German tank vulnerability

[Gryphonne]

Hey guys,

I have a question about the possible vulnerability of German tanks: mainly, the StuG and Pz IV.

I was looking at armour diagrams for both and noticed that for example, the Pz IV has a vulnerable upper glacis plate which provides only 20mm of protection. Despite the angle at which it is positioned it seems very vulnerable, how often would the upper glacis plate get penetrated? Or was the reasoning such that if anything could penetrate the upper glacis plate it would also probably penetrate the 80mm sections?

Same goes for the StuG, it has a very complex geometry for the superstructure and most of the sections only provide 40-45mm (? - was hard to find the figures) of armor protection. Again, these seem very vulnerable and the 80mm sections seem quite small in comparison. How vulnerable are these sections and is it the case here again that if anything can penetrate these it can probably also wreck the 80mm sections?

Finally, is all this geometry modelled in CMBN?

[Sergei]

What diagrams are you talking about?

[Bil Hardenberger]

A lot of these questions are going to be answered in the AAR.

[Gryphonne]

What diagrams are you talking about?

This one for example

@Bil

I'm looking forward to it

[UsF]

I think they all had the same absolute calculated thickness (depth plus angle), however they would become more vulnerable as a tank is being shot while driving down hill (which of course applies to all tanks). The frontal profile of that area is also small.

[Other Means]

I think they all had the same absolute calculated thickness (depth plus angle), however they would become more vulnerable as a tank is being shot while driving down hill (which of course applies to all tanks). The frontal profile of that area is also small.

AIUI it's modelled to the plate.

So if it hits a specific plate at a specific angle it will penetrate or not as it should.

Also, the equipment behind the plate is modelled and will be damaged realistically.

[Earl Grey]

Well, at that angle it'd be pretty hard to hit the top of the front hull in the first place and even if it gets hit chances are high the projectile is dflected into the 80mm front hull - which it might not penetrate.

Same goes for the StuG. Best course of action is to take out the enemy's big guns BEFORE they can shoot back at you, though.

[ShakyJake]

Well, at that angle it'd be pretty hard to hit the top of the front hull in the first place and even if it gets hit chances are high the projectile is dflected into the 80mm front hull - which it might not penetrate.

Same goes for the StuG. Best course of action is to take out the enemy's big guns BEFORE they can shoot back at you, though.

Out of curiosity, I took that technical diagram and actually measured the vertical profile for that thinner glacis, and it came out to be a bit bigger than I expected. It measures just under three-quarters as what the 30mm+50mm upper hull does, and two-thirds as much as the lower hull. If a shot were randomly to strike somewhere withing those three areas, my math estimates a 25% chance of that thinner plate being the point of impact. At about a 72° angle from the normal I'd imagine the slope multiplier would more than compensate for that thin 20mm plate, but I wonder how much good that would have done with overmatching involved from hits by larger caliber guns.

So after spending about half an hour digging through boxes in my closet looking for that copy of "World War II Ballistics: Armor and Gunnery" (whose cover has made an interesting change in color from bright orange to green in the decade since I bought it), I can make some calculations from the tables and equations. It seems that plate would have an effective resistance of 96mm to hits that are perfectly horizontal to it from 75mm APC/APCBC rounds. That's better than I'd expected. Anything bigger than 75mm would probably have a bigger impact to overmatching. Then again, any ordnance bigger than 75mm would also probably punch through the front of that with little trouble, anyway.

[UsF]

AIUI it's modelled to the plate.

So if it hits a specific plate at a specific angle it will penetrate or not as it should.

Also, the equipment behind the plate is modelled and will be damaged realistically.

What I meant was that the tank uses a thinner plate of steel here, because the plate is angled flatter towards direct fire and therefor the calculated thickness (angle and thickness of plate) is the same armor as a 90 degrees vertical plate (or the other plates at different angles seen in the picture).

I can't talk about the game engine, but I'm sure the calculation is realistic, so a tank driving downhill will be more vulnerable than one driving uphill (unless you get to shoot the tank belly of course).

[MikeyD]

There was an internal conversation on this a short while ago. PzIV really shouldn't be classed among the legendary German "überweapons" In 1940 it was outclassed by the Char B1-BIS! Someone commented that he couldn't really recall reading a combat account of a PzIV surviving a solid AP hit from a Sherman. The literature is filled with shot of all sorts bouncing off of Panthers and Tigers and Stalins and T34s. PzIVs don't fare so lucky.

[ZPB II]

Can anyone list all the shortcomings of the PzIV? I myself regard it as a mediocre design and would prefer a Sherman or a T-34 most of the time. This obsolete design that was patched together to keep up with the times had a lot of flaws, but I can't remember right now what they were. I mean there's the obvious stuff like woefully thin tracks and armour, but I remember reading a document by the Sovs that listed a lot of stuff they found flawed. I was surprised at the number of "soft" factors listed. Stuff like having an clunky, hard to operate gearbox sitting right next to the driver & making an infernal noise driving him mad? IIRC the T-34 crews said it was far gentler and easier to crew one than a PzIV. I always thought Soviet designs were the epitome of crew discomfort.

It didn't tackle harsh terrain nor conditions well. I think there were electric insulation problems too? Atleast this is what I remember reading, will a grog enlighten me? I think this was from a relatively early period too, before the quality control issues the Germans had in the later period...All things considered, in my opinion German engineering in WW2 is very overrated. I don't think the whole overstressed drivetrains & engines approach qualifies as somesort of engineering marvel feat, though they did make some nice, innovative stuff too.

[SleeStak]

The PzIV didn't have the same level of protection that the Panthers or the Tigers posessed but it did have a better gun than the Shermans and early T-34's. Well managed, the PzIV can take just about any allied tank except for the Russian heavies or maybe the late war churchills. In CMBB or CMAK, i tried to use them like US tank destroyers.

[Michael Emrys]

I always thought Soviet designs were the epitome of crew discomfort.

And I have read that the gearbox on the T34 was a bear to operate.

I don't think the whole overstressed drivetrains & engines approach qualifies as somesort of engineering marvel feat...

There was a lot of that going around for a while. The midwar British tanks were often even worse with tracks that would break if you were not careful how you turned and the famous overstressed engines and drive trains. And the American tanks with radial engines were not exactly first prize material either. It simply took a while for designers to work out how to build a good, reliable tank. The British tanks in North Africa were so unreliable that they were delighted to get their hands on even the M3 Stuart, which although only a light tank, was pressed into service as an MBT for a while.

Michael

[Michael Emrys]

The PzIV didn't have the same level of protection that the Panthers or the Tigers posessed but it did have a better gun than the Shermans and early T-34's.

The L42 possessed no significant advantage over the Sherman's 75. The L48 was better than the 75 but was easily matched by the 76.

Michael

[ZPB II]

Indeed, pretty much all tanks in the war had design flaws (hell, they do today), some in horrendous numbers. Sometimes it's just about opportunity cost, sometimes the circumstances, sometimes a grave oversight that leads to these.

It's just that, sometimes it feels like "German engineering" as a concept gets raised to a pedestal and hailed. I expect a lot of gnashing of teeth if CMx2 delivers a more visceral experience regarding the shortcomings of German kit. Though most of this, I reckon, is out of the CM scale and goes into the operational scheme of things.

Speaking of bad designs, this always makes me chuckle.

http://en.wikipedia.org/wiki/Valiant_tank

"Valiant's moment of glory was a trial of its suspension by the Fighting Vehicle Proving Establishment at Chertsey, in May 1945. The first day gave minor problems and was abandoned after a mere 13 miles of easy on-road driving. However the driver was already exhausted by this time: finding that the steering levers needed his full weight to actuate and the seat, footbrake and gearlever all carried risk of physical injury in using them. The Officer in Charge decided to abandon the trials there and then as it was impossible and unsafe to continue and, "in his view the entire project should be closed".

Then there's this gem from WW1.

http://en.wikipedia.org/wiki/St_Chamond_(tank)

A massive, heavy box on tracks with a main gun that digs into the ground, a gaping hole in the front that your gunner looks out of and an engine too big to fit into it, so it sticks out of the roof...Where do I sign up?

[SleeStak]

The L42 possessed no significant advantage over the Sherman's 75. The L48 was better than the 75 but was easily matched by the 76.

Michael

Yeah, when i wrote that, I meant to include that it beat the Sherman up til the end of 1944. The 17 lber was a better weapon and the 3" roughly equal though its penetration numbers are lower than the 75l48. Not enough to really impact the matchup between the Sherman and the PzIV though.

The l48 gives it enough punch to be useful through the war and the tank can contend with most of the allied mediums if its not suprised, but it fights the Russians at a disadvantage later in the war.

[MikeyD]

Indeed, pretty much all tanks in the war had design flaws (hell, they do today),

I must admit, watching those M1 Abrams spontaneously catching fire on the road to Bagdad in '03 did remind me somewhat of those brand new Panther Ds catching fire en route to the kickoff of operation Citadel in '43.

[Peregrine]

Haven't followed the latest AAR closely but I have had plenty of CMAK experience with PIVs v Shermans and in the mid 1944 period Shermans are better simply because virtually NOTHING bounces off a PIV turret.

With Shermans/T34s once you go beyond about 600m you will get some richochets. So unless there is a dramatic crew level difference and duelling tanks manage the some number of hits the PIVs will die faster.

The CMAK Cintheaux scenario has a good example of these sort of match-ups.

[Michael Emrys]

I must admit, watching those M1 Abrams spontaneously catching fire on the road to Bagdad in '03...

Was that due to the heat of the turbine?

Michael

[jjhouston]

Was that due to the heat of the turbine?

Michael

C-12 TF 1/64 AR. POL container in bustle rack was penetrated by small arms fire during "Thunder Run" into Baghdad. Dripping POL ignited on engine deck resulting in engine fire. Nothing spontaneous about it.

[SleeStak]

Haven't followed the latest AAR closely but I have had plenty of CMAK experience with PIVs v Shermans and in the mid 1944 period Shermans are better simply because virtually NOTHING bounces off a PIV turret.

With Shermans/T34s once you go beyond about 600m you will get some richochets. So unless there is a dramatic crew level difference and duelling tanks manage the some number of hits the PIVs will die faster.

The CMAK Cintheaux scenario has a good example of these sort of match-ups.

While its been awhile since I've played CMAK, the Sherman/PzIV match up seemed to go to who hit who first under 1000 meters. I always felt that if I could control that with the PzIV, I'd win the armor fight. Maybe I wasn't using my Shermans to their utmost effectiveness. With that said, the PzIv's turret armor is anemic and its hard to understand why the rest of the tank was up armored but the turret remained 50mm. It really does seem an oversight.

The point I was trying to make in my original post was that, despite its weaker armor (and Peregrine identified its Achillies heel, or turret in this case), its gun makes it a useful tank in tank versus tank combat from the introduction of the G model until the end of the war. I think that as long as you handle the tank as you'd handle a M10, you can do pretty well against the Shermans and the rest of the western Allied tank force for the most part. The heavily armored Churchills (mk VII I think) and the M4 jumbo are a little too much but the rest of the western arsenal can be destroyed.

I should probably dust off CMAK and give the Cintheaux scenerio a shot. I'm a sucker for the underdog and the PzIV really is the underdog of the German armored forces.

[ZPB II]

IIRC the turret ring & mechanism had pretty much reached it's weight limit. It was easier to add extra weight to the hull.

Yes, if you handle an PzIV like a TD, you get excellent results. But you can buy a much cheaper Marder II and achieve similar results if that's how you're going to employ it.

(I think someone ran extensive tests in CMx1 and concluded that you're less likely to lose your PzIVs if you don't put them in a hull down position. Which was really strange, since the turret silouette is rather small. I might remember wrong though.)

[Gryphonne]

Out of curiosity, I took that technical diagram and actually measured the vertical profile for that thinner glacis, and it came out to be a bit bigger than I expected. It measures just under three-quarters as what the 30mm+50mm upper hull does, and two-thirds as much as the lower hull. If a shot were randomly to strike somewhere withing those three areas, my math estimates a 25% chance of that thinner plate being the point of impact. At about a 72° angle from the normal I'd imagine the slope multiplier would more than compensate for that thin 20mm plate, but I wonder how much good that would have done with overmatching involved from hits by larger caliber guns.

So after spending about half an hour digging through boxes in my closet looking for that copy of "World War II Ballistics: Armor and Gunnery" (whose cover has made an interesting change in color from bright orange to green in the decade since I bought it), I can make some calculations from the tables and equations. It seems that plate would have an effective resistance of 96mm to hits that are perfectly horizontal to it from 75mm APC/APCBC rounds. That's better than I'd expected. Anything bigger than 75mm would probably have a bigger impact to overmatching. Then again, any ordnance bigger than 75mm would also probably punch through the front of that with little trouble, anyway.

I'm actually quite surprised about the plate's resistance to overmatching penetrators here. That section still provides a bigger target than one would initially think. So I guess the German engineer's reasoning was indeed that if anything could penetrate these thin plates at high angles, it would probably also penetrate the 80mm sections.

I wonder how, in comparison to the Pz IV, the StuG would fare; in absolute terms. The armor profile actually seems a bit less vulnerable, but I can't find any info on all the complex geometry of the superstructure. It appears that most plates are 40-45mm and are positioned at 45 degrees from vertical or higher (on par with T-34 front armor?); if true, this would actually provide a reasonable target in hull down position and would be impossible to penetrate by the Sherman's 75mm. Furthermore, I have however found that the upper glacis plate is 30mm and almost horizontal, providing both more protection and a smaller target.

I think the Pz IVs will have a hard time dealing with Shermans in CMBN, unless they spot those Shermans first, and even then, apparently the upper hull, which presents a very large target, provides fairly adequate protection against the 75/L48. Testing this in CMAK I actually reached the same conclusion, I was just surprised how often the turret is targeted instead of the hull and how easily that is penetrated in comparison. The StuG on the other hand, might be a good deal more survivable.

In any case, thanks for all the replies guys

[Bastables]

While its been awhile since I've played CMAK, the Sherman/PzIV match up seemed to go to who hit who first under 1000 meters. I always felt that if I could control that with the PzIV, I'd win the armor fight. Maybe I wasn't using my Sherman to their utmost effectiveness. With that said, the PzIv's turret armor is anemic and its hard to understand why the rest of the tank was up armored but the turret remained 50mm. It really does seem an oversight.

The point I was trying to make in my original post was that, despite its weaker armor (and Peregrine identified its Achillies heel, or turret in this case), its gun makes it a useful tank in tank versus tank combat from the introduction of the G model until the end of the war. I think that as long as you handle the tank as you'd handle a M10, you can do pretty well against the Shermans and the rest of the western Allied tank force for the most part. The heavily armored Churchills (mk VII I think) and the M4 jumbo are a little too much but the rest of the western arsenal can be destroyed.

I should probably dust off CMAK and give the Cintheaux scenerio a shot. I'm a sucker for the underdog and the PzIV really is the underdog of the German armored forces.

Up armoring the turret would have been impossible after they had squeezed the L43/48 7,5cm guns into it. The chassie was already overstressed by up armouring to 5cm hull plates and the gun upgrade. The PIV was a poorer design than the PIII chassie but had the one small and in the end overbearing advantage of having a turret ring large enough to fit the longer 7,5cm gun and turret that enabled it kill T34's through their glacis armour. By 1944 they were a bit long in the tooth and with the overstressed chassie were not much more reliable than '44 era panthers with none of the panthers advantages.

[James Crowley]

Hey guys,

I have a question about the possible vulnerability of German tanks: mainly, the StuG and Pz IV.

I was looking at armour diagrams for both and noticed that for example, the Pz IV has a vulnerable upper glacis plate which provides only 20mm of protection. Despite the angle at which it is positioned it seems very vulnerable, how often would the upper glacis plate get penetrated? Or was the reasoning such that if anything could penetrate the upper glacis plate it would also probably penetrate the 80mm sections?

Same goes for the StuG, it has a very complex geometry for the superstructure and most of the sections only provide 40-45mm (? - was hard to find the figures) of armor protection. Again, these seem very vulnerable and the 80mm sections seem quite small in comparison. How vulnerable are these sections and is it the case here again that if anything can penetrate these it can probably also wreck the 80mm sections?

Finally, is all this geometry modelled in CMBN?

This picture is from a Panzer IV/70 (A) at Saumur Tank Museum:

it clearly shows the fragility of the upper glacis plate, having been hit by a 75mm round. The other two rounds hit the lower superstructure for a full and partial penetration.