Long 88mm lacking punch?

[PzKpfw 1]

I got a reply from Robert Livingston. He has sent what he provided BTS concerning the KwK.43 penetration at 30^ vs a plate hardness range of 206-235 BHN.

The data was from the British 1947 BIOS report on German Tank Armor & original Krupp records concerning the KwK.43 & the late war version of Pzgr.39, Pzgr.39/44 APCBC below shows the diferences in the CM data & the data he provided:

KwK.43: Pzgr.39/44 Pen data @ 30^ provided by R.Livingston to BTS:

100m - 190mm

500m - 179mm

1000m -165mm

CM penetration data for the KwK. 43 @ 30^ Pzgr.39/43 APCBC:

100ms - 177

500ms - 165

1000ms - 151

Robert has no idea why the CM data is lower then what he provided, he replied:

<BLOCKQUOTE>quote:</font><HR> Possibly the BTS/CM game designers downgraded the German penetration to account for the fact that German PzGr was often of lesser "punch" than the WaPruf specs, due to mass production faults. However, much AFV plate was often way weaker than German test plate, so that any deficits in the German ammo could be more than compensated for by the weakness of the tank armor, which was mass produced. So I really don't know where or how BTS/CM came up with the data you quote.

--Robert <HR></BLOCKQUOTE>

I am waiting on his comments concerning other aspects of this thread, will post them when he replies.

Regards, John Waters

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[This message has been edited by PzKpfw 1 (edited 09-29-2000).]

[PzKpfw 1]

BTT........

[danielh]

From the best source available (http://www.wargamer.org/GvA/weapons/german_guns7.html):

The 88mm/KwK43 (Kingtiger)APCBC:

against plate BNH of 230 - 270 at 30°:

100 500 1000 1500 2000

202 185 165 148 132

And remember ALL german projectiles up from 20 mm had a HE filler which was very effective !!! (No US or british projectile), so after penetration the 88mm created a real mess.

Of course the 88 KwK43 and 88/L56 were far superior to anything the allieds had.

Greets

Daniel

[This message has been edited by danielh (edited 09-30-2000).]

[Combatboy]

Thanks DanielH!

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by danielh:

From the best source available (http://www.wargamer.org/GvA/weapons/german_guns7.html):

The 88mm/KwK43 (Kingtiger)APCBC:

against plate BNH of 230 - 270 at 30°:

100 500 1000 1500 2000

202 185 165 148 132

And remember ALL german projectiles up from 20 mm had a HE filler which was very effective !!! (No US or british projectile), so after penetration the 88mm created a real mess.

Of course the 88 KwK43 and 88/L56 were far superior to anything the allieds had.

Greets

Daniel

[This message has been edited by danielh (edited 09-30-2000).]<HR></BLOCKQUOTE>

Daniel please go to page 1 of this thread & read the 1st response from Charles concerning this, BTS does not accept the data you cite as accurate, nor does it accept Wa Pruf 6, Jentz, Speilberger etc.

Regards, John Waters

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[danielh]

John,

So what sources are accepted ?

The formulas used do undermine the wrong "Jentz" figures do not represent reality, but instead are rough assumptions of reality, for instance the effects of the explosive charge at a near penetrating hit are not represented. To get the real values through maths a much more complex model would have to be choosen incorporating an endless count of variables.

What is important is the following:

The 88/KwK43 and 88/L56 could kill any allied tank up to 1000 yards.

Shells from a 8,8 cm bouncing off a jumbo under 1000 m is ridicolous.

A US-tanker stated when asked to improve armor for the M4: "A 8.8 cm penetrates any practical armor."

Have you read the collected statements of US-tankers provided by Grisha ? (Or are these sources also rendered inacurate ?)

I quote just a few findings:

- Superior mobility of Pz V against M4 even with the new suspension

- Far superior sights

- Far superior guns

- Superior projectiles (Souped up...)

- Far superior acuraccy at ranges over 1000 m

- US 90 mm believed to be inferior to 88/KwK43

- HVAP remedies only partly for the 76 mm

These quotes are from men actually being there...

Why not accept it ?

Greets

Daniel

[This message has been edited by danielh (edited 09-30-2000).]

[This message has been edited by danielh (edited 09-30-2000).]

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by danielh:

John,

So what sources are accepted ? <HR></BLOCKQUOTE>

None to date, CM doesn't use tables or live fire data etc. It uses an formula developed from the British 1950 report on armor penetration and angle data provided by Robert Livingston & Lauren Bird.

<BLOCKQUOTE>quote:</font><HR>

The formulas used do undermine the wrong "Jentz" figures do not represent reality, but instead are rough assumptions of reality, for instance the effects of the explosive charge at a near penetrating hit are not represented. To get the real values through maths a much more complex model would have to be choosen incorporating an endless count of variables.

What is important is the following:

The 88/KwK43 and 88/L56 could kill any allied tank up to 1000 yards.

Shells from a 8,8 cm bouncing off a jumbo under 1000 m is ridicolous.

A US-tanker stated when asked to improve armor for the M4: "A 8.8 cm penetrates any practical armor."

Have you read the collected statements of US-tankers provided by Grisha ? (Or are these sources also rendered inacurate ?)

I quote just a few findings:

- Superior mobility of Pz V against M4 even with the new suspension

- Far superior sights

- Far superior guns

- Superior projectiles (Souped up...)

- Far superior acuraccy at ranges over 1000 m

- US 90 mm believed to be inferior to 88/KwK43

- HVAP remedies only partly for the 76 mm

This quotes are from men actually being there...

Why not accept it ?

Greets

Daniel

[This message has been edited by danielh (edited 09-30-2000).]<HR></BLOCKQUOTE>

Yes it has all been posted before it is all considered anecdotal from my understanding. Also note this discussion is not about the KwK.43's lethality, which is fine IMHO in CM it concerns the CM's @ 30^ penetration results, compared to the commonly accepted refrence material @ 30^ data from Wa Pruf, Krupp, Jentz, Spielberger etc.

Regards, John Waters

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[This message has been edited by PzKpfw 1 (edited 09-30-2000).]

[kipanderson]

John,hi,

I could not resist throwing in my 2 pence worth on this one.To cut a long story short I come down on the side of Charles in this debate. If you take as your starting point the "official" penetration figures for the 88mm L56 gun firing the Pzgr.39 projectile as 120mm at 100m against 30^ plate and assume identical definitions of penetration,identical quality of steel target plate and identical quality of projectile one would expect the L71 gun to penetrate 172mm of armour. So Charles's figure of 177mm is not unreasonable assuming the Pzgr.39/43 was of the same quality as the Pzgr.39 used by the L56 gun.

I remember I have explained before how these calculations are done so I will leave out the detail so as not to bore you too much.

All the best,

Kip.

PS. As I will explain in a far longer post in the next day or two in my view some of Charles's other figures are a bit off base, but nine out of ten, including the L71 figure, are right on the nail.

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by kipanderson:

John,hi,

I could not resist throwing in my 2 pence worth on this one.To cut a long story short I come down on the side of Charles in this debate.<HR></BLOCKQUOTE>

Looking forward to reading it Kip as always. We should have some other data comeing soon as well that you will be interested in well if we take this off the board as some wish you won't see it, do you want to be included in the E-mail? if we do.

Now what do you think of what Robert provided?.

Regards, John Waters

PS, Simon if you see this drop me an E-mail please, as your present one isn't working.

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[This message has been edited by PzKpfw 1 (edited 09-30-2000).]

[Guest machineman]

What seems up in the air right now is if the shells of the short and long 88's WERE actually the same. There has been some debate but from what I can see no one has yet to post the definitive answer.

[Vanir]

John, good job on getting that response from RL. You're the hardest working grog on this board

BTW, I hope you don't take Paul's advice to leave us and go join the esoteric bunch at TankNet.

Michael Graham

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So maybe you should listen to this Vanir guy instead of ignoring him -- he has the best take on the whole thing. - Combatboy

[This message has been edited by Vanir (edited 09-30-2000).]

[Claus B]

<BLOCKQUOTE>quote:</font><HR>Originally posted by machineman:

What seems up in the air right now is if the shells of the short and long 88's WERE actually the same. There has been some debate but from what I can see no one has yet to post the definitive answer. <HR></BLOCKQUOTE>

I'm looking at some photos I took of these shells at Panzermuseum Munster and the two projectiles look very similar in terms of size and construction. They weighed the same and were of the same type. The only difference I can find is that the 8,8cm PzGr 39/43 (for the KwK/PaK 43) had a different driving band, allowing it to be fired with sufficient accuracy by worn guns.

Of course, the propelling charges used for the rounds were different as were the guns so the PzGr 39/43 was fired at much higher muzzle velocities.

Claus B

[kipanderson]

John,

Yes, I am on to be included in the email, glad to be offered a place.

When it comes to what Robert provided its interesting stuff. My own view of why the "official" German figure of 202mm may be so high is that it may well be actual test results against their own rather low quality 200mm plate. The Germans, like many others, did have a lot of production problems with such thick plate. It may have had a high hardness but still may have been of low quality throughout its entire thickness. i.e. the figure of 202mm may not be against plate of the same quality as the figure of 120mm for the L56 gun. Hence the figure of 202mm may be correct against the plate they tested it against but Charles 177mm/or my 172mm may be correct if measured against plate of the quality used to produce the 120mm figure for the L56 gun. There is more to plate quality than surface hardness.

Of course this is only a hunch.

All the best,

Kip.

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by kipanderson:

John,

Yes, I am on to be included in the email, glad to be offered a place.

When it comes to what Robert provided its interesting stuff. My own view of why the "official" German figure of 202mm may be so high is that it may well be actual test results against their own rather low quality 200mm plate. The Germans, like many others, did have a lot of production problems with such thick plate. It may have had a high hardness but still may have been of low quality throughout its entire thickness. i.e. the figure of 202mm may not be against plate of the same quality as the figure of 120mm for the L56 gun. Hence the figure of 202mm may be correct against the plate they tested it against but Charles 177mm/or my 172mm may be correct if measured against plate of the quality used to produce the 120mm figure for the L56 gun. There is more to plate quality than surface hardness.

Of course this is only a hunch.

All the best,

Kip.<HR></BLOCKQUOTE>

K, if we end up goin that route you'll be added. Aye, Robert touches on the plate deviation & pen loss due to mass production practices thats why the Krupp data is important to this discussion.

Also look at the Krupp test plate BHN its not the same as cited by Jentz etc, nor does it achieve 202 @ 100ms @ 30^, its 190mm, then note the 165 @ 1000ms @ 30^ remains consistant with, the Wa Pruf specs, US tests, & Soviet tests etc. As I said hopefully we will have more data to ponder soon.

Regards, John Waters

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[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Vanir:

John, good job on getting that response from RL. You're the hardest working grog on this board

BTW, I hope you don't take Paul's advice to leave us and go join the esoteric bunch at TankNet.

Michael Graham

<HR></BLOCKQUOTE>

Thx Michael. Well I'm not to happy with the cheap shots being taken all along the front over this subject, so I haven't decided yet. BTW Their is a great bunch of ppl at Tankers I made many friends their, if your interest is in armor etc, thats the site you wana be visiting.

Regards, John Waters

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[This message has been edited by PzKpfw 1 (edited 09-30-2000).]

[Paul Lakowski]

Thick german armor plate , as on KT , was only 220 BHN compared to the 270 RHA standard. Inaddition david Honners site notes that substandard RHA plate my resist at 90% of norm . This was mentioned by Robert on the old Tankers Net, however I would remind you that in Roberts opinion the actual target armor was, in his words However,

"...much AFV plate was often way weaker than German test plate, so that any deficits in the German ammo could be more than compensated for by the weakness of the tank armor, which was mass produced."

As to the progress on the penetration formula its looking good, I got a surprisingly good fit to the data for Projectiles with an L/d of 2:1 up to 32:1 @ striking velocities of 900 - 1900 m/s. I'll post my findings to our Egroup after I've looked at Tates data on the subject.

I'm really surprised the formula is so simple at this early stage.

[The DesertFox]

Guys,

2 points here:

1st: The weight of the 88L71 projectiles: PzGr39-1=10,4kg; PzGr39/43=10,16kg; PzGr40/43=7,3kg; Sprenggranate43=9,4kg; Hohlladungsgranate39=7,65kg; Hohlladungsgranate39/43=7,65kg

Sources: Spielberger,Jentz,Senger und Etterlin, Hogg,

Fritz Hahn (Seite 61, Zitat: "Die am meisten verwendete Munition war die 1125mm lange Panzergranatpatrone 39/43 von 22,kg Gewicht. Das durch die 6,8kg schwere Treibladung mit einer Vo von 990m/s verfeuerte Geschoss von 10,2kg durchschlug auf 1000m Entfernung 165mm Panzerung."

2nd: A nice sketch which might be of common interest.

Whoops forgot to mention the source:

It is published in Walter Spielberger "Schwere Jagdpanzer - Entwicklung, Fertigung, Einsatz", Seite 22, Motorbuch Verlag 2. Auflage 1996, ISBN 3-613-01517-X

Cheers

Helge

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Sbelling chequed wyth MICROSOFT SPELLCHECKER - vorgs grate!

- The DesertFox -

Email: desertfox1891@hotmail.com

WWW: http://www.geocities.com/desertfox1891

[This message has been edited by The DesertFox (edited 10-01-2000).]

[Paul Lakowski]

Thanks Helge , the plate hardness translates into 135 BHN upto 309 BHN or Mild Steel upto RHA . This makes me wonder what is being shown here? Perhaps the effect of the blasting charge is embodied in these figures as there should be some difference between penetrating mild steel as opposed to RHA.

[PzKpfw 1]

Kip, question on the post on the3 other thread why choose demurs formula over Sopwiths formula? is it a better formula? does it, distinguish between rounds with different nose shapes, or different penetrator hardness, and materials, or the angle-dependant performance of APC, & performance of face hardened armour vs shot into account?.

Also you might want to post it on the Tankers list or I can if you want so Robert can read it. Still looking for your comment on ther Krupp data ...

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[This message has been edited by PzKpfw 1 (edited 10-01-2000).]

[Guest Big Time Software]

John (PzKw I),

<BLOCKQUOTE>quote:</font><HR>I got a reply from Robert Livingston. He has sent what he provided BTS concerning the KwK.43 penetration at 30^ vs a plate hardness range of 206-235 BHN.<HR></BLOCKQUOTE>

Combat Mission does not use tabular test results for armor penetration. I have stated this numerous times before, John, but you keep returning to the idea that Combat Mission uses such tabular data. It does not. Please try to remember that as the discussion moves forward.

The fact that CM does not match a particular set of 88 L/71 test data should come as no surprise to anyone following this thread. In fact that's what the whole controversy is about. The field of 88 L/71 test data is haphazardly strewn all over the map and most of it does not agree with itself - it's completely inconsistent. Choosing any one set of data to go with means that you'll automatically be in disagreement with other sets. In other words, if we pick Jentz' numbers, then we're in disagreement with the British War Office. If we pick the British War Office numbers, then we're in disagreement with Spielberger. If we pick Speilberger, then we're in disagreement with yet others. And on and on. There is not one clearly "correct" set of test data to go by. If anyone needs greater elaboration on this issue, please read my earlier comments in this thread.

The data I referred to having received from Robert Livingston was not 88 L/71 penetration test data. He may have sent me that (I don't remember) but I didn't use it. What I received from Mr. Livingston, and used, were his armor basis multipliers for given shell-diameter-to-plate-thickness ("T/D") ratios and armor slopes.

Mr. Livingston's armor basis multipliers for T/D and slope are, in my opinion the best of their kind, that I was able to locate. There could be errors or limitations in them, but until someone shows me something better I will stand by these numbers and continue to use them. If you feel there is a problem with these values, you'll have to take it up with Mr. Livingston.

Mr. Livingston's speculation that we "downgraded the German penetration to account for the fact that German PzGr was often of lesser 'punch' than the WaPruf specs", is incorrect. We did not do that.

I do find it interesting that Mr. Livingston states that field performance of typical (occasionally faulty) German mass-produced ammunition was below that of the top-quality ammo used at Wa Pruef. Combat Mission does not currently take that into consideration, but it does consider the (often) lower relative quality of Allied plate compared to Wa Pruef test plate. Therefore, because it allows for the weaker target plate, but does not downgrade for lower ammo quality as Mr. Livingston indicates, then CM may actually overstate penetration for a weapon like the 88 L/71. Proponents of the opposite case will now have to wrestle with Mr. Livingston's observation about the lower quality of mass-produced German ammunition used in the field.

Charles

[This message has been edited by Big Time Software (edited 10-02-2000).]

[PzKpfw 1]

Charles, thx for the reply I understand CM doesn't use tabular data, the post is Robert's 1st response to my questions to him since you imformed us the equasions were his & Laurens, not from the 1950 report, had I & others known this earlier much of the follow up posts speculations could have been avoided. I have sent him your replys & will post his responces when or if he responds to the 65% post & this one.

Regards, John Waters

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[This message has been edited by PzKpfw 1 (edited 10-02-2000).]

[Guest Big Time Software]

John,

Mr. Livingston would not have replied with his set of 88 L/71 data if it had been explained to him that Combat Mission does not use this sort of data. I'm sure you meant no harm, but I don't think that this notion was fully explained to him or else he would not have bothered to provide the test data since that's not what we use.

By posting another set of test data up in the thread, with no explanation that you are fully aware that CM does not use this form of data, you unintentionally help to propagate the mistaken notion that CM does indeed use test data directly. It doesn't, and I want everyone to be clear on that.

Otherwise people will think that the dispute centers simply on whose test data to use (or how to amalgamate/weight the disparate, inconsistent data sets), when in fact it is over whether to use tabular data at all. That is why I had to say something.

Charles

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Big Time Software:

John,

Mr. Livingston would not have replied with his set of 88 L/71 data if it had been explained to him that Combat Mission does not use this sort of data. I'm sure you meant no harm, but I don't think that this notion was fully explained to him or else he would not have bothered to provide the test data since that's not what we use.

By posting another set of test data up in the thread, with no explanation that you are fully aware that CM does not use this form of data, you unintentionally help to propagate the mistaken notion that CM does indeed use test data directly. It doesn't, and I want everyone to be clear on that.

Otherwise people will think that the dispute centers simply on whose test data to use (or how to amalgamate/weight the disparate, inconsistent data sets), when in fact it is over whether to use tabular data at all. That is why I had to say something.

Charles<HR></BLOCKQUOTE>

Charles you are correct, I told him we were belatedly imformed he provided the data, & asked him why CMs results were lower then Wa Prufs etc, and provided him CMs pen data for the KwK.43 etc, what you see, was his reply.

Regards, John Waters

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[PzKpfw 1]

Below is another reply from Robert Livingston:

<BLOCKQUOTE>quote:</font><HR>

----------

Dear John Waters, and the BTS/CM crew:

First of all, the slope effect modifiers used by the Beyond Overlord war game are apparently those developed by Lorrin Bird, who had the insight, ability, and tolerance for number crunching that their development required. I passed them along to Charles Moylan. These data were mainly based on analysis of published US data for APCBC andn HVAP, with AP based on British data.

Second of all, Charles Moylan is correct in stating that the 88 L/71 data is a wide and varied lot, some high and some low. My position has been that the higher British data is against British test plate, and is

a closer approximation of what the projectiles would do against allied AFV plate.

The WaPruf data is against German test plate, and is the most conservative (harder, tougher plate resulting in less penetration). Also, there were a variety of 88 projectiles in use, some better than others, and the exact type was not always specified in the published data. PzGr with a larger HE cavity gave way to PzGr 39 with a small cavity (and greater penetration), then PzGr 39 with a welded on head (same penetration), then PzGr 44 with a lower alloy content, and almost as good penetration. The 8.8 L/56 fired two weights of PzGr 39, both with the same designation. Further confounding the situation is the aspect of shot nose hardness, which could vary and could lead to differences in test data, especially in test programs of limited quantities of captured ammo.

Which leads to Paul's question about the welded head on the PzGr 39. This was an alloy conservation move and was noted as early as '42 in captured PzGr 39 for the 7.5. The head of the shot all the way to the bourrelet (where the ogive meets the sides) was of the richer alloy. This did not seem to affect the penetration significantly, except if the

shot failed.

There are some Geman combat stories which describe shots bouncing off when the official tables show a high percentage of

penetration, which can be explained by premature shot failure, although

the exact type of shot is not specified (these are combat anecdotes). Usually the German APCBC did hang together and do the job, far better than US AP and APCBC.

Lastly, let me point out the WWII ballistic research is ongoing, and that the whole picture is only beginning to emerge. Inconsistencies cannot always be explained, given what we know today.

--------------

<HR></BLOCKQUOTE>

A very interesting read eh.....

Regards, John Waters

[This message has been edited by PzKpfw 1 (edited 10-04-2000).]

[Dschugaschwili]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Big Time Software:

By posting another set of test data up in the thread, with no explanation that you are fully aware that CM does not use this form of data, you unintentionally help to propagate the mistaken notion that CM does indeed use test data directly. It doesn't, and I want everyone to be clear on that.

Charles<HR></BLOCKQUOTE>

I don't think you have to worry about that. Anybody who has followed this thread this far knows that you're using a formula to calculate penetrations, not some tables.

Dschugaschwili