STUGGED UP AGAIN

[Fionn]

Why doesn't a neutral party just restate the basic question here as a basis for further comment?

There is an answer but it won't be gotten by talking at cross-purposes and whilst some people are more concerned with being RIGHT than being CORRECT.

So, Tarqulene, would you like to have a go at restating the central argument and points of disagreement arising thereof?

[Tarquelne]

Your continued stated inability to understand the basis of the growling between Jason and I, is well to put it kindly, your problem.

Of course it is - I'm not much of a grog. I didn't see anything you posted as a "clincher" against JC's arguments. Because I didn't understand them? Possibly... possiby not. Given that, I just have to try to spot what might be errors in logic, ask questions, and ocasionally try my own "tests" in CMBB.

So, Tarqulene, would you like to have a go at restating the central argument and points of disagreement arising thereof?

Simple answer: No, I wouldn't _like_ to.

(The rest is going to ramble, and is quite a simplification... but it's been a 6 page thread so far, it's Sunday morning, and I make no claims to grogdom. This is as good as I'm willing to give.)

I'd like to comply, but - as B. so kindly pointed out - I don't understand some of the issues very well. I can't really give you the "central" argument. I'm not even sure there is one, actually. JC and B, for example, are both using several lines of attack, and referenced various reports to great mutual un-satifaction. A couple of "Partial Penetrations" and some "Armor Flaking", but as far as I can tell no brew-ups.

I can give state the central disagreement, though, as I understand it:

The early T-34's front turret penetrated too easily in CMBB.

Jason C. says it's penetrated too easily, and I imagine some others agree. B. says not so, and I think some others agree.

My understanding so far:

1) The front turret is indeed the Achiles heel of the early T-34s vrs. common (?) German guns.

This seems to completely consistent whith other "things a bloke in a pub told me", and trials in CMBB.

(The ? after "common" is a good example of my lack of expertise and possible errors in logic. B holds up JC's selection of the PzIIIH as misrepresentationl. But the same gun (I thought) was carried by the G and short-J, which I thought were more than common enough to warrent discussion. So one of them misrepresenting something. Maybe J, maybe B - I don't have the proper sources, so I don't know which)

2) J. says those front turret penetrations are too common in CMBB from the 50L42 guns (and, IIRC, which is quite questionable, from the 37 and longer 50s.) Or, perhaps: richocets are too uncommon.

There's been much discussion how common those penetrations really are in CMBB, and why they occour. (I'm going to avoid the "why" part - I think it'll really matter only if BFC agrees the current model is "off" far enough to merit correction.) Andreas did a fair number of tests, I did a few, and ~20% ricochets seems close to the CMBB truth. (Varies by range.)

You'll see accusations that JC overstated the infrequency of ricochets in CMBB. Personally, I think this is true. Not that it matters - he still thinks 2 out of 10 is too few.

That's it.

************

B's last post (not counting "Jason has built his argument of T-34 front turret should be impermeable to KwK 5cm (in 1941)", which is simply an especially annoying (repeated) bit of misrepresentation) seems to be a good summary of his criticism of many of JC.'s arguments. Maybe JC will make a _direct_ response to it, and the feeble minded, such as myself, will have recieved an easily digestable digest.

But JC does say that the T-34's armor shouldn't be penetrated "regularly" by the 50L42 at ranges well over 500m. Hits on the front turret in CMBB do regularly penetrate at between 500-1000m. However, the frequency of hitting the front turret (as opposed to missing or hitting the hull) still makes the issue unclear, even if JC is right about the penetration vrs. ricochet frequency.

I thought someone had made a statement about what the ricochet % should be, but I couldn't find it...

And I think that the JC post before B's should be usefull to: JC stated his combat expectations. Since they skip much of the who-said-what-to-who-and-why issues I hope they'll be easier to debate (and check in CMBB) than many other arguments. My thinking is that claims in that post, with regard to the acutal combat performance of the units involved in certain circumstances, will be easier to prove or disprove.

Two more things:

1) JC has argued based on an analysis of the shape of the T-34's turret. How much of the area was protected by armor at slope X.... Andreas pointed out that hits should often be clustered toward the center of the turret - it's most vulerable point. Since I don't remember seeing any figures about just how "clustered" such hits would be, and I suspect JC oversimplified the matter (though not egregiously) I've tossed that argument of JCs.

2)

Lt. Hortland:

My guess is that those two factors [turret shot-trap and the "all turrets are the same size" CM engine flaw] combined are the reason why we are seeing ahistorical results in the game. Tanks with a vulnerable turret front are handicapped by the game engine because it is too easy to score a hit on the vulnerable area.

Even if JC is wrong about the turret armor he still may be right, in that - and this is where it started - the armor performance of the T-34 is undermodeled.

A personal note: Why am I involving myself? Because I'd really like to see this resolved. The T-34 is an important and fascinating tank (assuming one is fascinated by this sort of thing.) I think it "neato" that the famous T-34's front turret was so vulnerable... likewise, it'd be "neato" to find that the front turret of the famous T-34 did "regularly" deflect the 50mm shells. I just like being able to think "neato".

[ February 02, 2003, 12:37 PM: Message edited by: Tarqulene ]

[A.E.B]

Hi all

Sorry to gate crash. I have posted a link to a online photo album that contains 14 pictures of 1939 to 1941 model T34s, their weak spots, and actual knocked out T34s on the battlefield. To see them go to the link in the Knocking out T34s in 1941 thread.

Regards

A.E.B

[Fionn]

Well that's very simple then:

ALL someone has to do is set up the following tests (obviously none of the major participants should do this as there would be accusations of bias).

Set up some unarmed (I'd suggest ten would be reasonable) T34 500m, 750m and 1000m from the following guns:

1. 37mm PaK

2. 5cm PaK.

Separate maps per PaK type and T34 range obviously. ATGs to be armed only with AP rounds ( no HC, no HE, no Tungsten).

Write down the results dividing them into total number of hits and ricochets, number of hits on turret front, number of ricochets from turret front, number of partial penetrations. Number of full penetrations. Numbers of T34s knocked out.

Obviously the game should be hotseat so that the tester can determine when a T34 is knocked out.

Then set up the same test with Panzers armed with 5cm L42, 5cm L60 and the 3.7cm guns. Repeat tests as described above.

Now repeat for the Soviet side.

At the end of that test run (I suggest a minimum of 5 repeats per side with up to 10 tanks per repeat to make a sample size of 50 tanks, obviously 100 would be better but time constraints may get in the way) all the data should be written down and posted.

The results will allow some very clear conclusions to be made re: ricochet potential at various ranges and penetrations to the turret front.

I won't do it since I have no desire to become a target for both sides at this stage.

[Jarmo]

I wouldn't thing there's need for more testing, since neither side seems to be disputing the results of this test by Andreas.

Well, just ran the 750m tests 8 more times.

Totals now come to, including the previous five runs:

Penetrations 63%

Partial penetrations 9%

Ricochets 18%

Gun hits 10%

Total T34 killed now 28

Total PIII killed now 36 (add to this a few shocked and one immobilised)

2-3 turns and it is all over. This is certainly affected by the fact that the T34s are dug in, therefore hull hits are much less likely.

What's happening, is J stating 72% penetrations or partial penetrations, 18% ricochets is too much penetration. I get the feeling he'd be happy with reversed percentages.

The "other side" seem to consider the results are in line with historic realities.

Rexford popped in, but damn if I understood which side he was taking.

Hi was mostly going on about 37mm and T-34 sides anyway...

[Tarquelne]

Whoops, Jarmo already posted.

[ February 02, 2003, 02:47 PM: Message edited by: Tarqulene ]

[JasonC]

I will try to restate what I believe the issue in dispute is, with much less advocacy than previously, since others interested may not have followed all of it, and I quite understand that seeing people argue one side of a case can seem hopelessly distorted to bystanders.

The question is whether CMBB gets the vunerability of the T-34 turret correct, or overstates it, and if so by amounts that matter, or not.

How vunerable CMBB makes the T-34 turret front is not, I think, seriously disputed by anyone at this point. It is not a matter of people not knowing what the game does. That data has been seen. The question is whether that data agrees with history or not.

To answer Fionn's questions, though, the T-34 turret front will defeat the 37mm PAK at the listed ranges. It will fail to defeat the 50L42 at the listed ranges, including 1000m. Not just "some of the time", as in 1/3 getting through, but "most of the time", as in 2/3rds or more of the hits on the turret front will be penetrations or partial penetrations.

The disagreement is about the historical vunerability of the T-34 turret front. Some, perhaps trusting CMBB armor modeling, also going by statements that the T-34 gun mantlet can be penetrated by 50L42, think the turret front could be penetrated most of the time out to ranges as far as 1 km.

At least, I think they do. They have repeatedly said that it *could* be penetrated (range unspecified). Which despite some representations of other's arguments, I do not think has been disputed here, since about page 2. Some have added, "out to 500m" - without specifying how frequently they'd expect it at that range. Asked if 80% of the time at 1 km would be historically correct, they say they do not know, but also don't know otherwise.

I don't think penetrations of the turret front by 50L42 were routine at 1 km range. I doubt they were routine at 500m range, though I don't claim they were impossible at that range. I think close enough, they probably did become routine.

What am I basing these assessments on? My reading of German tactical doctrine for dealing with T-34s. I am trying to put together two things - one, a chance of hitting and penetrating a particular plate at this or that range, and two, the overall methods of dealing with T-34s actually adopted by the Germans, and their reports about why.

I am well aware that there is distance between the two things. But I believe there are some conclusions about one side - this plate penetrated this reliably this far away - that are incompatible with known facts about the other side (the tactics). Other conclusions about the plate vunerability question, I believe would be compatible with those known facts.

I understand that anyone can disagree with me about which gun-armor match ups and chances have which tactical implications. But I think they need to explain why the tactics were the way we know they were, if the gun-armor match ups were the way they say they were.

Occasional "sticky" hits on the more vunerable bits of the turret leading to KOs at 500m, I find perfectly plausible and compatible with all of the evidence. If the chance of a turret resulting in such a penetration at medium range (500m, or marginally more) were on the order of 40%, I'd have no problem at all. If it rose to more like 80% (or 90%) as the range fell, again I'd have no problem at all.

Why do I think those figures would be believable, but 80% at 1 km is not? Because I think the tactical implications of the two are different. With the first set, you close; with the second, you needn't. And the German doctrine was "close".

I don't think that aspects of the vunerability of the T-34 that we've found in a few months of leisurely gaming, would have eluded professionals whose lives depended on getting it right. But I am now moving into advocacy, which I was trying to avoid in this post.

Is the dispute over whether 50L42 ever penetrated a T-34 turret front? No.

Is the dispute over whether such penetrations should be possible even at 500m, rather than point blank? No.

But 80% ("well more than half", not to make a fetish of the number) at ~1000m (A)

is not 40% ("half or somewhat less than half") at ~500m. (

And that is the dispute. A or B, historically.

In terms of CMBB game mechanics, the issue is what angle of armor does "curved" act as? And with what randomness or variance? One distribution of angles will give A, another B.

I hope this helps. Unfortunately, I will be away for the next two weeks, but I hope these things will not simply disappear, and I will be open to continued discussion of them when I get back.

[ February 02, 2003, 02:51 PM: Message edited by: JasonC ]

[JasonC]

"started a duel with Pz regt 35 at 1000m, the T-34s and KVs won the firefight handily because the Panzers were unable to close the range."

But in CMBB, I don't have to close the range, below 1000m, to fight T-34s. If I hit the turret at 1000m with 50L42, they get penetrations or partials and destroy T-34s.

"The Panzers only began knocking out T-34s and KV when they closed the range (Sub 500m look at the topo maps)"

So, closing to under 500m is the way to deal with T-34s. This is exactly the behavior I say is missing in CMBB, and that I want to see. If Panzers needed 500m and shorter ranges against T-34s, even when they hit the turret front, I'd be happy as a clam. They don't.

It is precisely proper tactics that I want to see. That means Germans encouraged to close, unless they have such numbers that hail fire can succeed even without penetrations - as I started off by demonstrating with my KV example.

If you don't like Hs, use Js. The uparmoring on the Hs was originally a field measure anyway - extra bolted on plates. That started earlier, but was done for the whole H series. It was done in the field to some late Gs, as well, making them Hs essentially. (Actually, Hs had other minor improvements, like wider tracks to accomodate the extra weight of the bolted on armor, a turret basket, etc - but in gun and armor terms, a late G with bolted armor is an H). The Js were much more numerous later on, but only in production for 3 months on the day of the invasion.

Your idea that all of the reports of T-34s being tough stem from 1942, I am willing to accept as the only way to maintain your conclusions in the face of the tactical evidence. Unfortunately, you conclude above yourself that in 1941 they started killing the T-34s only once inside 500m, which is exactly what I see as compatible with those training documents, but do not see in CMBB today.

[ February 02, 2003, 03:27 PM: Message edited by: JasonC ]

[Fionn]

Ok that clears things up.

I will say that given my experience with various physics calculations for determining ricochet potentials for various shells throughout the years I do feel that CMBO and CMBB have under-represented the ability of (and this bit is key) THREE-DIMENSIONALLY CURVED ARMOUR (as opposed to two-dimensionally curved armour) to create ricochets.

Also though we must bear in mind that the curving we are talking about would be most effective when the turret is not pointing directly at the firing unit ( since the incident angle would be made even more acute by said rotation away from the target) so that factor has to be borne in mind.

I believe though the answer lies in the absence of a 3-dimensionally curved armour label as opposed to the presence of "curved" which, as far as I have always understood applies only to 2-dimensional curving ( such as we see on the Panther mantlet).

I certainly do not buy much of Jason's argumentation in support of his position insofar as much cannot be proved and much else falls under the remit of "if we assume x, y and z (none of which can be proven) then the BF.C model is at fault". That's not the way to prove error.

I believe that the issue I have highlighted lies at the basis of the lack of ricochets and thus increased T34 frontal aspect vulnerability. I also believe it has the benefit of being something which can be checked (as to presence or absence), which could be rectified and would result in the following:

a) gun power staying as is ( current penetrations are realistic)

improving the armour model for the whole gamut of tanks, not just this single type of T34 .

I think people got too caught up in "can gun A kill at 500 m" etc... Sure they can. The reason they didn't was mostly because of ricochets. If they didn't ricochet they often killed. Fiddling with gun powers etc is the wrong way to approach this. Dealing with things which are lacking in the current armour model are the best way to do this.

I do not, however, have the inclination to bring this up with the powers that be personally.

[Bastables]

Originally posted by JasonC:

If you don't like Hs, use Js. The uparmoring on the Hs was originally a field measure anyway - extra bolted on plates. That started earlier, but was done for the whole H series. It was done in the field to some late Gs, as well, making them Hs essentially. (Actually, Hs had other minor improvements, like wider tracks to accomodate the extra weight of the bolted on armor, a turret basket, etc - but in gun and armor terms, a late G with bolted armor is an H). The Js were much more numerous later on, but only in production for 3 months on the day of the invasion.

Your idea that all of the reports of T-34s being tough stem from 1942, I am willing to accept as the only way to maintain your conclusions in the face of the tactical evidence. Unfortunately, you conclude above yourself that in 1941 they started killing the T-34s only once inside 500m, which is exactly what I see as compatible with those training documents, but do not see in CMBB today.

PIIIHs were not field measures, they were factory "stopgaps" that required stronger reworked suspension that eventually ended up in the 5cm armoured basis of the J. The few E, F, Gs that were up armoured/new suspension required a factory rebuild. The Highest number of PIII rebuilds during 1941apr was 39 of which only 11 were rebuilt to H standard. The first PIII E, F, G up gunned and up armoured to H standard where issued on the 15 of June of which there was only 11. Along with this G continued to be rebuilt at 2/3 ratio to H standard rebuilds. The H standard is not representative.

All the reports you’ve put forward, including the first time that an anti-T34 document had surfaced have been in 1942 Jason. But again it’s good to see you can now accept that the Front turret is vulnerable at 500m as opposed to one of your ever-changing ranges “While at 550 meters with a regular shooter only able to shock at 30 degrees, penetration would become impossible (-5% for range) and shock only 10% of the time. And there is your Pz Regt 203 and Panzer command training document behaviour, more or less.”(Jason 2003)

You did argue with my that 500m penetration ranges for several pages, don't try to state that that's what you secretly agreed to all this time.

Remember Pz Rgt 203 Combat trials =1942

“Panzer command training document” = first issued in May 1942

You don’t have to merely accept my word for it Jason, take a look your self.

500m “absolute” vulnerability is in line with the border battles with the 1500 T-34s, not all of them drove into swamps. Even the Tank commander of the western military districts (Morgunov) in a “report” to Front military council (after the first week of Tank combat) notes that KV and T-34 tank armour needs to be augmented for combat versus German Pak’s and Panzer’s. You’ve changed your argument from 500-800m invulnerability to 750 to 800 and now to 1000. That’s fine whatever you want to jump to next but the T-34 is not invulnerable to short 5cm as you first posited and attempted to fix with the magic 45 deg figures.

[ February 03, 2003, 07:31 AM: Message edited by: Bastables ]

[JasonC]

"at 550 meters with a regular shooter only able to shock at 30 degrees" does not refer to a 50L42, which if you looked at the numbers would be obvious. A 50L42 penetrates if the armor acts as 30 degree slope, well beyond 550. It has 52mm listed penetration at 500m vs. 30 degrees, and would fall only 1mm 50m farther on - more than enough.

It is the 75L24 that acts that way against decent turrets (47-48mm), while the 37L48 would act that way against the weaker ones (43-44mm). Please note that the statement is inside of an assumption, "with a shooter that can only shock at this range, you'd see etc".

Why was I talking about 75L24 behaviors at that point, not 50L42? Because I was trying to explain the difference my proposal would allow in penetration behavior for the best shooters and average ones, via modifiers to the "degree of slope" "die roll" for experience level of the shooter. I was specifically using the example of Wittman's StuG, which means 75L24 of course, not 50L42.

The training document date is 42, yes. That is when the reports of penetrations of the mantlet date from, too. So do you claim those are refering to penetrations of 75mm turret fronts? That 1941 model T-34s had all been KOed by then? That doctrine actually used in 1941 against T-34s was to stand off at 1 km?

I am still waiting for Bastables to say whether he believes 80% penetrations of the turret front by 50L42 at 1 km range is correct or not. I'd also like to hear what penetration chance he thinks would be proper for 500m. 80%, 90%? Or 40%, 50%?

So far I've heard much made of "possible", nothing about "reliable", when it is the tactical distortions introduced by "reliable" too far away that I most object to.

Did the panzers KO T-34s beyond 500m in the October 41 fight, or not? If not, why not? If they can in CMBB, and didn't in reality, why the difference? Is the region of our disagreement disappearing, as I would hope it would on repeated iterations between reasonable people, or are you defending CMBB results, including 80% penetrations out to 1 km?

As to Fionn's comments, I mostly agree with them. The solution I have proposed does not depend on changing penetration numbers for any of the guns - I never proposed such a thing, and indeed said directly (way back in the first 2 pages) that I trust CM and Rexford and company on such matters. The issue is simply what distribution of angles "curved" can be expected to give rise to. I agree with Fionn about why that is hard to model - 3D rather than 2D, etc.

I think the -variance- in the effective angle produced by "curved" is higher than CMBB is modeling it to be. I think that is all that is needed to correct the current behavior.

If 30% of the shots hit angles as low as CM now models, I would not see in that any deviation from AARs sufficient to call it innaccurate. The motives to close would still be there. If some significant portion of hits on the turret encounter angles around 45 degrees, then getting significantly closer makes it significantly more likely that a hit will penetrate.

I first proposed a model where instead of nearly deterministic 30 degree or less behavior (as one other tester put it, "might deflect if you are lucky but should be treated as though flat"), the nearly deterministic expectation would be clustered around 45 degree behavior. With some chance, similar to the existing chance of a high angle-deflection, of a particularly "flat" or particularly high angle hit.

After examination of the turret areas and listening to criticism from others, I see that this proposal was too low variance itself. So I revised it to 30-40% low angle (30 or less), 40-50% moderate angle (45 or so), 20-30% high angle. That I've moved in response to examination and criticism, I consider a point in favor of my views, not one against them.

If anyone bothered to look at my color coded diagram, those roughly correspond to the blue areas - "go", mantlet, turret ring, shot trap, gun itself - the yellow ones - mid turret, which I'd expect to be range dependent, close enough getting in and far enough deflecting - and the red ones - high angles and deflections.

The principle change here would seem to be the behavior in the "yellow" zone, where right now the CMBB "curved" model effectively gives 30 degree or less, and my proposal would give more like 45 - or roughly as hard to penetrate as the side aspect.

Overall, I think the modeling is as close to right as anyone can hope for if it encourages the tactics people actually used. And the modeling is only significantly off, if it allows and encourages tactics that historically were not attempted, and rewards them.

I think the undermodeling of "curved" does produce such an effect in fights against 1941 model T-34s. That just makes it easier to detect that such a modeling problem might exist - the difference from historical tactics is simply noticable in that case. That "curved" should give a higher variance of angles would then be a wider result.

For what it is worth.

[ February 02, 2003, 06:34 PM: Message edited by: JasonC ]

[Bastables]

Originally posted by JasonC:

The training document date is 42, yes. That is when the reports of penetrations of the mantlet date from, too. So do you claim those are refering to penetrations of 75mm turret fronts? That 1941 model T-34s had all been KOed by then? That doctrine actually used in 1941 against T-34s was to stand off at 1 km?

I am still waiting for Bastables to say whether he believes 80% penetrations of the turret front by 50L42 at 1 km range is correct or not. I'd also like to hear what penetration chance he thinks would be proper for 500m. 80%, 90%? Or 40%, 50%?

So far I've heard much made of "possible", nothing about "reliable", when it is the tactical distortions introduced by "reliable" too far away that I most object to.

Did the panzers KO T-34s beyond 500m in the October 41 fight, or not? If not, why not? If they can in CMBB, and didn't in reality, why the difference? Is the region of our disagreement disappearing, as I would hope it would on repeated iterations between reasonable people, or are you defending CMBB results, including 80% penetrations out to 1 km?

[/QB]

By golly you’re a tiresome little fellow.

2800 T34 were produced during 1941 another 115 were manufactured in 1940. The Russian managed to lose by 31 Dec 1941 2,300 T-34s. STZ during the 4th quarter was the main T-34 (900) supplier and built the up armoured T34- 41/42 with thicker gun mantlet, these where the survivors. Only 55 T34-41 where built by factory #183 during the 4th quarter. I don’t see how any of this leads to thousands of 1941 type T-34s causing the Germans enough trouble to warrant an Anti T-34 instruction set.

(*See: Krivosheev G.F. "Grif sekretnosti sniat: Poteri vooruzhennykk sil SSSR

v voinakh, boevykh deistviiakh, i voennykl konfliktakh". (Losses of the

armed forces of the USSR in wars, combat actions, and military conflicts).

Moscow: Voenizdat, 1993. pp. 349 – 350).

It’s interesting that the T-34 only causes enough headaches to warrant a tactical paper in May 1942, and no earlier. Just to head off Jason disassembly before it comes to a head, it does not take 11 months for assessments to travel from the front to OKH and back again. Comparisons can be made when after the end of AGC defence in February 1941 The Operations Branch of the Army General Staff had already issued assessments and lessons learnt by mid March, a mere two weeks had passed before the above were already disseminated to field commanders. (Addington, Larry H. The Blitzkrieg Era and the German General Staff, 1865-1941, New Brunswick, NJ: Rutgers University Press, 1971) and (Dupuy, T. N, A Genius for War: The German Army and General Staff, 1801-1945. Englewood Cliffs, NJ: Prentice-Hall, 1977).

Why does the T-34 become a problem in May 1942? Simplistically up armoured turrets growing from 45mm of T34-41 to the T34-42 60/65mm standard.

And no I’m not going to run around pulling percentages out of my arse Jason, you play that game well enough for both of us and I belive it’s irrelevent to my argument. Of course with your misunderstood and out of context sources you have to build your argument out of something don’t you.

[Dschugaschwili]

Originally posted by Fionn:

[...]

I will say that given my experience with various physics calculations for determining ricochet potentials for various shells throughout the years I do feel that CMBO and CMBB have under-represented the ability of (and this bit is key) THREE-DIMENSIONALLY CURVED ARMOUR (as opposed to two-dimensionally curved armour) to create ricochets.

[...]

I believe though the answer lies in the absence of a 3-dimensionally curved armour label as opposed to the presence of "curved" which, as far as I have always understood applies only to 2-dimensional curving ( such as we see on the Panther mantlet).

[...]

Finally a post that sounds useful. A few mathematical calculations:

When shooting at a cylinder (2D-curving), assuming that the hits are equally distributed (so hits in the center are not more likely than hits farther out), the probabilities to hit the surface at different angles are:

Ang. Prob. Diff.

10°: 17.4% 17.4%

20°: 34.2% 16.8%

30°: 50.0% 15.8%

40°: 64.3% 14.3%

50°: 76.6% 12.3%

60°: 86.6% 10.0%

70°: 94.0% 7.4%

80°: 98.5% 4.5%

90°: 100.% 1.5%

The Prob. column shows the probability of hitting at an angle of less than Ang.

The Diff. column shows the probability of hitting at an angle between the Ang-10° and Ang.

We see that half of the hits hit at an angle of 30° or less.

The same calculations done for a sphere (3d-curving) instead of a cylinder yield the following results:

Ang. Prob. Diff.

10°: 3.02% 3.0%

20°: 11.7% 8.7%

30°: 25.0% 13.3%

40°: 41.3% 16.3%

50°: 58.7% 17.4%

60°: 75.0% 16.3%

70°: 88.3% 13.3%

80°: 97.0% 8.7%

90°: 100.% 3.0%

Here only a quarter of the hits hit at less than 30°.

But that's still much more than JasonC's proposed round armor model on page 2 would allow. Obviously he hasn't thought his model through properly.

Dschugaschwili

[edited for spelling mistakes]

[ February 03, 2003, 05:53 AM: Message edited by: Dschugaschwili ]

[Tarquelne]

You're giving JC a good slapping around B, but I don't think you've quite connected all the dots. For example:

What range is "close" range for panzer (50L42) vrs. T-34 comhat?

And no I’m not going to run around pulling percentages out of my arse Jason, you play that game well enough for both of us and I belive it’s irrelevent to my argument.

Is your argument similar, then, to Andreas', in that you're simply trying to disprove a leg or two of JC's argument without making any claims of your own? (I hasten to add there's nothing wrong with that.) Or maybe just a claim that whatever is seen in CMBB is historically correct?

[ February 03, 2003, 06:02 AM: Message edited by: Tarqulene ]

[Andreas]

Tarquelene, I actually think that your question about how many of these duels actually occurred is exactly the right one to answer. If one looks at the context of the battles, it might be something like this (warning, heavy conjecture to follow):

1. Superior Soviet tank shows up and shoots up German Panzers at long range (1,000m or so), with German Panzer return fire seemingly ineffective (remember, they aim at centre mass, and will only hit vulnerable area by accident, since they do not know it is the vulnerable area).

2. Germans go "oh bugger" and retreat. Try to figure out a way to deal with these troublesome fellows. Now at this stage, a suggestion that the most vulnerable spot is the turret front is going to be received with incredulity - shurely the front is the most thickly armoured part of a tank. It must be elsewhere. Suggesting that you can knock out a tank from the front at longer ranges than you can from the flanks is exactly what gets one branded as "clinically insane" in the absence of firing trials.

Apart from that, I agree with Bastables that most complaints and shock stories I have seen regarding the Soviet tanks refer to "heavies", which I take to mean the KV1.

[Bastables]

Originally posted by Tarqulene:

You're giving JC a good slapping around B, but I don't think you've quite connected all the dots. For example:

What range is "close" range for panzer (50L42) vrs. T-34 comhat?

</font><blockquote>quote:</font><hr />And no I’m not going to run around pulling percentages out of my arse Jason, you play that game well enough for both of us and I belive it’s irrelevent to my argument.

Is your argument similar, then, to Andreas', in that you're simply trying to disprove a leg or two of JC's argument without making any claims of your own? (I hasten to add there's nothing wrong with that.) Or maybe just a claim that whatever is seen in CMBB is historically correct? </font>

[Tarquelne]

Now at this stage, a suggestion that the most vulnerable spot is the turret front is going to be received with incredulity - shurely the front is the most thickly armoured part of a tank. It must be elsewhere.

First large scale deceptive "operation" by the Soviets?

[Tarquelne]

I've stated a couple of times 500m.

The reports you cite spoke of "close range" penetrations, did they not? What then JC's insistance that CMBB penetrations are still frequent BEYOND 500m, and the CMBB tests that back that up?

Maybe you've moved beyond this, but here's a quote from early in the thread:

In addition, armour piercing shells fired at close range that hit the gun mantle result in penatrations and breaking open the weld seams.

Edited: Ah - I see you've added to the origional "500m" response. Well, I'll leave the above, maybe someone else will try to confirm that you're reading things right.

[ February 03, 2003, 06:45 AM: Message edited by: Tarqulene ]

[Bastables]

Originally posted by Tarqulene:

</font><blockquote>quote:</font><hr /> I've stated a couple of times 500m.

The reports you cite spoke of "close range" penetrations, did they not? What then JC's insistance that CMBB penetrations are still frequent BEYOND 500m, and the CMBB tests that back that up?

Maybe you've moved beyond this, but here's a quote from early in the thread:

In addition, armour piercing shells fired at close range that hit the gun mantle result in penatrations and breaking open the weld seams.

</font>

[JasonC]

Useful numbers, Dschusaschwili.

My initial proposal on page 2 was based on more than 1 Std deviation below leading to 30 degrees or less, more than 1 Std deviation above leading to 60 degrees or more, the middle of a bell leading to 40 to 50, centered on 45 degrees.

I revised that after measuring the turret areas pixel by pixel off of a bitmap, from the front aspect, and due to criticism by others, to 30-40 low angle, 30-40 middling, and 20-30 high angle.

Your cylinder numbers give a mean of 30, your sphere numbers a mean around 45. To a first approximation, the present CM numbers act like 30 degrees, and my page 2 initial proposal would have acted like 45. But in both cases with too little variance.

If you look at the CMBB deflection numbers, they are around 20%. (Understand, 40-45 still allows shorter range penetrations, but 30 and under allows long range ones, like 1 km).

What portion of hits are effectively 30 degrees or less, which are the ones that allow long range penetrations?

My page two proposal (45 mean, too low variance) - 15%

Your sphere numbers (45 mean, high variance) - 25%

My pixel-count based proposals (40-45 mean, high variance) - 30-40%

Your cylinder numbers (30 mean, high variance) - 50%

CMs effective behavior now (30 mean, too low variance) - 80%

"You will go safer by the middle course" - and by counting the actual pixels.

For what it is worth.

[ February 03, 2003, 07:09 AM: Message edited by: JasonC ]

[JasonC]

That makes a certain sense, Bastables. So, on your reading, they only began closing on flanks in the spring of 1942 as they faced 65mm turret fronts. So earlier, they should have been penetrating - you often say to 500m, and I haven't heard you defend 1000m.

In Oct 41, the panzers didn't get kills at 1000m, but did around 500m. Presumably you'd want to put that down to intermediate 52mm turret fronts in October, or at that battle, or some such? Obviously not 65mm turret fronts so soon. I do think the remaining differences are shrinking, which is good.

The only remaining bone of contention would seem to be, was in typical to need 500m in 1941, before the training document but in line with the October AAR? Or were turret front penetrations routine out to ~1 km, until turret uparmoring to 65mm?

If the latter, the empirical question would be, why didn't the panzers get kills at 1 km in the October fight? Might be put down to mere chance, I suppose.

Sorry I have to be away for a couple of weeks. It has been a fun discussion. Hope I haven't been too exasperating trying to hold up my end of it...

[Dschugaschwili]

JasonC:

How did you measure the turret area "pixel by pixel"? I imagine that it would be very difficult to get the impact angle by looking at a picture. I would prefer to model the surface of the turret front using some mathematical equation (like I did for the cylinder and sphere examples) and calculate the probabilities for hits at different angles from the equation.

And where did you get the mean angle of 30° for CM from? Some more tests would be needed, but it looks like CM may use the cylinder model internally. At least the test results so far don't show results that are statistically significantly different.

Dschugaschwili

[Andreas]

Originally posted by Tarqulene:

</font><blockquote>quote:</font><hr /> Now at this stage, a suggestion that the most vulnerable spot is the turret front is going to be received with incredulity - shurely the front is the most thickly armoured part of a tank. It must be elsewhere.

First large scale deceptive "operation" by the Soviets? </font>

[Bastables]

Originally posted by JasonC:

If the latter, the empirical question would be, why didn't the panzers get kills at 1 km in the October fight? Might be put down to mere chance, I suppose.

Also made unusable as "T-34 did the damage" by "von Lagermann" appreciation that half where 52ton Soviet heavies= KV-1E with enough hull armour to defeat 88s at long (+1000m) range during the soviets failed attack on the bridge. Remember of the 18 Soviet tanks destroyed 8 where KV-1E.

It seems that the initial ambush was led by KV-1 and the subsequent counter attack was led by T-34s with KV's leapfrogging as the T-34s where killed overrunning the guns/infantry and meeting Pz regt 35s own counter-counter attack.

Anger is fine I'm sure it was there on both sides of the fence, just a byproduct of "passion" I guess. Also sorry for my personal comments.

Tarq though is my new internet buddy after showing me the joy of MR rollyeyes what a fun little chap.

[ February 03, 2003, 07:48 PM: Message edited by: Bastables ]

[Tarquelne]

Jason reminded me that we were actually "talking" about 1941-era combat with 45mm turret front T-34s.

Hmm... the beginning of the thread makes much more sense now, seeing how J. was explicitly discussing the T-34 41, and how often Someone Else was talking about a later model. The 500m vrs. 800m bickering esp.

Though I don't understand this:

The frontal armour of the T-34 could be penetrated only by 5cm antitank shell, within 500m” (Glantz comparing 1941 tanks 1998). S.J Zaloga and James Grandsen 1985 work “Operation Barbarossa” also bear this out.

"Glantz comparing 1941 tanks..." The 1941 T-34?

"only by 5cm antitank shell, within 500m" So the 50mm guns _couldn't_ penetrate '41 T-34 front armor beyond 500m?

"frontal armor" - Or is that supposed to mean "front hull armor"?

:confused:

Tarq though is my new internet buddy after showing me the joy of MR rollyeyes

Remember, Mr. can be your friend, but like any emoticon, must be treated with respect.