Leopard 2A4 mantlet question

[Kyle Harmse]

Hey all

Long time fan, and a relatively recent purchaser of this fine sim here with a fairly specific technical question for all the Leo experts out there.

Its regarding the layout of the Leo 2 A4's (and previous versions') mantlet. As I understand it, it consists of (going outside in):

A) The mantlet shield, c. 420mm thick

B) The inner space, containing the elevation mechanism, stabilisation and gun trunnion block/cradle, aprox 240mm thick.

C) A back plate, seperating all the above from the crew compartment?

I base this layout on this article: http://btvt.narod.ru/raznoe/leopard2/Leo2a4.htm

And observations from www.kampfpanzer.de

My questions are:

1) What is the trunnion block made out of?

It seems like a pretty important integral part of the Leo's front armour. Aluminium? Titanium? Those sound too expensive to mill/brittle to withstand recoil force. Cast steel? Rolled? A quick wiki search shows that the L44 weighs 3317kg- including the gun(not too sure on that though). Minusing the 1190 kg of the gun tube, 2127kg seems consistent with a steel trunnion block and breech.

2) Is there really a back plate? I've looked on http://www.kampfpanzer.de/details/leo2a6, from the loader's position, and it seems possible either way.

Thanks in advance, and good to be here.

[Lt DeFault]

Welcome to the forum! I can't answer those questions, but I'm sure someone who can will be along very soon.

[Kyle Harmse]

Welcome to the forum! I can't answer those questions, but I'm sure someone who can will be along very soon.

Thanks LT

Say, are you named after the sim's Lt DeFault or is it vice versa?

[dejawolf]

Hey all

Long time fan, and a relatively recent purchaser of this fine sim here with a fairly specific technical question for all the Leo experts out there.

Its regarding the layout of the Leo 2 A4's (and previous versions') mantlet. As I understand it, it consists of (going outside in):

A) The mantlet shield, c. 420mm thick

B) The inner space, containing the elevation mechanism, stabilisation and gun trunnion block/cradle, aprox 240mm thick.

C) A back plate, seperating all the above from the crew compartment?

I base this layout on this article: http://btvt.narod.ru/raznoe/leopard2/Leo2a4.htm

And observations from www.kampfpanzer.de

My questions are:

1) What is the trunnion block made out of?

It seems like a pretty important integral part of the Leo's front armour. Aluminium? Titanium? Those sound too expensive to mill/brittle to withstand recoil force. Cast steel? Rolled? A quick wiki search shows that the L44 weighs 3317kg- including the gun(not too sure on that though). Minusing the 1190 kg of the gun tube, 2127kg seems consistent with a steel trunnion block and breech.

2) Is there really a back plate? I've looked on http://www.kampfpanzer.de/details/leo2a6, from the loader's position, and it seems possible either way.

Thanks in advance, and good to be here.

1) steel

2) the trunnion is the back plate.

you can see it here:

so configuration is pretty much armour-small air gap-trunnion.

on the 2A4 the whole configuration gives around 600mm vs KE.

[Kyle Harmse]

@ dejawolf:

Thanks very much! The article by Miltarysta on Narod is illuminating in terms of armour layout and such but I suspected that he may have been underestimating the mantlet. Going by the Lakowsi document, a titanium trunnion would have been reasonably good ballistically, but it doesnt make sense to engineer a trunnion out of titanium from a cost standpoint- and also whether it would survive recoil forces with 1980s material science is circumspect.

TL/DR: thanks deja

[dejawolf]

@ dejawolf:

Thanks very much! The article by Miltarysta on Narod is illuminating in terms of armour layout and such but I suspected that he may have been underestimating the mantlet. Going by the Lakowsi document, a titanium trunnion would have been reasonably good ballistically, but it doesnt make sense to engineer a trunnion out of titanium from a cost standpoint- and also whether it would survive recoil forces with 1980s material science is circumspect.

TL/DR: thanks deja

with western tanks in general, it's sensible to assume that it will protect against the ammunition of it's era 30 degrees off to either side.

so for the leopard 2A4 for example, it's contemporary round would be the DM-33, with penetration of around 550-600mm.

[Lt DeFault]

Thanks LT

Say, are you named after the sim's Lt DeFault or is it vice versa?

To be clear: no one in their right mind would name anything after me. :debile2:

I picked the name as a goof when I realized this town isn't big enough for two Seans. Some people were getting confused thinking I was the Sean that works for eSim and I didn't want to tarnish his reputation. So, in typical form, I picked an equally confusing name. Haha!

[Kyle Harmse]

with western tanks in general, it's sensible to assume that it will protect against the ammunition of it's era 30 degrees off to either side.

so for the leopard 2A4 for example, it's contemporary round would be the DM-33, with penetration of around 550-600mm.

Sure, that definitely makes sense as a design goal and gels with what I've read of the A4- I was just curious how they achieved that level of protection in terms of actual design and layout. Its interesting in that a BM-32 will make it through the mantlet shield but get stopped by the trunnion- and its really cool that SB models that by it causing damage to the stabilisation system The penny just dropped now.

How accurate is the article in terms of Militarysta's description of the upper glacis plate (40mm high hardness plate at 7 degrees)? 7 degrees is in theory beyond the ricochet range of 80s era APFSDS according to Lakowsi. But 40mm of high hardness steel sounds AWFULLY thin, even if its effectively 320mm thick from horizontal. Its a similar situation with the A4's roof. Its quite far from the 756mm of the SB model- effectively double (ie 80mm of RHA at 7 deg)? Does that include the "beak" module? The SB model then drops off further back again to a 40mm level again.

To be clear: no one in their right mind would name anything after me. :debile2:

I picked the name as a goof when I realized this town isn't big enough for two Seans. Some people were getting confused thinking I was the Sean that works for eSim and I didn't want to tarnish his reputation. So, in typical form, I picked an equally confusing name. Haha!

Hehehe, awesome. You never know, one day there may be a famous De Fault out there. Probably with parents with a twisted sense of humor.