adaptation of the US projectile to
the UK gun was successful and to check the required ballistics for the
fire control computers, but none were expended in combat.

Post by Paul J. Adam

Post by Alfred Montestruc
With the same muzzle energy a sabot round with 1/2.5 the diameter
made of steel with an l/d of 15 I get a muzzle velocity of 1218 m/s,
an impact velocity 815 m/s and up angle of only 1.9 degrees and time
of flight of just over 8.2 seconds. By the Krupp equation this will
punch through 618 mm flat, and that is close enough to true.

Just for giggles, I tried the Krupp formula for a 11" gun firing a
cast-iron cannonball at 1,800 metres per second, and got similar
penetration to Al's steel APFSDS for a much simpler, cheaper projectile:
just some handwavium for the required velocity and we're there.

Great fun when you take an equation right outside its validated limits,
isn't it?

[Alfred Montestruc]

Post by Paul J. Adam

Post by Paul J. Adam
Except that we fired no DU rounds during Granby, as was stated later
in Parliament.

A quick correction - no DU rounds fired *in combat*. Fewer than a
hundred were fired before the conflict stage in proving trials and
accuracy checks, to ensure that the adaptation of the US projectile to
the UK gun was successful and to check the required ballistics for the
fire control computers, but none were expended in combat.

Post by Paul J. Adam

Post by Alfred Montestruc
With the same muzzle energy a sabot round with 1/2.5 the diameter
made of steel with an l/d of 15 I get a muzzle velocity of 1218 m/s,
an impact velocity 815 m/s and up angle of only 1.9 degrees and time
of flight of just over 8.2 seconds. By the Krupp equation this will
punch through 618 mm flat, and that is close enough to true.

Just for giggles, I tried the Krupp formula for a 11" gun firing a
cast-iron cannonball at 1,800 metres per second, and got similar
just some handwavium for the required velocity and we're there.

I am not hand waving the velocities or ranges. The results of the Army paper show conclusively that very long ranges at hi-velocities are possible, all one need do is scale for the projectile size.

The 11" gun could shoot the projectile at about 1665 m/s assuming no losses, not 1800 m/s based on existing muzzle energy the gun can produce. The issue is a sphere has a huge drag coefficient set next to almost anything else at high mach numbers.

That will slow down very rapidly, the APFSDS shape will not.

Post by Paul J. Adam
Great fun when you take an equation right outside its validated limits,
isn't it?
--
He thinks too much, such men are dangerous.

[Alfred Montestruc]

Post by Paul J. Adam

Post by Alfred Montestruc

Post by Paul J. Adam
Really? Who's getting lethal hits with APFSDS at over three
kilometres? Ever?

Numbskull did you not see the paper I posted??

Yes, I saw the paper you posted. Nowhere in there, is a successful hit
mentioned.

Which is irreverent and moving the goal posts. We are not discussing tanks or tank kills, we are discussing the potential for use of APFSDS ammo on naval warships in WWI.

However, the paper clearly shows is that at 5km or even at 8 km the projectile was moving at over 1200 m/s which according to your reference will kill a T72 from the front, let alone a side shot. So even if DU never killed a tank at that range, it could have, from the front and the thickest armor on a T72.

Post by Paul J. Adam

Post by Alfred Montestruc
Aside from that A British Tank in Gulf War I killed a Iraqi tank at over 5 km.
http://en.wikipedia.org/wiki/Challenger_1

Unfortunately, Wiki is - as has been known to happen - wrong. The
engagement was correct, by a tank from the Royal Scots Dragoon Guards,
but the ammunition used was HESH.

Of course we are supposed to believe what Mr. Paul J. Adam AKA bozo the clown who thinks that "fluid drag is proportional to velocity cubed", says without evidence when the BBC and two other sources say otherwise.

Right sure, Mr. Paul J. Adam is smarter than everyone else and if the physical evidence says otherwise well then the physical evidence is lying. Right sure.

Nor should anyone take this as Mr. Paul J. Adam, as showing himself to be a colossally arrogant jerk who will never admit being wrong about anything.

Post by Paul J. Adam

Post by Alfred Montestruc
Quote the effing BBC--- "The longest range for a confirmed kill in
Desert Storm was a Challenger 1 engaging a tank at 5.1km using a DU
sabot round."

Except that we fired no DU rounds during Granby, as was stated later
in Parliament.

Of course we should accept what Mr. Paul J. Adam said as the gospel truth as if he says it that is all the proof anyone should ever need. Right sure.

Mr. Paul J. Adam AKA bozo the clown who thinks that "fluid drag is proportional to velocity cubed", should never be expected to provide any supporting evidence that what he claims is true even when others provide three sources that state otherwise.

Also of course no one has ever lied to Parliament, even once, and Paul J Adam should not be expected to provide any evidence of his claim that such was said to parliament (no don't I don't care.)

Post by Paul J. Adam

Post by Alfred Montestruc

Post by Paul J. Adam
Not "really fast" in APFSDS terms. Long rod penetrators need to be
in a very high velocity regime to be effective, though tungsten and
DU are less affected by this than steel. The graph at
http://www.longrods.ch/optv.php

Well Mr. Paul J. Adam AKA bozo the clown who thinks that "fluid drag
is proportional to velocity cubed". If you bother to look at that
site critically one would not be so quick to believe it.

You can also use technologies like light gas guns to generate utterly
implausible velocities of 5000-6000 metres per second, if you go into
the bunkers at Aberdeen or Fort Halstead.

Or like the light gas gun one of the professor's on my committee use to study combustion and shock wave theory at LSU, where I have an MS in mechanical engineering from and where I spent far too many years working on a PhD. I am very familiar with the theory and practice of a light gas gun thank you so very much.

The basic issue being that any gun is limited to firing projectiles at speeds below 5 x that of sound in the gun propellant gas at the temperature the gas is at at time zero (whenever the maximum temperature or piston push is reached for a gas gun. So using hydrogen gas to propel your projectile much faster is possible temperature of the gas in the gun.

In an ideal gas the speed of sound is Cs=square_root(gamma*R*T/m) where:

gamma is the adiabatic ratio of the gas (1.4 for both air (N2 & O2) and H2),
R is the universal gas constant I am assuming SI units
T is the absolute temperature in degrees K
and m is the molecular weight of the gas in the case of air it is ~ 29 in the case of hydrogen 2.

So even cold hydrogen will allow much higher speeds than hot air or products of combustion that have even higher molecular weight, like CO2. FYI - the products of reaction of nitrocellulose includes a lot of H2, and also H2O and CO which are also light in molecular weight. This is one reason why smokeless powder AKA cordite is a good propellant.

The maximum speed of the projectile is determined by the maximum unsteady/sudden expansion speed an expansion wave can get to. Which is given in the below.

http://yarchive.net/space/exotic/gun_velocity.html

"For an unsteady expansion, the maximum velocity is: Vmax = 2 a0 / (gamma-1)

Where "a0" is the *initial* speed of sound in the gas and "gamma" is the
ratio of specific heats (gamma = 1.4 for diatomic gases like nitrogen,
hydrogen, etc.)"

This is per professor Andrew J. Higgins of McGill University who worked on such programs. I should note that in case it is not clear to you the speed of sound is of the gas pushing the projectile out the gun at time zero, as in right after ignition has proceeded to 100% burn of the propellants, or for a light gas gun the point of maximum energy absorption of the light gas. Typically you have a piston hit the light gas which pushes it up in temperature and pressure which gets the projectile moving from the other end of the gas chamber.

Post by Paul J. Adam

Post by Alfred Montestruc
2) It says all the rods have a uniform kinetic energy of 10 MJ, which
means they cannot have the same mass, as the only thing that is now
allowed to vary as now the L/D and energy are constrained so all that
is left to make the kinetic energy equation balance is "M", that
means the rod diameters are variable. As in KE=m*v*v/2, must be, no
wiggle room at all.

Was this to supposed to make sense?

To someone who understands math, sure. He said (look at the site) constant kinetic energy of impact of 10 MJ for all projectiles.

Look at your own reference.

Post by Paul J. Adam
Vary the diameter (and hence length) to keep the mass the same, keep the
energy the same (since you're using the same gun, chamber,
propellant...) and the velocity remains constant.

No the mass varies (must very as KE=0.5*mv^2, the KE is constant and the L/D are constant in the site you pulled up. That means the mass varies with velocity such that at 1000 m/s the mass is 20 kg, and so on.

Post by Paul J. Adam
Agrees with Grabarek, who was well regarded in the field.

OK - fine so if calculations according to that site are good, then you should accept this.

http://www.longrods.ch/perfcalc.php

The above from your reference site is a perforation calculator.

644 mm armor penetrated at 45 degree angle using a steel rod 76mm diameter 1976 mm long moving at 1283 m/s with at tip hardness of 500 HBN, armor hardness of 250 HBN a taper on the rod of 90 mm and tip diameter of 10 mm. 1283 is the lowest speed the site states penetration values are reliable for steel.

Moving at 1400m/s it will punch through 794 mm. The slope of the penetration vs m/s curve is 1.28 mm lost per m/s lost. Obviously that the value cannot be reliably calculated by someone, does not mean it is zero or small.

British Battleship belt armor in that era was ~ 12" = 300 mm, we assumed 45 degrees so we should not have problems at those speeds, taking the slope and doubling it to 2.56 mm/m/s, I would be at 300 mm at about 1148 m/s.

Now you claimed it impractical to shoot projectiles from naval guns at the speeds we are discussing. That is simply not true, it has been done.

http://en.wikipedia.org/wiki/Project_HARP

"Project HARP, short for High Altitude Research Project, was a joint project of the United States Department of Defense and Canada's Department of National Defence created with the goal of studying ballistics of re-entry vehicles at low cost; whereas most such projects used expensive and failure-prone rockets, HARP used a non-rocket space launch method based on a very large gun to fire the models to high altitudes and speeds." , , ,

"The project was based on a flight range of the Seawell Airport in Barbados, from which shells were fired eastward toward the Atlantic Ocean using an old U.S. Navy 16-inch (410 mm), 50 caliber gun (20 m); it was later extended to 100 caliber (40 m). In 1966 the project installed its third and final 16-inch gun at a new test site in Yuma, Arizona. On November 18, 1966 the Yuma gun fired a 180 kg Martlet 2 projectile at 3,600 m/s (12,000 ft/s) sending it into space briefly and setting an altitude record of 180 km (590,000 ft; 110 mi); that world record still stands as of 2013.[1]"

Note that this was using standard propellants based on nitrocellulose, not exotic chemistry.

Again the same referece talking about maximum velocities of projectiles in theory.

http://yarchive.net/space/exotic/gun_velocity.html

"For an unsteady expansion, the maximum velocity is: Vmax = 2 a0 / (gamma-1)

Where "a0" is the *initial* speed of sound in the gas and "gamma" is the
ratio of specific heats (gamma = 1.4 for diatomic gases like nitrogen,
hydrogen, etc.)"

This is per professor Andrew J. Higgins of McGill University who worked on such programs. I should note that in case it is not clear to you the speed of sound is of the gas pushing the projectile out the gun at time zero, as in right after ignition has proceeded to 100% burn of the propellants.

Assume for the sake of argument that a0 is going to be about 3600m/s/5= 720 m/s, which is a conservative number, getting to 2.5 x the speed of sound of the propellant gas (1800 m/s) is not a problem, that is just a matter of available energy. So we know that the 11" gun had a normal muzzle velocity of about 910 m/s with a 300 kg projectile. KE=mv^2 so it has a muzzle energy of 124 MJ. The 76 mm x 1976 mm steel massing 70.36 kg, I estimate that a sabot should mass at or less than 13.7 kg, that is 2xL/D cylinder of wood. That gets me a total mass of 84.06 kg.

With the same muzzle energy that gets me a velocity of 1719 m/s with the sabot + lighter projectile assume some reasonable losses (10% of velocity gained over 910 m/s) I get a muzzle velocity minimum of 1638 m/s

That is not even remotely difficult, it is nothing approaching the difficulty of what the HARP project accomplished with the same technology base.

From the paper by the US Army using the Cd they give for air drag I will be moving at 1400 m/s at 7.43 km, at 1283 m/s at 11.13 km, and at 1148 m/s at 15.34 km downrange. The bottom line is I can punch through double the typical a British Battleships main belt armor thickness at 11 km or more which is on the horizon.

Paper on drag of APFSDS rounds

http://www.dtic.mil/dtic/tr/fulltext/u2/a224217.pdf
----------------------------snip

Post by Paul J. Adam

Post by Alfred Montestruc

Post by Paul J. Adam
You're claiming that using steel APFSDS rounds from battleship guns
- such as at Jutland - would have had a dramatic effect on the
outcome, apparently being far more effective, lethal, deadly et
cetera. Why is exploring that claim "moving the goalposts"?

You are not honestly exploring the idea, you are attacking it without
regard for reason.

Why is pointing out the proven engineering problems "attacking it"? This
has to offer some tangible benefit.

What pointing out of proven engineering problems are you bringing up by asserting that the British tank kill in Iraq was not with a DU round but with a a HESH round, even when 3 references state otherwise?

What is the basis of your claim that getting high velocities on naval guns is impossible, or even difficult when it has been done using such Naval guns and Sabot shot for purposes of scientific research and testing of various equipment more cheaply that could have been done using rockets, which I have provided evidence of?

What is the basis of your claim that the velocity of the projectile will be too slow to do any damage at useful ranges when such a Naval gun fired projectiles that flew straight up to altitudes of 180 km, punching all the way through the atmosphere to do it?

FYI simple calculation, neglecting air friction 180,000 m x 9.81= 1.7 MJ/kg which requires a launch velocity of 1879 m/s --NEGLECTING FRICTION.

Why do you ignore the Army paper that gives Cd (APFSDS shot air drag) on the basis of experimental evidence which shows high velocities of projectiles at 10 km downrange, on 120mm bore gun projectiles when we are talking 280 mm guns and there is such a thing as a cube square law?

Why do you ignore the cube/square law?

Why do you try to pass yourself off as being some sort of all-knowing all-wise oracle when it is blindingly obvious you aren't?

Post by Paul J. Adam

Post by Alfred Montestruc
Basic physics of projectile flight show that a long slender shape
with fins will travel farther without tumbling than a short stubby
shape. Arrows from prehistory on fly far set next to sling stones.

Were they travelling at four or five times the speed of sound? Appealing
to "common sense" by comparing caveman weapons, is hardly relevant to
penetration of battleship armour.

I am trying to find your level of education, you don't react as an educated person who has a reasonable understanding of physics would.. I am well aware of the drag issues, you seem to be lost in the weeds of needing to see that someone did exactly that thing to understand it is physically possible, and not getting that at high Mach numbers the skin drag is MUCH LESS important than at low Mach numbers.

Post by Paul J. Adam

Post by Alfred Montestruc
Yes there is such a thing as surface friction, but it is small set
next to drag from the frontal area. If that were not true
submarines and torpedoes would look like balls, they don't they are
long and slender.

It's highly velocity dependent. I thought you knew all about this?
Aren't you aware of different flow behaviours at different velocities?

Not so much velocities as Reynolds or Mach numbers. In air or any other low viscosity gas at high Mach numbers you can largely ignore the Reynolds number. In water the Reynolds number is dominant. In any case drag due to frontal area is very dominant in the high Mach # regime.

FYI my graduate work was on combustion and gas flows, which includes graduate level classes on fluid dynamics and especially compressible flows. Detonation waves are an important field in combustion engineering and to understand them you need to have a good education in compressible flow, which I have.

Post by Paul J. Adam
Why does an airliner have a bluff nose, but a supersonic fighter is
pointed? Why does an airliner carry its engines in underwing pods, but
nothing supersonic's done that since the B-58? Because different speeds
produce different impacts of different types of drag.

All Mach # dependent and the WI we are looking at is all in high Mach numbers even for ordinary AP projectiles. They are in the ballpark of Mach 2.5 to 3, drag coefficients DROP at over Mach 2.5 going toward Mach 5 as you can see by the Army paper.

Post by Paul J. Adam

Post by Alfred Montestruc

Post by Paul J. Adam
What range is this APFSDS-armed battlewagon fighting at?

Obviously as long as practical.

Which is going to be a serious problem, since you need to achieve impact
velocities of well over 1,100 metres per second (not muzzle velocity,
impact velocity) for steel long-rods to offer any detectable advantage
in penetration

This is crap as I have shown that even by your site at the velocity this guy claims is required the penetrations we can get are in the 600 mm ballpark at 45 degrees angle which is double the maximum thickness of British Battleship armor. Using the US Army paper reference I am getting velocity losses of at most about 32 m/s per kilometer moved downrange for that projectile at the speeds discussed above.

That is consistent with the Army paper results when scaled for mass of projectile and drag area. Ergo with my initial calculated velocity of 1638 m/s, which has been vastly exceeded by the HARP project using a Naval gun, the projectile is still trucking along at 1159 m/s at 15 km downrange, from an 11" gun.

That is well over the horizon.

Post by Paul J. Adam
assuming you can avoid yaw, buckle or shatter on impact.

Ductile steel is not going to shatter on impact it will plasticly deform both the armor and the rod whether the rod gets all the way through is the issue, not whether anything shatters.

Post by Paul J. Adam
Grabarek confirmed the critical velocity for hydrodynamic penetration
using tungsten alloy was 850 metres per second, while for steel it's
1150m/s: below that speed the penetration scaled with the diameter,
rather than the length, of the penetrator.

Oh and the mass x velocity of the projectile has NOTHING to do with the issue?

Really? So if I hit it with a steel foil pancake 0.001 inch thick but 20 inches in diameter it is the diameter of the pancake that matters? Right?

ROTFLOL!!

Post by Paul J. Adam
Achieving hits with impact velocity of over 1,150m/s at a 10,000 yard
fighting range using 1916 gun technology is... well, perhaps there's a
reason that regime wasn't explored for a few more decades.

It was done and more by HARP, velocities of 3600 m/s, with mild modification of a US Navy 16" gun - see above. I am not shooting for 3600 m/s , 1600 is just dandy. Probably 1100 would work as I think your armor reference is full of it, be that as it may I can get effective ranges over the horizon using an 11" gun and steel darts and penetration double that of British battleship belt armor of that era with 45 degree angle of inclination.

Also again if you want to argue that Mr. Bull and the Harp project modified the gun a lot, he did, later to make the high altitude shot, but got a lot of results with a standard 16" US naval gun first.

http://yarchive.net/space/exotic/gun_velocity.html


Quote Dr. Dunn
----------------------------quote ----------------------
In the 1960s, using standard military gun propellant in a 16 inch naval
cannon, Gerald Bull indicated that:

normal naval shells in the 3000 lb class could be fired at 2800 fps (850
m/s)

sub-calibre shots weighing 400 lb could be fired at 6000 feet per second
(1830 m/s)

sub-calibre 400 lb shots in a redesigned cannon with a longer barrel and
chamber could be fired at 7000 fps (2130 m/s)


See my writeup at the following address which describes the contents of
some hard-to-get literature on Bull's HARP project:

http://www.islandone.org/Propulsion/GeraldBullInfo.html


--
Dr. Bruce Dunn
General Astronautics Canada, Vancouver B.C.
http://www.genastro.com/
Reliable, low-cost transportation to low Earth orbit and beyond

----------------------end quote-----------------

Post by Paul J. Adam

Post by Alfred Montestruc

Post by Paul J. Adam
What targets is she shooting at, and what effect is she expecting
to achieve that's better than the APCBC and HE ammunition available
at the time?

The APFSDS will first off have much less drag than an equivalent
sized AP round, that means the trajectory is flatter, and so less
need to elevate, so in principle it is easier to aim. Also as it
loses less speed, it takes less time to hit the target.

And if it penetrates, it'll achieve very little effect on the target
ship, since it's a spray of fragments passing over the top of the
magazines and machinery spaces instead of descending into them and then
detonating an explosive payload.

Spray of very hot steel fragments with more than enough energy to punch through another 300 mm of armor. The energy used to penetrate the armor does not vanish, it is converted to heat, and even a few million joules will will heat it a lot.

The Cp of steel is 0.49 kJ/kg so we had a steel mass of 70 kg, assume an equal weight of armor is heated and sprayed, so 140 kg, assume 20% of the muzzle kinetic energy winds up as heat, that is 124000kJ*0.2/(140*.49)= 723 degree C temperature rise. A bit warm and toasty humm?

Post by Paul J. Adam
Getting through the armour is a means to an end: the intent is to stop
the ship from fighting, moving, and (if you hit it well enough) floating.

140 kg of fragments moving at more than Mach 1, and bouncing off armor inside the magazine at an average temperature of the ambient + 723 degrees C is not going to start a fire???? Really?

Post by Paul J. Adam

Post by Alfred Montestruc
With the same muzzle energy a sabot round with 1/2.5 the diameter
made of steel with an l/d of 15 I get a muzzle velocity of 1218 m/s,
an impact velocity 815 m/s and up angle of only 1.9 degrees and time
of flight of just over 8.2 seconds. By the Krupp equation this will
punch through 618 mm flat, and that is close enough to true.

Unfortunately, you won't achieve that level of penetration with a steel
long-rod penetrator striking at 815 metres per second: you're well below
the hydrodynamic limit, and the penetrator will either buckle or shatter
on 300mm armour.
Permutter L and Garratt A J, "The Development of Metal APDS Projectiles
for the QF 20pr Guns Including a New Theoretical Approach to the Design
of Piercing Projectiles", ARE Report 5/49, 1949 applies:-
+++++
Using the Milne formula, the energy necessary to produce a hole in a
given plate varies as d^1.57 where d is the shot calibre.
If the core mass is M and the mass of the other components is m and if
we assume shot energy is constant for a given gun, the ratio of the
kinetic energy of the core to that of the shot will be M/(M+m). If the
cored shot is to be superior to the solid shot M/(M+m)>l/r^(1.57), where
r is the ratio of the solid shot diameter to that of the core.
Experience shows that this condition cannot be satisfied with an
adequate margin, if the core is of steel, unless the steel core is made
very long. Further, the core cannot be made very long, both because it
would break up during angle attack and because it would tend to shatter.
+++++
Remember, the Krupp equation is for AP shell of L/D 3-4 at most,
striking well below the hydrodynamic limiting velocity for steel: it
takes no account of factors like yaw, buckling, barrelling or shatter,
which you dismiss out of hand yet which have always been major concerns.
Try Tate A, "Further results in the theory of long rod penetration",
Journal of Mech Phys Solids, no. 17 (1969).
+++++
Armour steel targets were struck by steel rods. The penetration (p) was
found to follow the form of
p/l = k(V)(Dp/Dt)^0.5
p = Penetration
l = Projectile length
V = Impact velocity
Dp, Dt = Densities of projectile and target respectively
k = Function describing effects of impact velocity
For the steel projectile and target the function k(V) is essentially
zero below about 500m/s, rises steeply in the region 1 to 3km/s and
reaches a limiting value of 1.2 to 1.3 between 3 and 4km/s. Again it was
found that above a certain critical angle 'trenching' occurs, and the
rod appears to collapse and form a long shallow crater.
+++++
...which, again, is why nobody uses steel APFSDS - it does moderately
well on a test range at normal impact if you throw it fast enough, but
it loses performance dramatically at lower velocities, and at oblique
impact it yaws, breaks up and fails to penetrate.

The works you bring up are all about results at smaller scale with tank guns with bore diameters of under 5", cube square law has major effects on projectiles.

The mass of the projectiles is rising as the cube of the bore, while the drag is rising as the square. The section modulus of the rod (which will have an effect on the rod breaking or shattering) will rise with the cube of the rod diameter.

Big tank APFSDS rods are generally well under 40 mm in diameter. The example I gave above tailored to your website's claimed needs for high velocity had a 76 mm diameter which for this purpose seems light to me. The rod mass is on the order of 10 times that of the DU rods being discussed by your reference, the section modulus of the rods is 6.8 x that of your rod.

We are in a different physical regime. I submit that I have proved this could work even using your references, but that your references as to Armor penetration are limited to smaller guns and do not show what penetration values are possible at lower velocities, they just assert they are "not good enough" for THEIR purpose of defeating tank armor of that time period using guns that could be fitted on tanks of that era.

They did not consider the use of these methods using naval guns against naval warships, which is understandable as aircraft had by this time made the point moot, so from their perspective no point in doing the research and testing.

That does not prove the penetration of armor by a long rod APFSDS projectile moving at 850 m/s with a diameter of 120 mm and length of 2 meters is going to not penetrate 300 mm. The kinetic energy of such a projectile is 63 MJ, which is nothing to sneeze at, and they did not test at this scale. Assuming your references are not bogus.

In any case one can make the argument that due to the drag coefficent being so much lower near Mach 5, that one will get much longer range as a result, that one should design the projectile and gun for a muzzle velocity of just over Mach 5, but again calculation shows that projectiles from an 11" gun will travel at speeds that will defeat WWI era battleship belt armor with ease at 11 km, or over 11000 yards.

[Paul.J.Adam]

Post by Alfred Montestruc

Post by Paul J. Adam
Yes, I saw the paper you posted. Nowhere in there, is a successful hit
mentioned.

Which is irreverent and moving the goal posts.

Ah, so actually hitting the intended targets is "irrelevant" to combat.

Fascinating!

Post by Alfred Montestruc
We are not discussing tanks or tank kills, we are discussing the potential > for use of APFSDS ammo on naval warships in WWI.

Okay - so, is there any documentary evidence for the accuracy of APFSDS rounds fired from warships?

No?

Then it seems that the only available data for APFSDS rounds will have to suffice.

Post by Alfred Montestruc

Post by Paul J. Adam
Unfortunately, Wiki is - as has been known to happen - wrong. The
engagement was correct, by a tank from the Royal Scots Dragoon Guards,
but the ammunition used was HESH.

Of course we are supposed to believe what Mr. Paul J. Adam AKA bozo the
clown who thinks that "fluid drag is proportional to velocity cubed", says
without evidence when the BBC and two other sources say otherwise.

No, you're supposed to investigate and check your facts: if we didn't fire any DU sabots in combat, how did we destroy an Iraqi tank with one?

Post by Alfred Montestruc
Nor should anyone take this as Mr. Paul J. Adam, as showing himself to be
a colossally arrogant jerk who will never admit being wrong about
anything.

The irony of this statement is just... hilarious.

Post by Alfred Montestruc

Post by Paul J. Adam
Except that we fired no DU rounds during Granby, as was stated later
in Parliament.

Mr. Paul J. Adam AKA bozo the clown who thinks that "fluid drag is
proportional to velocity cubed", should never be expected to provide any
supporting evidence that what he claims is true even when others provide
three sources that state otherwise.
Also of course no one has ever lied to Parliament, even once, and Paul J
Adam should not be expected to provide any evidence of his claim that such
was said to parliament (no don't I don't care.)

You know, you're posting an awful lot of words for someone who supposedly doesn't care.

Still, so be it, you don't care.

Post by Alfred Montestruc

Post by Paul J. Adam
You can also use technologies like light gas guns to generate utterly
implausible velocities of 5000-6000 metres per second, if you go into
the bunkers at Aberdeen or Fort Halstead.

Or like the light gas gun one of the professor's on my committee use to
study combustion and shock wave theory at LSU, where I have an MS in
mechanical engineering from and where I spent far too many years working
on a PhD. I am very familiar with the theory and practice of a light gas
gun thank you so very much.

Excellent! Then with your excellent engineering experience and education, you'll understand why getting the velocities you're looking for, at 10-15 kiloyards, is not a practical proposition.

Oh, wait, you're getting all angry and shouty about how it must be possible and easy because... well, just because!

To paraphrase Samuel Johnson:-

"Why, Sir, Montestruc is dull, naturally dull; but it must have taken him a great deal of pains to become what we now see him.

Such an excess of stupidity, Sir, is not in Nature."

Post by Alfred Montestruc

Post by Paul J. Adam

Post by Alfred Montestruc
2) It says all the rods have a uniform kinetic energy of 10 MJ, which
means they cannot have the same mass, as the only thing that is now
allowed to vary as now the L/D and energy are constrained so all that
is left to make the kinetic energy equation balance is "M", that
means the rod diameters are variable. As in KE=m*v*v/2, must be, no
wiggle room at all.

Was this to supposed to make sense?

To someone who understands math, sure. He said (look at the site)
constant kinetic energy of impact of 10 MJ for all projectiles.

Yes, but so what? I don't think you grasp the simple mathematics here.

Post by Alfred Montestruc

Post by Paul J. Adam
Vary the diameter (and hence length) to keep the mass the same, keep the
energy the same (since you're using the same gun, chamber,
propellant...) and the velocity remains constant.

No the mass varies (must very as KE=0.5*mv^2, the KE is constant and the
L/D are constant in the site you pulled up. That means the mass varies
with velocity such that at 1000 m/s the mass is 20 kg, and so on.

No, Al.

If all the projectiles have a KE of 10MJ, which for a nominal 1600 metres per second of velocity gets us a mass of 7.8 kilograms...

For a steel penetrator that's a cylinder 36mm in diameter with a length of 1085mm, for a tungsten penetrator it's a cylinder 25.8mm in diameter with a length of 774mm. Same mass, fired at 1600 metres per second, same KE of ten megajoules.

Post by Alfred Montestruc

Post by Paul J. Adam
Agrees with Grabarek, who was well regarded in the field.

OK - fine so if calculations according to that site are good, then you should accept this.
http://www.longrods.ch/perfcalc.php

I can't accept that, you said it's a wargamer's site and the author knows nothing about terminal ballistics.

Why are you using what you yourself proved - to your own complete satisfaction - to be a useless, ignorant site to support your arguments?

Post by Alfred Montestruc
The above from your reference site is a perforation calculator.
644 mm armor penetrated at 45 degree angle using a steel rod 76mm diameter
1976 mm long moving at 1283 m/s with at tip hardness of 500 HBN, armor
hardness of 250 HBN a taper on the rod of 90 mm and tip diameter of 10
mm. 1283 is the lowest speed the site states penetration values are
reliable for steel.

Okay, a L/D of 26 for a long-rod penetrator in 1916? We haven't got those working on a practical basis today, let alone back then.

Armour will be face-hardened, so higher BHN required; conversely the very high BHN you're claiming for the projectile is... problematic for the period.

Don't neglect the fact that the angle term is only calculating path length and no account is taken of projectile yaw or shear, which are critical limitations on steel long-rods and the reason they're not used in practical applications (multiple references _passim_)

And the calculator coughs up an error of "Actual velocity is less then v_min = 1.343 km/s. The perforation result may be inaccurate!"

Allow for the armour's hardness of, say, BHN350, and the penetration depth immediately drops to 475mm before we ask any other questions.


Of course, you hit the problem (not covered by this equation) that at even small obliquities the steel long-rod will be much more prone to yawing, breakup and trenching rather than penetration, as pointed out by a number of researchers over the years, but that's the sort of real-world trivia that never happens in a sea fight when we can be sure that every projectile will strike at perfect right angles to the target plate every time... can't we?

Post by Alfred Montestruc
Moving at 1400m/s it will punch through 794 mm. The slope of the
penetration vs m/s curve is 1.28 mm lost per m/s lost. Obviously that
the value cannot be reliably calculated by someone, does not mean it is
zero or small.
British Battleship belt armor in that era was ~ 12" = 300 mm, we assumed
45 degrees so we should not have problems at those speeds, taking the
slope and doubling it to 2.56 mm/m/s, I would be at 300 mm at about 1148 > m/s.

Or you could just follow the curve at http://www.longrods.ch/optv.php and scale from that.

If you're getting 644mm at 1280m/s, you'll see 365mm at 1000m/s.

Post by Alfred Montestruc
Now you claimed it impractical to shoot projectiles from naval guns at the
speeds we are discussing. That is simply not true, it has been done.
http://en.wikipedia.org/wiki/Project_HARP

In the 1960s, Al, using the improvements in interior ballistics and propellants made over the preceding fifty years (largely driven by experience in developing high-velocity tank and anti-aircraft guns)

By that argument, your APFSDS-firing battleships are irrelevant, because my supersonic jet bombers sink them with guided missiles: if we could do it in the 1960s why not in 1916?

Post by Alfred Montestruc
Note that this was using standard propellants based on nitrocellulose, not
exotic chemistry.

However, it needed bespoke batch production of the M8M propellant used, which took considerable trial and error to find the right geometries and composition. Not something that was anywhere near availability in 1916.

Post by Alfred Montestruc
Assume for the sake of argument that a0 is going to be about 3600m/s/5=
720 m/s, which is a conservative number, getting to 2.5 x the speed of
sound of the propellant gas (1800 m/s) is not a problem, that is just a
matter of available energy.

So easy, everyone did it.

In practice, a high-velocity gun (the UK's 17pdr, for instance, fielded in 1942 and one of the best of breed) firing full-bore APCBC shot at ~900 m/s, could generate about 1,200m/s firing saboted rounds. A 25% increase in muzzle velocity is extremely handy to have, but it wasn't possible to simply leap to 1,800 metres a second.

Post by Alfred Montestruc
So we know that the 11" gun had a normal muzzle velocity of about 910 m/s
with a 300 kg projectile. KE=mv^2 so it has a muzzle energy of 124 MJ.
The 76 mm x 1976 mm steel massing 70.36 kg, I estimate that a sabot
should mass at or less than 13.7 kg, that is 2xL/D cylinder of wood. That
gets me a total mass of 84.06 kg.
With the same muzzle energy that gets me a velocity of 1719 m/s with the
sabot + lighter projectile assume some reasonable losses (10% of velocity
gained over 910 m/s) I get a muzzle velocity minimum of 1638 m/s

It's amazing that anyone has ever struggled to get high velocity out of a gun when it was so easy all along, isn't it?

You'd think there were no problems anywhere, no sneaky little issues about pressure-time curves, the position of the all-burnt point, consistency of muzzle velocity...

The point you've overlooked, Al, is that you're accelerating the projectile *and the charge* down the barrel: the propellant gas has to follow the projectile and consumes some of the kinetic energy. The US Army ballistics manual suggest using one-third of muzzle velocity squared, to represent the energy taken by the propellant gases.

http://www.dtic.mil/dtic/tr/fulltext/u2/462060.pdf page 2.4

You're firing a 300kg shell with a 200kg charge, in your full-bore gun: assuming your 80kg sabot is using the same charge, and no other issues or losses, I show your muzzle velocity as 1420 metres per second even in this handwaved ideal scenario.

Post by Alfred Montestruc
That is not even remotely difficult

Life's so much easier when you ignore the difficult details, isn't it?

Post by Alfred Montestruc
From the paper by the US Army using the Cd they give for air drag I will
be moving at 1400 m/s at 7.43 km, at 1283 m/s at 11.13 km, and at 1148 m/s
at 15.34 km downrange.

Even by the rather optimistic assumption that we only correct for gas velocity, starting at 1420ms means you're out of the effective zone for penetration at useful battle ranges... which is back to my point.

And that's still only normal penetration: the well-documented susceptibility of steel long rods to yaw and shatter on anything other than a normal impact remains.

Post by Alfred Montestruc

Post by Paul J. Adam
Why is pointing out the proven engineering problems "attacking it"? This
has to offer some tangible benefit.

What pointing out of proven engineering problems are you bringing up by
asserting that the British tank kill in Iraq was not with a DU round but
with a a HESH round, even when 3 references state otherwise?

Didn't you explain, loudly and at length, that you didn't care?

Were you wrong then and you actually *do* care?

Were you right then and wrong now, and on reflection you *don't* care?

Can you actually keep track of what you're claiming even within a single post?

Are you beginning to see why your belligerent confusion is so comical?

Post by Alfred Montestruc
What is the basis of your claim that getting high velocities on naval
guns is impossible,

Please state, with references, where I stated it was impossible.

I pointed out some of the serious difficulties in achieving this goal in 1916.

Why, Al, making such careless statements and false attributions... anyone would think you were being reckless with the truth.

Post by Alfred Montestruc
or even difficult when it has been done using such Naval guns and Sabot.
shot

In 1966, fifty years after the period under discussion, and building on extensive work done to develop high velocity ordnance - including saboted projectiles - in anti-armour work - which you repeatedly declared to be irrelevant.

Since you've declared that work irrelevant, surely all that followed from it, like HARP, is also irrelevant?



By this argument, the Wright Brothers could and should have been breaking the sound barrier before Franz Ferdinand got shot.

Post by Alfred Montestruc
What is the basis of your claim that the velocity of the projectile will
be too slow to do any damage at useful ranges when such a Naval gun fired
projectiles that flew straight up to altitudes of 180 km, punching all the
way through the atmosphere to do it?

Two naval guns welded end-to-end, actually, using highly bespoke propellant that was effectively hand-crafted for each firing.

What's the relevance of a specialised ballistics experiment drawing on twenty years of high-velocity artillery work, to handwaving long-rod penetrators into existence in 1916? Might as well make the Dreadnoughts nuclear-powered while you're at it...

If you're introducing this change in the 1900s, you've got the 1900s industrial and technical base to work with, not some magical knowledge transfer from the future.

Post by Alfred Montestruc
Why do you try to pass yourself off as being some sort of all-knowing all-
wise oracle when it is blindingly obvious you aren't?

Please point out where I ever described myself as any sort of oracle. (Here's a hint, you can't)

Is this more of that Montestruc dishonesty? Or are you just confused? Again?


I just understand this subject rather better than you do, which admittedly doesn't seem to be at all difficult.

Post by Alfred Montestruc

Post by Paul J. Adam
Were they travelling at four or five times the speed of sound? Appealing
to "common sense" by comparing caveman weapons, is hardly relevant to
penetration of battleship armour.

I am trying to find your level of education, you don't react as an
educated person who has a reasonable understanding of physics would..

I'm not sure you and I agree on what a "reasonable understanding" of physics is, in this discussion: you seem to need an awful lot of it explaining to you.

Post by Alfred Montestruc
I am well aware of the drag issues, you seem to be lost in the weeds of
needing to see that someone did exactly that thing to understand it is
physically possible, and not getting that at high Mach numbers the skin
drag is MUCH LESS important than at low Mach numbers.

So, a larger, less dense projectile *has* less drag than a smaller, denser one.

I can see why we disagree on some fundamentals of physics here.

Post by Alfred Montestruc

Post by Paul J. Adam
Which is going to be a serious problem, since you need to achieve impact
velocities of well over 1,100 metres per second (not muzzle velocity,
impact velocity) for steel long-rods to offer any detectable advantage
in penetration

This is crap

No, this is reality, however uncomfortable you may find it.

Post by Alfred Montestruc
as I have shown that even by your site at the velocity this guy claims is
required the penetrations we can get are in the 600 mm ballpark at 45
degrees angle which is double the maximum thickness of British Battleship
armor.

Actually, you'll be getting nowhere near the velocities you're claiming with 1916 guns and propellants, which mean even your nominal penetrations are much lower (to the point that, at fighting range, you're not even defeating the armour).

Which is part of my point.

Post by Alfred Montestruc
Using the US Army paper reference I am getting velocity losses of at most
about 32 m/s per kilometer moved downrange for that projectile at the
speeds discussed above.

So now you're making a larger projectile out of a less dense material, with 1916 rather than 1970s machining technology, and you're going to get... less drag. Right.

More drag, lower impact velocity, even less penetration.

Post by Alfred Montestruc
That is consistent with the Army paper results when scaled for mass of
projectile and drag area. Ergo with my initial calculated velocity of
1638 m/s, which has been vastly exceeded by the HARP project using a Naval
gun, the projectile is still trucking along at 1159 m/s at 15 km > downrange, from an 11" gun.
That is well over the horizon.

Over the horizon? Are you kidding? At Jutland, dreadnoughts were sighting each other at 24 kilometres.

Seriously, Al, are you just making this up as you go along?

Post by Alfred Montestruc

Post by Paul J. Adam
assuming you can avoid yaw, buckle or shatter on impact.

Ductile steel is not going to shatter on impact

Steel at 550BHN - your selected value for your penetrator - isn't going to be very ductile, Al.

Post by Alfred Montestruc
it will plasticly deform both the armor and the rod whether the rod gets
all the way through is the issue, not whether anything shatters.

So, why is the shattering of uncapped steel projectiles on impact at high velocities such a problem, leading to the use of piercing caps before the switch to tungsten penetrators?

Did all those ordnance designers just imagine their difficulties?

If you're in the plastic deformation regime you're gaining very little, and losing a lot (in terms of yaw and breakup) by using a long rod. For a long rod penetrator to offer advantage, it needs a high striking velocity to bring it into the hydrodynamic regime rather than the plastic defomation zone, which for steel is uncomfortably fast even for tank fighting ranges.

This has been patiently, repeatedly, explained to you, documented, and referenced. There does come a point where abject stupidity proves insurmountable.

Post by Alfred Montestruc

Post by Paul J. Adam
Grabarek confirmed the critical velocity for hydrodynamic penetration
using tungsten alloy was 850 metres per second, while for steel it's
1150m/s: below that speed the penetration scaled with the diameter,
rather than the length, of the penetrator.

Oh and the mass x velocity of the projectile has NOTHING to do with the issue?

Depends on the velocity you're working at, among other factors. If you're foolish enough to wander off to ludicrous extremes, you'll get odd results.

Post by Alfred Montestruc
Really? So if I hit it with a steel foil pancake 0.001 inch thick but 20
inches in diameter it is the diameter of the pancake that matters? Right?

If your foil pancake is one inch in diameter, penetration will be zero, while a twenty-inch pancake will penetrate twenty times as deep, a hundred-inch pancake will penetrate to one hundred times that depth, and so on.

A penetration of zero will indeed scale with diameter - it's just that the result of "zero x D" will remain zero.

Post by Alfred Montestruc

Post by Paul J. Adam
Achieving hits with impact velocity of over 1,150m/s at a 10,000 yard
fighting range using 1916 gun technology is... well, perhaps there's a
reason that regime wasn't explored for a few more decades.

It was done and more by HARP,

*Fifty years later*. We're discussing the technology and knowledge of the 1900s, not the 1960s (the US had fifteen years solid research into APFSDS by 1966 and a solid body of work on APDS before that)

Post by Alfred Montestruc
velocities of 3600 m/s, with mild modification of a US Navy 16" gun

"Mild modification" is a rather unique description of welding two fifty-calibre guns together. How, exactly, do you propose to modify a German dreadnought - _Grosser Kurfust_, for example - thusly?

Post by Alfred Montestruc
- see above. I am not shooting for 3600 m/s , 1600 is just dandy.

1600 is, in practical terms, what's been found to be "bloody difficult" to actually achieve, and took a lot of hard work to get to - no matter how airily you handwave any inconvenient facts in your private fantasy world.

Post by Alfred Montestruc
be that as it may I can get effective ranges over the horizon

You've demonstrated that you don't even know where the horizon is, Al.

Post by Alfred Montestruc

Post by Paul J. Adam
And if it penetrates, it'll achieve very little effect on the target
ship, since it's a spray of fragments passing over the top of the
magazines and machinery spaces instead of descending into them and then
detonating an explosive payload.

Spray of very hot steel fragments with more than enough energy to punch
through another 300 mm of armor.

Really? Source for this rather optimistic, in fact fantastical, claim?

If a long-rod penetrator, having defeated 600mm of armour, could then defeat a further 300mm, doesn't that mean it can actually penetrate 900mm?

Why is a spray of spall and fragments able to smash through a foot of armour plate?

Can you show me a reference, a source, any evidence whatsoever for this?

Or did you just make up yet more nonsense?

Post by Alfred Montestruc

Post by Paul J. Adam
Getting through the armour is a means to an end: the intent is to stop
the ship from fighting, moving, and (if you hit it well enough) floating.

140 kg of fragments

No, the long-rod penetrator's effectively consumed during penetration (experiments with hollow penetrators, to increase the sectional modulus and resist bending, yaw and breakup of longer rods, sometimes resulted in penetrator material being sprayed backwards out of the target during penetration); if you're near the penetration limit you'll get much less passing through the armour. (It's extremely roughly a linear effect, with some velocity dependency: if your nominal penetration is twice the thickness you're defeating, about half the penetrator will emerge).

Spall will be variable, but dreadnought armour was generally backed by wood, sometimes cement, and additional backing plate: forming a useful spall lining that reduces the effectiveness of small fragments.

Post by Alfred Montestruc
moving at more than Mach 1, and bouncing off armor inside the magazine at > an average temperature of the ambient + 723 degrees C is not going to
start a fire???? Really?

How are you getting into the magazine? You're firing flat trajectory shots at extremely high velocity, you're not able to get your projectiles into the magazines even if you're getting through the armour.

Spraying a few kilograms of spall around the messdecks and flats won't significantly impair a dreadnought battleship's ability to float, move or fight.

By comparison, a 300kg shell penetrating the same armour will bring much more spall with it, it'll be more likely to be descending and thus able to reach magazines or machinery spaces... and then you've got the explosive bursting charge to concern yourself with.

There may be a reason why long-rod penetrators are only favoured for extremely dense targets like main battle tanks.

Post by Alfred Montestruc

Post by Paul J. Adam
Unfortunately, you won't achieve that level of penetration with a steel
long-rod penetrator striking at 815 metres per second: you're well below
the hydrodynamic limit, and the penetrator will either buckle or shatter
on 300mm armour.

<reference data removed for brevity>

Post by Alfred Montestruc

Post by Paul J. Adam
...which, again, is why nobody uses steel APFSDS - it does moderately
well on a test range at normal impact if you throw it fast enough, but
it loses performance dramatically at lower velocities, and at oblique
impact it yaws, breaks up and fails to penetrate.

The works you bring up are all about results at smaller scale with tank
guns with bore diameters of under 5", cube square law has major effects on > projectiles.

Then find some *evidence*, rather than your ill-understood fantasies, if you wish any hope of being taken seriously.

If there was advantage in using large-bore steel APFSDS - or even APDS, whether steel or tungsten - why has nobody, anywhere, ever been prepared to admit they conducted so much as a theoretical study into the notion?

Even back in the halcyon days of the early 1980s, when the US defence budget seemed bottomless and the "Bring Back the Battleships!" crowd were in full cry, advocating all manner of laser-guided, GPS-guided, rocket-boosted, bomblet-dispensing, and other shells for the main guns; nobody - not one single person - went on record as having looked at long-rod penetrators for the 16" guns despite the overwhelming advantages they'd supposedly offer against the strongly hardened point targets that the reactivated battleships were supposed to be the ultimate answer to.



Handwaving, imagination, and fantasy don't count: the sad fact remains that when steel APFSDS has been tried it was evaluated, proved to be ineffective, and the only country that fielded it, immediately relegated it to "training and export" is extremely well documented and proven. The first inherent problem of critical velocity can be addressed, though still with relatively poor performance, and the key issues of yaw, breakup and shatter worsen with increasing size.

I'm sorry that the world fails to conform to your dreams, but didn't you learn that at some point during the extensive engineering education you keep claiming to have experienced?

--
Paul J. Adam

He thinks too much, such men are dangerous.

[Alfred Montestruc]

Post by Paul.J.Adam

Post by Alfred Montestruc

Post by Paul J. Adam
Yes, I saw the paper you posted. Nowhere in there, is a successful hit
mentioned.

Which is irreverent and moving the goal posts.

Ah, so actually hitting the intended targets is "irrelevant" to combat.

It is irrelevant as to whether the DU round could kill the T72 at that range.

Post by Paul.J.Adam

Post by Alfred Montestruc
We are not discussing tanks or tank kills, we are discussing the potential > for use of APFSDS ammo on naval warships in WWI.

Okay - so, is there any documentary evidence for the accuracy of APFSDS rounds fired from warships?
No?
Then it seems that the only available data for APFSDS rounds will have to suffice.

But you refuse to look at it or use it.

Post by Paul.J.Adam

Post by Alfred Montestruc

Post by Paul J. Adam
Unfortunately, Wiki is - as has been known to happen - wrong. The
engagement was correct, by a tank from the Royal Scots Dragoon Guards,
but the ammunition used was HESH.

Of course we are supposed to believe what Mr. Paul J. Adam AKA bozo the
clown who thinks that "fluid drag is proportional to velocity cubed", says
without evidence when the BBC and two other sources say otherwise.

No, you're supposed to investigate and check your facts: if we didn't fire any DU sabots in combat, how did we destroy an Iraqi tank with one?

Excuse you bozo, but I am the one who posted three references contradicting you, you are the one who expects others to just take your word for it with no references. I don't need to prove squat, I already have proved my point several different ways, you are asserting with zero evidence and demanding we take your word for it.

Post by Paul.J.Adam

Post by Alfred Montestruc
Nor should anyone take this as Mr. Paul J. Adam, as showing himself to be
a colossally arrogant jerk who will never admit being wrong about
anything.

The irony of this statement is just... hilarious.

WHEN, I am wrong I have no problem admitting it, unlike you.

Post by Paul.J.Adam

Post by Alfred Montestruc

Post by Paul J. Adam
Except that we fired no DU rounds during Granby, as was stated later
in Parliament.

Mr. Paul J. Adam AKA bozo the clown who thinks that "fluid drag is
proportional to velocity cubed", should never be expected to provide any
supporting evidence that what he claims is true even when others provide
three sources that state otherwise.
Also of course no one has ever lied to Parliament, even once, and Paul J
Adam should not be expected to provide any evidence of his claim that such
was said to parliament (no don't I don't care.)

You know, you're posting an awful lot of words for someone who supposedly doesn't care.
Still, so be it, you don't care.

Exactly, whether or not DU was used in that case is irrelevant, as it could have been as the curve in the US Army paper I posted shows.

Post by Paul.J.Adam

Post by Alfred Montestruc

Post by Paul J. Adam
You can also use technologies like light gas guns to generate utterly
implausible velocities of 5000-6000 metres per second, if you go into
the bunkers at Aberdeen or Fort Halstead.

Or like the light gas gun one of the professor's on my committee use to
study combustion and shock wave theory at LSU, where I have an MS in
mechanical engineering from and where I spent far too many years working
on a PhD. I am very familiar with the theory and practice of a light gas
gun thank you so very much.

Excellent! Then with your excellent engineering experience and education, you'll understand why getting the velocities you're looking for, at 10-15 kiloyards, is not a practical proposition.

That is incorrect, and I showed you why.

---snip extremely lame attempt at insult, I hide your shameful excuse for an insult from the public as it is too embarrassing to you and your kin ---

Post by Paul.J.Adam

Post by Alfred Montestruc

Post by Paul J. Adam

Post by Alfred Montestruc
2) It says all the rods have a uniform kinetic energy of 10 MJ, which
means they cannot have the same mass, as the only thing that is now
allowed to vary as now the L/D and energy are constrained so all that
is left to make the kinetic energy equation balance is "M", that
means the rod diameters are variable. As in KE=m*v*v/2, must be, no
wiggle room at all.

Was this to supposed to make sense?

To someone who understands math, sure. He said (look at the site)
constant kinetic energy of impact of 10 MJ for all projectiles.

Yes, but so what? I don't think you grasp the simple mathematics here.

------------soooooo lame! --------------------

Post by Paul.J.Adam

Post by Alfred Montestruc

Post by Paul J. Adam
Vary the diameter (and hence length) to keep the mass the same, keep the
energy the same (since you're using the same gun, chamber,
propellant...) and the velocity remains constant.

No the mass varies (must very as KE=0.5*mv^2, the KE is constant and the
L/D are constant in the site you pulled up. That means the mass varies
with velocity such that at 1000 m/s the mass is 20 kg, and so on.

No, Al.
If all the projectiles have a KE of 10MJ, which for a nominal 1600 metres

He explicitly varies the velocity in that graph from the left to right side of the graph, ergo if the KE is constant, the mass and so diameter (as the L/D is constant) must vary. So no, one has no nominal velocity, one has velocities as stated in the graph varying linearly across the graph.



---------------snip silly rubbish -----

Post by Paul.J.Adam

Post by Alfred Montestruc

Post by Paul J. Adam
Agrees with Grabarek, who was well regarded in the field.

OK - fine so if calculations according to that site are good, then you should accept this.
http://www.longrods.ch/perfcalc.php

I can't accept that, you said it's a wargamer's site and the author knows nothing about terminal ballistics.

Either it is or it is not, but you claim it to not be so your should live by the results.

Post by Paul.J.Adam
Why are you using what you yourself proved - to your own complete satisfaction - to be a useless, ignorant site to support your arguments?

Post by Alfred Montestruc
The above from your reference site is a perforation calculator.
644 mm armor penetrated at 45 degree angle using a steel rod 76mm diameter
1976 mm long moving at 1283 m/s with at tip hardness of 500 HBN, armor
hardness of 250 HBN a taper on the rod of 90 mm and tip diameter of 10
mm. 1283 is the lowest speed the site states penetration values are
reliable for steel.

Okay, a L/D of 26 for a long-rod penetrator in 1916? We haven't got those working on a practical basis today, let alone back then.

That is not what your website claims.

Post by Paul.J.Adam
Armour will be face-hardened,

Nope, not on a warship of that era. I am really doubtful you could get a rolled plate of 250 HBN on 12" thick plate today. 250 HBN steel has a tensile strength of about 853 MPA ~ 123 ksi. Garden variety modern structural steel is about 452 MPA ~ 70 ksi tensile.

In my work it is really hard to get plate at just over 7" thick with HBN at 260. It costs about 2x per pound what ordinary steel plate of the same grade (260 HBN) in 1" thick plate costs, and you cannot get thicker steel as rolled plate. You cannot get it thicker in quantity.

Welding face hardened plates together is basically impossible. Perhaps they could be riveted together, but that means a whole lot of probably 20'x10' riveted plates with really heavy structure holding them up, and making the joints weak. A welded plate design was possible then, but not at that high a hardness.

So 250 HBN is a freebee for you, but 350 is BS nobody makes 12" plate with a tensile strength that high (1187 MPa 172 ksi tensile and it will have squat ductility, which is more important as armor).

Tank armor? That is another kettle of fish, that is possible as one can cast or better yet forge the various shapes of the tank armor, then weld them together with joints that do not hit the hardened outside of the plate.

Post by Paul.J.Adam
so higher BHN required; conversely the very high BHN you're claiming for the projectile is... problematic for the period.
Don't neglect the fact that the angle term is only calculating path length and no account is taken of projectile yaw or shear, which are critical limitations on steel long-rods and the reason they're not used in practical applications (multiple references _passim_)
And the calculator coughs up an error of "Actual velocity is less then v_min = 1.343 km/s. The perforation result may be inaccurate!"

After you changed the hardness of the armor wrongly.

Post by Paul.J.Adam
Allow for the armour's hardness of, say, BHN350, and the penetration depth immediately drops to 475mm before we ask any other questions.
Of course, you hit the problem (not covered by this equation) that at even small obliquities the steel long-rod will be much more prone to yawing, breakup and trenching rather than penetration, as pointed out by a number of researchers over the years, but that's the sort of real-world trivia that never happens in a sea fight when we can be sure that every projectile will strike at perfect right angles to the target plate every time... can't we?

But you ignore as usual the issue of scale.

Post by Paul.J.Adam

Post by Alfred Montestruc
Moving at 1400m/s it will punch through 794 mm. The slope of the
penetration vs m/s curve is 1.28 mm lost per m/s lost. Obviously that
the value cannot be reliably calculated by someone, does not mean it is
zero or small.
British Battleship belt armor in that era was ~ 12" = 300 mm, we assumed
45 degrees so we should not have problems at those speeds, taking the
slope and doubling it to 2.56 mm/m/s, I would be at 300 mm at about 1148 > m/s.

Or you could just follow the curve at http://www.longrods.ch/optv.php and scale from that.
If you're getting 644mm at 1280m/s, you'll see 365mm at 1000m/s.

Post by Alfred Montestruc
Now you claimed it impractical to shoot projectiles from naval guns at the
speeds we are discussing. That is simply not true, it has been done.
http://en.wikipedia.org/wiki/Project_HARP

In the 1960s, Al, using the improvements in interior ballistics

Nope, using a standard garden variety US Navy 16" gun.


and propellants made over the preceding fifty years (largely driven by experience in developing high-velocity tank and anti-aircraft guns)

BS, that is at much smaller bore diameters where the speed of reaction must be much higher. Big bore guns must have slower burn rates, or you can damage the damage the gun. look at the reference you cited below on the US Army ballistics manual.

You want a peak pressure under that which will damage the gun, with big guns that generally means larger slower burning propellent grains.


You claim otherwise cite it.

Post by Paul.J.Adam
By that argument, your APFSDS-firing battleships are irrelevant, because my supersonic jet bombers sink them with guided missiles: if we could do it in the 1960s why not in 1916?

Post by Alfred Montestruc
Note that this was using standard propellants based on nitrocellulose, not
exotic chemistry.

However, it needed bespoke batch production of the M8M propellant used,

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CB4QFjAA&url=http%3A%2F%2Fwww.dtic.mil%2Fcgi-bin%2FGetTRDoc%3FAD%3DAD0654370&ei=lTjQVKbQGJL7sASC2oH4CQ&usg=AFQjCNHgbs2qf6B0Z0jjSWEbQmAZDoRA_w&sig2=Po4FADG4NsC3D8usCcpf6A&bvm=bv.85076809,d.cWc

This was on the LATER gun where Bull had made major modifications to the 16" gun, his experiments started with a standard 16" gun with standard Ammo.

Post by Paul.J.Adam
which took considerable trial and error to find the right geometries and composition. Not something that was anywhere near availability in 1916.

I do not need to reach velocities of 7000 ft/sec =2133 m/s. Bull did.

Post by Paul.J.Adam

Post by Alfred Montestruc
Assume for the sake of argument that a0 is going to be about 3600m/s/5=
720 m/s, which is a conservative number, getting to 2.5 x the speed of
sound of the propellant gas (1800 m/s) is not a problem, that is just a
matter of available energy.

So easy, everyone did it.

Everyone with a naval gun and willing to reduce the mass of the projectile could have.

Post by Paul.J.Adam
In practice, a high-velocity gun (the UK's 17pdr, for instance, fielded in 1942 and one of the best of breed) firing full-bore APCBC shot at ~900 m/s, could generate about 1,200m/s firing saboted rounds. A 25% increase in muzzle velocity is extremely handy to have, but it wasn't possible to simply leap to 1,800 metres a second.

Claims Paul, with no proof.

Post by Paul.J.Adam

Post by Alfred Montestruc
So we know that the 11" gun had a normal muzzle velocity of about 910 m/s
with a 300 kg projectile. KE=mv^2 so it has a muzzle energy of 124 MJ.
The 76 mm x 1976 mm steel massing 70.36 kg, I estimate that a sabot
should mass at or less than 13.7 kg, that is 2xL/D cylinder of wood. That
gets me a total mass of 84.06 kg.
With the same muzzle energy that gets me a velocity of 1719 m/s with the
sabot + lighter projectile assume some reasonable losses (10% of velocity
gained over 910 m/s) I get a muzzle velocity minimum of 1638 m/s

It's amazing that anyone has ever struggled to get high velocity out of a gun when it was so easy all along, isn't it?

They were trying to do it with large mass projectiles, not sub-caliber munitions with sabot.

Post by Paul.J.Adam
You'd think there were no problems anywhere, no sneaky little issues about pressure-time curves, the position of the all-burnt point, consistency of muzzle velocity...

You can make the grains of powder smaller to speed up the burn rate to compensate for the early start. So what that is discussed in the reference you give. See figure 4-3 in that work.

Post by Paul.J.Adam
The point you've overlooked, Al, is that you're accelerating the projectile *and the charge* down the barrel: the propellant gas has to follow the projectile and consumes some of the kinetic energy. The US Army ballistics manual suggest using one-third of muzzle velocity squared, to represent the energy taken by the propellant gases.

NO!! 1/3 the propellent charge mass being accelerated to muzzle velocity this is looking at your reference, which explicitly states that C= the charge mass and that the simplified equation of the effective mass of the projectile is :

M= W*( 1 +theta)+C/3 where the theta term drops out for a smooth bore (as we have no energy of spin). W is the mass of projectile, and C is the charge mass. The charge mass is So we are talking an effective charge mass of 200kg/3 = 66.67 kg that makes muzzle energy 151.8 MJ and the new velocity with the changed charge mass is 1419 m/s and no need to calculate added losses.

Thanks!

Post by Paul.J.Adam
http://www.dtic.mil/dtic/tr/fulltext/u2/462060.pdf page 2.4
You're firing a 300kg shell with a 200kg charge, in your full-bore gun: assuming your 80kg sabot is using the same charge, and no other issues or losses, I show your muzzle velocity as 1420 metres per second even in this handwaved ideal scenario.

Which you check even though your theory is wrong as it is the effective mass thrown which is 1/3 the charge mass and we neglected to add the spin energy of the 300 kg projectile, which is small.

Hardly ideal.

So you agree that getting to the range where a steel sabot round could be effective is possible? Yes?

You should also realize that reducing the mass of the projectile reduces the peak pressure in the gun. So I could probably either adjust the size of the propellent grains (which was known in the late 19th century) or I might add more propellent, as the chamber size at peak pressure is larger as the projectile moved further, so the peak pressure is lower.

Post by Paul.J.Adam

Post by Alfred Montestruc
That is not even remotely difficult

Life's so much easier when you ignore the difficult details, isn't it?

Post by Alfred Montestruc
From the paper by the US Army using the Cd they give for air drag I will
be moving at 1400 m/s at 7.43 km, at 1283 m/s at 11.13 km, and at 1148 m/s
at 15.34 km downrange.

Even by the rather optimistic assumption that we only correct for gas velocity, starting at 1420ms means you're out of the effective zone for penetration at useful battle ranges... which is back to my point.

Nope, you are BSing about the armor hardness, you are getting a give away at 250 HBN, and I am not conceding a single HBN point higher. You concede above that "you'll see 365mm at 1000m/s. "


Evens so, no dice, as I can iterate on the projectile design and use a smaller mass one, I can also reexamine the sabot design and make it lighter, and I can punch up the propellent charge and still stay under the max pressure as my projectile is much lighter.

Then I can get fancy and drill out the dart from the fin side to within say 100 mm of the tip, with a bore of say 2/3 the max diameter, and fill the void with lead. Call them brass knuckle darts.

Post by Paul.J.Adam
And that's still only normal penetration: the well-documented susceptibility of steel long rods to yaw and shatter on anything other than a normal impact remains.

Post by Alfred Montestruc

Post by Paul J. Adam
Why is pointing out the proven engineering problems "attacking it"? This
has to offer some tangible benefit.

What pointing out of proven engineering problems are you bringing up by
asserting that the British tank kill in Iraq was not with a DU round but
with a a HESH round, even when 3 references state otherwise?

Didn't you explain, loudly and at length, that you didn't care?

But you do, and what you say is only an evasion.

Post by Paul.J.Adam
Were you wrong then and you actually *do* care?

I do not care whether the report was made to Parliament or what it said. It is just not pertinent to the subject.

I do care that you seem to think everyone should take your word for things that multiple references state otherwise on and no references I knows of agree with you.


- snip

Post by Paul.J.Adam

Post by Alfred Montestruc
What is the basis of your claim that getting high velocities on naval
guns is impossible,

Please state, with references, where I stated it was impossible.

Look at your post.

Post by Paul.J.Adam
I pointed out some of the serious difficulties in achieving this goal in 1916.

Well since I said 1890's that is another kettle of fish. The idea is that the basic idea of a smooth-bore gun firing a dart at high velocity occurs to someone in Germany circa 1890 to 1895. He, files for a German patent and gets Krupp interested as he has a shotgun and demonstrates the idea with hand-loaded darts in shotgun shells. While this is in the German patent office and the inventor has not discussed it with anyone but Krupp and the German military, it is declared secret and the man is paid off and given a job as research scientist with the project. By 1905 they have done a whole lot of experiments and have some idea of what they are doing. The 11" gun is selected for some of the experiments in the late 1890s. By 1905 they go into serious production and have a well developed design that can punch through 12" armor at 10 to 11 km range, and the design is still secret, with a bodyguard of lies protecting it.


I agree that suddenly doing this in the middle of WWI is not practical, but with my POD it is. That POD is in the early 1890s.

Post by Paul.J.Adam
Why, Al, making such careless statements and false attributions... anyone would think you were being reckless with the truth.

Post by Alfred Montestruc
or even difficult when it has been done using such Naval guns and Sabot.
shot

In 1966, fifty years after the period under discussion, and building on extensive work done to develop high velocity ordnance - including saboted projectiles - in anti-armour work - which you repeatedly declared to be irrelevant.

No Saboted projectiles date from the 18th century or before, I have already posted references to that on this thread. Sabot rods date from WWII, I think but were predicated on the APCR rounds with a center tungsten rod.

The APFSDS concept with a long rod was worked out by some engineer in the USSR in the 1950s, their is no reason on earth why someone at any time after the invention of tube guns could not have thought of and implemented this.

Muzzle loading smooth-bore cannon with such shot could have been made and would have shot further and more accurately than the smooth-bore muzzle loaders of the era.

Bull's use of sabots is more in line with the 18th and 19th century use as he was shooting scientific payloads not weapons at the time of HARP.

Post by Paul.J.Adam
Since you've declared that work irrelevant, surely all that followed from it, like HARP, is also irrelevant?

I declare your fixation as to whether a DU round killed a T72 in Gulf War I irrelevant. I did not declare the work on guns from 1900 through 1960 to be irrelevant to everything, just to the early work Bull did in Barbados with a 16" Naval gun. Bull showed that you could get 6000'/sec out of that gun by dropping the projectile mass.

Post by Paul.J.Adam
By this argument, the Wright Brothers could and should have been breaking the sound barrier before Franz Ferdinand got shot.

Well John Moses Browning was breaking said sound barrier with his projectiles, so what?

Post by Paul.J.Adam

Post by Alfred Montestruc
What is the basis of your claim that the velocity of the projectile will
be too slow to do any damage at useful ranges when such a Naval gun fired
projectiles that flew straight up to altitudes of 180 km, punching all the
way through the atmosphere to do it?

Two naval guns welded end-to-end, actually, using highly bespoke propellant that was effectively hand-crafted for each firing.
What's the relevance of a specialised ballistics experiment drawing on twenty years of high-velocity artillery work, to handwaving long-rod penetrators into existence in 1916? Might as well make the Dreadnoughts nuclear-powered while you're at it...
If you're introducing this change in the 1900s, you've got the 1900s industrial and technical base to work with, not some magical knowledge transfer from the future.

Post by Alfred Montestruc
Why do you try to pass yourself off as being some sort of all-knowing all-
wise oracle when it is blindingly obvious you aren't?

Please point out where I ever described myself as any sort of oracle. (Here's a hint, you can't)
Is this more of that Montestruc dishonesty? Or are you just confused? Again?
I just understand this subject rather better than you do, which admittedly doesn't seem to be at all difficult.

Post by Alfred Montestruc

Post by Paul J. Adam
Were they travelling at four or five times the speed of sound? Appealing
to "common sense" by comparing caveman weapons, is hardly relevant to
penetration of battleship armour.

I am trying to find your level of education, you don't react as an
educated person who has a reasonable understanding of physics would..

I'm not sure you and I agree on what a "reasonable understanding" of physics is, in this discussion: you seem to need an awful lot of it explaining to you.

Post by Alfred Montestruc
I am well aware of the drag issues, you seem to be lost in the weeds of
needing to see that someone did exactly that thing to understand it is
physically possible, and not getting that at high Mach numbers the skin
drag is MUCH LESS important than at low Mach numbers.

So, a larger, less dense projectile *has* less drag than a smaller, denser one.

Well that proves you are dense.

Post by Paul.J.Adam
I can see why we disagree on some fundamentals of physics here.

Post by Alfred Montestruc

Post by Paul J. Adam
Which is going to be a serious problem, since you need to achieve impact
velocities of well over 1,100 metres per second (not muzzle velocity,
impact velocity) for steel long-rods to offer any detectable advantage
in penetration

This is crap

No, this is reality, however uncomfortable you may find it.

Post by Alfred Montestruc
as I have shown that even by your site at the velocity this guy claims is
required the penetrations we can get are in the 600 mm ballpark at 45
degrees angle which is double the maximum thickness of British Battleship
armor.

Actually, you'll be getting nowhere near the velocities you're claiming with 1916 guns and propellants, which mean even your nominal penetrations are much lower (to the point that, at fighting range, you're not even defeating the armour).
Which is part of my point.

Post by Alfred Montestruc
Using the US Army paper reference I am getting velocity losses of at most
about 32 m/s per kilometer moved downrange for that projectile at the
speeds discussed above.

So now you're making a larger projectile out of a less dense material, with 1916 rather than 1970s machining technology, and you're going to get... less drag. Right.

Right, cube square law.

---------snip the rest of Paul's gibberish ----------

[Paul.J.Adam]

Post by Alfred Montestruc

Post by Paul.J.Adam
Ah, so actually hitting the intended targets is "irrelevant" to combat.

It is irrelevant as to whether the DU round could kill the T72 at that range.

If you can't reliably hit the target, you can't reliably kill it.

First you have to achieve a hit: then the hit has to do enough damage to defeat the target within an acceptable timescale.

There are entire treatises on the subject and the definitions of F-kill, M-kill, K-kill, and so forth, with arguments about in which circumstances a F30 kill is adequate while a M10 kill is not.

But Al, with his deep and broad expertise, declares this "irrelevant" to a discussion of projectile effectiveness. And Al is an *educated* man.

Post by Alfred Montestruc

Post by Paul.J.Adam
Then it seems that the only available data for APFSDS rounds will have to suffice.

But you refuse to look at it or use it.

Al, I've provided it, explained it to you, pointed out your errors and mistakes where you've failed to comprehend it.

I've shown you some of the accepted, definitive references on the subject, highlighted the known combat experience with the penetrators under question, corrected some of your more egregious "misunderstandings", pointed out where you're using information completely out of context or validation, and tried to explain where you're going wrong.

I've led the horse to water, pushed its head towards the trough, even demonstrated how to drink: at some point, you need to take a little bit of responsibility for yourself.

Post by Alfred Montestruc

Post by Paul.J.Adam
Excellent! Then with your excellent engineering experience and
education, you'll understand why getting the velocities you're looking
for, at 10-15 kiloyards, is not a practical proposition.

That is incorrect, and I showed you why.

Al, "making stuff up" isn't proof.

Claiming that "it was done in 1966 therefore it could be done in 1916" isn't proof.

I can "prove" that a Curtiss Jenny could have been breaking Mach 1 in level flight in 1916, because, y'know, Chuck Yeager - doesn't prove anything except that possibilities change with progress.

The Johnson quote remains painfully accurate:-

"Why, Sir, Montestruc is dull, naturally dull; but it must have taken him a great deal of pains to become what we now see him.

Such an excess of stupidity, Sir, is not in Nature."

Post by Alfred Montestruc

Post by Paul.J.Adam
If all the projectiles have a KE of 10MJ, which for a nominal 1600 metres

He explicitly varies the velocity in that graph from the left to right
side of the graph, ergo if the KE is constant, the mass and so diameter
(as the L/D is constant) must vary. So no, one has no nominal velocity,
one has velocities as stated in the graph varying linearly across the
graph

So, at the 1600 metres/second point, we have projectiles of the same mass and velocity as described above. Go faster, scale the dimensions down to keep the mass and hence KE the same as velocity increases, while keeping aspect ratio the same. Slower, same process.

This is billy-basics experimental design, Al.

Did your extensive engineering education not cover even easy stuff like this?

Post by Alfred Montestruc

Post by Paul.J.Adam

Post by Paul J. Adam
http://www.longrods.ch/perfcalc.php

I can't accept that, you said it's a wargamer's site and the author
knows nothing about terminal ballistics.

Either it is or it is not, but you claim it to not be so your should live by the results.

Are you confused, Al? Or have you no courage of your convictions?

If you have doubts about its validity, then produce a better equation that gives at least a first approximation of penetration for long-rod projectiles: with your extensive knowledge and experience, surely you know of several?

Don't rely on second-hand sources from someone you repeatedly claim knows nothing, find something credible of your own.

Shouldn't it be easy and straightforward for you to find?

Post by Alfred Montestruc

Post by Paul.J.Adam
Okay, a L/D of 26 for a long-rod penetrator in 1916? We haven't got those working on a practical basis today, let alone back then.

That is not what your website claims.

Really, Al? Who's fielding a steel long-rod penetrator of L/D 26?

You could, after much development work, get there with tungsten and DU, but with steel it's a lab curiosity for testing at normal impact: steel rods are too prone to yaw, breakup and shatter.

The one fielded steel APFSDS had a 400mm long penetrator, body diameter 40mm, and even at L/D 10 it was a practical failure. Nearly tripling its length will only cause it to fail even harder.

(Lanz, Odermatt and Weihrauch, "Kinetic Energy Projectiles: Development History, State Of The Art, Trends", 2001)

Post by Alfred Montestruc

Post by Paul.J.Adam
Armour will be face-hardened,

Nope, not on a warship of that era.

Al, we were using face-hardened armour for two decades by 1916, first using the Harvey process and then Krupp, with cemented Krupp being the state of the art by WW1.

I'm giving a lecture on the subject of armour and projectile interaction in this period to the Wessex Region of the Institute of Mechanical Engineers later this year - would you like to come along? Probably be April or May, down at the University of Portsmouth.

Post by Alfred Montestruc
Welding face hardened plates together is basically impossible.

Which is true, which is why armour plate was bolted to supporting frames rather than being welded. It was an expensive production process and highly customised: plates were made up, drilled and tapped for their attachment bolts, and then subjected to their final cementing. Once complete, the only changes to the hardened face possible were by grinding, the face was too hard to be machined otherwise.

Post by Alfred Montestruc

Post by Paul.J.Adam
Allow for the armour's hardness of, say, BHN350, and the penetration
depth immediately drops to 475mm before we ask any other questions.
Of course, you hit the problem (not covered by this equation) that at
even small obliquities the steel long-rod will be much more prone to
yawing, breakup and trenching rather than penetration, as pointed out by
a number of researchers over the years, but that's the sort of real-
world trivia that never happens in a sea fight when we can be sure that
every projectile will strike at perfect right angles to the target plate
every time... can't we?

But you ignore as usual the issue of scale.

Then find a reputable source for the performance of a steel long-rod penetrator at the dimensions you're citing.

Or, give some detailed evidence as to why effects that cripple the performance of steel long-rod penetrators at small and medium scale disappear at larger dimensions, as if by magic.

Why does a steel penetrator of L/D 10 fail at even ten or fifteen degrees off normal at subcalibre and tank-calibre testing, yet tripling its dimensions suddenly cause it to succeed? Is there any experimental evidence?

Why have none of the researchers in the field ever found this useful tipping point?

Post by Alfred Montestruc

Post by Paul.J.Adam
Or you could just follow the curve at http://www.longrods.ch/optv.php and scale from that.
If you're getting 644mm at 1280m/s, you'll see 365mm at 1000m/s.

Post by Paul J. Adam
Now you claimed it impractical to shoot projectiles from naval guns at the
speeds we are discussing. That is simply not true, it has been done.
http://en.wikipedia.org/wiki/Project_HARP

In the 1960s, Al, using the improvements in interior ballistics

Nope, using a standard garden variety US Navy 16" gun.

They began with a standard 16"/50 gun, but extended it to get the velocity they needed.

Post by Alfred Montestruc
and propellants made over the preceding fifty years (largely driven by
experience in developing high-velocity tank and anti-aircraft guns)
BS, that is at much smaller bore diameters where the speed of reaction
must be much higher. Big bore guns must have slower burn rates, or you
can damage the damage the gun. look at the reference you cited below on
the US Army ballistics manual.
You want a peak pressure under that which will damage the gun, with big
guns that generally means larger slower burning propellent grains.

Al, do you ever actually *understand* what you're shown?

If you go for a slow burn with a high-velocity projectile, you've thrown it out of the muzzle before you get to all-burned. Your lower peak pressure, and the high acceleration of the round, further slows the combustion rate of stick propellant (which is what you're working with in 1916) so your charge is even less efficient.

You need multitube propellant (where the burn rate increases with time) to prevent a very high pressure spike early, while maintaining working pressure along the barrel behind the rapidly-accelerating projectile, for very high velocity applications.

That's something that simply didn't exist in 1916 and which was developed in response to the requirements for firing light projectiles at high velocity. Project HARP had to set up their own propellant plant to produce, by trial and error, the grain geometries they needed.

This is not absolutely impossible in 1916, but once again it is much more significant than simply changing the projectile: it's transplanting two decades of hard-won experience in propellant design from the future and assuming it's magically available to make the projectile change work easily.

Post by Alfred Montestruc

Post by Paul.J.Adam
So easy, everyone did it.

Everyone with a naval gun and willing to reduce the mass of the projectile could have.

So say you, yet plenty of people were experimenting with subcalibre projectiles (whether necking down large cases, using non-rigid projectiles from tapered bores, or discarding sabots) and low-mass projectiles (arrowhead shot, APCR) and discovering all manner of problems and difficulties.

Oh, if only those morons, fools and idiots back then had been gifted with Al's wisdom and insight!

Post by Alfred Montestruc

Post by Paul.J.Adam
In practice, a high-velocity gun (the UK's 17pdr, for instance, fielded
in 1942 and one of the best of breed) firing full-bore APCBC shot at
~900 m/s, could generate about 1,200m/s firing saboted rounds. A 25%
increase in muzzle velocity is extremely handy to have, but it wasn't
possible to simply leap to 1,800 metres a second.

Claims Paul, with no proof.

The proof is up the hill from me, at the Royal Armouries' Museum of Artillery: there's a 17pdr gun there among the exhibits, citing those numbers for its performance. Some of the staff are pretty knowledgeable and will happily talk your ears off if you let them.

Or you could read "Fire and Movement", a historical work by the Royal Armoured Corps, published in 1975 which went into some detail on the performance of tank and anti-tank guns of the period, with the 17pdr held up as an excellent example (as indeed it was).

Or, indeed, you could try pointing out where those figures are wrong (hint - they aren't).

Perhaps this is another conspiracy and I've enlisted everyone who ever worked on the 17pdr gun project, ever, to produce false results so I can deceive you today? Shall we go with that claim again?

Post by Alfred Montestruc

Post by Paul.J.Adam
It's amazing that anyone has ever struggled to get high velocity out of
a gun when it was so easy all along, isn't it?

They were trying to do it with large mass projectiles, not sub-caliber
munitions with sabot.

Even when they were using sabots, reality proved a little less straightforward.

Oh, I forgot - reality is irrelevant in Al's world, he's been to university and knows that if you shout really loudly, reality goes away and does what you want. For Al is an *educated* man.

Post by Alfred Montestruc

Post by Paul.J.Adam
You'd think there were no problems anywhere, no sneaky little issues
about pressure-time curves, the position of the all-burnt point,
consistency of muzzle velocity...
You can make the grains of powder smaller to speed up the burn rate to
compensate for the early start. So what that is discussed in the
reference you give. See figure 4-3 in that work.

I'm confused, Al, didn't you claim that Project HARP never needed custom propellant and just used standard USN cordite?

So why do you now need to change the propellant just because you're firing a sabot?

Were you wrong then, or are you wrong now?

Post by Alfred Montestruc

Post by Paul.J.Adam
The point you've overlooked, Al, is that you're accelerating the
projectile *and the charge* down the barrel: the propellant gas has to
follow the projectile and consumes some of the kinetic energy. The US
Army ballistics manual suggest using one-third of muzzle velocity
squared, to represent the energy taken by the propellant gases.

NO!!

Why not? You proceed to prove me right.

Post by Alfred Montestruc
So you agree that getting to the range where a steel sabot round could be
effective is possible? Yes?

At the muzzle, yes; a 25% improvement in muzzle velocity is typical for going to a saboted round. 1420m/s is optimistic, but let's roll with it for the sake of argument.

Post by Alfred Montestruc

Post by Paul.J.Adam
Even by the rather optimistic assumption that we only correct for gas velocity, starting at 1420ms means you're out of the effective zone for penetration at useful battle ranges... which is back to my point.

Nope, you are BSing about the armor hardness, you are getting a give away at 250 HBN, and I am not conceding a single HBN point higher.

Would this be on those welded battleships using homogenous steel armour that you tell us were so widespread in 1916?

How about looking at *actual* armour from the period?

http://www.combinedfleet.com/metalprp.htm

Krupp non-cemented gives you 220BHN, USN Class B came in at 240 around that point - but Harvey plate had a face hardness of 680BHN and typical British face-hardened armour of WW1 had a face hardness of 650BHN.

Post by Alfred Montestruc
Then I can get fancy and drill out the dart from the fin side to within
say 100 mm of the tip, with a bore of say 2/3 the max diameter, and fill
the void with lead. Call them brass knuckle darts.

So you're taking a projectile that'll yaw, break up and shatter because of buckling loads at impact, and simultaneously weakening it while adding more buckling loads at impact.

Excellent, that's going to take away whatever marginal effectiveness you might have enjoyed.

Post by Alfred Montestruc

Post by Paul.J.Adam
Didn't you explain, loudly and at length, that you didn't care?

But you do

Do I? I'm just amused that you're either so confused that you can't remember what you've said, or so dishonest you can't keep your mendacities organised.

Post by Alfred Montestruc

Post by Paul.J.Adam
Were you wrong then and you actually *do* care?

I do not care

Then why are you wibbling on, and on, after loudly declaring you don't care?

Post by Alfred Montestruc
It is just not pertinent to the subject.

Then why keep shouting about it?

Post by Alfred Montestruc
I do care that you seem to think everyone should take your word for things
that multiple references state otherwise on and no references I knows of
agree with you.

So you *do* care and you're just confused, dishonest or both.

Fair enough.

Post by Alfred Montestruc

Post by Paul.J.Adam
Please state, with references, where I stated it was impossible.

Look at your post.

Where at no point did I say "impossible". Difficult and far harder than simply swapping 11" APCPC shells for saboted penetrators, but not impossible.

So, you're dishonest. Again.

Post by Alfred Montestruc

Post by Paul.J.Adam
I pointed out some of the serious difficulties in achieving this goal in 1916.

Well since I said 1890's that is another kettle of fish. The idea is that
the basic idea of a smooth-bore gun firing a dart at high velocity occurs
to someone in Germany circa 1890 to 1895. He, files for a German patent >
and gets Krupp interested as he has a shotgun and demonstrates the idea
with hand-loaded darts in shotgun shells. While this is in the German
patent office and the inventor has not discussed it with anyone but Krupp > and the German military, it is declared secret and the man is paid off and
given a job as research scientist with the project. By 1905 they have
done a whole lot of experiments and have some idea of what they are doing.
The 11" gun is selected for some of the experiments in the late 1890s. By
1905 they go into serious production and have a well developed design
that can punch through 12" armor at 10 to 11 km range, and the design is
still secret, with a bodyguard of lies protecting it.

This is sensible, with some limitations and issues.

The weak spot is the leap to finned, long-rod penetrators, which in reality was a lengthy, evolutionary transition requiring a number of developments and advancements. However, let's give this a fair hearing from a sceptical but not hostile viewpoint.


Hand-loaded darts in shotgun shells: skip over the "why?", perhaps we've got a frustrated wannabee hunter trying to produce an improved load for tiger or elephant, and who discovers that he's blowing holes in the backstop (as well as exploding his first few shotguns) during trial firings. This gets us the sabot principle fifty years early (the first examples I know of were fielded by Brandt for French field guns in 1940, he brought his work to the UK where he helped produce the 6pdr APDS).

However, we're not doing long rods with hydrodynamic penetration, we're getting a high-velocity, finned, subcalibre dart with usable accuracy out of what's otherwise a heavy-barrelled shotgun - for, again, hunting really big game where neither shot nor full-bore slug would achieve the penetration desired (maybe our inventor's brother was eaten by an angry hippopotamus and he wanted vengeance).

This highlights the possibilities of getting a significant jump in muzzle velocity, albeit with some screwing around with the propellant charge required (which here would be available, it's a high priority project), from using a subcalibre projectile in a discarding sabot. This is a nice way to sidestep all the elegant but almost unproduceable taper-bore stuff from Gerlich.

In practice, getting the sabot to separate reliably without affecting projectile accuracy was a serious problem that IRL took most of a decade to solve (not really fixed until the 20pdr AT in UK service) and that was with the benefit of projectile spin to assist separation. Acceptable for a shotgun, but not for hitting ships at seven miles.

For practical purposes, I can see the sabot principle coming in, giving a 25% boost to muzzle velocity for a subcalibre projectile and rising to 33%ish as experience is gained (so, 1,200 metres per second of MV with a saboted round from an 11" gun - in line with what was being achieved in the 1940s with sabots). It's still from a rifled gun: the energy lost in spin is trivial, the spun round is much easier to design a cleanly-seperating sabot for, and the ability to fire full-bore HE remains important. Also, we've not got into the hydrodynamic regime where long-rods start to show advantage, instead remaining limited by projectile shatter.

Now the question is, what to do with this? It's not hugely effective firing steel AP rounds, for all the reasons well known and understood that drove AT gun designers towards tungsten (as cores, then as penetrators). The great conceptual leap towards unspun long-rod projectiles came after exploring tungsten APDS rounds of increasing L/D and velocity, but here there's a local ceiling where most experiments just result in failure: finding the combination of velocity and geometry that allows what performance a steel long-rod penetrator possesses to be demonstrated, is unlikely to be found by accident.

The higher velocity gives longer theoretical range, but fire control and visibility still limit that for practical purposes, and the smaller projectile - as APCBC - has less penetration and behind-armour effect when it does hit than a full-bore shell, so it's not very attractive.

Tungsten is likely to be noticed as a possibility, but at this point I'll say it's ignored on cost grounds (it'll take a lot per penetrator, after all).

However, there are several ways to skin cats: I'll offer you a contrary suggestion that since 1905 brings us the Battle of Tsushima, where Russian ships were devastated and left unfightable by Japanese HE shell. Rather than struggle with making steel shot penetrate face-hardened armour by increased velocity alone, I can see the dastardly Germans instead using these sabots to fire subcalibre HE shell, which takes us nicely back to Brandt's 1940 concept.

The higher velocity and flatter trajectory get them significantly more hits, and scoring those hits on the superstructure and above the armour belt where HE shell would be more telling. Basically, a continuation of the predreadnought "hail of fire" concept: the German ships intend to open the fight by hitting first and more often with subcalibre (but still dangerous) HE shell at ranges where the enemy is struggling to hit at all, switching to full-bore AP rounds as the range closes on their damaged opponents.

Effective? With hindsight based on experience, not as much as hoped (Jutland led the RN to follow the USN down the all-or-nothing armour route instead of armouring to keep out HE shell from large areas) but it's in line with the doctrine and the limited combat experience (Spanish-American and Russo-Japanese wars) of the period.

Post by Alfred Montestruc
No Saboted projectiles date from the 18th century or before, I have
already posted references to that on this thread. Sabot rods date from
WII, I think but were predicated on the APCR rounds with a center
tungsten rod.

The first recognisable saboted rounds from breech-loading guns were fielded by France in 1940 as a means to extend the range of their 75mm field gun; Brandt fled to the UK where he worked on the 6pdr APDS round, which very successfully replaced the APCR and APCRNR previously in use.

The US began work on long-rod penetrators in 1951, probably before the Soviets did (I'm not sure when the Soviets went to APDS - they were sticking with APCR a lot longer than we were)

Post by Alfred Montestruc
The APFSDS concept with a long rod was worked out by some engineer in the
USSR in the 1950s, their is no reason on earth why someone at any time
after the invention of tube guns could not have thought of and implemented
this.

The concept is fine, the problem comes with the experimentation and design.

Firstly, until you've moved away from steel shot, all more impact velocity gets you between ~800 metres/sec (the shatter limit for capped steel shot) and the hydrodynamic regime (which for steel, is getting towards twice that) is broken projectiles and relatively unimpressive damage to the target. Hence, part of why in the real world muzzle velocities settled where they did. (Brandt's work on sabots was originally intended to extend range with subcalibre HE shell, not to pierce armour).

Secondly, getting the sabot off the penetrator proved to be harder in practice than in reality: even spun APDS, with a finless penetrator and centrifugal force to help throw the pieces away, suffered serious early problems with interference from the sabot disrupting projectile accuracy.

Once those had been solved by the late 1940s, it became apparent that penetration by tungsten projectiles at ~1200m/s was no longer proceeding according to plastic deformation, and that in fact hydrodynamic penetration was occurring (in other words, L/D was the driving parameter) which led to a steady extension of penetrator length towards the limit possible with spin-stabilised projectiles. This intermediate stage (spun APDS) is the precursor of APFSDS.

In the UK, US and Germany, while work on unspun, finned penetrators was done, it was found more effective to concentrate on improving the (very effective) APDS and retain spin stabilisation until the 1970s, when the advent of composite armours drove the move to unspun long-rods, first in tungsten and then in depleted uranium.

There are a number of steps required to get to APFSDS projectiles from full-bore APC, and simply saying "what happens if I fire a long thin steel dart in a sabot out of an 11" gun?" will generally end in disappointment until the supporting work is available - by which point the sensible answer is "why on earth are you still using steel?"

To stick with the aviation analogy, supersonic projectiles, internal combustion engines, aluminium alloys and rocket motors all existed in 1903, so why did Orville and Wilbur merely build the Wright Flyer when there's no reason on earth they couldn't have jumped directly Glamorous Glennis and the B-29 to drop her from? Idiots, obviously, no imagination.

--
Paul J. Adam

He thinks too much, such men are dangerous.

[Alfred Montestruc]

Post by Paul.J.Adam

Post by Alfred Montestruc

Post by Paul.J.Adam
Okay, a L/D of 26 for a long-rod penetrator in 1916? We haven't got those working on a practical basis today, let alone back then.

http://www.vti.mod.gov.rs/ntp/rad2010/2-10/9/09.pdf

Page 1 L/D com

Post by Paul.J.Adam

Post by Alfred Montestruc
That is not what your website claims.

Really, Al? Who's fielding a steel long-rod penetrator of L/D 26?
You could, after much development work, get there with tungsten and DU, but with steel it's a lab curiosity for testing at normal impact: steel rods are too prone to yaw, breakup and shatter.
The one fielded steel APFSDS had a 400mm long penetrator, body diameter 40mm, and even at L/D 10 it was a practical failure. Nearly tripling its length will only cause it to fail even harder.
(Lanz, Odermatt and Weihrauch, "Kinetic Energy Projectiles: Development History, State Of The Art, Trends", 2001)

Post by Alfred Montestruc

Post by Paul.J.Adam
Armour will be face-hardened,

Nope, not on a warship of that era.

Al, we were using face-hardened armour for two decades by 1916, first using the Harvey process and then Krupp, with cemented Krupp being the state of the art by WW1.
I'm giving a lecture on the subject of armour and projectile interaction in this period to the Wessex Region of the Institute of Mechanical Engineers later this year - would you like to come along? Probably be April or May, down at the University of Portsmouth.

Post by Alfred Montestruc
Welding face hardened plates together is basically impossible.

Which is true, which is why armour plate was bolted to supporting frames rather than being welded. It was an expensive production process and highly customised: plates were made up, drilled and tapped for their attachment bolts, and then subjected to their final cementing. Once complete, the only changes to the hardened face possible were by grinding, the face was too hard to be machined otherwise.

Post by Alfred Montestruc

Post by Paul.J.Adam
Allow for the armour's hardness of, say, BHN350, and the penetration
depth immediately drops to 475mm before we ask any other questions.
Of course, you hit the problem (not covered by this equation) that at
even small obliquities the steel long-rod will be much more prone to
yawing, breakup and trenching rather than penetration, as pointed out by
a number of researchers over the years, but that's the sort of real-
world trivia that never happens in a sea fight when we can be sure that
every projectile will strike at perfect right angles to the target plate
every time... can't we?

But you ignore as usual the issue of scale.

Then find a reputable source for the performance of a steel long-rod penetrator at the dimensions you're citing.
Or, give some detailed evidence as to why effects that cripple the performance of steel long-rod penetrators at small and medium scale disappear at larger dimensions, as if by magic.
Why does a steel penetrator of L/D 10 fail at even ten or fifteen degrees off normal at subcalibre and tank-calibre testing, yet tripling its dimensions suddenly cause it to succeed? Is there any experimental evidence?
Why have none of the researchers in the field ever found this useful tipping point?

Post by Alfred Montestruc

Post by Paul.J.Adam
Or you could just follow the curve at http://www.longrods.ch/optv.php and scale from that.
If you're getting 644mm at 1280m/s, you'll see 365mm at 1000m/s.

Post by Alfred Montestruc
Now you claimed it impractical to shoot projectiles from naval guns at the
speeds we are discussing. That is simply not true, it has been done.
http://en.wikipedia.org/wiki/Project_HARP

In the 1960s, Al, using the improvements in interior ballistics

Nope, using a standard garden variety US Navy 16" gun.

They began with a standard 16"/50 gun, but extended it to get the velocity they needed.

Post by Alfred Montestruc
and propellants made over the preceding fifty years (largely driven by
experience in developing high-velocity tank and anti-aircraft guns)
BS, that is at much smaller bore diameters where the speed of reaction
must be much higher. Big bore guns must have slower burn rates, or you
can damage the damage the gun. look at the reference you cited below on
the US Army ballistics manual.
You want a peak pressure under that which will damage the gun, with big
guns that generally means larger slower burning propellent grains.

Al, do you ever actually *understand* what you're shown?
If you go for a slow burn with a high-velocity projectile, you've thrown it out of the muzzle before you get to all-burned. Your lower peak pressure, and the high acceleration of the round, further slows the combustion rate of stick propellant (which is what you're working with in 1916) so your charge is even less efficient.
You need multitube propellant (where the burn rate increases with time) to prevent a very high pressure spike early, while maintaining working pressure along the barrel behind the rapidly-accelerating projectile, for very high velocity applications.
That's something that simply didn't exist in 1916 and which was developed in response to the requirements for firing light projectiles at high velocity. Project HARP had to set up their own propellant plant to produce, by trial and error, the grain geometries they needed.
This is not absolutely impossible in 1916, but once again it is much more significant than simply changing the projectile: it's transplanting two decades of hard-won experience in propellant design from the future and assuming it's magically available to make the projectile change work easily.

Post by Alfred Montestruc

Post by Paul.J.Adam
So easy, everyone did it.

Everyone with a naval gun and willing to reduce the mass of the projectile could have.

So say you, yet plenty of people were experimenting with subcalibre projectiles (whether necking down large cases, using non-rigid projectiles from tapered bores, or discarding sabots) and low-mass projectiles (arrowhead shot, APCR) and discovering all manner of problems and difficulties.
Oh, if only those morons, fools and idiots back then had been gifted with Al's wisdom and insight!

Post by Alfred Montestruc

Post by Paul.J.Adam
In practice, a high-velocity gun (the UK's 17pdr, for instance, fielded
in 1942 and one of the best of breed) firing full-bore APCBC shot at
~900 m/s, could generate about 1,200m/s firing saboted rounds. A 25%
increase in muzzle velocity is extremely handy to have, but it wasn't
possible to simply leap to 1,800 metres a second.

Claims Paul, with no proof.

The proof is up the hill from me, at the Royal Armouries' Museum of Artillery: there's a 17pdr gun there among the exhibits, citing those numbers for its performance. Some of the staff are pretty knowledgeable and will happily talk your ears off if you let them.
Or you could read "Fire and Movement", a historical work by the Royal Armoured Corps, published in 1975 which went into some detail on the performance of tank and anti-tank guns of the period, with the 17pdr held up as an excellent example (as indeed it was).
Or, indeed, you could try pointing out where those figures are wrong (hint - they aren't).
Perhaps this is another conspiracy and I've enlisted everyone who ever worked on the 17pdr gun project, ever, to produce false results so I can deceive you today? Shall we go with that claim again?

Post by Alfred Montestruc

Post by Paul.J.Adam
It's amazing that anyone has ever struggled to get high velocity out of
a gun when it was so easy all along, isn't it?

They were trying to do it with large mass projectiles, not sub-caliber
munitions with sabot.

Even when they were using sabots, reality proved a little less straightforward.
Oh, I forgot - reality is irrelevant in Al's world, he's been to university and knows that if you shout really loudly, reality goes away and does what you want. For Al is an *educated* man.

Post by Alfred Montestruc

Post by Paul.J.Adam
You'd think there were no problems anywhere, no sneaky little issues
about pressure-time curves, the position of the all-burnt point,
consistency of muzzle velocity...
You can make the grains of powder smaller to speed up the burn rate to
compensate for the early start. So what that is discussed in the
reference you give. See figure 4-3 in that work.

I'm confused, Al, didn't you claim that Project HARP never needed custom propellant and just used standard USN cordite?
So why do you now need to change the propellant just because you're firing a sabot?
Were you wrong then, or are you wrong now?

Post by Alfred Montestruc

Post by Paul.J.Adam
The point you've overlooked, Al, is that you're accelerating the
projectile *and the charge* down the barrel: the propellant gas has to
follow the projectile and consumes some of the kinetic energy. The US
Army ballistics manual suggest using one-third of muzzle velocity
squared, to represent the energy taken by the propellant gases.

NO!!

Why not? You proceed to prove me right.

Post by Alfred Montestruc
So you agree that getting to the range where a steel sabot round could be
effective is possible? Yes?

At the muzzle, yes; a 25% improvement in muzzle velocity is typical for going to a saboted round. 1420m/s is optimistic, but let's roll with it for the sake of argument.

Post by Alfred Montestruc

Post by Paul.J.Adam
Even by the rather optimistic assumption that we only correct for gas velocity, starting at 1420ms means you're out of the effective zone for penetration at useful battle ranges... which is back to my point.

Nope, you are BSing about the armor hardness, you are getting a give away at 250 HBN, and I am not conceding a single HBN point higher.

Would this be on those welded battleships using homogenous steel armour that you tell us were so widespread in 1916?
How about looking at *actual* armour from the period?
http://www.combinedfleet.com/metalprp.htm
Krupp non-cemented gives you 220BHN, USN Class B came in at 240 around that point - but Harvey plate had a face hardness of 680BHN and typical British face-hardened armour of WW1 had a face hardness of 650BHN.

Post by Alfred Montestruc
Then I can get fancy and drill out the dart from the fin side to within
say 100 mm of the tip, with a bore of say 2/3 the max diameter, and fill
the void with lead. Call them brass knuckle darts.

So you're taking a projectile that'll yaw, break up and shatter because of buckling loads at impact, and simultaneously weakening it while adding more buckling loads at impact.
Excellent, that's going to take away whatever marginal effectiveness you might have enjoyed.

Post by Alfred Montestruc

Post by Paul.J.Adam
Didn't you explain, loudly and at length, that you didn't care?

But you do

Do I? I'm just amused that you're either so confused that you can't remember what you've said, or so dishonest you can't keep your mendacities organised.

Post by Alfred Montestruc

Post by Paul.J.Adam
Were you wrong then and you actually *do* care?

I do not care

Then why are you wibbling on, and on, after loudly declaring you don't care?

Post by Alfred Montestruc
It is just not pertinent to the subject.

Then why keep shouting about it?

Post by Alfred Montestruc
I do care that you seem to think everyone should take your word for things
that multiple references state otherwise on and no references I knows of
agree with you.

So you *do* care and you're just confused, dishonest or both.
Fair enough.

Post by Alfred Montestruc

Post by Paul.J.Adam
Please state, with references, where I stated it was impossible.

Look at your post.

Where at no point did I say "impossible". Difficult and far harder than simply swapping 11" APCPC shells for saboted penetrators, but not impossible.
So, you're dishonest. Again.

Post by Alfred Montestruc

Post by Paul.J.Adam
I pointed out some of the serious difficulties in achieving this goal in 1916.

Well since I said 1890's that is another kettle of fish. The idea is that
the basic idea of a smooth-bore gun firing a dart at high velocity occurs
to someone in Germany circa 1890 to 1895. He, files for a German patent >
and gets Krupp interested as he has a shotgun and demonstrates the idea
with hand-loaded darts in shotgun shells. While this is in the German
patent office and the inventor has not discussed it with anyone but Krupp > and the German military, it is declared secret and the man is paid off and
given a job as research scientist with the project. By 1905 they have
done a whole lot of experiments and have some idea of what they are doing.
The 11" gun is selected for some of the experiments in the late 1890s. By
1905 they go into serious production and have a well developed design
that can punch through 12" armor at 10 to 11 km range, and the design is
still secret, with a bodyguard of lies protecting it.

This is sensible, with some limitations and issues.
The weak spot is the leap to finned, long-rod penetrators, which in reality was a lengthy, evolutionary transition requiring a number of developments and advancements. However, let's give this a fair hearing from a sceptical but not hostile viewpoint.
Hand-loaded darts in shotgun shells: skip over the "why?", perhaps we've got a frustrated wannabee hunter trying to produce an improved load for tiger or elephant, and who discovers that he's blowing holes in the backstop (as well as exploding his first few shotguns) during trial firings. This gets us the sabot principle fifty years early (the first examples I know of were fielded by Brandt for French field guns in 1940, he brought his work to the UK where he helped produce the 6pdr APDS).
However, we're not doing long rods with hydrodynamic penetration, we're getting a high-velocity, finned, subcalibre dart with usable accuracy out of what's otherwise a heavy-barrelled shotgun - for, again, hunting really big game where neither shot nor full-bore slug would achieve the penetration desired (maybe our inventor's brother was eaten by an angry hippopotamus and he wanted vengeance).
This highlights the possibilities of getting a significant jump in muzzle velocity, albeit with some screwing around with the propellant charge required (which here would be available, it's a high priority project), from using a subcalibre projectile in a discarding sabot. This is a nice way to sidestep all the elegant but almost unproduceable taper-bore stuff from Gerlich.
In practice, getting the sabot to separate reliably without affecting projectile accuracy was a serious problem that IRL took most of a decade to solve (not really fixed until the 20pdr AT in UK service) and that was with the benefit of projectile spin to assist separation. Acceptable for a shotgun, but not for hitting ships at seven miles.
For practical purposes, I can see the sabot principle coming in, giving a 25% boost to muzzle velocity for a subcalibre projectile and rising to 33%ish as experience is gained (so, 1,200 metres per second of MV with a saboted round from an 11" gun - in line with what was being achieved in the 1940s with sabots). It's still from a rifled gun: the energy lost in spin is trivial, the spun round is much easier to design a cleanly-seperating sabot for, and the ability to fire full-bore HE remains important. Also, we've not got into the hydrodynamic regime where long-rods start to show advantage, instead remaining limited by projectile shatter.
Now the question is, what to do with this? It's not hugely effective firing steel AP rounds, for all the reasons well known and understood that drove AT gun designers towards tungsten (as cores, then as penetrators). The great conceptual leap towards unspun long-rod projectiles came after exploring tungsten APDS rounds of increasing L/D and velocity, but here there's a local ceiling where most experiments just result in failure: finding the combination of velocity and geometry that allows what performance a steel long-rod penetrator possesses to be demonstrated, is unlikely to be found by accident.
The higher velocity gives longer theoretical range, but fire control and visibility still limit that for practical purposes, and the smaller projectile - as APCBC - has less penetration and behind-armour effect when it does hit than a full-bore shell, so it's not very attractive.
Tungsten is likely to be noticed as a possibility, but at this point I'll say it's ignored on cost grounds (it'll take a lot per penetrator, after all).
However, there are several ways to skin cats: I'll offer you a contrary suggestion that since 1905 brings us the Battle of Tsushima, where Russian ships were devastated and left unfightable by Japanese HE shell. Rather than struggle with making steel shot penetrate face-hardened armour by increased velocity alone, I can see the dastardly Germans instead using these sabots to fire subcalibre HE shell, which takes us nicely back to Brandt's 1940 concept.
The higher velocity and flatter trajectory get them significantly more hits, and scoring those hits on the superstructure and above the armour belt where HE shell would be more telling. Basically, a continuation of the predreadnought "hail of fire" concept: the German ships intend to open the fight by hitting first and more often with subcalibre (but still dangerous) HE shell at ranges where the enemy is struggling to hit at all, switching to full-bore AP rounds as the range closes on their damaged opponents.
Effective? With hindsight based on experience, not as much as hoped (Jutland led the RN to follow the USN down the all-or-nothing armour route instead of armouring to keep out HE shell from large areas) but it's in line with the doctrine and the limited combat experience (Spanish-American and Russo-Japanese wars) of the period.

Post by Alfred Montestruc
No Saboted projectiles date from the 18th century or before, I have
already posted references to that on this thread. Sabot rods date from
WII, I think but were predicated on the APCR rounds with a center
tungsten rod.

The first recognisable saboted rounds from breech-loading guns were fielded by France in 1940 as a means to extend the range of their 75mm field gun; Brandt fled to the UK where he worked on the 6pdr APDS round, which very successfully replaced the APCR and APCRNR previously in use.
The US began work on long-rod penetrators in 1951, probably before the Soviets did (I'm not sure when the Soviets went to APDS - they were sticking with APCR a lot longer than we were)

Post by Alfred Montestruc
The APFSDS concept with a long rod was worked out by some engineer in the
USSR in the 1950s, their is no reason on earth why someone at any time
after the invention of tube guns could not have thought of and implemented
this.

The concept is fine, the problem comes with the experimentation and design.
Firstly, until you've moved away from steel shot, all more impact velocity gets you between ~800 metres/sec (the shatter limit for capped steel shot) and the hydrodynamic regime (which for steel, is getting towards twice that) is broken projectiles and relatively unimpressive damage to the target. Hence, part of why in the real world muzzle velocities settled where they did. (Brandt's work on sabots was originally intended to extend range with subcalibre HE shell, not to pierce armour).
Secondly, getting the sabot off the penetrator proved to be harder in practice than in reality: even spun APDS, with a finless penetrator and centrifugal force to help throw the pieces away, suffered serious early problems with interference from the sabot disrupting projectile accuracy.
Once those had been solved by the late 1940s, it became apparent that penetration by tungsten projectiles at ~1200m/s was no longer proceeding according to plastic deformation, and that in fact hydrodynamic penetration was occurring (in other words, L/D was the driving parameter) which led to a steady extension of penetrator length towards the limit possible with spin-stabilised projectiles. This intermediate stage (spun APDS) is the precursor of APFSDS.
In the UK, US and Germany, while work on unspun, finned penetrators was done, it was found more effective to concentrate on improving the (very effective) APDS and retain spin stabilisation until the 1970s, when the advent of composite armours drove the move to unspun long-rods, first in tungsten and then in depleted uranium.
There are a number of steps required to get to APFSDS projectiles from full-bore APC, and simply saying "what happens if I fire a long thin steel dart in a sabot out of an 11" gun?" will generally end in disappointment until the supporting work is available - by which point the sensible answer is "why on earth are you still using steel?"
To stick with the aviation analogy, supersonic projectiles, internal combustion engines, aluminium alloys and rocket motors all existed in 1903, so why did Orville and Wilbur merely build the Wright Flyer when there's no reason on earth they couldn't have jumped directly Glamorous Glennis and the B-29 to drop her from? Idiots, obviously, no imagination.
--
Paul J. Adam
He thinks too much, such men are dangerous.

[Alfred Montestruc]

------------------------------------snip

Post by Paul.J.Adam
Really, Al? Who's fielding a steel long-rod penetrator of L/D 26?
You could, after much development work, get there with tungsten and DU, but with steel it's a lab curiosity for testing at normal impact: steel rods are too prone to yaw, breakup and shatter.

Nope, APDFSDS rounds with tungsten or Uranium, are far from pure Tungsten or Uranium. Most of them use steel jackets for long time after they started using tungsten or uranium. Later still tough tungsten and uranium alloys were developed.

http://www.vti.mod.gov.rs/ntp/rad2010/2-10/9/09.pdf

-------------quote----------
The first APFSDS penetrators were made of steel, but at a later stage, more efficient tungsten-carbide was introduced. As this material was relatively brittle, it was placed in a steel sleeve, or jacket. Furthermore, by the development of tungsten-nickel-iron-cobalt, as well as depleted uranium-titanium alloys with higher ductility, the steel sleeve was dropped as unnecessary, leading to monoblock APFSDS projectiles.
--------------end quote----------

Good alloys of steel are good enough to do the job at small and medium scale but for one issue -- density. That is the only issue that makes Tungsten more attractive, Uranium is also flammable. The metallurgic properties are otherwise mostly in steel's favor.

Post by Paul.J.Adam
The one fielded steel APFSDS had a 400mm long penetrator, body diameter 40mm, and even at L/D 10 it was a practical failure. Nearly tripling its length will only cause it to fail even harder.

http://www.vti.mod.gov.rs/ntp/rad2010/2-10/9/09.pdf

Look at page 1. L/D 30

Post by Paul.J.Adam
(Lanz, Odermatt and Weihrauch, "Kinetic Energy Projectiles: Development History, State Of The Art, Trends", 2001)

Post by Alfred Montestruc

Post by Paul.J.Adam
Armour will be face-hardened,

Nope, not on a warship of that era.

Al, we were using face-hardened armour for two decades by 1916, first using the Harvey process and then Krupp, with cemented Krupp being the state of the art by WW1.
I'm giving a lecture on the subject of armour and projectile interaction in this period to the Wessex Region of the Institute of Mechanical Engineers later this year - would you like to come along? Probably be April or May, down at the University of Portsmouth.

So I presume you have heard of case crushing and the fact that a case is not going to be very thick. That case thickness of 1/8" thickness are considered very thick?

That the armor link you were good enough to post shows through hardness of the vast majority of the thickness of steel of less than 250 HBN (220 HBN IIRC), that for any AP round that can punch through several hundred mm of 250 HBN steel plate, a 1/8" case has about the famous tissue paper dog's chance of catching the asbestos cat in hell of having a meaningful effect on penetration.

Going to 350 HBN through hardened steel is cheating when your own site shows the through hardness are well under 250. If you know half what you claim to you know that.

Post by Paul.J.Adam

Post by Alfred Montestruc
Welding face hardened plates together is basically impossible.

Which is true, which is why armour plate was bolted to supporting frames rather than being welded. It was an expensive production process and highly customised: plates were made up, drilled and tapped for their attachment bolts, and then subjected to their final cementing. Once complete, the only changes to the hardened face possible were by grinding, the face was too hard to be machined otherwise.

How very heavy, and all that steel wasted that could have been dual function as structure.

Post by Paul.J.Adam

Post by Alfred Montestruc

Post by Paul.J.Adam
Allow for the armour's hardness of, say, BHN350, and the penetration
depth immediately drops to 475mm before we ask any other questions.
Of course, you hit the problem (not covered by this equation) that at
even small obliquities the steel long-rod will be much more prone to
yawing, breakup and trenching rather than penetration, as pointed out by
a number of researchers over the years, but that's the sort of real-
world trivia that never happens in a sea fight when we can be sure that
every projectile will strike at perfect right angles to the target plate
every time... can't we?

But you ignore as usual the issue of scale.

Then find a reputable source for the performance of a steel long-rod penetrator at the dimensions you're citing.
Or, give some detailed evidence as to why effects that cripple the performance of steel long-rod penetrators at small and medium scale disappear at larger dimensions, as if by magic.

Not magic, cube square law.

Force of drag=force of inertia of deceleration

Force of Drag=Cd*A*(V^2)/2

Inertial force = Ma, where a is the deceleration. so a=Cd*A*(V^2)/(2M)

M is proportional to L*D*D*rho=(L/D)*D*D*D*rho, A is (in high Mach #s) proportional to D^2.

a will be smaller for a more massive projectile, so they will shoot further.

rho only makes a small one time difference, and in reality the rods are not pure tungsten or uranium. Older designs used steel jackets, newer ones have alloying elements and are not pure uranium or tungsten.

In any case the mass will be proportional to (26/10)*(7850/19600)*(76/38)^3=8.33

The drag will be proportional to (76/38)^2=4

So the inertia term of a 76mm diamx 1920 mm long steel rod is 8.33 times that of a tungsten 38mm x 380 mm rod. The drag term is only 4 times that of the tungsten rod. The loss of velocity per unit time will be half that of the tungsten rod.

The cube square law is powerful.

Post by Paul.J.Adam
Why does a steel penetrator of L/D 10 fail at even ten or fifteen degrees off normal at subcalibre and tank-calibre testing, yet tripling its dimensions suddenly cause it to succeed? Is there any experimental evidence?

Your posted site claimed their was.

This:

http://www.vti.mod.gov.rs/ntp/rad2010/2-10/9/09.pdf

claims their is

--------quote

Today, the L/D ratio reached around 30. Beyond this value, with
present materials, a number of failures may occur, in an
interior ballistic, flight ballistic and terminal ballistic phase.
------------------------end quote---------------

Post by Paul.J.Adam
Why have none of the researchers in the field ever found this useful tipping point?

You own citations claim it is 30.

Post by Paul.J.Adam

Post by Alfred Montestruc

Post by Paul.J.Adam
Or you could just follow the curve at http://www.longrods.ch/optv.php and scale from that.
If you're getting 644mm at 1280m/s, you'll see 365mm at 1000m/s.

Post by Alfred Montestruc
Now you claimed it impractical to shoot projectiles from naval guns at the
speeds we are discussing. That is simply not true, it has been done.
http://en.wikipedia.org/wiki/Project_HARP

In the 1960s, Al, using the improvements in interior ballistics

Nope, using a standard garden variety US Navy 16" gun.

They began with a standard 16"/50 gun,

Exactly and got as much as 6000 ft/sec (1828 m/s) using that. I posted the reference already.



---------------------------snip

Post by Paul.J.Adam
If you go for a slow burn with a high-velocity projectile, you've thrown it out of the muzzle before you get to all-burned. Your lower peak pressure, and the high acceleration of the round, further slows the combustion rate of stick propellant (which is what you're working with in 1916) so your charge is even less efficient.
You need multitube propellant

Smaller propellent rods will do the job thanks.

Post by Paul.J.Adam

Post by Alfred Montestruc

Post by Paul.J.Adam
So easy, everyone did it.

Everyone with a naval gun and willing to reduce the mass of the projectile could have.

So say you, yet plenty of people were experimenting with subcalibre projectiles (whether necking down large cases, using non-rigid projectiles from tapered bores, or discarding sabots) and low-mass projectiles (arrowhead shot, APCR) and discovering all manner of problems and difficulties.
Oh, if only those morons, fools and idiots back then had been gifted with Al's wisdom and insight!

Or that of the unknown by me Engineer in the USSR who thoughts of it in the 1950s.

FYI I hold 4 US patents.

Post by Paul.J.Adam

Post by Alfred Montestruc

Post by Paul.J.Adam
In practice, a high-velocity gun (the UK's 17pdr, for instance, fielded
in 1942 and one of the best of breed) firing full-bore APCBC shot at
~900 m/s, could generate about 1,200m/s firing saboted rounds.

Spin stabilized short l/d sabot right?

Post by Paul.J.Adam
A 25%

Post by Alfred Montestruc

Post by Paul.J.Adam
increase in muzzle velocity is extremely handy to have, but it wasn't
possible to simply leap to 1,800 metres a second.

Claims Paul, with no proof.

The proof is up the hill from me, at the Royal Armouries' Museum of Artillery: there's a 17pdr gun there among the exhibits, citing those numbers for its performance. Some of the staff are pretty knowledgeable and will happily talk your ears off if you let them.
Or you could read "Fire and Movement", a historical work by the Royal Armoured Corps, published in 1975 which went into some detail on the performance of tank and anti-tank guns of the period, with the 17pdr held up as an excellent example (as indeed it was).
Or, indeed, you could try pointing out where those figures are wrong (hint - they aren't).
Perhaps this is another conspiracy and I've enlisted everyone who ever worked on the 17pdr gun project, ever, to produce false results so I can deceive you today? Shall we go with that claim again?

17 pounder, is ~ 5" right? Factor of ~ 39 less mass of shot than an 11" right. Factor of more than 10 smaller in shot mass? Right?

If I am not allowed to point out how the cube square law makes the effective range of bigger guns longer, why do you think posting results of a gun that is by objective standards an order of magnitude smaller is meaningful?

I have no problem with scaling results, if you do it honestly, but you are not, and you keep evading the facts.




----------------------------------------------------snip

Post by Paul.J.Adam

Post by Alfred Montestruc

Post by Paul.J.Adam
The point you've overlooked, Al, is that you're accelerating the
projectile *and the charge* down the barrel: the propellant gas has to
follow the projectile and consumes some of the kinetic energy. The US
Army ballistics manual suggest using one-third of muzzle velocity
squared, to represent the energy taken by the propellant gases.

NO!!

Why not? You proceed to prove me right.

Post by Alfred Montestruc
So you agree that getting to the range where a steel sabot round could be
effective is possible? Yes?

At the muzzle, yes; a 25% improvement in muzzle velocity is typical for going to a saboted round. 1420m/s is optimistic, but let's roll with it for the sake of argument.

Post by Alfred Montestruc

Post by Paul.J.Adam
Even by the rather optimistic assumption that we only correct for gas velocity, starting at 1420ms means you're out of the effective zone for penetration at useful battle ranges... which is back to my point.

Nope, you are BSing about the armor hardness, you are getting a give away at 250 HBN, and I am not conceding a single HBN point higher.

Would this be on those welded battleships using homogenous steel armour that you tell us were so widespread in 1916?
How about looking at *actual* armour from the period?
http://www.combinedfleet.com/metalprp.htm
Krupp non-cemented gives you 220BHN, USN Class B came in at 240 around that point - but Harvey plate had a face hardness of 680BHN and typical British face-hardened armour of WW1 had a face hardness of 650BHN.

with a case depth of maybe 1/8", , , so what?? Tissue paper dog, asbestos cat, hell, who wins?

The thickness of the case is maybe 1/8" and the bulk of the steel is at 225 HBN with the tensile at maybe 92 ksi. 250 HBN is a better representation than 350 through hardened

http://www.longrods.ch/optv.php

This also lists L/D=30

Post by Paul.J.Adam

Post by Alfred Montestruc
Then I can get fancy and drill out the dart from the fin side to within
say 100 mm of the tip, with a bore of say 2/3 the max diameter, and fill
the void with lead. Call them brass knuckle darts.

So you're taking a projectile that'll yaw, break up and shatter because of buckling loads at impact, and simultaneously weakening it while adding more buckling loads at impact.

ROTFLOL!

Buckling strength of a rod is proportional to D^4 as in moment of inertia. If I hollow out .66 of the diameter on the center I have 100*(1-.66^4)/1=81% of the buckling strength of the original rod. Try again!


-------------------snip--------------

Post by Paul.J.Adam

Post by Alfred Montestruc

Post by Paul.J.Adam
I pointed out some of the serious difficulties in achieving this goal in 1916.

Well since I said 1890's that is another kettle of fish. The idea is that
the basic idea of a smooth-bore gun firing a dart at high velocity occurs
to someone in Germany circa 1890 to 1895. He, files for a German patent >
and gets Krupp interested as he has a shotgun and demonstrates the idea
with hand-loaded darts in shotgun shells. While this is in the German
patent office and the inventor has not discussed it with anyone but Krupp > and the German military, it is declared secret and the man is paid off and
given a job as research scientist with the project. By 1905 they have
done a whole lot of experiments and have some idea of what they are doing.
The 11" gun is selected for some of the experiments in the late 1890s. By
1905 they go into serious production and have a well developed design
that can punch through 12" armor at 10 to 11 km range, and the design is
still secret, with a bodyguard of lies protecting it.

This is sensible, with some limitations and issues.

I said that maybe 10 posts ago? You really are hard of listening aren't you.

Post by Paul.J.Adam
The weak spot is the leap to finned, long-rod penetrators, which in reality was a lengthy, evolutionary transition requiring a number of developments and advancements. However, let's give this a fair hearing from a sceptical but not hostile viewpoint.
Hand-loaded darts in shotgun shells: skip over the "why?", perhaps we've got a frustrated wannabee hunter trying to produce an improved load for tiger or elephant, and who discovers that he's blowing holes in the backstop (as well as exploding his first few shotguns) during trial firings.

Intellectual curiosity. Had read about Amazonian blow-gun hunters, thought it was an interesting idea, sees that this is a way a smooth bore gun can shoot a straighter shot.

Post by Paul.J.Adam
This gets us the sabot principle fifty years early

Amazonian Indians thought of shooting a dart with fetching out of a (blow) gun with a smooth bore a long, long time before that, they were introduced to Europeans (the hard way) some time in the 16th century I think.

Post by Paul.J.Adam
(the first examples I know of were fielded by Brandt for French field guns in 1940,

You never heard of Amazonian Indians with blow guns???? really? You live a sheltered life,

Post by Paul.J.Adam
he brought his work to the UK where he helped produce the 6pdr APDS).

Spin stabilized from a rifled gun, right. This has an intrinsic limit l/d as long rods are more stable turning end over end than around the center-line. That is probably where you get the l/d of 10 from.

Post by Paul.J.Adam
However, we're not doing long rods with hydrodynamic penetration, we're getting a high-velocity, finned, subcalibre dart with usable accuracy out of what's otherwise a heavy-barrelled shotgun - for, again, hunting really big game where neither shot nor full-bore slug would achieve the penetration desired (maybe our inventor's brother was eaten by an angry hippopotamus and he wanted vengeance).

You will get a lot more velocity with a lighter projectile that will carry the velocity further. Reasons explained above and we are talking more than Mach 1, skin drag is not important in that regime

Post by Paul.J.Adam
This highlights the possibilities of getting a significant jump in muzzle velocity, albeit with some screwing around with the propellant charge required (which here would be available, it's a high priority project), from using a subcalibre projectile in a discarding sabot. This is a nice way to sidestep all the elegant but almost unproduceable taper-bore stuff from Gerlich.
In practice, getting the sabot to separate reliably without affecting projectile accuracy was a serious problem that IRL took most of a decade to solve (not really fixed until the 20pdr AT in UK service) and that was with the benefit of projectile spin to assist separation. Acceptable for a shotgun, but not for hitting ships at seven miles.

If the sabot is in three pieces held together on the rod by the bore, and has a cup shape in front that will catch the fluid it moves it, it will come loose.

Post by Paul.J.Adam
For practical purposes, I can see the sabot principle coming in, giving a 25% boost to muzzle velocity for a subcalibre projectile and rising to 33%ish as experience is gained (so, 1,200 metres per second of MV with a saboted round from an 11" gun - in line with what was being achieved in the 1940s with sabots). It's still from a rifled gun: the energy lost in spin is trivial,

The fin stabilization is not, and allows a much longer more effective rod.

Post by Paul.J.Adam
the spun round is much easier to design a cleanly-seperating sabot for, and the ability to fire full-bore HE remains important. Also, we've not got into the hydrodynamic regime where long-rods start to show advantage, instead remaining limited by projectile shatter.
Now the question is, what to do with this? It's not hugely effective firing steel AP rounds, for all the reasons well known and understood that drove AT gun designers towards tungsten (as cores, then as penetrators).

1 - you misrepresented the propellent mass it was 189.5 kg not 200 kg, small difference but that shows carelessness and bias on your part.

2- As I said, that was a first iteration, several more would be needed.

3- as I pointed out the density is the issue not the steel, and cube square law will be of aid here.

4- a 1/8" case depth of 600 HBN on top of 11 7/8" of 220 HBN steel, is a joke, if I were your naval advisory I would be happy to see you blow your budget on that.

5- Getting a real innovative engineering project to get results requires strength of will and a refusal to concede defeat. Rolling over and playing dead at the first difficulty will never get you anywhere, nor will listening too much to the can't be done crowd. You listen to them to understand how to get over the obstacles, not to take them at their word.

Post by Paul.J.Adam
The great conceptual leap towards unspun long-rod projectiles came after exploring

The AMAZON!!! By stone age people!! 14,000 years ago!!

Post by Paul.J.Adam
tungsten APDS rounds of increasing L/D and velocity, but here there's a local ceiling where most experiments just result in failure: finding the combination of velocity and geometry that allows what performance a steel long-rod penetrator possesses to be demonstrated, is unlikely to be found by accident.
The higher velocity gives longer theoretical range, but fire control and visibility still limit that for practical purposes, and the smaller projectile - as APCBC - has less penetration and behind-armour effect when it does hit than a full-bore shell, so it's not very attractive.
Tungsten is likely to be noticed as a possibility, but at this point I'll say it's ignored on cost grounds (it'll take a lot per penetrator, after all).
However, there are several ways to skin cats: I'll offer you a contrary suggestion that since 1905 brings us the Battle of Tsushima, where Russian ships were devastated and left unfightable by Japanese HE shell. Rather than struggle with making steel shot penetrate face-hardened armour by increased velocity alone, I can see the dastardly Germans instead using these sabots to fire subcalibre HE shell, which takes us nicely back to Brandt's 1940 concept.
The higher velocity and flatter trajectory

Nope, not unless they had very long L/D, air drag is dependent on section area in the Mach 2.5 + regime. the projectiles slow very fast and drop in the water.

Drag= M*a where a is the deceleration of the projectile. a=Drag/M

if M is small or Drag is large, your speed goes away fast.

Post by Paul.J.Adam
get them significantly more hits, and scoring those hits on the superstructure and above the armour belt where HE shell would be more telling. Basically, a continuation of the predreadnought "hail of fire" concept: the German ships intend to open the fight by hitting first and more often with subcalibre (but still dangerous) HE shell at ranges where the enemy is struggling to hit at all, switching to full-bore AP rounds as the range closes on their damaged opponents.
Effective? With hindsight based on experience, not as much as hoped (Jutland led the RN to follow the USN down the all-or-nothing armour route instead of armouring to keep out HE shell from large areas) but it's in line with the doctrine and the limited combat experience (Spanish-American and Russo-Japanese wars) of the period.

Post by Alfred Montestruc
No Saboted projectiles date from the 18th century or before, I have
already posted references to that on this thread. Sabot rods date from
WII, I think but were predicated on the APCR rounds with a center
tungsten rod.

The first recognisable saboted rounds from breech-loading guns were fielded by France in 1940 as a means to extend the range of their 75mm field gun; Brandt fled to the UK where he worked on the 6pdr APDS round, which very successfully replaced the APCR and APCRNR previously in use.

Sabots were used in muzzle loaders hundreds of years ago, and through the 19th century on muzzle loaders. This is well known.

Post by Paul.J.Adam
The US began work on long-rod penetrators in 1951, probably before the Soviets did (I'm not sure when the Soviets went to APDS - they were sticking with APCR a lot longer than we were)

The USSR made the first APFSDS shooting smooth bore anti-tank gun in 1955, a 100mm. That for that era was with a steel rod, could kill the heaviest western tanks in existence.


http://en.wikipedia.org/wiki/T-12_antitank_gun

http://en.wikipedia.org/wiki/Kinetic_energy_penetrator

" Germany developed modern sabots under the name "treibspiegel" ("thrust mirror") to give extra altitude to its anti-aircraft guns during the Second World War. Before this, primitive wooden sabots had been used for centuries in the form of a wooden plug attached to or breech loaded before cannonballs in the barrel, placed between the propellant charge and the projectile. The name "sabot" is the French word for clog (a wooden shoe traditionally worn in some European countries)."

Post by Paul.J.Adam

Post by Alfred Montestruc
The APFSDS concept with a long rod was worked out by some engineer in the
USSR in the 1950s, their is no reason on earth why someone at any time
after the invention of tube guns could not have thought of and implemented
this.

The concept is fine, the problem comes with the experimentation and design.
Firstly, until you've moved away from steel shot, all more impact velocity gets you between ~800 metres/sec (the shatter limit for capped steel shot) and the hydrodynamic regime (which for steel, is getting towards twice that) is broken projectiles and relatively unimpressive damage to the target. Hence, part of why in the real world muzzle velocities settled where they did. (Brandt's work on sabots was originally intended to extend range with subcalibre HE shell, not to pierce armour).

You already conceded I can get to over 1420 m/s out of an 11" gun, with that speed I do not drop below 1150 m/s till after I pass 7.15 km.

Using the same methods and lead fill of the middle 70% of the diameter to within 100 mm of the tip, a 64 mm diameter and 1920 mm length I am at 1192 m/s at 10 km with a muzzle velocity of 1509 m/s. The mean density of lead+ steel is 9475 km/m^3 The rod is 76% of the buckling strength of a solid rod, assuming the lead takes no stress at all. Armor 250 HBN at 45 degrees, penetrator hardness 600 HBN on tip. Fustum is 100 mm tip diameter 10 mm

http://www.longrods.ch/perfcalc.php

per the site penetration is 756 mm no weaseling that is at 10 km

Post by Paul.J.Adam
Secondly, getting the sabot off the penetrator proved to be harder in practice than in reality: even spun APDS, with a finless penetrator and centrifugal force to help throw the pieces away, suffered serious early problems with interference from the sabot disrupting projectile accuracy.

1895 till 1914 to fix it. If the Krigsmarine sees the potential and they throw money at it, it will get fixed in a year or two.

Post by Paul.J.Adam
Once those had been solved by the late 1940s, it became apparent that penetration by tungsten projectiles at ~1200m/s was no longer proceeding according to plastic deformation, and that in fact hydrodynamic penetration was occurring (in other words, L/D was the driving parameter) which led to a steady extension of penetrator length towards the limit possible with spin-stabilised projectiles. This intermediate stage (spun APDS) is the precursor of APFSDS.

And they figured out that long l/d spinning objects like to tumble to minimum entropy as in the spin around an axis with max moment of inertia, so fins work better for that purpose.

But Amazonian Indians figured that out a long time ago. Blow guns with curare darts, who owns the deep rainforest? The guys with the blow guns and curare darts.

Post by Paul.J.Adam
In the UK, US and Germany, while work on unspun, finned penetrators was done, it was found more effective to concentrate on improving the (very effective) APDS and retain spin stabilisation until the 1970s, when the advent of composite armours drove the move to unspun long-rods, first in tungsten and then in depleted uranium.

The Russians introduced this in the 1950s, and the Germans introduced sabot on breech-loader guns in WWII for anti-aircraft shot.

Post by Paul.J.Adam
There are a number of steps required to get to APFSDS projectiles from full-bore APC, and simply saying "what happens if I fire a long thin steel dart in a sabot out of an 11" gun?"

You are one of those guys with zero imagination humm? Amazonian Indians with blow-guns and curare have no good ideas on guns huh?

Post by Paul.J.Adam
will generally end in disappointment until the supporting work is available - by which point the sensible answer is "why on earth are you still using steel?"
To stick with the aviation analogy, supersonic projectiles, internal combustion engines, aluminium alloys and rocket motors all existed in 1903, so why did Orville and Wilbur merely build the Wright Flyer when there's no reason on earth they couldn't have jumped directly Glamorous Glennis and the B-29 to drop her from? Idiots, obviously, no imagination.

As I said, 1895 ish till ~ 1914, lots of scratch to pay for stuff, a government crazy to get a naval advantage over the UK. It could be done.

Give the Wright Brothers a specific achievable goal in aviation in 1905 with a huge monetary incentive and ~ 20 years to do it, I think it might get done.

[Paul.J.Adam]

Post by Alfred Montestruc

Post by Paul.J.Adam
Really, Al? Who's fielding a steel long-rod penetrator of L/D 26?

(The answer, after much evasion and confusion, remains “nobody, ever”)

Post by Alfred Montestruc

Post by Paul.J.Adam
You could, after much development work, get there with tungsten and
DU, but with steel it's a lab curiosity for testing at normal
impact: steel rods are too prone to yaw, breakup and shatter.

Nope, APDFSDS rounds with tungsten or Uranium, are far from pure
Tungsten or Uranium.

And who claimed they were, exactly? One reason we’ve got to a L/D of 30 is through extremely close control of the material used, both in composition and manufacture.

Post by Alfred Montestruc
Good alloys of steel are good enough to do the job at small and medium
scale

No, they aren’t. See Hohler and Stilp, "Penetration of steel and high density rods in steel and high density rods in semi-infinite steel targets", Proceedings of 3rd International Symposium on Ballistics, Karlsruhe 1977.

Post by Alfred Montestruc
but for one issue -- density. That is the only issue that makes
Tungsten more attractive, Uranium is also flammable. The metallurgic
properties are otherwise mostly in steel's favor.

So, who uses steel APFSDS?

Nobody.

Perhaps your understanding remains deficient.

Post by Alfred Montestruc

Post by Paul.J.Adam
The one fielded steel APFSDS had a 400mm long penetrator, body
diameter 40mm, and even at L/D 10 it was a practical failure. Nearly
tripling its length will only cause it to fail even harder.

http://www.vti.mod.gov.rs/ntp/rad2010/2-10/9/09.pdf
Look at page 1. L/D 30

“Today, the L/D ratio reached around 30.” So, that’s achieved *after* sixty years of research, development and experience, and moving away from steel long ago.

We’ve reached a L/D ratio of around thirty, using either tungsten or DU alloys, after a *lot* of experimentation and analysis.

However, the only fielded steel APFSDS round had an L/D of 10 and even then it was a failure.

Post by Alfred Montestruc

Post by Paul.J.Adam
Al, we were using face-hardened armour for two decades by 1916,
first using the Harvey process and then Krupp, with cemented Krupp
being the state of the art by WW1.
I'm giving a lecture on the subject of armour and projectile
interaction in this period to the Wessex Region of the Institute of
Mechanical Engineers later this year - would you like to come along?
Probably be April or May, down at the University of Portsmouth.

So I presume you have heard of case crushing and the fact that a case
is not going to be very thick. That case thickness of 1/8" thickness
are considered very thick?

+++++
At about the same time Krupp developed a process of deepening the hardening on one side of a cemented steel plate. To do this, the plate was imbedded in clay or loam, with the cemented side exposed, and then the exposed face was subjected to a very hot and quick heat. As the heat penetrated gradually, the exposed face became much hotter than the back, thus permitting “decremental hardening” by water spraying...

...the plane of critical temperature was only allowed to sink between 30 per cent and 40 per cent of the thickness, and when that position was reached, the plate was hurriedly withdrawn from the furnace, put in a spraying pit and subjected to a powerful spray of water, at first on the superheated side and a moment later on both sides, the double spraying being done to prevent, as much as possible, the warping which a spray on but one side would produce.

This process, called decremental face hardening, produces a very hard face, between 30 per cent to 40 per cent of the plate’s thickness, and at the same time leaves the other 60 per cent to 70 per cent of the thickness in its original tough condition. It should be specifically noted that this method of hardening depends on the decremental heating and does not necessarily involve any variations in carbon content. In other words, in this type of face hardening, the front portion of the plate is super-hardened because of its higher temperature, the depth of the hardening being subject to regulation, and greater than the depth of cementation, if desired.
+++++
http://www.eugeneleeslover.com/ARMOR-CHAPTER-XII-A.html

Post by Alfred Montestruc
That the armor link you were good enough to post shows through
hardness of the vast majority of the thickness of steel of less than
250 HBN (220 HBN IIRC), that for any AP round that can punch through
several hundred mm of 250 HBN steel plate, a 1/8" case has about the
famous tissue paper dog's chance of catching the asbestos cat in hell
of having a meaningful effect on penetration.’

Armour is another of those subjects you don’t know much about, isn’t it, Al?

Krupp armour wasn’t simply case-hardened to a fraction of an inch; about a third of the plate’s thickness was at the high hardness level required to reject AP shot.

The RN’s Gunnery Manual of 1915 documented the results of firing trials: twelve inches of rolled steel armour were considered equivalent in protection to 7.5 inches of Harvey face-hardened armour, or 5.5 inches of the further improved Krupp armour.

Post by Alfred Montestruc

Post by Paul.J.Adam
Then find a reputable source for the performance of a steel long-rod
penetrator at the dimensions you're citing.
Or, give some detailed evidence as to why effects that cripple the
performance of steel long-rod penetrators at small and medium scale
disappear at larger dimensions, as if by magic.

Not magic, cube square law.

Which even by your own numbers, doesn’t give you the retained velocity you need for hydrodynamic penetration using a steel penetrator at fifteen thousand yards.

Post by Alfred Montestruc

Post by Paul.J.Adam
Why does a steel penetrator of L/D 10 fail at even ten or fifteen
degrees off normal at subcalibre and tank-calibre testing, yet
tripling its dimensions suddenly cause it to succeed? Is there any
experimental evidence?

Your posted site claimed their was.

No, I’m afraid that’s your incomprehension and fantasy at work.

Post by Alfred Montestruc
http://www.vti.mod.gov.rs/ntp/rad2010/2-10/9/09.pdf
claims their is
--------quote
Today, the L/D ratio reached around 30. Beyond this value, with
present materials, a number of failures may occur, in an
interior ballistic, flight ballistic and terminal ballistic phase.
------------------------end quote---------------

Al, we know – because we’re doing it, firing it, using it – that tungsten APFSDS has successfully reached a L/D ratio of about thirty, because that’s the current limit. Baloš, Nikačević, Ristić and Šiđanin at no point or place describe using steel APFSDS, and highlight the dangers of taking lab results against vertical RHA as the only figure of merit.

+++++
Although the penetration against simple, vertical, rolled homogenous armour (RHA steel) may be expected to improve, an even more slender projectile compared to monoblock projectiles with L/D>30, may have a different effectiveness against sloped and/or spaced armour types. Furthermore, spaced and sloped targets proved to be the most difficult targets made of ductile materials for slender long-rods, which may cause significant efficiency drop for jacketed projectiles as well.
+++++

We also know – because it’s been exhaustively trialled, investigated, briefly fielded and quickly discarded – that steel is a very poor material for APFSDS and that even at a L/D of ten it failed badly at anything except normal impact.

Your repeating the data that proves my point… only serves to prove my point.

Post by Alfred Montestruc

Post by Paul.J.Adam
Why have none of the researchers in the field ever found this useful tipping point?

You own citations claim it is 30.

For tungsten and DU, yes. Did you not read the material you’re citing, or did you not understand it?

Post by Alfred Montestruc

Post by Paul.J.Adam
So say you, yet plenty of people were experimenting with subcalibre
projectiles (whether necking down large cases, using non-rigid
projectiles from tapered bores, or discarding sabots) and low-mass
projectiles (arrowhead shot, APCR) and discovering all manner of
problems and difficulties.
Oh, if only those morons, fools and idiots back then had been gifted
with Al's wisdom and insight!

Or that of the unknown by me Engineer in the USSR who thoughts of it in the 1950s.

It predated him, and both the UK and US did significant work on fin-stabilised projectiles.

+++++
Much has been claimed for smooth bore (SB) gun systems, especially as regards superior penetration. The fact is that if a projectile is fully spun only a quite insignificant proportion of the total energy goes into achieving that spin (a fraction of 1% in fact) and results in a muzzle velocity difference of a few metres/sec. If fin stabilised ammo is used from a rifled gun then there is no difference at all in energy wasted, since both systems need a similar small amount of spin to correct inaccuracies in flight; how the projectile achieves that spin is immaterial since in both systems it is at the expense, however, small of the ultimate striking velocity. In fact the rifled system has no disadvantage at all, and many advantages, since any type of ammunition can be fired, whilst the SB system is restricted to very few types or to very inefficient designs.

RARDE carried out experiments with sabot ammunition of both APDS and FS types, in both rifled and smooth bore guns, as long ago as the
mid-1950s. Both types of gun successfully launched their respective projectiles, but for the reasons given above it was decided that SB gun
systems represent a retrograde step, and so further work on them was abandoned.

In the late 1960s it began to be obvious that existing types of KE ammunition were nearing the maximum performance that they could achieve with existing materials. Pending the development of new alloys, it was decided to resurrect FS designs which had been developed in the
1950s.

Certain parameters for FS KE projectiles had long been established in UK but only now were suitable materials available, having been developed for APDS shot. Other new parameters were also established. The full list included: -
a. very high 1/d ratios
b. tough but malleable alloys for penetrators
c. monobloc projectiles
d. central drive for sub projectile (as distinct from push or pull);
e. tuning the projectile/gun/mounting system for complete compatibility.
+++++
“UK Kinetic Energy Ammunition - An Historical Note” by S M James

Post by Alfred Montestruc

Post by Paul.J.Adam
Or, indeed, you could try pointing out where those figures are wrong
(hint - they aren't).

17 pounder, is ~ 5" right?

Wrong.

Al, the muzzle velocity of the 17pdr with APCBC was about 900m/s, with APDS about 1215m/s.

You claimed I was lying and the numbers were... something else. Very well: what are the actual numbers?

Post by Alfred Montestruc

Post by Paul.J.Adam
Would this be on those welded battleships using homogenous steel armour that you tell us were so widespread in 1916?
How about looking at *actual* armour from the period?
http://www.combinedfleet.com/metalprp.htm
Krupp non-cemented gives you 220BHN, USN Class B came in at 240
around that point - but Harvey plate had a face hardness of 680BHN
and typical British face-hardened armour of WW1 had a face hardness
of 650BHN.

with a case depth of maybe 1/8", , , so what??

With a hardness depth of a third of the plate thickness (this isn’t mere case hardening)

Post by Alfred Montestruc

Post by Paul.J.Adam
So you're taking a projectile that'll yaw, break up and shatter
because of buckling loads at impact, and simultaneously weakening it
while adding more buckling loads at impact.

ROTFLOL!

I know, when you actually analyse it it’s absolutely ludicrous.

Post by Alfred Montestruc
Buckling strength of a rod is proportional to D^4 as in moment of
inertia. If I hollow out .66 of the diameter on the center I have
100*(1-.66^4)/1=81% of the buckling strength of the original rod.
Try again!

Al, perhaps engineers in the US use different mathematics to the rest of the world, but over here 81% is less than 100%.

If your projectile has inadequate buckling strength and experimental results show it prone to failure on impact, reducing it by a further 19% is not *exactly* a step forwards.

Post by Alfred Montestruc

Post by Paul.J.Adam
This gets us the sabot principle fifty years early

Amazonian Indians thought of shooting a dart with fetching out of a
(blow) gun with a smooth bore a long, long time before that, they
were introduced to Europeans (the hard way) some time in the 16th
century I think.

Firing finned projectiles from smoothbore guns is documented five hundred years before that. Take a look at the picture of “De Nobilitatibus Sapientii Et Prudentiis Regum", by Walter de Milemete, dating to 1326 or so.

Post by Alfred Montestruc

Post by Paul.J.Adam
he brought his work to the UK where he helped produce the 6pdr APDS).

Spin stabilized from a rifled gun, right. This has an intrinsic limit
l/d as long rods are more stable turning end over end than around the
center-line. That is probably where you get the l/d of 10 from.

No, L/D 10 comes from the Soviet 115mm AFPSDS steel round.

Post by Alfred Montestruc

Post by Paul.J.Adam
In practice, getting the sabot to separate reliably without
affecting projectile accuracy was a serious problem that IRL took
most of a decade to solve (not really fixed until the 20pdr AT in UK
service) and that was with the benefit of projectile spin to assist
separation. Acceptable for a shotgun, but not for hitting ships at
seven miles.

If the sabot is in three pieces held together on the rod by the bore,
and has a cup shape in front that will catch the fluid it moves it, it
will come loose.

Yep, that’s the two fundamental principles of sabot design right there.

Now, make them work reliably and efficiently without disturbing the projectile’s flight or damaging it – that turned out to take a lot of hard work and experimentation even for spun rounds, and proved to be even more challenging for unspun projectiles. It took a decade to get it reliably right for spin-stabilised guns and another decade before smoothbores firing APFSDS were reliably getting the sabots clear.

Post by Alfred Montestruc

Post by Paul.J.Adam
The great conceptual leap towards unspun long-rod projectiles came after exploring

The AMAZON!!! By stone age people!! 14,000 years ago!!

What thickness of steel armour were the Amazonians defeating? Oh, right, this is another of Al’s confusions.

Presumably the High Seas Fleet have forsaken the goal of defeating the Royal Navy; and instead intend to steam up the Amazon delta, hunting exotic small game for the Kaiser’s dinner table?

Post by Alfred Montestruc

Post by Paul.J.Adam
The first recognisable saboted rounds from breech-loading guns were > > fielded by France in 1940 as a means to extend the range of their
75mm field gun; Brandt fled to the UK where he worked on the 6pdr
APDS round, which very successfully replaced the APCR and APCRNR
previously in use.

Sabots were used in muzzle loaders hundreds of years ago, and through
the 19th century on muzzle loaders. This is well known.

Yes, Al, which is why I specifically referred to “the first recognisable saboted rounds from breech-loading guns”. The first known depiction of a cannon in European art shows it firing a finned projectile, and I’d be *amazed* if that gun had been rifled.

The concept is not new, it’s leaping the uncanny valley where firing steel projectiles faster and faster at face-hardened plate just makes them break up even louder that’s the problem.

Post by Alfred Montestruc

Post by Paul.J.Adam
The US began work on long-rod penetrators in 1951, probably before
the Soviets did (I'm not sure when the Soviets went to APDS – they
were sticking with APCR a lot longer than we were)

The USSR made the first APFSDS shooting smooth bore anti-tank gun in
1955, a 100mm.

Entered service 1961 (Jane’s Artillery and Air Defence)

Post by Alfred Montestruc
That for that era was with a steel rod, could kill
the heaviest western tanks in existence.

“The penetrator rod is steel with a tungsten core, and the general configuration of the projectile assembly and the penetrator rod follows the same lines as the larger-calibre equivalents... its armour-penetration performance potential is considered to be well below those of its Western counterparts.” (Jane's Ammunition Handbook)

“The 100 mm 3-BM-20 APFSDS-T projectile assembly is reported to have a muzzle velocity of 1,430 m/s, although some references mention 1,575 m/s. Armour penetrations of 225 mm have been reported, but at what ranges is not recorded.” (ibid.)

Steel-jacketed tungsten, limited performance: this is achieving the same sort of penetration in 1961 that we were getting in 1944 with our 17pdr. Amazing!

Curiously, the BM-2 penetrator shown for the T-12 gun is also *tungsten*, not steel, and has a 14:1 L/D ratio not the 30 you claim as standard.

Strange, that... every time you pull out a source, you end up agreeing with me.

Post by Alfred Montestruc

Post by Paul.J.Adam
Firstly, until you've moved away from steel shot, all more impact
velocity gets you between ~800 metres/sec (the shatter limit for
capped steel shot) and the hydrodynamic regime (which for steel, is
getting towards twice that) is broken projectiles and relatively
unimpressive damage to the target. Hence, part of why in the real
world muzzle velocities settled where they did. (Brandt's work on
sabots was originally intended to extend range with subcalibre HE
shell, not to pierce armour).

You already conceded I can get to over 1420 m/s out of an 11" gun,
with that speed I do not drop below 1150 m/s till after I pass 7.15
km.

So, nowhere near the fighting range you actually need.

Post by Alfred Montestruc
Using the same methods and lead fill of the middle 70% of the diameter
to within 100 mm of the tip, a 64 mm diameter and 1920 mm length I am
at 1192 m/s at 10 km with a muzzle velocity of 1509 m/s. The mean
density of lead+ steel is 9475 km/m^3 The rod is 76% of the buckling
strength of a solid rod, assuming the lead takes no stress at all.
Armor 250 HBN at 45 degrees, penetrator hardness 600 HBN on tip.
Fustum is 100 mm tip diameter 10 mm
http://www.longrods.ch/perfcalc.php
per the site penetration is 756 mm no weaseling that is at 10 km

Except your target is face-hardened armour at 650BHN, so your projectile shatters and the effective penetration is only 203mm at normal impact.



And at any sort of normal impact, your steel penetrator is just trenching anyway, as found by considerable experimental work. Permutter and Garratt summed up their exhaustive work with “Experience shows that this condition cannot be satisfied with an adequate margin, if the core is of steel, unless the steel core is made very long. Further, the core cannot be made very long, both because it would break up during angle attack and because it would tend to shatter."


Others explored firing steel long rods into angled targets and discovered that they yawed on impact and then broke up:-

+++++
For the steel projectile, it was found that above a certain critical angle 'trenching' occurs, and the rod appears to collapse and form a long shallow crater.
+++++
Bless, Barber, Bertke, Swift”: "Penetration Mechanics of Yawed Rods", International Journal of Engineering Science, no 16 (1978)

Further data was presented by Roecker and Grabarek in their paper "The Effects of Yaw and Pitch on Long Rod Penetration into Rolled Homogeneous Armour at Various Obliquities", which was presented at the 9th International Symposium on Ballistics, RMCS Shrivenham, May 1986 which confirmed the yaw, breakup and shatter of steel long-rod penetrators at any significant oblique impact.


Hence, why the only fielded attempt at a steel LRP limited itself to a 10:1 L/D ratio, and why it was not a success in service.

Post by Alfred Montestruc

Post by Paul.J.Adam
Secondly, getting the sabot off the penetrator proved to be harder
in practice than in reality: even spun APDS, with a finless
penetrator and centrifugal force to help throw the pieces away,
suffered serious early problems with interference from the sabot
disrupting projectile accuracy.

1895 till 1914 to fix it. If the Krigsmarine sees the potential and
they throw money at it, it will get fixed in a year or two.

It took ten years to get APDS sabot separation reliably right even during the Second World War with the urgent need to kill Panthers and Tigers, and then the nasty shock of seeing the next-generation Soviet tanks, leaving Western planners worrying “how the hell are we going to kill those?”, and another decade after that with the Cold War focussing everyone’s attention (and Soviet heavies like the T-10 appearing) before APFSDS began to be practical.

So, it’s a little unrealistic to expect the Germans to do significantly better in peacetime, fifty years earlier.

Handwaving miracles and ignoring reality is not a solution: as it is, even in real life with the priorities of wartime it proved to be bloody difficult.

+++++
Although this early work showed that a sabot scheme could be made to work, it was far from satisfactory. There were problems of gas leakage round the sabot, the centring of the shot was not always very good, the round was quite often unstable and the accuracy not very good. In the first report on the sabot projectile by Permutter and Coppock they conclude that although data is limited "there is sufficient evidence to show that the performance of this projectile as it stands is rather worse than that of the 6pr composite rigid in terms of velocity."
+++++
A Tate, "A Review of the Post World War II Military Approach to the Terminal Ballistics of KE Projectiles"

Run into those problems, coupled to the dismal penetration performance of steel in that unhappy valley between shatter velocity (around ~760 metres per second) and the beginning of hydrodynamic performance (~1600m/s for steel) and it’s clearly apparent why nobody leapt from full-bore AP to steel APFSDS in reality.

Post by Alfred Montestruc

Post by Paul.J.Adam
Once those had been solved by the late 1940s, it became apparent
that penetration by tungsten projectiles at ~1200m/s was no longer
proceeding according to plastic deformation, and that in fact
hydrodynamic penetration was occurring (in other words, L/D was the
driving parameter) which led to a steady extension of penetrator
length towards the limit possible with spin-stabilised projectiles.
This intermediate stage (spun APDS) is the precursor of APFSDS.

And they figured out that long l/d spinning objects like to tumble to
minimum entropy as in the spin around an axis with max moment of
inertia, so fins work better for that purpose.
But Amazonian Indians figured that out a long time ago.

As did cavemen throwing spears and then making bows. There’s no magical surprise about long, slender, aerodynamically-stabilised projectiles: ask any Agincourt veteran.

The problem remains that adding velocity was perfectly feasible; it wasn’t done, because throwing steel projectiles at face-hardened armour at higher velocities simply led to them shattering and failing. Hence, battleship guns grew in size rather than rising in velocity.

Post by Alfred Montestruc

Post by Paul.J.Adam
In the UK, US and Germany, while work on unspun, finned penetrators
was done, it was found more effective to concentrate on improving
the (very effective) APDS and retain spin stabilisation until the
1970s, when the advent of composite armours drove the move to unspun
long-rods, first in tungsten and then in depleted uranium.

The Russians introduced this in the 1950s, and the Germans introduced > sabot on breech-loader guns in WWII for anti-aircraft shot.

And we made considerable, and very effective, use of saboted penetrators for anti-tank fire. Are you confused again, Al?

Post by Alfred Montestruc

Post by Paul.J.Adam
There are a number of steps required to get to APFSDS projectiles
from full-bore APC, and simply saying "what happens if I fire a long
thin steel dart in a sabot out of an 11" gun?"

You are one of those guys with zero imagination humm?

Imagination isn’t the issue, understanding terminal ballistics matters rather more.

Post by Alfred Montestruc
Amazonian
Indians with blow-guns and curare have no good ideas on guns huh?

Not when it comes to defeating a foot of face-hardened plate, no: otherwise we’d have issued longbows instead of bazookas for anti-tank combat.

--
Paul

He thinks too much, such men are dangerous

[Paul J. Adam]

Post by Alfred Montestruc
---snip rubbish----------

Always a good start whge

Post by Alfred Montestruc

Post by Paul J. Adam
When they were used as a desperation measure by the Iraqis, they
failed to achieve a single penetration, breaking up on impact.

Which is neither here nor there,

They failed, because they shattered.

Post by Alfred Montestruc
nor have you proved they broke up on impact.

Very well, let us believe that steel APFSDS from 125mm Rapira-3 is
actually a capable and effective round.

How many tanks were destroyed by it? Even Kuwaiti Chieftains, the year
before, were immune to it, most withdrawing when their ammunition ran
low rather than being destroyed (one was abandoned after being
immobilised by a hit on the running gear). (Jane's International Defence
Review, November 1990)

Steel APFSDS was not effective when used in combat: do you have any
evidence to counter this?

Post by Alfred Montestruc
You said "If you fire a steel long-rod penetrator at useful
velocities, it'll simply shatter on impact" --that is not the same
as "fail to penetrate" the best tank armor in the world at this time
which was designed 20 + years after those specific weapons were in
the field.

Indeed, it'll penetrate *some* armour: just not much. Hence why the
115mm steel APFSDS could defeat about a foot of RHA on a proof range at
normal impact. However, even on the proof range, sloping the target
destroyed that performance.

Post by Alfred Montestruc
The point is you said "If you fire a steel long-rod penetrator at
useful velocities, it'll simply shatter on impact"
Which is stupid ridiculous and wrong.

From
http://akx.landforces.r.mil.uk/baebb/admin/Products/TISOO/Volume%204a%20links/Annex%2003A.pdf

+++++
An Early Purpose-Designed AP Round
An early purpose-designed AP round was the British '2 pounder'.

This retained the principle of a high chamber pressure to achieve high
muzzle velocity, a feature of all kinetic energy anti-armour ammunition.
In addition, careful attention was paid to the shape of the head of the
shot, to defer the onset of failure by shatter and to minimise any
tendency to ricochet. This shot had a muzzle velocity of the order of
760 ms^-1 which, for a straightforward steel shot, is about the maximum
that can be tolerated without shatter.
+++++

Post by Alfred Montestruc

Post by Paul J. Adam
Which I did, pointing to the description of how they provided a
25-50% improvement in effectiveness *from the very same reference*
you said proved they didn't exist and weren't effective.

No it does not say 25 to 50% it does not state any percentage and the
shattering has to do with poor material quality of effing CAST IRON
SHOT, made in the late 19th century more than 100 years ago, not
forged steel.

Al, please don't flaunt your ignorance *quite* so proudly. Capped AP
shot appeared during the Second World War.

Same source:-
+++++
"6 Pounder" APCBC Round.
Improvements in gun design allowed the development of a larger calibre
solid steel shot, the "6 Pounder".

With the higher muzzle velocity of some 850 ms^-1 available from this
gun, steps had to be taken to prevent failure of the shot due to
shatter. This was overcome by the addition of a penetrative (or
piercing) cap.
+++++


+++++
Chapter 3, "Attack of Armour"
Shatter.
Raising the hardness of a steel shot, whilst increasing its compressive
strength, makes the shot brittle. On impact severe tensile hoop stresses
are set up in the nose of the shot (small cross sectional area). At high
striking velocities, which raise the loading on the shot, the shot nose
can fail under these stresses and longitudinal cracks are formed along
the length of the shot. The shot is said to "break up", where effect is
more catastrophic and the shot disintegrates, this is known as "shatter".

To increase resistance to shatter, a penetrative cap is fitted to the
front end of the shot. This starts the penetrative process going. The
cap then shatters and allows the shot to pass through into the
indentation which the shattered cap has made. The nose of the shot is
now supported by the armour material itself, and the onset of shatter is
delayed to even higher striking velocities. However, if the shot impacts
the target at less than shatter velocity and the cap fails to shatter,
the cap can impede penetration.

The poor external ballistic properties of good penetrative shapes is
compensated for by fitting a light ballistic cap over the front of the
shot. The ballistic cap takes no part in the penetration process. Such a
round is known as the Armour Piercing (AP), Penetrative - or Piercing -
Capped (C), Ballistic Capped (BC) - APCBC round.
+++++

Post by Alfred Montestruc
We started this discussion about WWI warships using steel APFSDS as a
hypothetical, the question is not whether "these days" it is the best
shot to use.
The question is would it have been of significant advantage at the time in WWI.

And the answer is "no".

It isn't possible, with the technology of the day (particularly limited
by propellant), to build practical naval guns that can achieve the
necessary velocity to get projectiles into the hydrodynamic regime where
long-rod penetrators become significantly more effective.

Using steel as the penetrator material produces no significant
advantage: the penetrator breaks up on impact, greatly reducing its
performance.

The external ballistics inescapably force the projectile's velocity down
over WW1 fighting ranges: thus even if you'd built a gun that could
launch taking them outside the hydrodynamic regime

Post by Alfred Montestruc
The question is would a good grade of forged steel available in ~1910
made into shot put on an APFSDS mode penetrate better than standard
cast steel AP shot of WWI. Obviously it would be better given the
use by the USSR,

It was *not* used by the USSR, it was relegated to "training and export"
roles.

Are you incapable of reading your own source material, Al?

Post by Alfred Montestruc
What matters is you were flatly wrong in stating that "If you fire a
steel long-rod penetrator at useful velocities, it'll simply shatter
on impact" and I proved it and you know it.

I fear you've only proved your own arrogance, incompetence, intemperance
and stupidity - not that these were ever in doubt.

[unknown]

Post by Paul J. Adam
. Capped AP
shot appeared during the Second World War.

In naval gunnery it was much earlier. The shell problems at Jutland were
in part due to optimising caps for a normal impact. And according to Marder the slack testing regime. However as you are aware the Germans had
tightened up anti flash precautions after Dogger Bank. While it is fairly
certain the RN took what shortcuts to improve rate of fire they could.

[Alfred Montestruc]

Post by Paul J. Adam

Post by Alfred Montestruc
---snip rubbish----------

Always a good start whge

Such masterful spelling,

Post by Paul J. Adam

Post by Alfred Montestruc

Post by Paul J. Adam
When they were used as a desperation measure by the Iraqis, they
failed to achieve a single penetration, breaking up on impact.

Which is neither here nor there,

They failed, because they shattered.

Still neither here nor there. You are so busy moving goal posts around that you can't do anything but spew more rubbish.

We are not discussing tanks, or tank ammo of the late 20th century, we are discussing WWI battleships.

Post by Paul J. Adam

Post by Alfred Montestruc
nor have you proved they broke up on impact.

Very well, let us believe that steel APFSDS from 125mm Rapira-3 is
actually a capable and effective round.

No the 3VBM-3 (3BM-9 projectile; 3BM-10 projectile assembly) APFSDS round which was introduced in 1962

http://fofanov.armor.kiev.ua/Tanks/ARM/apfsds/ammo.html


http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&ved=0CDEQFjAD&url=http%3A%2F%2Fmilitaryrussia.ru%2Fforum%2Fdownload%2Ffile.php%3Fid%3D17600&ei=fJDAVMKOJcOfggSU_oCoAg&usg=AFQjCNHN4mTymvDKhxdC5jOjm3ecsQGgEg&sig2=yhlj29CN9D2aag8zpD8ytQ&bvm=bv.83829542,d.eXY&cad=rja

LOOK ON PAGE 29 THE PURE STEEL SHOT 3BVM-3 APFSDS ROUND HAS A PENETRATION RATING OF 290 MM 2000 METERS DOWNRANGE FROM THE GUN. THIS PROJECTILE WAS INTRODUCED IN 1962, 290 MM (11.42") PENETRATION IS NOTHING TO SNEEZE AT

Round/ Projectile /Penet / Date Intro/ Muzzle V (m/s)/ Wt (kg)/ Pen (mm)*
3VBM-3/ 3BM-10 / 3BM-9 / 1962 / 1,800 / 3.6 / 290


*penetration of steel at 2000 m range 0 degree angle. See the table on page 29

Also on page 29 of the latter reference it clearly states "3BM-32 depleted-uranium penetrator with penetration capability of 560mm at 2km - about double the performance of the 3VBM-3 used by the Iraqis."

So your point is that DU and tungsten carbide APFSDS ammo works better than steel APFSDS ammo, DUH!!

I never said otherwise. DU only gets about double the penetration.

So British Battleships of WWI had armored belts of steel with thickness maximums at ~ 12".

Let us scale, a 125 mm (4.92") gun with a steel APFSDS round can punch through 290 mm, (11.42") so an 11" naval gun with a steel APFSDS round might possibly be able to penetrate 11.42*(11/4.92)= 25.5 inches of armor.

Get my drift now?

Post by Paul J. Adam
How many tanks were destroyed by it? Even Kuwaiti Chieftains, the year
before,

Chieftains were introduced in 1966, some 4 years after the ammo we are discussing was made for the 125 mm gun. Probably closer to 10 years after that type of ammo was introduced by the soviets, and years after western engineers had a chance to look at it and the effects on plain Jane steel armor during various Arab-Israeli wars.

http://en.wikipedia.org/wiki/Chieftain_tank

"The Chieftain FV4201 was the main battle tank of the United Kingdom during the 1960s, 1970s and 1980s. It was one of the most advanced tanks of its era, and at the time of its introduction in 1966 had the most powerful main gun and most effective armour of any tank in the world."

So you think that because the ammo cannot penetrate the armor of a tank deliberately designed with the intent to stop that specific type of round, that proves that introduction of a similar type of round on 11" naval gun in 1900 say, would be ineffective, , , ,

Your abysmal lack of logic is stupefying.

Post by Paul J. Adam
were immune to it, most withdrawing when their ammunition ran
low rather than being destroyed (one was abandoned after being
immobilised by a hit on the running gear). (Jane's International Defence
Review, November 1990)

Again, that tank was introduced some 10 years after the steel APFSDS ammo was introduced and the designers of that tank were not fools, and had opportunities to study the effects of APFSDS ammo on steel armor.

And again you outdo yourself in moving goalposts. I am not claiming that steel APFSDS ammo out of a 125 mm or 115 mm gun is good enough to be a first rate weapon in a modern tank battle. I am claiming that if it had been introduced in 1910 or 1900 in naval guns, the effects would have been immense.

Post by Paul J. Adam
Steel APFSDS was not effective when used in combat: do you have any
evidence to counter this?

Post by Alfred Montestruc
You said "If you fire a steel long-rod penetrator at useful
velocities, it'll simply shatter on impact" --that is not the same
as "fail to penetrate" the best tank armor in the world at this time
which was designed 20 + years after those specific weapons were in
the field.

Indeed, it'll penetrate *some* armour: just not much.

Not much meaning a bit over half what it will with a DU ammo which is not available in 1910 which is the bottom line.

It will punch through far far more than a solid AP round of 1900 vintage fired from the same gun at the same range.
-------------------------snip

Post by Paul J. Adam

Post by Alfred Montestruc
No it does not say 25 to 50% it does not state any percentage and the
shattering has to do with poor material quality of effing CAST IRON
SHOT, made in the late 19th century more than 100 years ago, not
forged steel.

Al, please don't flaunt your ignorance *quite* so proudly. Capped AP
shot appeared during the Second World War.

http://en.wikipedia.org/wiki/Armor-piercing_shot_and_shell

"During the 1890s and subsequently, cemented steel armor became commonplace, initially only on the thicker armor of warships. To combat this, the projectile was formed of steel--forged or cast--containing both nickel and chromium. Another change was the introduction of a soft metal cap over the point of the shell - so called "Makarov tips" invented by Russian admiral Stepan Makarov."

It may have appeared in tank ammo then, but it was being used in Naval gun ammo in the 1890s, and

WE ARE NOT TALKING ABOUT LATE 20TH CENTURY TANK BATTLES.

Post by Paul J. Adam

Post by Alfred Montestruc
What matters is you were flatly wrong in stating that "If you fire a
steel long-rod penetrator at useful velocities, it'll simply shatter
on impact" and I proved it and you know it.

I fear you've only proved your own arrogance, incompetence, intemperance
and stupidity - not that these were ever in doubt.

look in the mirror Paul.

[Paul J. Adam]

Post by Alfred Montestruc

On 20/01/2015 03:40, Alfred Montestruc wrote: They failed, because
they shattered.

Still neither here nor there. You are so busy moving goal posts
around that you can't do anything but spew more rubbish.
We are not discussing tanks, or tank ammo of the late 20th century,
we are discussing WWI battleships.

Which aren't protected by steel armour?

Experience in trying to pierce steel armour plate and achieve serious
destructive effect behind it, is irrelevant to trying to pierce steel
armour plate and achieve serious destructive effect behind it?

Who would ever have guessed? What a strange world Al must live in.

Post by Alfred Montestruc

Very well, let us believe that steel APFSDS from 125mm Rapira-3 is
actually a capable and effective round.

No the 3VBM-3 (3BM-9 projectile; 3BM-10 projectile assembly) APFSDS
round which was introduced in 1962

Which has never, ever been credited with a lethal hit on a tank. It
didn't work well enough to be useful, which is why it was dropped

Post by Alfred Montestruc
LOOK ON PAGE 29 THE PURE STEEL SHOT 3BVM-3 APFSDS ROUND HAS A
PENETRATION RATING OF 290 MM 2000 METERS DOWNRANGE FROM THE GUN.
THIS PROJECTILE WAS INTRODUCED IN 1962, 290 MM (11.42") PENETRATION
IS NOTHING TO SNEEZE AT

It's pretty dismal, actually - you could, and everybody did, do much
better with conventional APDS, and nearly as well with APCBC.

In other words, "no particular advantage" when it comes to naval gunnery
in 1916 or so - especially because getting through the armour is merely
one step of the process.

Post by Alfred Montestruc
And again you outdo yourself in moving goalposts. I am not claiming
that steel APFSDS ammo out of a 125 mm or 115 mm gun is good enough
to be a first rate weapon in a modern tank battle. I am claiming
that if it had been introduced in 1910 or 1900 in naval guns, the
effects would have been immense.

Okay - it's no more effective at penetrating armour than APCBC shell,
it's got much less effect behind armour, and its combat range is much
shorter.

Agreed, the effects would have been immense: whichever side adopted it
would be massacred by the side that didn't.

Post by Alfred Montestruc

Indeed, it'll penetrate *some* armour: just not much.

Not much meaning a bit over half what it will with a DU ammo which is
not available in 1910 which is the bottom line.

And no better than APCBC, particularly if the target has the temerity to
present any sort of off-normal angle.

No advantage over good APCBC - so no point to using it.

Post by Alfred Montestruc
It will punch through far far more than a solid AP round of 1900
vintage fired from the same gun at the same range.

No, it won't, you've already (if inadvertently) demonstrated that.


To give some perspective, the British 15" gun on the QEs at Jutland
fired a 870kg shell with a muzzle velocity of 732 metres per second. At
10,000 yards (short battle range) it struck at a velocity of 629 metres
per second, striking at 5.7 degrees. At 15,000 yards, its impact was 564
m/s-1 and an angle of ten degrees. Penetrating performance was 422mm and
353mm respectively.

How, exactly, does replacing that shell (with explosive payload) with a
finned dart produce either more penetration *at those ranges* or more
effect behind the armour once pierced?

Your own mathematics show you can't calculate what real shells did, so
why is your opinion valuable when your own numbers are badly wrong?

[Alfred Montestruc]

Post by Alfred Montestruc
In the 1960s smooth-bore tank guns were reintroduced by the USSR where some clever engineer figured out one could use fins to stabilize a projectile and have less loss of muzzle velocity.
http://en.wikipedia.org/wiki/Smoothbore
" To reliably penetrate the thick armor of modern armored vehicles, a very long, thin kinetic-energy projectile is required. The longer the projectile is in relation to its diameter, the higher the spin rate must be to provide stability. Practical rifling can only stabilize projectiles of a limited length-to-diameter ratio, and these modern rounds are simply too long. These rounds are instead formed into a dart shape, using fins for stabilization. With the fins for stability, rifling is no longer needed, and in fact the spin imparted by rifling would degrade the accuracy of a finned projectile. The first tank with a smoothbore gun was the Soviet T-62, introduced into service in 1961; today all main battle tanks except the British Challenger 2 and Indian Arjun MBT use smoothbore guns. The Russian navy conducted experiments with large-caliber smoothbore naval guns, which were halted by budget cuts."
This is a matter of thinking the problem through, not of high technology. This innovation could have been introduced at any time after the invention of rifling. Using sub-caliber armor piercing shot with a sabot and fin stabilization would have a huge advantage in armor penetration
For sake of discussion, suppose this was thought of by the German Navy prior to WWI and kept a deep dark secret, and numerous German battleships and battle-cruisers are given smooth-bore main guns with APFSDS (Armor Piercing Fin Stabilized Discarding Sabot) ammo for them.
Without question, German heavy naval units with such weapons could roll over British heavy units of similar size. One hit from a hypothetical German 11" APFSDS round would be worth several from a British standard 12" AP round, at much longer ranges.
Again for the sake of argument, the German navy puts to sea shortly after the outbreak of hostilities in 1914 and trounces the RN inflicting very heavy losses, and forcing a retreat where the RN clearly no longer dominates the North Sea or Atlantic.
Now what?

It occurs to me that this could have been thought of even earlier, during the age of sail. In that era smooth-bore cannons were often used to fire subcaliber ball shot, as well as grape-shot, chain-shot and so on that commonly used wood or papier-mâché sabots.


http://en.wikipedia.org/wiki/Sabot

This being the case, had someone with the resources and inclination to experiment with the matter done so, what might have been called arrow shot.

Shot sizes is shown in the below link for various common sizes of cannon in pound category of the age of sail.


http://www.civilwarartillery.com/

(on the left hand side of the link pulldown technical information then shot tables)

So a common 12 pounder cannon has a bore of 4.62" and a typical shot diameter of 4.52". Commonly wadding or a wooden sabot. Imagine a three finned cast iron arrow 2" diameter about 10" long. It would weigh about 8 lb.

If you go back to the civil war artillery site and go to technical information then range tables, then scroll down to 12 pounder field gun with 5 degree elevation, and 2.5 lbs of black powder (maximum recommended) you get a range of 1663 yards. I set up a program using a spherical projectile drag coefficient of 0.48, and the mass of the ball (5.64 kg ~ 12lb) the size and mass of the projectile and back-solved for the muzzle velocity. I get 480 meters per second at the muzzle and an impact velocity of 98 meters per second, and a plunging angle of 22.9 degrees while the up angle was 5 degrees.

I use the same program for an arrow with a launch velocity of 480 meters per second 50 mm in diameter, up angle of 5 degrees, and weighing 8 lb, with a streamlined body drag coefficient of 0.04. The range where the arrow hits the ground is now 4217 yards with an impact velocity of 430 meters per second, with a plunging angle of 5.55 degrees on an up angle of 5 degrees.

Why would an age of sail naval officer prefer this?

1) Range and hitting power, arrow shot would more than double his effective range, while hitting the target at a large fraction of the muzzle velocity, and doing a large fraction of the damage round shot would do at point blank range.

2) Accuracy, un-rifled round shot was notoriously inaccurate. The reason for this was the round shout would get random rotational vectors coming out the barrel as the ball touched the bore of the gun at random locations. Arrow shot would have fins and would fly straight as an arrow [ ;-) ].

Net effect, a much smaller ship, say a frigate, could fire devastating broadsides, that will do great damage on a ship of the line at ranges the SOL could not reply with any effect at using standard round shot.

Discuss

[JennyB]

Post by Alfred Montestruc

Post by Alfred Montestruc
In the 1960s smooth-bore tank guns were reintroduced by the USSR where some clever engineer figured out one could use fins to stabilize a projectile and have less loss of muzzle velocity.
http://en.wikipedia.org/wiki/Smoothbore
" To reliably penetrate the thick armor of modern armored vehicles, a very long, thin kinetic-energy projectile is required. The longer the projectile is in relation to its diameter, the higher the spin rate must be to provide stability. Practical rifling can only stabilize projectiles of a limited length-to-diameter ratio, and these modern rounds are simply too long. These rounds are instead formed into a dart shape, using fins for stabilization. With the fins for stability, rifling is no longer needed, and in fact the spin imparted by rifling would degrade the accuracy of a finned projectile. The first tank with a smoothbore gun was the Soviet T-62, introduced into service in 1961; today all main battle tanks except the British Challenger 2 and Indian Arjun MBT use smoothbore guns. The Russian navy conducted experiments with large-caliber smoothbore naval guns, which were halted by budget cuts."
This is a matter of thinking the problem through, not of high technology. This innovation could have been introduced at any time after the invention of rifling. Using sub-caliber armor piercing shot with a sabot and fin stabilization would have a huge advantage in armor penetration
For sake of discussion, suppose this was thought of by the German Navy prior to WWI and kept a deep dark secret, and numerous German battleships and battle-cruisers are given smooth-bore main guns with APFSDS (Armor Piercing Fin Stabilized Discarding Sabot) ammo for them.
Without question, German heavy naval units with such weapons could roll over British heavy units of similar size. One hit from a hypothetical German 11" APFSDS round would be worth several from a British standard 12" AP round, at much longer ranges.
Again for the sake of argument, the German navy puts to sea shortly after the outbreak of hostilities in 1914 and trounces the RN inflicting very heavy losses, and forcing a retreat where the RN clearly no longer dominates the North Sea or Atlantic.
Now what?

It occurs to me that this could have been thought of even earlier, during the age of sail. In that era smooth-bore cannons were often used to fire subcaliber ball shot, as well as grape-shot, chain-shot and so on that commonly used wood or papier-mâché sabots.
http://en.wikipedia.org/wiki/Sabot
This being the case, had someone with the resources and inclination to experiment with the matter done so, what might have been called arrow shot.
Shot sizes is shown in the below link for various common sizes of cannon in pound category of the age of sail.
http://www.civilwarartillery.com/
(on the left hand side of the link pulldown technical information then shot tables)
So a common 12 pounder cannon has a bore of 4.62" and a typical shot diameter of 4.52". Commonly wadding or a wooden sabot. Imagine a three finned cast iron arrow 2" diameter about 10" long. It would weigh about 8 lb.
If you go back to the civil war artillery site and go to technical information then range tables, then scroll down to 12 pounder field gun with 5 degree elevation, and 2.5 lbs of black powder (maximum recommended) you get a range of 1663 yards. I set up a program using a spherical projectile drag coefficient of 0.48, and the mass of the ball (5.64 kg ~ 12lb) the size and mass of the projectile and back-solved for the muzzle velocity. I get 480 meters per second at the muzzle and an impact velocity of 98 meters per second, and a plunging angle of 22.9 degrees while the up angle was 5 degrees.
I use the same program for an arrow with a launch velocity of 480 meters per second 50 mm in diameter, up angle of 5 degrees, and weighing 8 lb, with a streamlined body drag coefficient of 0.04. The range where the arrow hits the ground is now 4217 yards with an impact velocity of 430 meters per second, with a plunging angle of 5.55 degrees on an up angle of 5 degrees.
Why would an age of sail naval officer prefer this?
1) Range and hitting power, arrow shot would more than double his effective range, while hitting the target at a large fraction of the muzzle velocity, and doing a large fraction of the damage round shot would do at point blank range.
2) Accuracy, un-rifled round shot was notoriously inaccurate. The reason for this was the round shout would get random rotational vectors coming out the barrel as the ball touched the bore of the gun at random locations. Arrow shot would have fins and would fly straight as an arrow [ ;-) ].
Net effect, a much smaller ship, say a frigate, could fire devastating broadsides, that will do great damage on a ship of the line at ranges the SOL could not reply with any effect at using standard round shot.
Discuss

I wonder what the accuracy would have been like at that range?

[Alfred Montestruc]

Post by JennyB

Post by Alfred Montestruc

Post by Alfred Montestruc
In the 1960s smooth-bore tank guns were reintroduced by the USSR where some clever engineer figured out one could use fins to stabilize a projectile and have less loss of muzzle velocity.
http://en.wikipedia.org/wiki/Smoothbore
" To reliably penetrate the thick armor of modern armored vehicles, a very long, thin kinetic-energy projectile is required. The longer the projectile is in relation to its diameter, the higher the spin rate must be to provide stability. Practical rifling can only stabilize projectiles of a limited length-to-diameter ratio, and these modern rounds are simply too long. These rounds are instead formed into a dart shape, using fins for stabilization. With the fins for stability, rifling is no longer needed, and in fact the spin imparted by rifling would degrade the accuracy of a finned projectile. The first tank with a smoothbore gun was the Soviet T-62, introduced into service in 1961; today all main battle tanks except the British Challenger 2 and Indian Arjun MBT use smoothbore guns. The Russian navy conducted experiments with large-caliber smoothbore naval guns, which were halted by budget cuts."
This is a matter of thinking the problem through, not of high technology. This innovation could have been introduced at any time after the invention of rifling. Using sub-caliber armor piercing shot with a sabot and fin stabilization would have a huge advantage in armor penetration
For sake of discussion, suppose this was thought of by the German Navy prior to WWI and kept a deep dark secret, and numerous German battleships and battle-cruisers are given smooth-bore main guns with APFSDS (Armor Piercing Fin Stabilized Discarding Sabot) ammo for them.
Without question, German heavy naval units with such weapons could roll over British heavy units of similar size. One hit from a hypothetical German 11" APFSDS round would be worth several from a British standard 12" AP round, at much longer ranges.
Again for the sake of argument, the German navy puts to sea shortly after the outbreak of hostilities in 1914 and trounces the RN inflicting very heavy losses, and forcing a retreat where the RN clearly no longer dominates the North Sea or Atlantic.
Now what?

It occurs to me that this could have been thought of even earlier, during the age of sail. In that era smooth-bore cannons were often used to fire subcaliber ball shot, as well as grape-shot, chain-shot and so on that commonly used wood or papier-mâché sabots.
http://en.wikipedia.org/wiki/Sabot
This being the case, had someone with the resources and inclination to experiment with the matter done so, what might have been called arrow shot.
Shot sizes is shown in the below link for various common sizes of cannon in pound category of the age of sail.
http://www.civilwarartillery.com/
(on the left hand side of the link pulldown technical information then shot tables)
So a common 12 pounder cannon has a bore of 4.62" and a typical shot diameter of 4.52". Commonly wadding or a wooden sabot. Imagine a three finned cast iron arrow 2" diameter about 10" long. It would weigh about 8 lb.
If you go back to the civil war artillery site and go to technical information then range tables, then scroll down to 12 pounder field gun with 5 degree elevation, and 2.5 lbs of black powder (maximum recommended) you get a range of 1663 yards. I set up a program using a spherical projectile drag coefficient of 0.48, and the mass of the ball (5.64 kg ~ 12lb) the size and mass of the projectile and back-solved for the muzzle velocity. I get 480 meters per second at the muzzle and an impact velocity of 98 meters per second, and a plunging angle of 22.9 degrees while the up angle was 5 degrees.
I use the same program for an arrow with a launch velocity of 480 meters per second 50 mm in diameter, up angle of 5 degrees, and weighing 8 lb, with a streamlined body drag coefficient of 0.04. The range where the arrow hits the ground is now 4217 yards with an impact velocity of 430 meters per second, with a plunging angle of 5.55 degrees on an up angle of 5 degrees.
Why would an age of sail naval officer prefer this?
1) Range and hitting power, arrow shot would more than double his effective range, while hitting the target at a large fraction of the muzzle velocity, and doing a large fraction of the damage round shot would do at point blank range.
2) Accuracy, un-rifled round shot was notoriously inaccurate. The reason for this was the round shout would get random rotational vectors coming out the barrel as the ball touched the bore of the gun at random locations. Arrow shot would have fins and would fly straight as an arrow [ ;-) ].
Net effect, a much smaller ship, say a frigate, could fire devastating broadsides, that will do great damage on a ship of the line at ranges the SOL could not reply with any effect at using standard round shot.
Discuss

I wonder what the accuracy would have been like at that range?

The intrinsic accuracy of a smooth bore cannon firing round shot was notoriously bad. The civil war artillery site I looked at indicated a range of 1663 yards, or 0.94 miles on a 12 pounder with 2.5 lbs of gunpowder (the max safe charge) and 5 degrees of elevation. I work that out to be a muzzle velocity of 482 m/s on a 12.45 lb cast iron round ball.

An ~ 8 lb arrow shot 50 mm diameter about 250 mm long with three fins on the back each about 25 mm out and 50 mm long and maybe 7 mm thick fired with a sabot from the same cannon with the same charge would have at least as high a muzzle velocity and no aerodynamic inclination to wander from a straight path, as round shot does. With the same up angle and 4200 yards and impact with many times the kinetic energy of the round shot. How accurate? I cannot say off hand but much more accurate than a smooth-bore cannon shooting round shot, and devastating at more than double the range.

A small sailing warship ship armed with them, and a crew and captain that know how to use them, would be able to beat a much larger sailing warship without them and not even be injured.

[Malcom "Mal" Reynolds]

Post by Alfred Montestruc

Post by JennyB

Post by Alfred Montestruc

Post by Alfred Montestruc
In the 1960s smooth-bore tank guns were reintroduced by the USSR where
some clever engineer figured out one could use fins to stabilize a
projectile and have less loss of muzzle velocity.
http://en.wikipedia.org/wiki/Smoothbore
" To reliably penetrate the thick armor of modern armored vehicles, a
very long, thin kinetic-energy projectile is required. The longer the
projectile is in relation to its diameter, the higher the spin rate
must be to provide stability. Practical rifling can only stabilize
projectiles of a limited length-to-diameter ratio, and these modern
rounds are simply too long. These rounds are instead formed into a dart
shape, using fins for stabilization. With the fins for stability,
rifling is no longer needed, and in fact the spin imparted by rifling
would degrade the accuracy of a finned projectile. The first tank with
a smoothbore gun was the Soviet T-62, introduced into service in 1961;
today all main battle tanks except the British Challenger 2 and Indian
Arjun MBT use smoothbore guns. The Russian navy conducted experiments
with large-caliber smoothbore naval guns, which were halted by budget
cuts."
This is a matter of thinking the problem through, not of high
technology. This innovation could have been introduced at any time
after the invention of rifling. Using sub-caliber armor piercing shot
with a sabot and fin stabilization would have a huge advantage in armor
penetration
For sake of discussion, suppose this was thought of by the German Navy
prior to WWI and kept a deep dark secret, and numerous German
battleships and battle-cruisers are given smooth-bore main guns with
APFSDS (Armor Piercing Fin Stabilized Discarding Sabot) ammo for them.
Without question, German heavy naval units with such weapons could roll
over British heavy units of similar size. One hit from a hypothetical
German 11" APFSDS round would be worth several from a British standard
12" AP round, at much longer ranges.
Again for the sake of argument, the German navy puts to sea shortly
after the outbreak of hostilities in 1914 and trounces the RN
inflicting very heavy losses, and forcing a retreat where the RN
clearly no longer dominates the North Sea or Atlantic.
Now what?

It occurs to me that this could have been thought of even earlier, during
the age of sail. In that era smooth-bore cannons were often used to fire
subcaliber ball shot, as well as grape-shot, chain-shot and so on that
commonly used wood or papier-mâché sabots.
http://en.wikipedia.org/wiki/Sabot
This being the case, had someone with the resources and inclination to
experiment with the matter done so, what might have been called arrow
shot.
Shot sizes is shown in the below link for various common sizes of cannon
in pound category of the age of sail.
http://www.civilwarartillery.com/
(on the left hand side of the link pulldown technical information then shot tables)
So a common 12 pounder cannon has a bore of 4.62" and a typical shot
diameter of 4.52". Commonly wadding or a wooden sabot. Imagine a three
finned cast iron arrow 2" diameter about 10" long. It would weigh about
8 lb.
If you go back to the civil war artillery site and go to technical
information then range tables, then scroll down to 12 pounder field gun
with 5 degree elevation, and 2.5 lbs of black powder (maximum
recommended) you get a range of 1663 yards. I set up a program using a
spherical projectile drag coefficient of 0.48, and the mass of the ball
(5.64 kg ~ 12lb) the size and mass of the projectile and back-solved
for the muzzle velocity. I get 480 meters per second at the muzzle and
an impact velocity of 98 meters per second, and a plunging angle of 22.9
degrees while the up angle was 5 degrees.
I use the same program for an arrow with a launch velocity of 480 meters
per second 50 mm in diameter, up angle of 5 degrees, and weighing 8 lb,
with a streamlined body drag coefficient of 0.04. The range where the
arrow hits the ground is now 4217 yards with an impact velocity of 430
meters per second, with a plunging angle of 5.55 degrees on an up angle
of 5 degrees.
Why would an age of sail naval officer prefer this?
1) Range and hitting power, arrow shot would more than double his
effective range, while hitting the target at a large fraction of the
muzzle velocity, and doing a large fraction of the damage round shot
would do at point blank range.
2) Accuracy, un-rifled round shot was notoriously inaccurate. The reason
for this was the round shout would get random rotational vectors coming
out the barrel as the ball touched the bore of the gun at random
locations. Arrow shot would have fins and would fly straight as an arrow
[ ;-) ].
Net effect, a much smaller ship, say a frigate, could fire devastating
broadsides, that will do great damage on a ship of the line at ranges the
SOL could not reply with any effect at using standard round shot.
Discuss

I wonder what the accuracy would have been like at that range?

The intrinsic accuracy of a smooth bore cannon firing round shot was
notoriously bad. The civil war artillery site I looked at indicated a range
of 1663 yards, or 0.94 miles on a 12 pounder with 2.5 lbs of gunpowder (the
max safe charge) and 5 degrees of elevation. I work that out to be a muzzle
velocity of 482 m/s on a 12.45 lb cast iron round ball.
An ~ 8 lb arrow shot 50 mm diameter about 250 mm long with three fins on the
back each about 25 mm out and 50 mm long and maybe 7 mm thick fired with a
sabot from the same cannon with the same charge would have at least as high a
muzzle velocity and no aerodynamic inclination to wander from a straight
path, as round shot does. With the same up angle and 4200 yards and impact
with many times the kinetic energy of the round shot. How accurate? I
cannot say off hand but much more accurate than a smooth-bore cannon shooting
round shot, and devastating at more than double the range.
A small sailing warship ship armed with them, and a crew and captain that
know how to use them, would be able to beat a much larger sailing warship
without them and not even be injured.

makes me wonder, aside from the costs, the benefits of using something
like this in rifles, especially snipers

[Alfred Montestruc]

Post by Malcom "Mal" Reynolds

Post by Alfred Montestruc

Post by JennyB

Post by Alfred Montestruc

Post by Alfred Montestruc
In the 1960s smooth-bore tank guns were reintroduced by the USSR where
some clever engineer figured out one could use fins to stabilize a
projectile and have less loss of muzzle velocity.
http://en.wikipedia.org/wiki/Smoothbore
" To reliably penetrate the thick armor of modern armored vehicles, a
very long, thin kinetic-energy projectile is required. The longer the
projectile is in relation to its diameter, the higher the spin rate
must be to provide stability. Practical rifling can only stabilize
projectiles of a limited length-to-diameter ratio, and these modern
rounds are simply too long. These rounds are instead formed into a dart
shape, using fins for stabilization. With the fins for stability,
rifling is no longer needed, and in fact the spin imparted by rifling
would degrade the accuracy of a finned projectile. The first tank with
a smoothbore gun was the Soviet T-62, introduced into service in 1961;
today all main battle tanks except the British Challenger 2 and Indian
Arjun MBT use smoothbore guns. The Russian navy conducted experiments
with large-caliber smoothbore naval guns, which were halted by budget
cuts."
This is a matter of thinking the problem through, not of high
technology. This innovation could have been introduced at any time
after the invention of rifling. Using sub-caliber armor piercing shot
with a sabot and fin stabilization would have a huge advantage in armor
penetration
For sake of discussion, suppose this was thought of by the German Navy
prior to WWI and kept a deep dark secret, and numerous German
battleships and battle-cruisers are given smooth-bore main guns with
APFSDS (Armor Piercing Fin Stabilized Discarding Sabot) ammo for them.
Without question, German heavy naval units with such weapons could roll
over British heavy units of similar size. One hit from a hypothetical
German 11" APFSDS round would be worth several from a British standard
12" AP round, at much longer ranges.
Again for the sake of argument, the German navy puts to sea shortly
after the outbreak of hostilities in 1914 and trounces the RN
inflicting very heavy losses, and forcing a retreat where the RN
clearly no longer dominates the North Sea or Atlantic.
Now what?

It occurs to me that this could have been thought of even earlier, during
the age of sail. In that era smooth-bore cannons were often used to fire
subcaliber ball shot, as well as grape-shot, chain-shot and so on that
commonly used wood or papier-māché sabots.
http://en.wikipedia.org/wiki/Sabot
This being the case, had someone with the resources and inclination to
experiment with the matter done so, what might have been called arrow
shot.
Shot sizes is shown in the below link for various common sizes of cannon
in pound category of the age of sail.
http://www.civilwarartillery.com/
(on the left hand side of the link pulldown technical information then
shot tables)
So a common 12 pounder cannon has a bore of 4.62" and a typical shot
diameter of 4.52". Commonly wadding or a wooden sabot. Imagine a three
finned cast iron arrow 2" diameter about 10" long. It would weigh about
8 lb.
If you go back to the civil war artillery site and go to technical
information then range tables, then scroll down to 12 pounder field gun
with 5 degree elevation, and 2.5 lbs of black powder (maximum
recommended) you get a range of 1663 yards. I set up a program using a
spherical projectile drag coefficient of 0.48, and the mass of the ball
(5.64 kg ~ 12lb) the size and mass of the projectile and back-solved
for the muzzle velocity. I get 480 meters per second at the muzzle and
an impact velocity of 98 meters per second, and a plunging angle of 22.9
degrees while the up angle was 5 degrees.
I use the same program for an arrow with a launch velocity of 480 meters
per second 50 mm in diameter, up angle of 5 degrees, and weighing 8 lb,
with a streamlined body drag coefficient of 0.04. The range where the
arrow hits the ground is now 4217 yards with an impact velocity of 430
meters per second, with a plunging angle of 5.55 degrees on an up angle
of 5 degrees.
Why would an age of sail naval officer prefer this?
1) Range and hitting power, arrow shot would more than double his
effective range, while hitting the target at a large fraction of the
muzzle velocity, and doing a large fraction of the damage round shot
would do at point blank range.
2) Accuracy, un-rifled round shot was notoriously inaccurate. The reason
for this was the round shout would get random rotational vectors coming
out the barrel as the ball touched the bore of the gun at random
locations. Arrow shot would have fins and would fly straight as an arrow
[ ;-) ].
Net effect, a much smaller ship, say a frigate, could fire devastating
broadsides, that will do great damage on a ship of the line at ranges the
SOL could not reply with any effect at using standard round shot.
Discuss

I wonder what the accuracy would have been like at that range?

The intrinsic accuracy of a smooth bore cannon firing round shot was
notoriously bad. The civil war artillery site I looked at indicated a range
of 1663 yards, or 0.94 miles on a 12 pounder with 2.5 lbs of gunpowder (the
max safe charge) and 5 degrees of elevation. I work that out to be a muzzle
velocity of 482 m/s on a 12.45 lb cast iron round ball.
An ~ 8 lb arrow shot 50 mm diameter about 250 mm long with three fins on the
back each about 25 mm out and 50 mm long and maybe 7 mm thick fired with a
sabot from the same cannon with the same charge would have at least as high a
muzzle velocity and no aerodynamic inclination to wander from a straight
path, as round shot does. With the same up angle and 4200 yards and impact
with many times the kinetic energy of the round shot. How accurate? I
cannot say off hand but much more accurate than a smooth-bore cannon shooting
round shot, and devastating at more than double the range.
A small sailing warship ship armed with them, and a crew and captain that
know how to use them, would be able to beat a much larger sailing warship
without them and not even be injured.

makes me wonder, aside from the costs, the benefits of using something
like this in rifles, especially snipers

Smooth-bore muskets maybe. The ammo would be a lot more expensive than a musket ball. You could still cast the projectile out of lead or bronze or something, but the sabot would be harder, especially one that would reliably separate from the projectile.

Heck you could do that with a modern 12 gauge shotgun, and a plastic sabot.


And wonder of wonders it is commercially available.

http://www.cheaperthandirt.com/product/8-HORN-8623

"Brand: Hornady 8623
Item: 8-HORN-8623
UPC: 090255386233

Hornady makes superb ammo just about any use. This 12 Gauge SST Sabot Slug round comes in a 2-3/4" shell with an innovative 300 grain FTX projectile lead and fires it at a blistering 2000 fps. It's an excellent round for hunting medium game, personal defense, or law enforcement.

The SST Shotgun Slug delivers true 200 yard accuracy and you'll achieve sub-2" groups at 100 yards. No other slug gun ammo can come close to the performance of the SST. The sharp point increases the ballistic coefficient of the FTX, allowing it to fly faster, farther and on a flatter trajectory. On impact, the Flex Tip initiates expansion at all velocities.

2,000 fps muzzle
2,664 ft/lbs. muzzle
1,816 fps at 50 yards
2,196 ft/lbs. at 50 yards
1,641 fps at 100 yards
1,793 ft/lbs. at 100 yards"

2" groups at 100 yards out of a smooth-bore gun is impressive to me.

http://en.wikipedia.org/wiki/Shotgun_slug#Saboted_slugs

"The projectile was a wasp waisted hourglass shape made of a hard lead alloy. While many equate sabot to rifled barrel, this slug design was specifically designed for and tested in smoothbores. Testing even included over/unders and side-by-sides. The same slug, made of zinc and about 260 grains was marketed to police for car body penetration. The self-stabilizing shape allowed it to be used with bore cylinder or improved cylinder barrels.[6][7]"

[mike]

Without question, German heavy naval units with such weapons could roll >over British heavy units of similar size. One hit from a hypothetical >German 11" APFSDS round would be worth several from a British standard 12" >AP round, at much longer ranges.

After all the posts of if 1910 era APFSDS could be done, and how much armor it could penetrate, lets get to the point of what you want to happen after the penetrator get thru the belt. Let us just say it does, a handwave.

You will have a red hot rod, sparks, and a bit of spalling, moving fast

A Battleship is a very big vessel, you can punch holes thru without hitting anything vital at worst: at best, a magazine--Boom.

Long Rod penetrators work very well because there isn't much interior volume inside an AFV.

A few red hot fragments are probably going to set off the ammunition or hydraulic fluid, if thats is used for the traverse motor.

But the guaranteed killer in that AFV that been hit, is the crew dying.

Even if the crew members are missed by the rod, the pressure wave of the rod passing thru, won't miss.

They will get turned to jelly. It gets worse, as the rod exits the other side of the AFV, a vacuum is created, that sucks the once human jelly out thru that hole in a cone shaped spray.

Not pretty.

As I said, battleship is very large, lots of open spaces where that pressure buildup won't happen, and the rod may not hit anything vital, and killing a handful of guys won't mission kill the ship

That's one reason why Navies stopped using AP Shot in the 1890s. The tiny percentage of HE burster inside was far more effective at causing damage,than just KE

Look at Taffy 3, DDs and DEs getting IJN 15 and 18" AP rounds passing thru the ship, causing little damage because the hull plating and bulkheads were not thick enough to initialize the fuzes


**
mike
**

[Dean]

Post by mike

Without question, German heavy naval units with such weapons could roll >over British heavy units of similar size. One hit from a hypothetical >German 11" APFSDS round would be worth several from a British standard 12" >AP round, at much longer ranges.

After all the posts of if 1910 era APFSDS could be done, and how much armor it could penetrate, lets get to the point of what you want to happen after the penetrator get thru the belt. Let us just say it does, a handwave.
You will have a red hot rod, sparks, and a bit of spalling, moving fast
A Battleship is a very big vessel, you can punch holes thru without hitting anything vital at worst: at best, a magazine--Boom.
Long Rod penetrators work very well because there isn't much interior volume inside an AFV.
A few red hot fragments are probably going to set off the ammunition or hydraulic fluid, if thats is used for the traverse motor.
But the guaranteed killer in that AFV that been hit, is the crew dying.
Even if the crew members are missed by the rod, the pressure wave of the rod passing thru, won't miss.
They will get turned to jelly. It gets worse, as the rod exits the other side of the AFV, a vacuum is created, that sucks the once human jelly out thru that hole in a cone shaped spray.
Not pretty.
As I said, battleship is very large, lots of open spaces where that pressure buildup won't happen, and the rod may not hit anything vital, and killing a handful of guys won't mission kill the ship
That's one reason why Navies stopped using AP Shot in the 1890s. The tiny percentage of HE burster inside was far more effective at causing damage,than just KE
Look at Taffy 3, DDs and DEs getting IJN 15 and 18" AP rounds passing thru the ship, causing little damage because the hull plating and bulkheads were not thick enough to initialize the fuzes
**
mike
**

A more suitable analogy would be 5 years before at the Battle of Tsushima. There, the Japanese inflicted enormous damage on the Russian battleships using mostly high explosive shells. Conversely, the Russians inflicted negligible damage on the Japanese battleships using armor piercing shells. Now image either side had used these newfangled APFSDS. The Russians would probably have run through the straits and made Vladivostok although they may have sustained holes from the Japanese APFSDS rounds. Although its possible the Japanese torpedo boats would have inflicted damage. If it was the Russians firing APFSDS rounds, then the Japanese probably would not have seen much difference.

Dean

[Alfred Montestruc]

Post by mike

Without question, German heavy naval units with such weapons could roll >over British heavy units of similar size. One hit from a hypothetical >German 11" APFSDS round would be worth several from a British standard 12" >AP round, at much longer ranges.

After all the posts of if 1910 era APFSDS could be done, and how much armor it could penetrate, lets get to the point of what you want to happen after the penetrator get thru the belt. Let us just say it does, a handwave.
You will have a red hot rod, sparks, and a bit of spalling, moving fast

We will have a lot of pieces of broken armor and pieces of the rod ricocheting around inside the ship at supersonic speeds, on the rough order of 100 to 200 kg of material per penetration.

Post by mike
A Battleship is a very big vessel, you can punch holes thru without hitting anything vital

Don't think so. Do you really think you can have a significant probability of a penetration through the belt armor that does not wind up in something vital?

Ammo (both powder and shells of several sizes) fuel, live steam lines, conveyors of powder & shot from magazines to the turrets, ,

Battleships are crowded on the inside. Have you been on one?

Post by mike
at worst: at best, a magazine--Boom.
Long Rod penetrators work very well because there isn't much interior volume inside an AFV.

Do you think the % of magazines and fuel storage is smaller or larger on a tank than on a BB? I suspect that due to the long distances battleships must travel, the fuel bunkers are proportionately larger. Coal fires can be really hard to put out,

Post by mike
A few red hot fragments are probably going to set off the ammunition or hydraulic fluid, if thats is used for the traverse motor.
But the guaranteed killer in that AFV that been hit, is the crew dying.
Even if the crew members are missed by the rod, the pressure wave of the rod passing thru, won't miss.

And they will miss in a BB? I don't think that one APFSDS shot that does not hit a magazine will kill 100% of the crew BB immediately, but it is going to cause casualties, a lot of them, partly by shockwaves, partly by flying shards of metal.

Post by mike
They will get turned to jelly. It gets worse, as the rod exits the other side of the AFV, a vacuum is created, that sucks the once human jelly out thru that hole in a cone shaped spray.

Which is overkill and not really pertinent to this discussion.

Post by mike
Not pretty.
As I said, battleship is very large, lots of open spaces where that pressure buildup won't happen,

Nonsense. Go on a BB and crawl around in one.

Post by mike
and the rod may not hit anything vital, and killing a handful of guys won't mission kill the ship

It will not be a handful and the other issue is that you will get much higher % hits as the trajectory is much flatter and time of flight is lower so you need less correction, and the impact probability footprint is longer due to the flat trajectory. So instead of 2-3% hits, you will get double or more the number of hits.

Post by mike
That's one reason why Navies stopped using AP Shot in the 1890s. The tiny percentage of HE burster inside was far more effective at causing damage,than just KE

Those AP rounds had tiny amounts of KE per shot.

Post by mike
Look at Taffy 3, DDs and DEs getting IJN 15 and 18" AP rounds passing thru the ship, causing little damage because the hull plating and bulkheads were not thick enough to initialize the fuzes

And not enough armor to cause the AP round to break into chunks on the way through and no armor on the other side to reflect shock-waves (which is what is deadly repeated pummeling by a shock-wave being reflected back and forth in the compartment), or ricochet fragments, on and on. This is not a good way to make your case.

Post by mike
**
mike
**