The german tank be weaken or the Russian ammo be strengthen in the CMRT?

[Erwin.Rommel]

7% is high probability?

actually the 10%, and for the upper hull front of panther, theoretically 85mm APBC should never penetrate it if there is no armor flaw. Use the index given by the CMBB, the 85mmAPBC penetrate 51mm/60 in 500m, the panther has 80mm/55 glacis, for the vast gap, and for something that should never happened, 10% is really a high probability.

[akd]

You are getting 10% by counting the ball mount and edge penetrations. So what is the correct probability to account for flawed armor?

[Vanir Ausf B]

I am about 99% sure that CM does not model edge effects. As for CMBB penetration stats, when I checked them a few days ago for the T-35/85, the numbers appeared to have been for strikes on face hardened armor. The Panther G glacis plate is rolled homogenous, against which the T-34's penetration will be higher.

[kipanderson]

Erwin, hi,

Good tests...

Your tests represent a 1 in 10 chance of the Panther’s glacis plate suffering a sudden decrease in protection of around 30%. Given that it considered flawed by Lorrin... what is there to debate?

All seems to fine....

All interesting stuff..

All the best,

Kip

[xellos]

I am about 99% sure that CM does not model edge effects. As for CMBB penetration stats, when I checked them a few days ago for the T-35/85, the numbers appeared to have been for strikes on face hardened armor. The Panther G glacis plate is rolled homogenous, against which the T-34's penetration will be higher.

I think the penetration stats numbers in cmbb is for strikes on RHA,not for strikes on FHA which presents in cmak.

[Amizaur]

I suspect that the flaws in Panther's front upper hull plate were much more likely to matter when attacked by heavy, high calibre projectiles (like 100 or 122mm) than when striken by something with 1:1 or less T/D ratio. I doubt 85mm or 76mm shell could break Panther's front plate, even a brittle one. Sure an armor tempering flaw could decrease it's protection rating even against 85mm shell, but we don't see frontline reports of Panther front upper hull being vunerable to 85mm, do we ? It was rather considered invunerable to anything short 100 or 122mm.

[xellos]

Erwin, hi,

Good tests...

Your tests represent a 1 in 10 chance of the Panther’s glacis plate suffering a sudden decrease in protection of around 30%. Given that it considered flawed by Lorrin... what is there to debate?

All seems to fine....

All interesting stuff..

All the best,

Kip

Erwin has already said that in cmbb ,the PantherG's glacis plate cant be penetrated by 85mm APBC

[Oddball_E8]

I suspect that the flaws in Panther's front upper hull plate were much more likely to matter when attacked by heavy, high calibre projectiles (like 100 or 122mm) than when striken by something with 1:1 or less T/D ratio. I doubt 85mm or 76mm shell could break Panther's front plate, even a brittle one. Sure an armor tempering flaw could decrease it's protection rating even against 85mm shell, but we don't see frontline reports of Panther front upper hull being vunerable to 85mm, do we ? It was rather considered invunerable to anything short 100 or 122mm.

well, 10% chance and then factor in the number of times the vehicle couldn't be recovered and you'll see that it might very well be possible that every now and then they got penetrated by 85mm guns and we just don't hear much about it.

[Vanir Ausf B]

I think the penetration stats numbers in cmbb is for strikes on RHA,not for strikes on FHA which presents in cmak.

Doubtful. For the the ZiS-S-53 cannon CMBB lists the following penetration at range 0 against vertical armor:

AP: 133

APBC: 120

Actual penetration is (per WW2 Ballistics)

vs FHA

AP: 135

APBC: 128

vs RHA

AP: 146

APBC: 143

Neither matches up exactly, but the RHA numbers are closer.

Nevertheless, after finally getting time to run some numbers it appears there may be something slightly off.

First, I will assume CMRT uses 83mm for the Panther glacis plate thickness. Note that this is an assumption only, based on that being the CMAK thickness. It could be modeled at the official 80mm thickness as it was in CMBB. In fact, the latter would more closely match the reported test results.

At 83mm thickness the glacis plate resists 85mm APBC equivalent to 169.4mm vertical thickness for good quality armor. Armor flaw modifiers for low, medium and high severity flaws are .96, .92 and .84 (for T/D=.9765, 55° angle impact). Application of modifiers gives us end values of 162.6mm, 155.8mm and 142.3mm

At 600 meters Soviets 85mm APBC penetration is 119mm vs RHA. This has no chance at all against low and medium flawed armor, and only a very small chance against highly flawed armor --.84 (119/142.3) penetration/resistance ratio = 0% chance using US penetration data, 1% using Soviet penetration data. In order to get a 10% penetration chance per Soviet data the average armor flaw modifier would have to be 77%, which is prohibitively severe. In CMBB it was 85% across the board and even that was probably too harsh.

If we reduce the glacis place thickness to 80mm then the effective resistance of highly flawed armor goes down to 134.4mm, giving us a P/R ratio of .89 which translates to a penetration chance of 6% under Soviet criteria. That would be within the margin of error for a test showing 10% with a sample size of 131.

At some point this weekend I will hopefully get time to run a proper test with a proper sample size. If the actual penetration percentage is around 5-6% that would be consistent with a Panther glacis plate modeled as in CMBB -- 80mm thick and 85% quality across the board (the 0 penetrations reported in the CMBB test could be explained by the lower ZiS-S-53 cannon penetration in that game). However, the manual states that the Panther G has only "occasional manufacturing flaws" in CMx2, which would be more historically accurate. 83mm thickness is also closer to reality.

[Vanir Ausf B]

Neither matches up exactly, but the RHA numbers are closer.

Meant to say FHA...

[Skwabie]

Meant to say FHA...

Was confused there for a while thinking some hidden calculation rule I didn't know about!...

[xellos]

Doubtful. For the the ZiS-S-53 cannon CMBB lists the following penetration at range 0 against vertical armor:

AP: 133

APBC: 120

Actual penetration is (per WW2 Ballistics)

vs FHA

AP: 135

APBC: 128

vs RHA

AP: 146

APBC: 143

Neither matches up exactly, but the RHA numbers are closer.

Nevertheless, after finally getting time to run some numbers it appears there may be something slightly off.

First, I will assume CMRT uses 83mm for the Panther glacis plate thickness. Note that this is an assumption only, based on that being the CMAK thickness. It could be modeled at the official 80mm thickness as it was in CMBB. In fact, the latter would more closely match the reported test results.

At 83mm thickness the glacis plate resists 85mm APBC equivalent to 169.4mm vertical thickness for good quality armor. Armor flaw modifiers for low, medium and high severity flaws are .96, .92 and .84 (for T/D=.9765, 55° angle impact). Application of modifiers gives us end values of 162.6mm, 155.8mm and 142.3mm

At 600 meters Soviets 85mm APBC penetration is 119mm vs RHA. This has no chance at all against low and medium flawed armor, and only a very small chance against highly flawed armor --.84 (119/142.3) penetration/resistance ratio = 0% chance using US penetration data, 1% using Soviet penetration data. In order to get a 10% penetration chance per Soviet data the average armor flaw modifier would have to be 77%, which is prohibitively severe. In CMBB it was 85% across the board and even that was probably too harsh.

If we reduce the glacis place thickness to 80mm then the effective resistance of highly flawed armor goes down to 134.4mm, giving us a P/R ratio of .89 which translates to a penetration chance of 6% under Soviet criteria. That would be within the margin of error for a test showing 10% with a sample size of 131.

At some point this weekend I will hopefully get time to run a proper test with a proper sample size. If the actual penetration percentage is around 5-6% that would be consistent with a Panther glacis plate modeled as in CMBB -- 80mm thick and 85% quality across the board (the 0 penetrations reported in the CMBB test could be explained by the lower ZiS-S-53 cannon penetration in that game). However, the manual states that the Panther G has only "occasional manufacturing flaws" in CMx2, which would be more historically accurate. 83mm thickness is also closer to reality.

Sounds resonable ,I had noticed the Panther G's glacis plates were much tougher than those in CMRT.

In my CMBB tests(10vs10,hotseat mode) ,they could not be penetrated by 85mm APBC beyond 500m range just like Erwin had stated.

Can you do some tests with the Kingtigers's mantlet and the low hull armor against 122mm AP?In CMRT ,they seem too weak to be penetrated at 500m.

[siffo998]

And further tests with 85mm vs Panther G shows more penetration on the glacis, then give us a explain,BFC!

happened as well in my test run with a panther A mid against a t34-85 at 1000m distance. after around 4 hits at the glacis the panther received a full glacis penetration (1000m distance). By the way i doubt that CM is modelling decreasing armor strengh with multiple hits.

and additionally the manual mentions only the panther G (early) with manufaction flaws. theres nothing about manufactioning flaws at the panther A, or D.

[siffo998]

That's actually kinda simple.

Sometimes when a shell impacts at an extremely shallow slope like that, the engine just leaves a flat impact marker as if it was hit from straight above, but it has in fact been hit at a very shallow angle.

Happens in theatre of war too with their decals.

So the shell actually hit from the front but it looks like it hit from above. Am I making any sense here?

EDIT:

Aw hell, I drew a picture for ya.

i doubt it that a t34-76 (or any other compareable tank) can achieve a full penetration (maybe some spalling) against a plate in this angle.

it would just slide off!

especially when using a kinetic energy AP shell. maybe the t34 used a modern HEAT shell ?!

[Vanir Ausf B]

happened as well in my test run with a panther A mid against a t34-85 at 1000m distance. after around 4 hits at the glacis the panther received a full glacis penetration (1000m distance). no way even with a flawed glacis ! By the way i doubt that CM is modelling decreasing armor strengh with multiple hits.

Could you show that with hit text turned on? There appears to be penetration decals on the lower hull.

I have never been able to get 85mm to penetrate the Panther A glacis, even when testing at 200 meters.

[siffo998]

Could you show that with hit text turned on? There appears to be penetration decals on the lower hull.

I have never been able to get 85mm to penetrate the Panther A glacis, even when testing at 200 meters.

happened a second time just moments ago

range 1030m t34-85 against panther A (mid) using AP shells. the panther took quite a beating but finally a penetration through glacis.

i do not think that its because of manufacion flaws because this would lead to additional armor spalling and partial penetration hits but there are only riochets and a full glacis penetration (leading to a desturcion of the tank).

theres still the question if CM is modelling armor weakening after additional hits but this would also lead to armor spalling/partial penetration hits first.

i have the screenshots available. maybe you can send me your mail adress per pm and i will invite you to the dropbox folder with the pics. or is there another way to post pics without hosting them on a site ?

[siffo998]

forget it i think i`ve figured it out how to upload and include at least the hit picture. i`ve got another one showing the distance. you can still pm me and i can invite you to the dropbox folder.

[Vanir Ausf B]

No need. I have my own test scenario.

[Amizaur]

I did the same thing you do - 10 x Panther A mid vs 20 x T-34/85 (both models) at 1000m.

For long time I didn't get any penetrations, only one partial. But suddenly I started to get one penetration of Panther glacis after another, 1-2 of them happened in each turn.

You know what ? They were done with HE shells.

After T-34s are down to 10-7 APs, they become to conserve them and using HE shells instead. And they are much more effective in penetrating Panther front upper hull. To penetrate at any range, I guess.

So watch carefully with what kind of ammo pentration was achieved.

Larger than usuall explosion at hit and no ricochet sound may suggest HE ammo.

edit: I just got a true AP penetration of Panther A mid by T-34 85mm from 1000m. The AP ammo counter on T-34 decreased, the Panther become pierced and burning. So it happens too.

But 85mm HE penetrations of 80mm plate are a bit worrying for me.....

edit2: 85mm HE penetrations are not that often as it seemed at first.

Now I got only one 1000m penetration of 85mm He against Panther front upper hull for 73 hits on that plate. But I also got one HE penetration of Panther front turret too... That gives ~2 HE penetrations for 100 hits total.

In first test - identical setup, same scenario, nothing changed - I had zero penetrations fro several turns, and then suddenly got 4 HE penetrations in just two turns of HE shooting .

I wish I could load a tank with only AP or only HE in the scenario editor, like in CMx1....

[Vanir Ausf B]

Really! That is interesting.

[Skwabie]

After T-34s are down to 10-7 APs, they become to conserve them and using HE shells instead.

indeed come to think of it.... my case were the IS-2s. AI switched to HE when they still had AP but barely.

[Amizaur]

Edited my previous post, check please. Summary:

The 85mm HE penetrations at 1000m DO happen, against both upper front plate and front turret of Panther A mid. I've seen at least 3 of them that I double checked the kind of ammo used.

85mm AP penetrations of upper hull at 1000m also DO happen. I've seen two so far.

Both are rather rare occurences.

Interesting fact: there are more full penetrations than partial penetrations or spalling so far (only one partial penetration, can't remember any spalling after upper plate hit).

There is just lot of clean ricochets from front upper plates, with zero spalling and zero partial penetrations, it feels that the armor is well in the safe zone, and suddenly sometimes - BOOM - a single full penetration, with nasty effects - usually it sets the target tank of fire or even detonates the ammo.

This raises for me a suspicion that some kind of purely random "weakpoint penetration" dice which may be triggered sometimes. Something like 1-2% chance for 50% of effective armor. Such kind of random event existed in CMx1 engine, have no idea if it was in any form retained in CMx2.

Or maybe the 85mm HE shell has just mistakenly got same penetration parameters of AP shell ?

P.S. I have one suggestion that I would like to pass to BF about the hit decals - HE hits against armor should rather leave "HEAT ricochet" type marks, than ordinary "AP ricochet" ones.

I see that now ineffective 85mm HE hits against Panther front plate looks the same as AP ricochets.

HE penetration could get in the future it's own distinct decal mark - somethinng like a big, irregular hole.

[Vanir Ausf B]

Did a bit of testing vs Panther A at 1000 meters. I pretty much got the same results. Out of 154 AP hits on the glacis there was 1 partial and 1 full penetration. It's hard to say what that means. As you mentioned, it could be a random weak point penetration a la CMx1.

No spalling. But I have confirmed in another test that the panther glacis never produces spall. No idea why. You are also correct that full penetrations on the glacis are much more likely that partials, even when the chance of penetration is low.

As for the HE, I got 1 partial and 1 full penetration there too, out of 65 hits on the glacis. I also saw an HE penetration of the lower hull and one through the front turret. So HE penetrations don't seem much more likely that AP, but not much less likely either. I'm probably going to submit this as a bug.

I am a bit concerned over the performance of Soviet APBC vs face hardened armor. I was not keeping track, but it seemed like about half of the hits on the lower hull were penetrating at 1000 meters. That would be about right vs RHA (assuming 63mm thickness as per the CMRT manual), but the Panther A lower hull is FHA. Soviet blunt nosed APBC is a special case in that it should not be using the same slope multiplier for FHA as it does for RHA. I will probably bring this up internally also, after I get some solid test results.

[Oddball_E8]

I had a thought...

At 1000m, what kind of arc is the 85mm shell going at?

Is it still really shallow or does it arc enough to hit the front plate at less of an angle then if fired at 100m?

That could make a difference... a pretty big one even.

[Vanir Ausf B]

For 85mm APBC the angle of decent at 1000 meters is .5 degrees.