Sherman 75mm Effectiveness

[Username]

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

Several posters on other sites have speculated that German armor was oversize so it would pass inspection. If the tank armor was a few millimeters short the whole output might be rejected, so make it a few mm too thick on average and make sure it passes.

.<HR></BLOCKQUOTE>

It was spec'd dude. You must know what that means (I hope).

It was something like -0 and +5%. That means not less than Xmm and no more than +X*1.05. If its 80mm, then its 80mm and no less. 84mm would be the max.

Everything technical is this way. Its mechanical drawing 101. Its basic tolerance understanding.

Lewis

[Andrew H.]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Jeff Duquette:

Andrew...whats page number for this account. I only read about 1/2 the book (not that its not a good read).<HR></BLOCKQUOTE>

I don't have my copy of TfT with me, so I'm not sure of the page number. This incident just got one or two sentences, though, so I'm not really sure how you could find it quickly.

[PzKpfw 1]

Thinking about what Lorrin said & the extra 5 or 10mm's as well as the 'specs' used in construction. And pondering how the Germans who were sticklers on exactness & frowned on waste of materials would allow their tank's to be produced above spec's especialy with the shortage of raw materials they began to encounter in mid 1943. I also think they would have made allownces on the armor thickness to an small extent as Lewis brought up.

But all the xtra 5, 10, & 20 mm of armor though seeming small would add up, in the end as well as, use more materials then allotted, thus raising material & AFV cost. Someome would have caught on to this IMHO & put a kibosh on it, especialy with the problems German armaments factories were haveing getting contract payment from 1943 on.

Regards, John Waters

[Jeff Duquette]

I can guarantee, having written a fair amount of design\construction specifications for a numerous projects, that you will not find something that reads 80mm +/- 0mm. No one could manufacture anything to such strict tolerance levels and still maintain reasonable production rates. No Contractor would bid on the work for that matter. We are talking about mass produced steel plate after all, not precision machined steel for medical instruments.

Pick yourself up a Text book on Steel LRFD design and you will note in Chapter 1, that even steel produced from modern rolling mills has clearly defined levels of tolerance within -- for example -- a wide flange (an I-beam to you lay folk), tube steel, channel steel etc. Acceptable yield strength envelopes, Acceptable camber, and Acceptable thickness of flange and web. Germans Engineers may have been sticklers for precision but there is a limit to how precise a rolling mill is.

Steel below Acceptable tolerance levels is rejected out right. Steel in excess is okee dokee. Get caught peddling non-spec steel…your goin to jail. Several head Engineers and Contractors in Turkey are facing the death penalty for using non-ridged rebar in numerous structures that pancaked in Ankara during the last big seismic event there.

Wouldn’t surprise me if the engineers and contractors associated with that wedding reception floor collapse in Jerusalem spend the rest of their lives behind bars. The floor system they employed has been outlawed in United States Uniform Building Code for years. Those guys knew it and they still skimped on design and building materials.

Regarding wastefulness, It is far more wasteful to a manufacturer to have a batch of 79mm glacis plate end up in the scrape heap as a result of being rejected outright than it is to sneak on an couple extra millimeters in order to match or exceed design thickness specifications.

Look at the thickness values I emailed over to you in the Watertown Arsenal Report. Same routine for Watertown reports on a captured MK III. All the same trend…all plates examined are in excess of commonly referenced plate thicknesses. In fact the Mk III report actually details contrasts in thickness across individual plates (i.e. left side of plate was thicker than right side). “As designed” and “as built” is not necessarily the same beast.

[ 07-05-2001: Message edited by: Jeff Duquette ]

[Vanir Ausf B]

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

When two face-hardened plates are bolted or welded together, the total may be more resistance than the sum of the thicknesses.<HR></BLOCKQUOTE>

Well, crap. That means the Jumbo armor in CM may be wrong. IIRC after learning that Jumbo glacis was 2 plates Charles lowered its resistance significantly.

[PzKpfw 1]

Oh I agree Jeff, & I'll leave the books to you . I just find it interesting that the plates were 5, 10 or even 15mm above spec & no one caught this, 5mm etc, changes the resistance of the plate even if its only minuscule right? & it increases the plate thickness above what is modeled in CM. I also as thinking on the problems the armaments factories were haveing getting paid for AFV deleveries.

And this brings me back the same problem I had with the T-34, can anyone empirecly prove all Panther glacis armor was 85mm, or all Panther nose armor was 65 - 70mm or PzKpfw IV H front hull armor was 85mm etc, based on a few examples of mass produced AFVs.

Regards, John Waters

[rexford]

John,

You're asking a question that is impossible to answer, and it may be an unfair question because the answer you ask for cannot be found. If one looks at a number of Panthers and most have 85mm, and the Russians, British and Americans use 85mm in most of their paper studies based on measurements, the data suggests that 85mm is it.

Since we will usually have incomplete information on many or most WW II issues, all we can use is identified trends that cannot be proved statistically but seem correct. That is the best we can do.

It is like asking for battlefield "proof" beyond a few anecdotes that the CM hit probabilities are too low for experienced and elite crews. There is no way to disprove the probabilities.

Every time someone asks for "proof" beyond a few tank examinations it diverts attention from the basic character of WW II research, where we are all drawing conclusions from incomplete data on the basis of what sounds reasonable.

With regard to T34 armor quality, that is also a non-issue. Americans and British looked at a few samples (1942 T34 and 1945 T34/85), and they were high hardness with irregular quality. Germans looked at a whole lot more and they were all high hardness.

As I noted previously, armor quality is a relatively insignificant issue with T34 high hardness armor cause 45mm won't resist 75mm hits very well regardless of quality. Poor quality high hardness only makes poor T34 resistance even poorer.

People have the right to ask for proof, just realize that this is not a tightly controlled experiment where everything is available and that we are using different levels of "proof".

If the Russians, British and Americans use 85mm thickness for Panther glacis and 65mm for the nose, and measurements support oversize armor, that is good enough for me. They certainly don't appear to be repeating the 80mm thickness the Germans used.

[mensch]

For all thos grogs out there "Kip" at the Kessel wrote up a interesting article about German Gun effectiveness.

comparing Chucks Numbers by what Kip has in research

it can be found under Design Tips / Articles at Der Kessel.

[rexford]

Since we have looked at armor thickness variations from design specs and changes from other published figures for over 15 years, we considered that the variations we saw might have been the upper range of the 0% to +5% allowable factory variation.

85mm is 6.3% over the 80mm spec, and 65mm is 30% over the 50mm spec, so it was obvious that we were not seeing normal variations, we were looking at oversize armor as a way of life.

And some SU 100 glacis thicknesses are almost 10% below the 75mm spec.

Instead of seeing many 80mm and 81mm results and a few 85mm, it seemed like everyone used 85mm for Panther glacis thickness in most cases. Knowing how careful the British were during the war about things, why would they use 85mm for firing tests and calculations when the average was 82.5mm? For the Tiger armor, the British use 102mm and 82mm and 62mm even though German sources have 100 and 80 and 60.

Over and under size armor thicknesses are discussed in our book along with presentation of cases where the design specs and actual measurements did not match up and in some cases exceeded +5%.

Robert measured tank armor thicknesses at Aberdeen and other locations (including tanks in front ot VFW and Legion Halls that he would drive by and then stop), and he carefully tabulated actual thicknesses measured during Allied and Russian analysis of captured German vehicles. The Ferdinand/Elefant armor measured over 5% thicker than spec for several armor pieces.

Robert Livingston wrote a section in the Introduction to our book entitled ARMOR HISTORY, where armor hardness and quality is discussed as a function of thickness and year, as well as examples of armor thicknesses that have significant variations from the spec.

Jeff's response to an earlier post was on the mark, during wartime bigger may be better when less stands a chance of being rejected.

Our book is based on acceptance of the following assumptions:

1. Panther front hull armor is 5mm thicker than the design spec, for penetration range calculation purposes.

2. T34 armor is high hardness and conforms to the resistance-vs-T/D ratio trend noted during American and German firing tests (which assumes the same average armor quality as occurred during those tests).

3. Panther glacis quality varies widely, but about half the tanks have good quality plate (and half have lowered resistance which can vary from tank to tank).

4. Other than a 2mm increase above specs for Tiger I and plus 5mm for PzKpfw IVH front hull (85 instead of 80), we didn't see any trend for other tanks or armor areas that implied significant oversize armor. So 30mm on side of PkPfw III and IV is listed as 30mm, and 50mm on front of PzKpfw III and IV tanks is listed as 50mm.

5. If readers of the book or other folks wish to use 80mm and 60mm for Panther front hull, that is their right, we choose to use the commonly accepted 85mm and 65mm which is supported by firing test measurements.

We wish someone would go out and measure the front hull armor on all of the Panthers lying and sitting around in Europe, in Museums and out doors. Without that we look at what was measured and the figures most people used during the war, and we accepted that as reasonable.

P.S.

One other little tidbit that was noted to me by a poster was that German armor had to pass ballistic tests, and an 85mm plate stood a better chance of passing than 80mm. While materials were in short supply, getting out Panthers without mass rejection may have been an important consideration.

Oddly enough, there is little published evidence that T34 armor varied significantly from 45mm design thickness. A few references to 47mm thickness is about it. However, the 45mm side armor on SU 100 did not measure 45mm, and varied by some really large amounts. Maybe T34 armor specs allowed less variation due to speed and material conservation consideration on a mass produced vehicle, while SU 100 was a relativeley limited run specialty vehicle, late in the war, where tight controls were relaxed (45mm plus or minus 15%).

The 45mm bow armor on one SU 100 measured over 55mm thickness, which exceeds 20% overage.

Our book may be one of the first publications to look at actual measured thicknesses instead of using design specs, and to go with alternative thicknesses that looked reasonable.

Robert Livingston did a great job summarizing armor history in the book Introduction, and provided examples of major variations from design spec thicknesses that appear to be the rule rather than the exception. The armor history section is 7 pages long and covers American, British, German, Russian and Italian armor to varying levels of detail. We did not find any significant examples where Italian or British armor varied widely from design thickness, but most of the reports available to us that could be used to compare armor measurements to design thickness were on German, American and Russian vehicles.

American armor actually did not have a limit for oversize thickness, and Robert provided some examples where the measured thickness was more than 10% greater than the spec.

[rexford]

Regarding Kips' analysis of German, American, British and Russian penetration on the Der Kessel site, nose hardness figures varied widely. Averages are German at 61 Rockwell C, American at 54.5, Russian at 52, based on actual measurements taken during the war. British rounds use same DeMarre constant as U.S. ammo when we compared penetration.

DeMarre cannot be used for Russian APBC since it has a flat nose and other ammo has rounded nose with armor piercing caps. And DeMarre cannot be applied to rounds with different nose hardnesses.

We have actual U.S. tests of Russian APBC against American armor plate, and T34 76.2mm APBC penetrates about 91mm at 0m and 0°.

WW II British tested various rounds at 610 m/s impact against vertical plate, Miles Krogfus published test results in AFV News magazine. German 75mm penetrated 103mm, U.S. 76.2mm penetrated 90mm and Russian 76.2mm penetrated 75mm. 17 pounder APCBC penetrated 107mm.

All of this can be explained on basis of nose hardness, nose shape and whether a round is solid shot.

17 pounder is solid shot and outweighs the other rounds, so direct comparison cannot be made using test figures. HE cavities decrease penetration by 10% or more.

U.S. tests of German ammo show that German 75mm would outpenetrate American 75mm by over 16% at same velocity and weight. British tests showed a 15.7% advantage of German 75mm over American 75mm at 610 m/s, when U.S. 76.2mm penetration in British test is used to estimate U.S. 75mm APCBC penetration at 610 m/s.

If German 75mm penetrates 136mm at 0m at 750 m/s, U.S. 75mm APCBC in CM should penetrate about 89mm at 0m and 619 m/s after nose hardness differences are considered, which is consistent with TM9-1907. Based on British test data, U.S. 75mm APCBC would penetrate 89mm at 610 m/s, and muzzle velocity at 0m was 619 m/s.

CM has about 100mm penetration for Sherman 75mm at 0m, which appears to be about 11% too high.

Our book goes into penetration data analysis considering nose hardness and the impact of armor piercing caps and solid shot-vs-HE cavity rounds, and presents data that is consistent with actual firing tests.

[ 07-04-2001: Message edited by: rexford ]

[ 07-04-2001: Message edited by: rexford ]

[rexford]

The penetration figures for Russian APBC ammunition in our book are based on American tests using good quality armor, and yield results that are slightly below the published test results on the Russian Battlefield.

However, the U.S. tests we have are for 50% success criteria and are based on ALOT of rounds fired. And the results are consistent with the British tests for 76.2mm APBC against vertical armor.

Russian APBC penetrates less than German APCBC at 0° and 610 m/s due to nose hardness and nose shape. Russian APBC also follows a different penetration-vs-velocity curve than the DeMarre equation assumes, which is another reason why a DeMarre analysis of Russian APBC penetration does not work.

The interesting thing is that at 610 m/s, U.S. 76.2mm APCBC outpenetrates Russian 76.2mm APBC by 90mm to 75mm at 0°. However, and this is the strange part of it, at 610 m/s Russian 76.2 APBC will penetrate a 40mm plate at 60° and U.S. 76.2 APCBC will not penetrate.

The difference between a Russian flat nose round and U.S. APCBC is that the Russian round has less penetration at low angles but is exceptional at greater impact angle due to the flat nose that digs into the armor. Flat noses counter ricochet by turning the round into the armor.

The U.S. tests showed this and theory supports the test results. The British report PENETRATION OF ARMOUR PLATE, and American reports, present the theory of flat nose projectiles and anticipate lower slope effects.

Regarding German tests of Russian 76.2mm, one must be careful that they are not looking at test results for German made 76.2mm APCBC fired from rechambered 76.2 guns. Jentz and other sources published German penetration data for Russian 76.2 guns against German armor, and the rounds were German made.

German made 76.2 rounds fired from captured 76.2 field gun and T34 76.2 weighed over 7 kg (7.6?), while T34 fired a 6.3 to 6.5 kg projectile. German rounds fired from Russian guns were at 61 Rockwell C nose hardness, Russian rounds were at 52 Rockwell C. This is in our book and was originally presented by Miles Krogfus, which strongly suggests that Russian rounds penetrate less than German under certain conditions (slope angle and impact velocity) due to nose hardness differences. See our book for American firing tests where nose hardness was varied and impact on penetration was analyzed.

If one is looking at a test of Russian guns firing German made ammo they would penetrate the same as German rounds. The British and American tests of Russian APBC show that Russian ammo penetrated much less than German APCBC at 610 m/s and 0°.

[ 07-04-2001: Message edited by: rexford ]

[Username]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Jeff Duquette:

I can guarantee, having written a fair amount of design\construction specifications for a numerous projects, that you will not find something that reads 80mm +/- 0mm. No one could manufacture anything to such strict tolerance levels and still maintain reasonable production rates. No Contractor would bid on the work for that matter. We are talking about mass produced steel plate after all, not precision machined steel for medical instruments.

<HR></BLOCKQUOTE>

Same thing would apply to hardness of AP rounds. The main point is that there is a variance.

I dont know if rex gets this because he wants to go around measuring all the panthers left in the world in the year 2001. There is a very small sample of the 5000+ panthers and I am not sure what he thinks he will get with that data. He sounds like a buff to me.

I guess that BTS could use a bell curve type of distribution of the thickness from 80 to 85mm. Maybe the reason that theres a few 85mm panthers around is because they survived longer with that extra armor!

Lewis

[rexford]

85mm is based on prevalent thickness measured and publicized during WW II, and my posts have indicated that oversize armor thicknesses do not appear to follow a bell curve distribution between 80mm and 85mm. They tend to be greater than 80mm, and by more than 1 or 2 millimeters.

It would be nice if remaining Panthers could be measured, but this probably won't be done. Would this tend to show mostly oversize thickness Panthers since might have a theoretically higher chance to survive?

No, since practically all Panther kills in Europe were penetrations of armor on side, rear or turret/mantlet. U.S. 75, 76 and 90 guns did not rack up impressive number of Panther kills through glacis penetrations, or even more than a handful.

Panther penetrations on Russian front would have more glacis penetrations, and difference between 80mm and 85mm may be less important than armor quality in many or most cases.

[PzKpfw 1]

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

John,

You're asking a question that is impossible to answer, and it may be an unfair question because the answer you ask for cannot be found.

<HR></BLOCKQUOTE>

Yes Lorrin in a sense it is an unfair question but you opened the door & it has to be asked as this concerns CM's armor model now & usualy Steve & Charles want evidence thats quantifible to make changes.

Regards, John Waters

[Jeff Duquette]

<BLOCKQUOTE>quote:</font><HR>And this brings me back the same problem I had with the T-34, can anyone empirically prove all Panther glacis armor was 85mm, or all Panther nose armor was 65 - 70mm or PzKpfw IV H front hull armor was 85mm etc, based on a few examples of mass produced AFVs.<HR></BLOCKQUOTE>

Your startin’ to sound like some technician that always complains that he doesn’t have enough test data to make a decision on weather a concrete pour for a sidewalk has strength of 3000 psi or 3100 psi.

In the real world things are not precise and nobody ever has as much data as they would like. But decisions get made anyway. You want 3000 lab reports with a nice standard deviation, correlation, mean, saying all Panther Glacis were 84.325mm’s. It ain’t there. But that nice 80mm you see on design drawings by Doyle, that aint real.

Do I personally give a **** weather some wargame has a Panther with a glacis of 80 or 82mm? No.

Lemme open this door…since we’re opening doors . Where did BTS come up with their 85% across the board reduction in Panther Glacis Plate. This is based on 3000 reports saying Panthers had a uniform 85% reduction in plate resistance?

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Jeff Duquette:

Your startin’ to sound like some technician that always complains that he doesn’t have enough test data to make a decision on weather a concrete pour for a sidewalk has strength of 3000 psi or 3100 psi.

Do I personally give a **** weather some wargame has a Panther with a glacis of 80 or 82mm? No.

<HR></BLOCKQUOTE>

Jeff personaly I don't care how you think I sound, or how you feel about wargameing modeling of the Panther glacis, thats your opinion & your entiteled to it.

The question is legitamate as CM models the Ie, Panther glacis armor at 80mm , and calculates penetration vs 80mm not 82 or 85 etc.

And again are an few examples of a mass produced AFV, emperical evidence that all Panther glacis's were 85mm. I dunno, are all Panther glacis's spec'd at 80mm, dont know that either.

Are an few examples eneough to re-evaluate the armor thickness in the CM model, dunno thats up to BTS. As to the 85% quality IIRC thats from Robert's discussions on the Panther glacis. & thanks for the scan....

Regards, John Waters

[ 07-04-2001: Message edited by: PzKpfw 1 ]

[rexford]

John,

Since we only have a small picture of WW II tank combat and armor analysis, we have to take what we have and use it to extend the results to all the tanks. When someone asks for definite statistical proof that a conclusion is valid it obviously can't be found, and that tends to discredit ALL conclusions.

Is that your intent, to discredit everything that is not based on analysis of at least 10% of the tank sample? Then we would have next to nothing.

That is why asking for statistically valid conclusions is not a fair question because it invalidates almost everything.

CM uses a single quality modifier for Panther that is not valid across the board. All Panthers did not have flawed glacis, only the glacis tended to be flawed, and the quality factor varies with the T/D ratio.

Six Panthers have been analyzed and half were flawed, half were not. This suggests that half were good if we extrapolate to all the Panthers. That conclusion is statistically invalid and stuff like this in construction design would lose an engineering license quick as can be, but we're dealing with a subject with tremendous uncertainty and one has to draw conclusions based on limited data.

When 17 pounder APCBC hits Panther glacis the quality is 0.95.

CM is not an exact duplication of our work, and underestimates Panther resistance against 17 pounder APCBC.

Now, since our work on flaws is only based on a few armor tests, should it be tossed due to small sample size? And our results on 75mm hits against 45mm high hardness? And cast armor deficiency to rolled armor?

Russians assumed 85mm for Panther glacis, British do, Americans do. We do.

What CM does is up to them. I'am not asking them to change anything, just pointing out that the WW II combatants thought the Panther frontal armor thickness was best described as 85mm and 65mm, based on their measurements and experience.

[rexford]

John,

I would appreciate it if you would share the German tests of 76.2mm BR-350A APBC with me and others on this board. They were at 30°?

To summarize my previous posts, WW II projectile penetration did not occur on the same basis but varied according to nose hardness, nose shape, whether the ammo was solid shot or HE filler and if it had armor piercing caps.

German 75mm APCBC outpenetrates U.S. 75mm APCBC at the same velocity, and both outperform Russian 76.2mm APBC at 0°. One can assume that they all penetrate according to the same equation but they don't appear to.

We are not basing Panther 85mm on a few tests, but what the nations who fought the Panther found to be the case.

[PzKpfw 1]

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

John,

I would appreciate it if you would share the German tests of 76.2mm BR-350A APBC with me and others on this board. They were at 30°?

<HR></BLOCKQUOTE>

What test's Lorrin?.

German tests 76.2 cm L/30 @ 30^

500m - 66mm

1000m - 58mm

1500m - 51mm

German tests 76.2 cm L/41 @ 30^

500m - 75mm

1000m - 67mm

1500m - 60mm

Soviet tests 76mm L/30 @ 30^:

500m - 47mm

1000m - 41mm

1500m - 36mm

Soviet tests 76mm L/41 @ 30^:

500m - 58mm

1000m - 54mm

1500m - 46mm

Regards, John Waters

[ 07-04-2001: Message edited by: PzKpfw 1 ]

[Jeff Duquette]

<BLOCKQUOTE>quote:</font><HR>The question is legitamate as CM models the Ie, Panther glacis armor at 80mm , and calculates penetration vs 80mm not 82 or 85 etc.<HR></BLOCKQUOTE>

The question is not legitimate if the implication is that plate strength is purely a function of plate thickness. Design tolerance levels are not limited to acceptable plate thickness. Look at the chemical analysis of that lab data I emailed. Do you see anything odd represented in the lack of consistency of internal plate hardness. Anything odd about alloy composition? Does the lack of nickel jump out at you at all? You reckon there’s a potential that a 80mm plate manufactured by the same rolling mill is actually stronger than an 82mm plate?

<BLOCKQUOTE>quote:</font><HR>this concerns CM's armor model now & usually Steve & Charles want evidence that’s quantifible to make changes.<HR></BLOCKQUOTE>

This sounds real noble but it is relatively apparent from past discussions that BTS occasionally makes decisions --- like any normal human does --- on limited amounts of data. It is seemingly only when one of their “gut feel” decisions is questioned that suddenly the cry arises for 3000 lab reports to prove 1 + 1 = 2. That’s their prerogative. It’s their design after all.

What we’re really talking about is acceptance criteria for limited amounts of data. When I see several lab reports from Watertown detailing thickness measurements consistently thicker than commonly detailed design thickness, I think well that’s interesting. Now lets throw into the ring several ballistic test reports derived from a different army on what is quite probably a totally different production lot of plate and again there is this trend toward over thickened plate. Hmmm.

Perhaps this is a reflection of fairly stringent German Quality control or Quality assurance policies. 79.5mm...raspberry from the inspector. Seems to me I recall reading that Panther glacis were sometimes rejected out right do to excessive camber resultant from the face hardening process (slight curvature resultant from differential cooling in the plate). Why not just put the thing in a 1000 ton press and get that darn plate straight again?

[ 07-04-2001: Message edited by: Jeff Duquette ]

[PzKpfw 1]

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

John,

Is that your intent, to discredit everything that is not based on analysis of at least 10% of the tank sample? Then we would have next to nothing.

<HR></BLOCKQUOTE>

Lorrin my intent is to learn, which is done by asking questions, if my asking hard questions of your conclusions, you have posted here is percieved as an attempt to discredit your work, you are mistaken as I have the greatest respect for you & Robert.

But that respect, will not at the same time stop me from asking questions which you may be uncomforatable with, or posting my opinion on your posts here which you may not agree with.

& I'd add that even though your conclusions posted here may not in your mind concern CM, they are being posted on an Wargame forum where ppl will look at the data & despite Jeff's last post's comments on BTS makeing an decision 'on limited amounts of data' ppl will still, say 'look CM undermodels the armor on these <insert tank name here>', and this will lead to questonion's being raised about changeing the armor values etc.

And changes have occured in the past when questions have been made with limited data being presented by posters Ie, the Tiger E mantlet, the Jumbo armor etc.

So should CM increase the armor thickness based on Lorrin & Robert's findings is an valid not an 'noble' question concerning an wargame as it also affects CM2 where Soviet armor was found by Robert to be below specs etc.

Jeff, the data is interesting & the nickel issue is in a few other repoerts I have as well. I'm not a metalurgist or an Eng I'm merely posting an simple laymans opinion concerning the posts, and CM is a game useing set numbers for armor thickness etc.

If that thickness is incorrect then should not it be presumed someone will eventualy ask it be adjusted based on Lorrin's posts here? especialy concerning the attention German uber tank's get here.

Regards, John Waters

[ 07-04-2001: Message edited by: PzKpfw 1 ]

[rexford]

John,

Given the limited data available to draw conclusions, the question should not have been that one needs a wealth of unobtainable data but whether there were enough different bits of data to support one figure over another.

I am not uncomfortable with your question, it is the manner in which it is posed which may tend to shut down the communications. If the question is posed such that a positive answer is impossible, then that ends the discussion.

Why not ask what is the total picture that favors using one or another, which leaves the door open. Refusing to go one way or the other unless unobtainable data is presented shuts all doors and locks them tight.

That is my point.

[rexford]

John,

what is the weight of the 76.2 rounds in those German tests.

Thank you.

[kipanderson]

Rexford, hi,

It is very interesting what you say about Russian APBC rounds. At a given velocity they perform less well against vertical, but better against sloped armour, than US rounds.

This does show that Charles will have to be very careful about how he models Soviet APBC penetration in CM.

As I say in my post I agree with Charles that in the contest of CM, or any wargame, the way to go is to start with a De Marre style analysis and then to look at the quality of the rounds. This is what I tried to do. What you bring in bucket loads is information to help in making a judgement on the quality of the different nations rounds.

Rexford, may I take the opportunity of asking how I can get hold of a copy of your book? I live in the UK. I am sure there was an announcement but I must have missed it. I have tried the search engine with no luck. As you can imagine, someone with my interests is hugely looking forward to reading your book.

All the best,

Kip.

[PzKpfw 1]

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

John,

what is the weight of the 76.2 rounds in those German tests.

Thank you.<HR></BLOCKQUOTE>

7.6Kg

Regards, John Waters