2 Pounder problems?

[John Kettler]

Jeff Duquette,

I think it's great that we get to see two versions of the 5 cm APHE projectile, of which one is the close in age older design sibling and the other more like college age big brother. As expected by me, it's a capped projectile sporting some very substantial side walls. Was this projectile also used in the 5 cm Lang?

Michael Kenny,

Thanks for posting the two King Tiger damage shots. It would appear that if repetition is the soul of advertising, then exaggeration must be the soul of war propaganda when extolling one's own weapons!

MikeyD,

It would be interesting to see what the actual AP ammo split was for the 45mm ATG early war vs. late war. Offhand, I'd expect to see a lot of arrowhead shot in the latter case.

Regards,

John Kettler

[JasonC]

Methinks the photo is being seriously misinterpreted. It is not the case that the fragments well behind the foremost ones are from spall and the ones up with the main shell are from the burster. All a fragment being co-located with others tells you is that it hasn't appreciably changed its velocity vector.

A few bits went sideways and have probably already bounced once, thus haven't traveled as far. The rest, whether coming from the plate hit or not, will be right up with the mass because they are moving as fast as the mass.

The degree of clumping is also specific to a very thin wall seriously overpenetrated, leaving almost all the initial V of the shell body, uniformly, in all the bits however created. With instead a penetration close to the armor resistence, you would instead expect a typical boltzman-like velocity dispersion for the fragments. (Meaning, a small mass in tiny ones going about as fast as the original shot, larger pieces moving slower, etc).

JK continues to present the case of a solid shot stuck in the armor, through but not "through and through", as unlikely to cause any damage - without any justification. The displaced plug has in that case been shot into the tank with nearly the momentum of the original exterior impact. In pieces, of course.

[JasonC]

As for switching the comparison from 37mm vs. 2 pdr (which is a 40mm caliber round) up to 50mm, why not compare that to 6 pdr (57mm?) Heck, let's keep going, and compare a 120mm arrow penetrator to a 20mm AA MG round with a 2 gram bursting charge. It is just silly. Total energy is the operational distinction, charge or not is dramatically secondary. 50L42 APHE does not outperform 57L43 AP, because the latter has vastly higher total E.

[John Kettler]

JasonC,

The reason for bringing the 5cm into the investigation is that, for much of the fight in the Western Desert, the principal matchup was the British 2 pdr., on all sorts of platforms, vs. the German 5cm. Kurz. It was this issue which was investigated in the Middle East series Volume 2, then revisited, with different conclusions, in Volume 3.

Turning now to your claim regarding mine for the case in which 2 pdr. AP shot pierces the armor but gets stuck rather than entering the fighting compartment and bouncing around, I did NOT say it was unlikely to cause damage. I said it would be much less lethal than in the gross overmatch scenario. The reason is intuitively obvious: far less total KE available than in the overmatch situation. If the AP shot had so little energy remaining after piercing the armor that it couldn't even exit the far side of the plate, then

aside from whatever effects impact shock creates, all that's left for a damage mechanism consists of any shot breakup material which carries into the fighting compartment, but chiefly the spall and/or plugging generated by the complete piercing of the fighting compartment in the first place. How a marginal penetration can be as damaging as a gross overmatch is simply beyond me, and I say this based on studying such issues going clear back to numerous ironclad engagements in the American Civil War. Let me compare and contrast.

When the Monitor met the Virginia, neither vessel was properly equipped for war. The Monitor's guns hadn't been proofed, hence were fired with only half the design charge. The Virginia went into the fray without hardened steel projectiles. What happened?

The Monitor came out of the engagement with a dinged up turret, zero penetrations other than the shellburst on the face of the pilothouse directly over the vision slot, and fully functional. The Virginia had a cracked casemate plate, but the real injury was significant flooding caused, not by the Monitor's cannon, but by what happened when the ram ripped out while attacking Union wooden warships.

Jump the calendar to a later date, and we find a much bigger, nastier Confederate ironclad called the Atlanta against the Monitor on steroids the Weehawken. Where the Monitor had 11" Dahlgrens,

the Weehawken has a pair of proofed 15" Dahlgren guns. The battle would've been much more interesting had the Atlanta not run aground on a sandbar, allowing the Weehawken to close range and fire from a blind spot in the Atlanta's gun coverage. One salvo later, the Atlanta was done for, for that thundering volley tore the casemate wide open over a span of feet, piercing and shattering armor and heavy wood underlayment alike and exposing the gun deck to fire from stem to stern, not to mention causing a slew of crew casualties.

Now, are you really going to stick to your claim that the marginal penetration is as lethal as or even close to the gross overmatch case when analyzing 2 pdr. AP shot terminal effectiveness?

If so, we need to talk about a bridge I have for sale!

Regards,

John Kettler

[ February 03, 2007, 07:14 PM: Message edited by: John Kettler ]

[Other Means]

Oh John, you've not bought another bridge have you?

[John Kettler]

JasonC,

Forgot to mention that since we now have the Monitor's turret, it has been discovered that, even firing without steel shot, the Virgina came awfully close to severely damaging the Monitor's turret, in that we now know that the innermost layer was pushed in so far that it nearly failed.

Had it done so, there would've been bolt parts and chunks of iron an inch thick whizzing about the densely packed turret. Since there was no way to roll 8" thick plate, it was constructed of concentric one inch rings, which were then bolted together. Also, the Confederates put such heavy fire on the turret that it was found necessary to reload the guns with the turret turned completely away, for fear that the port shutters would be jammed shut, leaving the Monitor helpless.

All,

Returning to the primary topic, I managed to find some specific descriptions of German 3.7cm antitank guns in action. In Delaney's FIGHTING THE DESERT FOX, p. 39, we find "close-range 37mm and 50mm fire" as being responsible for having knocked out 8 Matilda IIs. Page 40, in describing action around Point 208, talks about how entrenched 37mm guns at the reverse slope base of a rise apparently took out two A9 cruiser tanks and drove the rest of the squadron off when the attack came over the ridgetop.

On the Italian side, we have the clash of the 22nd Armoured Brigade with Italian defenses at Bir el Gubi, as described on pp. 58-59. 47mm guns in both AT configuration and on M-13/40s and seven 102mm naval guns in portee mounts killed 50 Crusaders for a loss of 34 tanks, 8 47mm ATGs (which have no shields), and a 65mm IG. What's especially interesting is the damage characterization: "Many of the Axis vehicles were later recovered and repaired. The British lost 50 Crusaders, the majority of them being permanently disabled by the Italians."

Seems to me that this outcome is precisely what I've been talking about all along. 2pdr AP shot victims are frequently repairable, whereas Axis APHE victims generally are not. I believe Russian

experience reflected this, too. ISTR only 25% of the tanks disabled by German fire were repairable.

As we know, the standard German AP projectile was APHE in various configurations.

Regards,

John Kettler

[Andreas]

The passages do not support your conclusions.

All the best

Andreas

[John Kettler]

Andreas,

A sweeping rejection with no evidence cited in support? Fabulous rhetorical move, but not helpful to the discussion!

In the mixed 3.7cm and 5.0cm ATGs vs. the Matildas, though Delaney doesn't say so, I would expect that the lighter ATG went after two chief aimpoints: the exposed turret ring (to create traversing jams) and the tracks, while the heavier ATG, probably firing PzGr 40, tried to kill the tanks outright.

At Point 208, though the writing is maddeningly unclear, what is clear is that a handful of 3.7cm ATGs formed an important component of the overall reverse slope defense and did some damage. If you continue the story, when the guns and troops pull back and have to fight sans trenches, it gets much uglier for the Germans, until the Panzers arrive to save the day.

The results at Bir el Gubi would appear to speak for themselves. The Italians took on an entire Armoured Brigade and despite generally much inferior equipment, gave worse than they got and more permanently. As for the Russians, we need to look at the repair rates for the time before the Panzerfaust and Panzerschreck really became major factors.

Regards,

John Kettler

[John Kettler]

JasonC,

You previously asserted that a partial penetration of the armor, sans projectile actually entering and careening about the fighting compartment, would be bad news. Guess what? I've found an actual example of a tank hit twice in this manner. Please refer to pp. 178-179 of Heckmann's ROMMEL'S WAR IN AFRICA and read about Tim Palmer's fourth unhorsing of the day.

From a range of ~1500 meters, his Crusader is accurately fired upon by a Panzer III and hit repeatedly. One shot pierces the turret wall and lodges there, causing the RTO to drop down into the turret in fright. A second shot does the same to the portal armor, emerging right in front of the driver and so unhinging him that he temporarily disassociates and leaves the tank, winding up a POW. The third shot takes out the gun. Granted that these men were incredibly blessed to have neither round fuze and detonate, but note what happens in the marginal penetration cases cited. Pretty much nothing! This suggests that what I said about energy being given up by the AP shot through heat, dissipation by the tank's suspension, and hyperplastic flow was indeed correct. Your expected behind armor effects are nowhere to be seen.

Turning now to a very good for you case, on pp. 180-181 we find a Panzer III on the receiving end of no less than four clean 2pdr penetrations. The tank takes a big jolt, followed by screeching metal and shouts. The fighting compartment took four direct hits, with three right through the ammo bins, opening many of the casings, and one through collecting ring for the turret's electric drive. Traversing gear, MG trigger pedal linkage and radio--all destroyed. Description clearly indicates, too, that a big piece of flank armor entered the fighting compartment. Crew casualties? Zero! The tank, though obviously hors de combat, was able to leave the battlefield on its own to seek repair.

Now, let's look at (p.177) one 5cm hit which penetrated and detonated. "The tank immediately burst into flames." TC's hands are in shreds, driver's dead, RTO and gunner are severely burned. Recall my prior mention of incapacitated crews in tanks hit by APHE which detonates effectively?

In case you think I'm making up the vulnerability issue, consider what the selfsame Palmer had to say as the sun set and the British surveyed the fires of burning armor in the distance. "I can only see Cruisers; the Jerries don't burn as easily as we do."

On page 171, the Germans come acropper on a British 2pdr Pakfront. Fenck's tank takes a slew of hits, taking off the driver's leg with one and turning the interior of the tank into a "complete wreck." He is the only primary casualty, for anyone else is hurt after abandoning the tank. Fenck takes a splinter wound from a storage bin penetration, and the RTO dies from causes unknown after leaving the tank. The tank neither burns nor explodes and is apparently collected later and evacuated for repair (p. 172) by "low-loaders" no doubt part of a Panzer Werkstatt Kompanie.

Regards,

John Kettler

[JasonC]

The civil war ironclads comparison is simply laughable. I'll pass.

The Italian example does not show that APHE is more effective. It shows that standing on defense with a gun and 2 tanks for every 2 attacking tanks, you can fight off the enemy. Also, the loss figures you give are Italian claims, and by Brit records are high by a factor of 2. Also, the reason they were not recovered and repairable is not because they blew up like firecrackers as soon as struck with 47L32 AP, but because the Italians retained possession of the battlefield.

As for the notion that APHE always kills the crew, since the Germans used it pretty much exclusively from midwar on, it predicts allied tanker to tank loss ratios of approximately 5. Instead they are approximate 2, with on average half a man killed and one and a half wounded each time a tank was taken out by enemy fire.

You also predict there will be few or no recoveries in case of large scale tank loss. The evidence does not bear this out. Up to half the tanks lost in Goodwood were apparently recovered, for example. It has more to do with movement of the front and the availability of rear services and support, than with the method of loss.

As for anecdotes, one time Sergeant Rock took out a Tiger by jumping on it and stuffing a grenade in the muzzle brake. Another time a Finn immobilized a T-34 will a log. It is all utterly meaningless. Surely you do not intend to claim that no one was every injured by flying metal produced by a plain AP penetration, nor that it never happened than the small burster in an APHE round went off successfully, without causing any serious injury to the struck crew. But only such extreme claims, which I do not put in your mouth, are addressed by single incidents. To show an *average* outperformance is another matter entirely, and you have not remotely done so.

You seem to have missed the point of my rhetorical invitation to compared 6 pdrs with 50L42 next, and then perhaps 75s with those, and on up. The point was and is, much higher total energy guns are clearly in a much higher class for behind armor effect. You would not dream of pretending that 37mm APHE is more effective, behind armor, than 17 pdr solid shot (if there is such a thing), with 50 times the energy. Agreed? That would be apples to oranges.

OK, why? What determines the species of fruit? Why is the far higher overall power of a 17 pdr clearly the more important thing, and not the presence or absence of an "order 10 grams" smidgen of explosive?

Because the main linear determiner of BAE is not shell or shot, it is energy.

As for ease of burning, it has been pointed out to you already in this thread that it is an ammo stowage issue, not a round taken issue. Shermans burned easily for the same reason until the got wet stowage, then they didn't, despite the Germans still having APHE.

[John Kettler]

JasonC,

If you have a British casualty breakdown for Bir el Gubi, I'd love to see it. I didn't say they "blew up like firecrackers." The book I cited characterized them as "permanently disabled," a term I interpret as being synonymous with "not repairable." Thus, it mattered not if the British had controlled the battle zone at the end of the day.

I didn't say APHE "always kills the crew." To the contrary, I have repeatedly said that when it penetrates sufficiently and detonates, it generally wrecks the crew as a fighting entity or incapacitates it. This, BTW, was the conclusion of the British OR study and is buttressed by the 2pdr APHE test firings against M-13/40s with sandbags inside as crew simulators.

Turning now to Goodwood tank recoveries, it doesn't necessarily follow that a recovered tank is a repairable tank. Do you happen to have any figures on that, please? For comparison, I believe that Belton Cooper did his assessment thing in 3rd AD AFTER the tank had been evacuated to a collection point. Before that, it was all about finding the battle damaged and arranging to guard them until they could be removed. From what I remember of DEATH TRAPS, lots of time he couldn't repair the tank, but he was able to salvage various much needed parts.

I think invoking Sgt. Rock and uberFinns to attack my argument is spurious and a distraction tactic.

Even so, you know perfectly well that I'm NOT asserting that vanilla AP shot penetrations never injured anyone (remember the wounded Panzer IV driver hit by 2pdr fire in the driver's plate?), nor that no one ever survived an APHE detonation unscathed, though I couldn't quote you an example at present. I marvel, though, at your incredible ability to ignore the conclusions the British themselves drew of the typical outcome in the Western Desert when a tank was penetrated

by the typical projectile of, say, the Battleaxe

op. I repeat. Effective 2pdr AP = disabled tank and likely unharmed/barely hurt crew; effective German APHE from 3.7cm up = destroyed tank and unfit for combat/incapacitated/wrecked crew. For the record, the British reached the same conclusion regarding converted German 75mm APHE fired from Grants. A hit tank = a destroyed tank.

And yes, I grok that there is a large difference, to put it mildly, between the KE of a 3.7cm APHE and a 17pdr firing APC or APCBC, both forms of AP shot. That's not what I'm arguing. I'm saying that the principal British conclusion was that even a small APHE detonation inside the tank, or partially inside as described above, was sufficient, at least when the British ran the tests and conducted their OR study, to destroy the tank and take out the crew as a fighting entity.

Whether it was quite as bad a year or two later, when the typical Allied tank was no longer a thin skinned Cruiser but the typical German gun was much bigger and more powerful than in the Western Desert, I don't know. ISTR the Allies did do some work on protected ammo stowage, but Wet Shermans

came relatively late in the game. Did the British use Wet storage on Cromwells, Churchills, etc.?

To answer your final point, let's go to naval warfare for an analogy. Why did guns get bigger and bigger, ultimately reaching the whopping 18.1"

on the Yamato and the Musashi? It comes down to two things: maximum armor penetration and maximum range, consistent with needed accuracy, against some defined armor array. And what's the ultimate objective of this tremendous outpouring of resources? Delivering a series of burster charges deep into the vitals of the targeted vessel. If KE per se was the sine qua non you apparently believe it to have been, then logic tells me that

the British would've gone to pure KE projectiles for battleship combat, but they didn't. Not at Jutland, not against the Bismarck, and not at Oran. Every single main battery battleship round fired there was some form of APHE. Indeed, if the objective were simply shock, then the hypothetical pure KE weapon would need to be deoptimized so as

to trade penetration for optimum energy transfer.

IOW, for maximum shock, the best approach would be a capped blunt projectile.

So, the British used APHE for battleship projectiles, yet used AP shot for most of their tank killing. Why? The answer seems to be twofold: 1) they didn't trust their own shell designs to hold together under impact and detonate properly, and 2) they were desperately searching for the last few percentage points of penetration

in an effort to get through ever thicker and tougher German armor plate. Thus, we see such bizarreness as removing the fuze and plugging the fuze well on perfectly good American supplied APHE. We also see a bunch of statements which blithely ignored their own direct combat experience.

Regards,

John Kettler

[ February 08, 2007, 12:40 AM: Message edited by: John Kettler ]

[Andreas]

Originally posted by John Kettler:

Andreas,

A sweeping rejection with no evidence cited in support? Fabulous rhetorical move, but not helpful to the discussion!

Almost as useful as throwing around quotations that don't give any detail, and then claiming they support your thesis. You'll excuse me if I don't give a toss for a lecture in debating technique from you of all people.

Originally posted by John Kettler:

In the mixed 3.7cm and 5.0cm ATGs vs. the Matildas, though Delaney doesn't say so, I would expect that the lighter ATG went after two chief aimpoints: the exposed turret ring (to create traversing jams) and the tracks, while the heavier ATG, probably firing PzGr 40, tried to kill the tanks outright.

So, WTF does that have to do with APHE? Oh, that's right, nothing. It does not even mention it. It is impossible to understand which gun did which kind of damage. We can surmise all we want, but the quote itself does not tell us anything about the question being debated here. That 37mm guns could kill tanks is not news to anyone.

Originally posted by John Kettler:

At Point 208, though the writing is maddeningly unclear, what is clear is that a handful of 3.7cm ATGs formed an important component of the overall reverse slope defense and did some damage. If you continue the story, when the guns and troops pull back and have to fight sans trenches, it gets much uglier for the Germans, until the Panzers arrive to save the day.

So, WTF does that have to do with APHE? Oh, that's right, nothing. They did damage against A9 cruisers. Cruisers... Aren't those the paper-thin armoured things that burst in flames when hit by a rock thrown by a 5-year old? So what does this tell us about the effectiveness of 37mm APHE vs. 40mm AP shot? Nada.

Originally posted by John Kettler:

The results at Bir el Gubi would appear to speak for themselves. The Italians took on an entire Armoured Brigade and despite generally much inferior equipment, gave worse than they got and more permanently. As for the Russians, we need to look at the repair rates for the time before the Panzerfaust and Panzerschreck really became major factors.

No we don't as a first item. We need to look at who owned the battlefield and could recover tanks first. Then, maybe you can make a case that APHE has some impact. But OTOH, we are talking 47mm here, not Pak 35/36, so we are back to: WTF does this have to do with the question of Pqk 35/36 APHE? Oh, that's right, nothing.

Are we there yet?

All the best

Andreas

[John Kettler]

Andreas,

Before I spend a lot of time on a point by point response to your latest post, does it take into account the material I presented in my Feb. 7, 7:55 p.m. and Feb. 8, 12:35 a.m. posts? If not, then it would probably be more efficient and useful for you to do so. And just so you understand where I'm coming from, this thread isn't about the 3.7cm, for that's a sidebar to the main thought, which I consider to be the difference between the typical combat outcome of a 2pdr AP shot penetration of a Panzer III/IV vs. an effective APHE penetrating hit (or partial penetration as outlined above) of 3.7cm or greater, whether of German or Italian origin, against typical British tanks of the period: A9/10

and Crusader. Jarrett, the Beda Fomm tests, and British OR all concluded that APHE was much more lethal to both tank and crew than was the 2pdr AP shot. If you go through my last two posts, I give some actual examples from action in and around Sidi Rezegh.

Regards,

John Kettler

[Andreas]

Originally posted by John Kettler:

And just so you understand where I'm coming from, this thread isn't about the 3.7cm, for that's a sidebar to the main thought, which I consider to be the difference between the typical combat outcome of a 2pdr AP shot penetration of a Panzer III/IV vs. an effective APHE penetrating hit (or partial penetration as outlined above) of 3.7cm or greater,

Oh yes. Let's have a debate on the difference between an 88mm APHE and a 2-pdr solid shot penetrating. I bet that will keep me awake at night, while I wait in suspense on what the no doubt totally unexpected conclusion might be.

Your post, and your clarifications, add nothing but a few anecdotes (see my sig) on the APHE debate, and on the comparison between INSERT A NUMBER HEREmm APHE vs. 2-pdr AP shot. They certainly are not "precisely what I've been talking about all along. ", and they do not support the laughable idea of the 37mm APHE being "highly destructive".

The reason why they don't do so is outlined in my previous post. You are jumping to conclusions on the basis of little evidence, and ignoring obvious factors influencing the conclusion, as always.

All the best

Andreas

[John Kettler]

Andreas,

I simply don't understand your intransigence on the main issue. The Beda Fomm tests (p. 2. of the thread) showed that 2pdr APHE, fired at 900 yards against against captured M-13/40s with sandbags inside as crew simulators, was markedly more lethal than 2pdr AP shot. This was specifically

commented upon when it was noted that the APHE shell splinters had ripped into the sandbags; there was no such equivalent sandbag damage comment for the 2pdr AP shot case.

British OR, whether conducted by MELF or whomever, concluded that given an effective APHE hit, the British were likely permanently out the tank and with a crew hors de combat as well, whereas the 2 pdr AP shot generally left a repairable tank and

a functioning, minimally damged crew. Jarrett came to the same general conclusion, as did someone who used converted German 75mm APHE on the former owners at Gazala (a tank hit was a tank destroyed). Indeed, I presented real life examples of such outcomes from Heckmann's well respected book.

In case that's not enough for you, if you skip down the Jentz quotes on the cited thread page, to the section on armor penetration curves, you can see the German conclusions of the relative merits and capabilities of different AP projectile types. In them, you can read for yourself that ANY effective APHE hit (detonation inside the armor protected space) possesses "annihilating power,"

as clearly contrasted with the lesser outcomes as outlined in the passage.

From there, it logically follows that since 3.7cm PzGr 39 is APHE, and an effective APHE hit, per British tests and OR, American field observations, British combat experience (giving and receiving), and German weapon trials, generally destroys the tank and incapacitates the crew, whereas 2pdr AP shot doesn't, I feel safe in asserting that the projectile in question is indeed highly destructive. If not, what do you think the expression "possessed of annihilating power" means? Please don't forget either that the German projectile has a burster whose explosive, on a like amount basis alone, is 1.6 X more powerful than what filled the 2pdr APHE shells at the Beda Fomm trials.

Regards,

John Kettler

[McIvan]

But Johm, how do you square your conclusions with the fact that the average crew casualties in tanks hit in the Western ETO, by presumably substantially bigger than 37mm APHE on average, resulted in one kill and one wound per crew, and not complete crew incapacitation by any means?

[John Kettler]

McIvan,

The statements that others and I cited on relative lethality apply specifically to the situation obtaining in the Western Desert at the time, a time when British ammo stowage practices were terrifyingly bad. Apparently, after that OR study I'm still trying to locate, measures began to be taken to provide armored ammo stowage and, I believe, to reposition ammo in the tanks to where it was less exposed. Thes measures alone would've made a marked difference in the outcome of the typical APHE hit case, in that the single biggest driver in what happens to the crew is whether or not the ammunition explodes. This, after all, is

so enormous as to simply dwarf what even an 88's detonating inside could achieve, for it would exceed it by orders of magnitude.

You can see this beautifully reflected in the way the U.S. M1 tank is designed, with the vulnerable ammunition all stored in a separate bustle, open to the crew compartment only long enough to extract a round of ammunition, otherwise protected by a sliding armored door. If the ammo is hit after all this, the blast is designed to be swiftly and safely dissipated via blowout panels on the turret roof.

At a stroke, this design protects the crew from the single biggest danger to it, and this works in conjunction with a lightning quick fire suppression system which can stifle all sorts of threats which would otherwise wreck crew and tank alike. These design features were literally paid for in blood and weren't available in the Western Desert back when. What was available then was in German use, was noticed by British combat analysts, and was pretty effective: armored ammo stowage.

Granted that the incident was truly extraordinary, but I refer to the case from Heckmann in which a Panzer III took three 2 pdr shot smack into the ammo lockers, so hard the casings were torn open, yet not only didn't explode or burn, but was still driveable.

I think that nicely illustrates the point I'm trying to make. Also, I'd bet that your Western ETO figures lump in the arrival of the Wet ammo stowage system on Shermans (and other tanks?), further reducing the likelihood of crew injuries. Do you have any figures for the period after the typical guns encountered got nastier but before Wet stowage arrived? That, I would think, would give us a better sense of typical crew casualties for the period after the British started incorporating the expensive lessons taught them by the Germans.

For a look at these matters from the American side, please see TANKS FOR THE MEMORIES (readable online) and the highly relevant section Interviews with many accounts from surviving tankers. There are also audio files.

http://www.tankbooks.com/

If you look at Kenneth Titman's account in chapter 5 of the book, one 88 hit causes the tank to first explode (shell detonation?) then catch fire. He is badly wounded in the leg, the loader abandons the tank as a human torch, the gunner's dead. Driver and assistant driver are okay. That's 3 out of 5 men in the crew becoming casualties, and the tank's toast. This is Normandy.

Am sure there are similar things on the British side, but I don't have them handy. Would expect some real treasures are on the BBC's WW II site, though, based on what I've already explored there.

Regards,

John Kettler

[ February 10, 2007, 08:27 PM: Message edited by: John Kettler ]

[JasonC]

"This is in Normandy" - and it is an anecdote. 40% of Brit tanks initially KOed in Goodwood were recovered and repairable. Brit tanker losses there were quite modest.

An 88 hitting a tank has good BAE not because it has a larger burster but because it hits with 7 to 10 million joules (depending on which sort of 88 we are talking about, etc).

No, you are not relating the unexceptional conclusions of Brit OR, as has been repeatedly pointed out to you. They do not say what you pretend they say, and the claims being advanced here are yours not theirs. Trying to pretend otherwise this late in a 6 page thread is an argument by exhaustion fallacy.

The Brit OR describing hits on Italian tanks does not say 2 pdr plain AP was ineffective or contrast the effectiveness with 2 pdr APHE. It calls both effective and then dilates on the splinters seen from the latter. You infer they is a comparison or claim being made and that they meant that 2 pdr plain AP was ineffective, but they simply do not say this, when discussing the M13/40 examples.

Noting that 2 pdr was less effective against Pz IIIs than against M13/40s is tolerably obvious, the issue being inability to penetrate beyond about 500 yards, and sometimes shattering against face hardening inside that distance.

It has also been repeatedly pointed out to you that no document you have cited claims that 37mm APHE was particularly effective or effective at all. That 50mm APHE was effective is tolerable obvious, and since it is a gun with about 3 times the muzzle energy of a 2 pdr, not exactly surprising, and fails utterly to address your claim that adding a tiny burster causes shell effectiveness to skyrocket.

That poor ammo stowage in early Brit and US tanks made fires more frequent and irrecoverable losses more common is also clear and undisputed, but it no way addresses your claim. You might try to advance it by looking to see whether 50L60 APCR usually failed to KO things or left them recoverable - since it is plain penetrator - compared to APHE. This is to say the least the opposite of the participants opinion about the matter, since they believed greater penetration power vastly more important.

You are supposed to be providing evidence that even a gun as dinky in overall energy as the German 37mm, could get good BAE through addition of a tiny HE burster. Instead you have failed to provide any evidence whatever that the German 37mm was effective against anything whatever. Independent of anything you have said, I know it was tolerably effective against T-26s and BTs. I sincerely doubt it was every very effective against anything else. Which is sort of why the German army referred to them without affection as "army doorknockers" and withdrew them from service at the first opportunity.

No, Brit reports that 2 pdr solid shot reliably penetrated M13/40s are not evidence of the effectiveness of 37mm APHE. No, battleship designs or civil war ironclad AARs are not evidence of the effectiveness of 37mm APHE. No, effectiveness of 50L42 against thin tanks with poor ammo stowage is not evidence of the effectiveness of 37mm APHE. No, what happened to one tank in Normandy hit by an 88 is not evidence of the effectiveness of 37mm APHE.

Even a report of one tank hit and disabled by a single round of 37mm APHE, would not rise to the level of evidence of the effectiveness of APHE, since it would be mere anecdote - but at least it would be remotely on point, which none of the rest of this is.

No, you can't lump together guns from under 200,000 joules up to 10,000,000 joules and pretend all of them must have been effective is any of them at the top end were, because they all have HE in their shell name (when some of them have a firecracker's worth and others a satchel charge's worth).

The point in dispute is whether burster or no matters *more* than overall energy. You can only address it by holding overall energy *fixed*, or nearly so. The reason other people are trying to get you to stick to 37mm APHE vs. 2 pdr solid shot, is there the overall energies are quite comparable. The muzzle energy of the 2 pdr is higher but not significantly so. The chemical energy carried by the small charge in the 37mm APHE pushes its total energy beyond the 2 pdr, again by an immaterial amount (comparable in scope).

They are therefore apples to apples. If having a modest portion of the total E in chemical energy form rather than kinetic energy form dramatically boosts effectiveness, than a 37mm should be dramatically more effective than a 2 pdr. It should therefore be easy to find evidence that specifically 37mm dramatically outperformed 2 pdrs.

But you haven't shown that it does, remotely. The effectiveness of 50L42, the closest you came, does not speak to the point.

[John Kettler]

Some of you may find this Steve Zaloga paper on Soviet tank ops during the SCW of interest because it shows what the 3.7cm PaK 36 was capable of against the contemporary threat of the period. Fighting the most produced basic tank model of the period, the Vickers used by a slew of countries, the 3.7cm tore up a tank highly regarded by the Russians themselves. I especially liked the one hauled up to a church steeple, from whence it exacted a dozen kills.

http://www.libraryautomation.com/nymas/soviet_tank_operations_in_the_sp.htm

Regards,

John Kettler

[Andreas]

Interesting, and a good find. But in the context of this debate, what's next? A paper on how the Pak 35/36 did against trucks?

Or one on how it did against motorcycles?

All the best

Andreas

[JasonC]

Yeah, kinda thought I covered that with my "Independent of anything you have said, I know it was tolerably effective against T-26s and BTs."

Of course the following line was "I sincerely doubt it was every very effective against anything else."

[John Kettler]

Andreas and JasonC,

Your bountiful barbs aside, I posted the link because the SCW, unlike the Western Desert, did not feature the plethora of antitank means found in the latter, theoretically allowing us to isolate the actual combat performance of the PaK 36.

All,

In an attempt to get this once most interesting thread back on track, how does T-26 armor stack up against that of A9,A10, and Crusader I Cruiser tanks, all of which arguably were the PaK 36's prey?

Jeff Duquette,

Since you seem to have a grog's feast worth of great ordnance documents, do you happen to have any German combat assessments of PaK 36 performance in the SCW? If so, then we may learn

something useful about what kind of damage they typically inflicted when they took out tanks. Some of the verbiage Zaloga used would seem to imply K-kills, rather than mere disablement.

Regards,

John Kettler

[John Kettler]

The linked book is part of a recent (1989) HMSO set on British tank design. Am including this one because it specifically addresses in an excerpt from the review what the British found out about why they were having their tanks go up in flames when hit.

http://stonebooks.com/archives/961208.shtml

Regards,

John Kettler

[John D Salt]

Originally posted by John Kettler:

The linked book is part of a recent (1989) HMSO set on British tank design. Am including this one because it specifically addresses in an excerpt from the review what the British found out about why they were having their tanks go up in flames when hit.

http://stonebooks.com/archives/961208.shtml

Does this mean that you now accept the point that it was the ammunition stowage policy, rather than any magical effects of tiny HE bursters, that produced the disparity in brew-ups when penetrated between British and German tanks in the Western Desert?

All the best,

John.

[John Kettler]

John D Salt,

Considering that the APHE generates (insert temperature) fragments via penetration and still more when it detonates, I would argue that British ammo stowage practices optimized the effectiveness of APHE. Further, as I repeatedly stated, the studies done found that if only half of the APHE projectile extended into the fighting compartment, and the shell detonated, that this was generally enough by itself to kill the tank and wound the crew badly enough to incapacitate it.

I presented several instances in which a projectile penetrated, then lodged, with no mention being made of fragments therefrom slicing and dicing the crew. This, IMO, supports my notion of hyperplastic flow at work, as contrasted with the shattering observable, for example, on the face hardened armor of the IWM Jadgpanther.

If I'm right, then 2pdr shot which only partially penetrated, at least before the Germans began face hardening their armor, may not have done much at all. The Beda Fomm tests, though, coupled with the observations of how deadly even partial APHE penetrations could be, suggest that it was precisely the APHE which made German tank and PaK fire so effective against British tanks in the Western Desert. When you spray the interior of a tank with high velocity, very hot fragments (APHE), there's a much better chance of hitting the ammo and crew than there is when relying on kinetic effects alone (2pdr shot), acting primarily along a very narrow shotline. This is particularly true any time the armor quality's good (German, as opposed to reportedly brittle Italian) and/or the penetration's marginal. In cases where the 2pdr got a gross overmatch against the armor, I would naturally expect higher lethality than in marginal penetration cases, seeing as how there'd presumably be lots more secondary missiles created, not to mention a big chunk of shot whining about inside. Ultimately, the APHE acts over a much larger zone inside the tank than does the shot, in turn translating into a greater chance of hitting ammo and crew alike, thus a greater chance of causing the former to explode and the latter to be wounded or even killed.

Here's an easy way to visualize it. You're in a thinwalled small room. Though unseen, your presence is known. Which is more likely to hit you on a random shot, a rifle bullet or an unchoked sawed off 12 ga. shotgun firing 00 buckshot? The answer's obvious, as is which represents what in the analogy. An even better visual model would be that you're fighting room to room, in the dust and gloom. You know there's a foe in the next room, but you can't see him. You've got to enter the room and clear it, but you have only a bolt action rifle, ammo for same, and hand grenades. Do you pop around the corner and fire a single single shot, then duck back, or do you instead flip a grenade in and let all those fragments scythe through practically the entire space, then charge in on the heels of that?

That's basically what we're talking about--a small grenade detonation, this time, in a tiny, densely packed closed steel room full of explosives, wiring, flammables, fragile optics, and even more fragile men.

Regards,

John Kettler

[ February 26, 2007, 08:28 PM: Message edited by: John Kettler ]