Definition of a Partial Penetration in CM

[shift8]

So what exactly does this mean in CM? I originally thought that it might just be round making it part of the way through the armor....but that would apply to just about any hit that doesn't penetrate.

 

So in a PP does some of the round make it through?

[womble]

I expect it means the armour is breached, with at least part of the round poking through the other side. It might mean more chance of some fragments of armour or broken penetrator whizzing round inside the tank than "Spalling" (where the round has partially disrupted the integrity of the armour without actually breaching it), or it might mean something else. Doesn't really matter.

[shift8]

It matters to me since it tells me how the penetration mechanics in the game work. 

[womble]

It matters to me since it tells me how the penetration mechanics in the game work. 

Not really it doesn't. Since you would have to run hundreds or thousands of instances to be able to tell the difference in practical terms between "spalling" and "partial pen" hits. Are you going to do that?

[shift8]

Not really it doesn't. Since you would have to run hundreds or thousands of instances to be able to tell the difference in practical terms between "spalling" and "partial pen" hits. Are you going to do that?

 

That doesn't even make sense, much less bear any relevance to the question. When the game was designed, specific parameters had to have defined what a "partial penetration" was. So there IS a clear definition, and Im posting here to find out if the devs or someone else has ever known or put out what that was. 

 

Knowing the difference between a Penetration and a partial penetration as it was defined by the dev's makes a huge difference with regard to understanding the game and its mechanics. Is a PP part of the projectile making it through but not all? Or perhaps the shell is lodged in the armor and sticking out? Or perhaps it just means a large bulge in the interior without a crack or hole in the plate? Or maybe its all or none of these things at the same time. It matters because it helps to know how effective a round is being when it PP's, and if the game is being accurate.

 

If noone knows the difference then oh well, but you needn't walk in here and disregard the question just because you dont have the info to answer it.  Your not going to sit here and have the gall to tell me what does or does not matter to me, or what should matter to me. That is my prerogative, not yours. Dont have the answer or dont personally care? Fine, but dont try to push it on me. 

Edited June 20, 2015 by shift8

[womble]

 

If noone knows the difference then oh well, but you needn't walk in here and disregard the question just because you dont have the info to answer it.  Your not going to sit here and have the gall to tell me what does or does not matter to me, or what should matter to me. That is my prerogative, not yours. Dont have the answer or dont personally care? Fine, but dont try to push it on me. 

BFC  know. They won't tell. The game isn't amenable to the analysis you're trying to draw, and for all practical purposes the difference is irrelevant. It's flavour. There are so many other variables that the difference between partial and spalling or full is just, effectively, Charles showing off his programming skills: he can design a system that draws the distinction more finely than any other game, even if it's largely, practically irrelevant.

[shift8]

BFC  know. They won't tell. The game isn't amenable to the analysis you're trying to draw, and for all practical purposes the difference is irrelevant. It's flavour. There are so many other variables that the difference between partial and spalling or full is just, effectively, Charles showing off his programming skills: he can design a system that draws the distinction more finely than any other game, even if it's largely, practically irrelevant.

I only want to know out of curiosity. And Im not so sure the distinction is as small as you think. Ive seen many a tank downed by a PP, which is one of the main reasons I want to know what it entails. I haven't seen a tank knocked out by spalling yet--not that it cant happen...but clearly the PP is a more significant effect. But oh well. If nobody is saying oh well. 

[Holien]

My take on it is that it is a round that does limited damage and nearly got through. It might not even do any damage but gives you an idea that it did better than a non penetration.

[agusto]

I only want to know out of curiosity.

 

It hadnt occured to me to ask what the definition of a partial penetration in CM terms, but now i want to know the answear too.

Edited June 20, 2015 by agusto

[Warts 'n' all]

I have to agree with the OP... It must make a big enough difference otherwise BFC wouldn't have bothered to have "spalling" and "partial penetration" indicated.

 

My own personal take on it, in terms of game play. When I see "spalling" I think, "Good, the enemy crew are getting little flakes of hot metal in their faces". When I see "partial penetration" I think "Even better, we've dented the b*******, one more shot like that and we've got 'em". This may not be the most technical of answers. But, I wouldn't want "spalling" and "partial penetration" to be replaced by the single word "hit".

[shift8]

At first I always thought that a partial penetration was as defined in certain US Army tests: A bulge on the inside armor but no break in the armor. 

 

In CMx1 this made sense to me, as tanks rarly went down due to PP, but might bail if they were rookie crews. 

 

In CMx2, PP seems to kill tanks about as often as it does nothing, making me think it might be alot more than just a bulge in the armor, as I seriously doubt the abillity of such a bulge to cause the tank to explode or catch fire......as can happen in CMx2. 

 

It makes me wonder if the PP in CMx2 if not just a bulge, but perhaps varying states of "less than complete" clearance of the projectile through the armor. For example, half the shell might get stuck in the armor, and the rest breaks off and fly though. Or in other cases perhaps only a chink of the projectile makes it in. In any case, the more testing I do the less likely it seems that it is just a bulge in the inside armor, as and damage caused by that would seem more in line with spalling. 

[Bulletpoint]

Maybe it's just flavour text, with no real difference. Would be easy to program in to give people the impression that amazing simulation is going on under the hood.

[shift8]

Maybe it's just flavour text, with no real difference. Would be easy to program in to give people the impression that amazing simulation is going on under the hood.

This isnt the case. Even since CMx1 the AP simulation has been near perfect. Virtually everything is taken into account in CMx2 especially. 

 

This is why the CM series of games is basically the only thing out there will accurate WW2 tank combat. 

[Baneman]

I've had Panthers KO'd by Partial Penetrations, both with and without crew casualties, whereas Spalling often causes casualties, but never (in my experience) a KO.

 

So there is definitely a difference, but I can't imagine exactly how a "partial" would look in real life.

[John Kettler]

shift8,

 

If you think BFC's got the armor model perfect, then you haven't played CMBB, the second CMx1 game! Jason C is the man on this stuff--along with much else--, and you will learn a great deal from what he has to say. A little digging, will, I believe, produce similar complaints on the CMRT Forum.

 

http://community.battlefront.com/topic/83301-is-the-t-34s-gun-really-under-modeled-in-the-game/

 

Regards,

 

John Kettler

Edited June 22, 2015 by John Kettler

[George MC]

Here's an image of what a partial penetration may look,like!

 

It's captioned as being a 17pdr AP shell that hit a Tiger's front glacis.

Edited June 22, 2015 by George MC

[shift8]

shift8,

 

If you think BFC's got the armor model perfect, then you haven't played CMBB, the second CMx1 game! Jason C is the man on this stuff--along with much else--, and you will learn a great deal from what he has to say. A little digging, will, I believe, produce similar complaints on the CMRT Forum.

 

http://community.battlefront.com/topic/83301-is-the-t-34s-gun-really-under-modeled-in-the-game/

 

Regards,

 

John Kettler

 

Well I haven't read the entire thread, the the opening statement in the thread is nonsense. The 76mm ZiS would have been very hard pressed to get though the 80mm on a Stug, even at 500m---in fact youd need to be at least 200m or less, given that the 0 degree penetration for the 76mm in the T-34 was only 69mm at NORMAL. and 88mm at 100m. 

 

Also, I disagree that the CMBB has any serious issues. The AP simulation in that games is one the the best ever done. 

Edited June 22, 2015 by shift8

[shift8]

Here's an image of what a partial penetration may look,like!

 

It's captioned as being a 17pdr AP shell that hit a Tiger's front glacis.

Indeed, I have seen this image. Question is, how does CMBN view it. 

[George MC]

Indeed, I have seen this image. Question is, how does CMBN view it. 

Only conjecture - it would I suspect depend on what is behind this in the vehicle model. So if a crewmember is behind that armor at that spot you can expect them to be killed. If it's a fuel tank then it could be the fuel goes up and the vehicle catches fire.

 

So you'd have to know how the vehicles are modelled in game terms and how the game engine handles the data for differing type of hits. Assuming of course it does.

 

This could account for why some players see a tank being hit - partial penetration and the tank continues to operate whilst other tanks (depending on where hit) showing a partial penetration may be KO'd or have the crew bail due to losing crew members/damage to systems.

 

See where I'm going? i think there are a great many variables - from penetration/armour harness/angles; vehicle damage models; crew member 'soft' factors e.g. morale etc potentially at play that any of which may affect the outcome. So it may be difficult to provide a black and white answer?

[Holien]

What a Paperweight to have on your desk...

 

 

Which site has that on display?

[George MC]

What a Paperweight to have on your desk...

 

 

Which site has that on display?

Hi H

Not sure where you'd see it. i just came across it whilst googling 'partial penetration' - always a risky business when at work! Same image but different angle - even more remarkable. although TBh I don't like I'd like to have been inside that Tiger tank when that came through! Partial or not...

 

[BLSTK]

...i just came across it whilst googling 'partial penetration' - always a risky business when at work!

 

 

Do us all a favour, George. Google "full penetration" and send us the results.

 

While you're at it, enjoy your "enforced vacation".

[George MC]

Do us all a favour, George. Google "full penetration" and send us the results.

 

While you're at it, enjoy your "enforced vacation".

Great advice ta

[John Kettler]

shift8,

 

The issues raised have been extensively looked into: from firing trials by both the Germans and the Russians, penetration calculations and combat experience. You can learn a great deal from reading the thread, which gets into the arcana of test targets, test target composition and hardness, penetration criteria, armor quality and much more. Back when JasonC was holding forth in fine fashion, I'm pretty sure he didn't have the advantage of the grog fest that is Archive Awareness. Here, for example, is a post which shows original Russian penetration test data for a whole series of guns. The comments after the post go into considerable detail not discussed in the post proper. Russian firing trials: T-34's F-34 gun vs every German tank type from Czech 38-T through Panzer IV. Full details available from Peter Samsonov, whose site it is.

 

Let's do some spot comparisons, shall we? T-34 M41 (cast turret) (F-34 gun, L/42) vs Panzer IV/E (inferred based on other tanks tested, we're talking a Barbarossa period version, but with 20 mm add-on side plate, thus "E" model). From the CMBB Strategy Guide, page 2/31, the penetration numbers in mm are as follows:

 

100   meters (69)

500   meters (71) Delta may be shatter gap related, since Germans are using face hardened armor.

1000 meters (62)

 

Panzer IV/E, ibid. , page 2-47, Upper Hull is 30 + 30, giving an apparent 60 mm protection. I say apparent because there are other factors at work here, depending on what's fired, where and how it hits, etc. Spaced armor isn't the same as monobloc armor. Even so, it's apparent the T-34's gun marginally penetrates the Panzer IV/E's frontal Upper Hull at 1000 meters. This fits the Russian test results in which at 800 meters (max range tested) the AP shell goes smashing through.

 

(Fair Use)

 

The PzIV is tested next. Its front armour is penetrated at 500 meters (entrance diameter 90 mm, exit diameter 100 mm). From 800 meters, another penetration. The front armour plate is shattered into two pieces. Another shot from 800 meters penetrates the front. The testers switch to firing at the side at 800 meters.

 

Now, let's look at the Sturmgeschutz III/F, with its 50 + 30 Upper Hull. A straightforward comparison of that armor with the F-34's CMBB penetration figures indicates getting through the armor is hopeless--at any range from zero out. Really?

 

The German test data shows the F-34 can defeat the StuG's thick frontal armor as follows:

76.2mm. L.42.5 F-34.

APHE (propellant black powder with nitro-celuose primer).

81mm. at 100 metres.
69mm. at 500 metres.
61mm. at 1,000 metres.

HVAP "Arrowhead" (propellant nitro acetone based).

104mm. at 100 metres.
94mm. at 500 metres.
85mm. at 1,000 metres.

 

The same F-34 gun can defeat a dead-on Tiger 1's frontal armor at 100 meters. This being the case, how is it, then, that a Tiger 1's Upper Hull (110 mm @ 9 deg slope--calculator used below gave erroneous results on effective thickness) can be defeated by the F-34, presumably firing AP shell, at 100 meters based on Russian firing tests conducted after Kursk, else Ferdinand wouldn't be in list, but in CMBB, 80 mm of armor on the StuG III/F can't be defeated at zero range? What's wrong with this picture?

 

The above is but one example of why there are long threads talking about the undermodeling of Russian guns. In game terms, the StuG III/F is a super AFV vs the T-34/76s (immune vs it frontally at all ranges), but it can kill the T-34/76 M41 (effective Upper Hull armor is 52 mm--45 mm @ 60 deg) out to 2000 meters.

 

KwK L/43 penetration

 

100   meters (128)

500   meters (117)

1000 meters (104)

2000 meters (82)

 

Still think CMBB is right in how it models Russian gun performance vs German AFVs?

 

Regards,

 

John Kettler

Edited June 22, 2015 by John Kettler

[Bulletpoint]

Only conjecture - it would I suspect depend on what is behind this in the vehicle model. So if a crewmember is behind that armor at that spot you can expect them to be killed. If it's a fuel tank then it could be the fuel goes up and the vehicle catches fire.

 

So you'd have to know how the vehicles are modelled in game terms and how the game engine handles the data for differing type of hits. Assuming of course it does.

 

Sorry, the location of crewmembers and fuel tanks is not taken into account.

 

I once guessed at how the game models damage, and much to my surprise Steve actually confirmed I was basically correct (darned if I can find the post now though...).

 

It works in this way:

 

1: Shot energy checked against armour thickness and angle at point of impact. Extra modifiers might be given for type of munition. In this way, hollow-charge weapons can penetrate despite their low velocity.

 

2: If there is enough energy to penetrate, the combined armour value is subtracted from the shot energy.

 

3: A "dice roll" is made on a lookup table, with a modifier for the amount of energy that penetrated the armour. Possibly with a bonus for AP-shells that have an explosive charge. This gives the total "damage value"

 

4: Depending on the damage value, the tank suffers damage to random components and crewmembers, with high values more likely to make the tank blow up.

 

It might be that there are different look-up tables for the main parts of the tank, and maybe there's a separate table for crew damage and component damage. That would mean that shots that almost penetrated but were deflected still had the chance to cause spalling, but that spalling then only gives a roll on the crew damage table. This is conjecture on my part.

 

If I'm correct, then this means "partial penetration" might be like spalling, a hit that barely made it through the armour, but which has a chance to roll on both component and crew damage tables, albeit with a low damage value.

Edited June 22, 2015 by Bulletpoint