Question about vehicle weapon hit probability

[Magpie_Oz]

Shermans had a commander's vane sight in at least some versions.

That was just for a general idea wasn't it? could the gun actually be fired based on aiming with the vane ?

[gunnergoz]

No the vane was to help the commander lay the turret close enough for the gunner's limited view aiming scope to be able to pick up the target. Unless you were really close, I doubt you could get a hit using the vane by itself.

Here's a picture of one on a Jumbo being uncrated at the ordnance shops:

[Redwolf]

I think this supports the notion that hits to the main gun/mantlet were highly likely. You might find that most tanks heaviest armour was the turret front/mantlet as this was the part of the tank most likely to be exposed.

I don't think you can take that conclusion as a given. The reason for the thick mantlet can also be mechanical. It is a weak point in the front and you have to cover it up. The new cover isn't part of the original plate. So you do extra thickness.

Either way it doesn't answer the question whether a hard hit on the mantlet (that doesn't penetrate the turret) can disable the gun.

I would think it would be almost impossible to aim the main gun using the tracks. They just aren't that sensitive and the gunner would have to be coaching the driver onto target, running away is a more likely option. In assault guns the gun was not fixed, merely in a limited traverse so the tracks where used to point in the general direction but the fine aiming was done by traversing and elevating the gun, much like an ATG.

Right, that was what I was aiming for.

However, certainly the gun is not dead-dead as it is in CMBN. It can very well be used to e.g. support an assault on an infantry line, even if it can't be used to fire on moving vehicles anymore.

[Guest]

Thanks for that, Mr. Vulture. I am relieved to know that all this talk of complex modelling actually comes down to picking some random numbers within a defined spread. It certainly makes the results I see in game a lot more understandable, for all Steve's talk about gunner memory and the rest of it. My guys just keep rolling ones when they need sixes.

No. I won't go into the details of the modeling involved, but your understanding is incorrect. The number of variables that go into engaging a target of any kind is... very large. Steve has hinted at only the barest fringes of the model used.

[MikeyD]

Twenty AP hits from 600m is a LOT of metal gouged out of the front of any tank. I can't actually recall getting a weapon put out of commission in CM:BN (it used to happen all the time in CMx1), but neither can I recall letting my tank be used for target practice like that either. Sounds like you're trusting too much in your tank's legendary über status. You're lucky a round didn't get deflected off the lower gun shield down into the driver's compartment.

[Magpie_Oz]

I don't think you can take that conclusion as a given. The reason for the thick mantlet can also be mechanical. It is a weak point in the front and you have to cover it up. The new cover isn't part of the original plate. So you do extra thickness.

Either way it doesn't answer the question whether a hard hit on the mantlet (that doesn't penetrate the turret) can disable the gun.

The mount is not particularly strong, mainly because it has to be able to move in elevation so any hit to the mantlet is going to jeopardise the gun.

What I was meaning is that the mantlet constitutes the main area of the front of the turret and therefore must be more likely to receive a hit than any other part of the turret.

[jocke_p]

Twenty AP hits from 600m is a LOT of metal gouged out of the front of any tank. I can't actually recall getting a weapon put out of commission in CM:BN (it used to happen all the time in CMx1), but neither can I recall letting my tank be used for target practice like that either. Sounds like you're trusting too much in your tank's legendary über status. You're lucky a round didn't get deflected off the lower gun shield down into the driver's compartment.

I don´t know about "target practice", as i stated in the OP i was AI playtesting my scenario when i came across this. I playtested it in real time with scenario designers mode. I advanced the panthers to a semi good overwatch position on a rather keywholed firelane towards a bridge 500 meters ahead, the AT gun was a further 150 m beyond in a treeline. As i playtested in real time i did not babysit the panthers. When i eventually payed attention to the panthers i was suprised to see all 3 of them operational but with their guns destroyed. That made me curious enough to make a mental note on the location of the panthers and to try again, this time paying close attention to what was happening. I thought it might be a fluke, but i was able to reproduce the results on the first try. I was NOT surprised by the number of hits per shots fired, but by the number of weapon hits per hit to the turret.

Also, remember that it was roughly 7 shots against each panther. From the historical accounts that i have read regarding tigers on the eastern front it was not all that uncommon for tigers to recieve dussins of turret hits from AT guns and enemy tanks when being hull down (plinking on the armour) and still remain operational and capable of shooting back.

In my battle it was panthers, but i bet the results will be the same with 3 tigers in the same situation. Their 200 mm front turret armour will not help, being hull down, against a 40% chance of a weapon hit (and becoming "gun disabled") with each shot fired by a hidden AT gun. Again, if this is proven to be historicly accurate then i will not argue.

When i have time i will remake my test with tigers instead of panthers.

Regarding your comment on "uber status" of the panthers, i normaly do not count myself a fanboy of the german "uber tanks". I know fully and well that panthers and tigers where not invincible, at least that is not how i usually use them. I usually play WEGO and would have backed the panthers out of harms way within a minute of them getting hit by an unseen AT gun.

Again, my question is same. Is it realistic that 40% of the shots fired, at a hull down tank, will be hitting the weapon?

Now MickeyD, the test i did specificly for the purpose of testing this, THAT was target practice

Hi again!

Ok i did a quick restest, 700 m open field, AT gun in tree line. All three panthers where in hull down and facing the gun.

The AT gun fired 22 shots:

3 misses

1 hit the "front turret"

9 hit the "weapon mount"

9 hit the weapon.

Result : 3 panthers with their guns disabled. That is roughly 41% gun hits of all shots fired at the hull down panthers. Does not that seem a bit high?

Edit! Also, let me explain how i got the test to run that long without the AT gun being knocked out. I manually "refaced" the panthers every couple of seconds, and i also buttoned them to lessen the chance of them spotting the AT gun. The Panthers did spot the gun after a couple of minutes but lost their contact sporadicly. I was also suprised it took 5-6 hits per panther before they started popping smoke.

[WineCape]

Run some 'more' tests to see if there is a trend of such results or not, so as to make at least some limited observation wrt the high percentage gun hits compared to other hits on the turret.

[Redwolf]

The mount is not particularly strong, mainly because it has to be able to move in elevation so any hit to the mantlet is going to jeopardise the gun.

What I was meaning is that the mantlet constitutes the main area of the front of the turret and therefore must be more likely to receive a hit than any other part of the turret.

Well that is a gross oversimplification. There is a huge difference between the mantlet on a Pz IV which is more of a knight's shield covering the gun mount, a Panther mantlet which is more of a bulb that seems not to be connected to the gun mechanism at all and a StuG's Saukopfblende.

The latter two look like hits on them will do nothing to the gun or the gun mechanism.

[gunnergoz]

Well that is a gross oversimplification. There is a huge difference between the mantlet on a Pz IV which is more of a knight's shield covering the gun mount, a Panther mantlet which is more of a bulb that seems not to be connected to the gun mechanism at all and a StuG's Saukopfblende.

The latter two look like hits on them will do nothing to the gun or the gun mechanism.

I can't say as I fathom the idea of a panther mantlet as a "bulb unconnected to the gun mechanism." It is a very wide squarish shield with a semi-circular cross section that extends across the entire forward face of the turret. The Pz IV shield covers a smaller portion of the turret front than does the panther's.

In any hit to a gun mantlet, one has to consider that the amount of kinetic energy transferred to the mantlet, will in turn be conveyed to the gun trunnion. Damage to the trunnion could have some possibly very negative effects, such as throwing the gun mount out of alignment, damaging the trunnion's bearings or jamming the elevation machinery. Not to mention that the optics could well be jarred out of alignment if not broken in the process.

[Bastables]

"My point though is that i would like to know if there is some historic/realism similarities with the results i am seeing. 40% off all shots fired hitting the weapon on a hull down tank"

I suppose the question could be rephrased into what % of the target area is made up by the gun in a head on aspect. Is it 40%? Seems unlikely, on fag-packet calculation I would think it no more than 5%. However, that 5% is smack in the middle of the target area, which does seem to suggest one of two things; the gunners are very good or Redwolf's complex probability model to decide on the precise point of aim is perhaps not as complex or as probabalistic as one might think (and neither, perhaps, is the in-flight balistics model).

The only one of those options a user can test is the crew quality. Do you get the same sort of results with Green, Regular, Veteran etc. crews?

As for confirmation of your results by a historical facts, you might well be out of luck. However, if there ever was a WWII study on such detailed accuracy of AT guns one of the grown ups on this site will know of it.

Good luck.

Post zittidele the Panthers were reported to have a much higher incidence of main gun being rendered in operable due to AR rifle hits and APHE, HE splinters from mantlet hits. Jentz has the reports reproduced in his Panzertruppen Vol II and his Panther book.(over blown as the figures he gave to gurdian was only 5 panthers with gun damage after 3 days of charging Soviet gun lines) Tangentially aiming cards for panzertruppen usually inform the gunner that aiming at the mantle of T-34's Churchill's ect is a good idea. I don't think that has much to do with how CMBN models aiming within it's calculations. But it does tell you that going hull down in game is dangerous as either you lose your main gun if the armour is good (Panther Tiger) or you lose your tank if turret armour is indifferent (PIV).

Lesson is don't go hull down.

[gunnergoz]

If your tank armor is indifferent, hull down at least minimizes what can be seen of your vehicle and thus decreases your odds of being hit. It makes no sense to expose more of your vehicle if your armor is indifferent everywhere including the mantlet.

[dieseltaylor]

Oh no not the MkIV hulldown argument again!!!

I am sure overtime the question will get resolved incidentally as we play. My own feeling is that rarely will I have my tanks and my enemies tanks llined up square on and level ever - so it is academic. : )

[Bastables]

13th Pz div Panther abt 20th oct '43 :The telescopes of the T.Z.F. 12 gun sight break apart as a result of hits on the gun mantlet. The expenditure of protective lens for the T.Z.F. 12 is very high.

(the TZF 12 is the binocular sight in the ausf d and early ausf a turret)

[Bastables]

If your tank armor is indifferent, hull down at least minimizes what can be seen of your vehicle and thus decreases your odds of being hit. It makes no sense to expose more of your vehicle if your armor is indifferent everywhere including the mantlet.

I think it should decrease the ability of enemies being able to spot you, the problem is once you are spotted they are aiming at your weaker turret and or your optics/gun combination as the turret is now centre of mass. (and now the only visible/hittable target).

[Lee_Vincent]

No. I won't go into the details of the modeling involved, but your understanding is incorrect. The number of variables that go into engaging a target of any kind is... very large. Steve has hinted at only the barest fringes of the model used.

Surely some elements are random, such as variation in projectile path from dispersion?

[gunnergoz]

So tell me, statistically, is a larger target easier to hit than a smaller or not? There are always benefits from being hull down: even if it only gives a marginal benefit, on the battlefield that can be critical.

If you expose yourself fully and you are not well armored, then you better keep moving. In WW2 terms moving generally means you cannot shoot back if your enemy is distant. Better to hide, not be noticed for as long as you can, hit the target when they do not yet see you and then scoot to a new position if you fear someone will lock on to you. That was basic TD doctrine during the war.

Going hull down's first and foremost benefit always has been concealment but it will also minimize the enemy's aim point, perhaps long enough for you to either move or get off another shot.

But if for some reason you must stay in one position and the enemy is distant, I see no benefit to taking a hit in the hull - which is easier to hit - than taking one in the mantlet, which is a smaller target.

[stikkypixie]

So tell me, statistically, is a larger target easier to hit than a smaller or not? There are always benefits from being hull down: even if it only gives a marginal benefit, on the battlefield that can be critical.

But if for some reason you must stay in one position and the enemy is distant, I see no benefit to taking a hit in the hull - which is easier to hit - than taking one in the mantlet, which is a smaller target.

Are you talking about in-game? I would reckon so, seeing that hits are determined by intersecting the polygons of the tank with the path of the shell. For most tanks, the mantlet is better protected than the hull, the difference now is that the subsystems of a tank are better modelled and tracked and you can lose any of them. Getting hit is always a bad idea, but you can minimize the risks by going hull-down.

[stikkypixie]

Surely some elements are random, such as variation in projectile path from dispersion?

Most definitely I would guess, although not uniformly distributed but according to some probability distribution. If done well, it would give you the same variation as in real life. So although you end up with a number that is influenced by random variables, it is not the same as "picking a random number".

[gunnergoz]

I'm talking both in game and real life. The game models the latter pretty well in this respect.

I'd just never heard anyone pose an argument against going hull down, beyond the loss of use of the hull/bow MG, that's all. If you need to move to survive, move; if you have to hit someone accurately, stay in one spot; if you're going to stay in one spot, minimize your exposure and vulnerability. And yes, your mantlet is traditionally one of your strongest defensive points on most tanks, so by all means take advantage of that.

[Lee_Vincent]

Most definitely I would guess, although not uniformly distributed but according to some probability distribution. If done well, it would give you the same variation as in real life. So although you end up with a number that is influenced by random variables, it is not the same as "picking a random number".

I see, so generating a variation in the projectile path from dispersion by using a random number(s) as (some of) the input(s) to an algorithm that models a probability distribution is not in fact generating a random number, but a number influenced by random variables. I guess you could spin it that way, sorta

[stikkypixie]

I see, so generating a variation in the projectile path from dispersion by using a random number(s) as (some of) the input(s) to an algorithm that models a probability distribution is not in fact generating a random number, but a number influenced by random variables. I guess you could spin it that way, sorta

. My point is that is more involved. There is picking a random number and there is picking a random number .CMx1 modelled the outcome, i.e. the hit percentages, a target is hit before the shell leaves the barrel, whereas CMx2 models the input, i.e. the vector of the shell. Once it's loose, it can interact with the game world. So yeah, it is more than just picking a random number, at least compared to CMx1. Of course general outcome will be the same.

[Bastables]

So tell me, statistically, is a larger target easier to hit than a smaller or not? There are always benefits from being hull down: even if it only gives a marginal benefit, on the battlefield that can be critical.

If you expose yourself fully and you are not well armored, then you better keep moving. In WW2 terms moving generally means you cannot shoot back if your enemy is distant. Better to hide, not be noticed for as long as you can, hit the target when they do not yet see you and then scoot to a new position if you fear someone will lock on to you. That was basic TD doctrine during the war.

Going hull down's first and foremost benefit always has been concealment but it will also minimize the enemy's aim point, perhaps long enough for you to either move or get off another shot.

But if for some reason you must stay in one position and the enemy is distant, I see no benefit to taking a hit in the hull - which is easier to hit - than taking one in the mantlet, which is a smaller target.

Well a hit to the 8cm hull at certain ranges or off angles is survivable in a PIV. In the carbid senario a PIV had survived 2 initial 400m oblique hull hits before another of my Shermans put him down with a turret shot after losing another Sherman to tellingly a shot to the turret. A hit to the 5cm turret you're dead at ranges even above 1km. If the game models center of mass targeting and then you're better exposing the hull.

It's like shooting a fellow (specious I know), a chap standing up, about 1000rds from a section at him. He's hit 7 times in the chest area from 300m away. Similar incident but with the chap's head above a rock line about 6-700 rds fired two rounds to the face. Guess who died immediately(skull holes) and who bled out (no hits to the central nervous system). Center of mass changes depending on what is exposed.

The Panther has a stronger Hull and hits to the glascis is not going to knock your optics around. Lower mantlet hits may also bounce the round into the hull roof. With the exception of the Tiger all of the normandy tanks have better frontal hull protection due to sloping or thicker glacis plates.

[gunnergoz]

Hits to the panthers lower mantlet only matter in the early versions, the later ones altered the mantlet design with a vertical section of armor across the bottom width which stopped the problem with rounds being deflected into the front compatment.

I see where you are coming from if we are speaking of a tank duel with tanks like the panther and tiger that had some substantial armor in the hull. Tanks like the Pz IV and Sherman were the ones that had the most to gain from being hull down, as did the lighter TD's like the Marder.

In part we are speaking of different engagement scenarios. In the end, if a tank battle boils down to maneuver, as it often did, being hull down was not really a factor unless you happened to find such a spot as you were moving around. If the battle starts off with one AFV being in a static position and looking to ambush the other, being hull down is the way to go. Even today, Abrams tankers, with a world of frontal armor to hunker down behind, still are trained to look for hull down positions if at all possible.

I don't see us reconciling our views on some of these details so I'll leave it with that said.

[Magpie_Oz]

Well that is a gross oversimplification. There is a huge difference between the mantlet on a Pz IV which is more of a knight's shield covering the gun mount, a Panther mantlet which is more of a bulb that seems not to be connected to the gun mechanism at all and a StuG's Saukopfblende.

The latter two look like hits on them will do nothing to the gun or the gun mechanism.

Well no it isn't it is the crux of the issue. The gun can only be mounted on single fulcrum and so has limits to its strength, as the other fellow have pointed out the trunnion is quite sensitive. The mantlets on nearly all WW2 tanks covered the whole front of the tank so the gun and mount would bear the full force of any hit to the turret front.

Granted the Stugs, particularly the ones with the pig's head mantlet, mitigated this, so too the Tiger II, but the mount is still vulnerable.

The best proof of this is to take a look at the M1, Leo2A6, Merkava and T80 , tiny mantlets