German tanks and cast armour

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German tanks and cast armour

Joined: August 3rd, 2005, 6:52 pm

May 8th, 2012, 6:44 am #1

Folks, I have been unable to find a satisfactory explanation as to why Germans did not use any major cast armour in their tanks? I.e. was it a "default policy" or what? I am aware of the potentially slightly better quality of rolled armour, but nevertheless, one gets a feeling that German policy did shoot itself in the foot...
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Joined: November 18th, 2009, 10:04 am

May 8th, 2012, 7:59 am #2

Hi Jukka

Generally the use of castings in WW2 depended on the industrial history of a particular plant (or indeed country). So many US fabricators for inst, had long experience of making large castings whereas the same experience did not exist in Germany. The Germans were however, undoubtedly the world's best fabricators and welders of plate armour in the 1940s. One could say equally that US factories turned to casting from their earlier rivetting in WW2 purely because of their lack of experience with deep-welding armour plate.

So I'm not sure why you're setting up a cast vs.rolled plate argument as if cast armour was/is in some ways superior. Assuming that cast armour trumps rolled by default is just wrong. The cast-hull M4A1s were actively avoided by some US units as they were convinced that they were ballistically inferior to the welded M4s and M4A3s in combat. The all-cast M26 Pershing had equivalent armour thickness to the Tiger I yet was in some respects an inferior machine ballistically, the turret and hull often taking rounds that the Tiger I's would shrug off.

The Germans were definitely far better at producing (particularly interlocked) plate armour than any other combatant, and this served them well throughout, particularly on the Panther/Tiger series. One only has to look at the beautifully trunkated pyramid shape of the Pz.Jg.38 for a seminal illustration of the ability of German interlocked armour designers and fabricators.

Finally, the Israelis hired many ex-German slave labour armour technicians in the 1950s to help them with their newly-setup plate armour welding facility. And what the Israelis don't know about armour performance in combat isn't worth knowing.

And German industry DID use plenty of castings. What about all the myriad of topfblende mantlet variants for inst? Or MG34 Kügelblendes? Maybe you need to relook at your sources.

Ron
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Joined: June 23rd, 2003, 4:53 pm

May 8th, 2012, 8:06 am #3

Folks, I have been unable to find a satisfactory explanation as to why Germans did not use any major cast armour in their tanks? I.e. was it a "default policy" or what? I am aware of the potentially slightly better quality of rolled armour, but nevertheless, one gets a feeling that German policy did shoot itself in the foot...
To add to Ron's comments, the superstructure front of the Jagdtiger was a single casting, of considerable size.

Rob
There's nothing cushy about life in the Women's Auxiliary Balloon Corps
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Joined: July 24th, 2000, 8:18 pm

May 8th, 2012, 3:27 pm #4

Hi Jukka

Generally the use of castings in WW2 depended on the industrial history of a particular plant (or indeed country). So many US fabricators for inst, had long experience of making large castings whereas the same experience did not exist in Germany. The Germans were however, undoubtedly the world's best fabricators and welders of plate armour in the 1940s. One could say equally that US factories turned to casting from their earlier rivetting in WW2 purely because of their lack of experience with deep-welding armour plate.

So I'm not sure why you're setting up a cast vs.rolled plate argument as if cast armour was/is in some ways superior. Assuming that cast armour trumps rolled by default is just wrong. The cast-hull M4A1s were actively avoided by some US units as they were convinced that they were ballistically inferior to the welded M4s and M4A3s in combat. The all-cast M26 Pershing had equivalent armour thickness to the Tiger I yet was in some respects an inferior machine ballistically, the turret and hull often taking rounds that the Tiger I's would shrug off.

The Germans were definitely far better at producing (particularly interlocked) plate armour than any other combatant, and this served them well throughout, particularly on the Panther/Tiger series. One only has to look at the beautifully trunkated pyramid shape of the Pz.Jg.38 for a seminal illustration of the ability of German interlocked armour designers and fabricators.

Finally, the Israelis hired many ex-German slave labour armour technicians in the 1950s to help them with their newly-setup plate armour welding facility. And what the Israelis don't know about armour performance in combat isn't worth knowing.

And German industry DID use plenty of castings. What about all the myriad of topfblende mantlet variants for inst? Or MG34 Kügelblendes? Maybe you need to relook at your sources.

Ron
I had the impression for a long time, and more so after reading the report that was available here some months ago, that the interlocking of german armour plate was made as a solution to the cracked butt welds that were marring german hulls and turrets, specially from mid-war on, due to a mix of poor workmanship, poor materials and poor quality control. More so, I've been in a couple of shipyards for weeks due to a contract with my company, and have talked a lot (well, I blasted them with questions) with the engineering staff about all things related to metal construction, including this one. As a cracked weld would develope all along it's length, they agreed a posible way to prevent that at war could very well be interlocking, as it gets out a lot of the linear stress of the weld.

As for the comment that cast-hull M4A1s were avoided by some US units, just the same can be said from others crews that didn't like the welded ones, I think that has more to do with the tankers "ballistic mythology" than with objective reasons.

Javier de Luelmo - Diesel

http://dieselwerk.blogspot.com/
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Joined: November 8th, 2003, 2:51 am

May 8th, 2012, 3:29 pm #5

Hi Jukka

Generally the use of castings in WW2 depended on the industrial history of a particular plant (or indeed country). So many US fabricators for inst, had long experience of making large castings whereas the same experience did not exist in Germany. The Germans were however, undoubtedly the world's best fabricators and welders of plate armour in the 1940s. One could say equally that US factories turned to casting from their earlier rivetting in WW2 purely because of their lack of experience with deep-welding armour plate.

So I'm not sure why you're setting up a cast vs.rolled plate argument as if cast armour was/is in some ways superior. Assuming that cast armour trumps rolled by default is just wrong. The cast-hull M4A1s were actively avoided by some US units as they were convinced that they were ballistically inferior to the welded M4s and M4A3s in combat. The all-cast M26 Pershing had equivalent armour thickness to the Tiger I yet was in some respects an inferior machine ballistically, the turret and hull often taking rounds that the Tiger I's would shrug off.

The Germans were definitely far better at producing (particularly interlocked) plate armour than any other combatant, and this served them well throughout, particularly on the Panther/Tiger series. One only has to look at the beautifully trunkated pyramid shape of the Pz.Jg.38 for a seminal illustration of the ability of German interlocked armour designers and fabricators.

Finally, the Israelis hired many ex-German slave labour armour technicians in the 1950s to help them with their newly-setup plate armour welding facility. And what the Israelis don't know about armour performance in combat isn't worth knowing.

And German industry DID use plenty of castings. What about all the myriad of topfblende mantlet variants for inst? Or MG34 Kügelblendes? Maybe you need to relook at your sources.

Ron
How long did it take to pump out a M4A1 upper hull and turret compared to a Pz.Kpfw. IV upper hull and turret? Also could you state your sources for the units actively avoiding the cast hulled tanks because they thought their armour was inferior to the welded hull tanks. I actually thought they thought the opposite but many prefered the welded hull tanks because they were roomier but I am always willing to further my education.

Roy
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Joined: August 3rd, 2005, 6:52 pm

May 8th, 2012, 4:16 pm #6

Hi Jukka

Generally the use of castings in WW2 depended on the industrial history of a particular plant (or indeed country). So many US fabricators for inst, had long experience of making large castings whereas the same experience did not exist in Germany. The Germans were however, undoubtedly the world's best fabricators and welders of plate armour in the 1940s. One could say equally that US factories turned to casting from their earlier rivetting in WW2 purely because of their lack of experience with deep-welding armour plate.

So I'm not sure why you're setting up a cast vs.rolled plate argument as if cast armour was/is in some ways superior. Assuming that cast armour trumps rolled by default is just wrong. The cast-hull M4A1s were actively avoided by some US units as they were convinced that they were ballistically inferior to the welded M4s and M4A3s in combat. The all-cast M26 Pershing had equivalent armour thickness to the Tiger I yet was in some respects an inferior machine ballistically, the turret and hull often taking rounds that the Tiger I's would shrug off.

The Germans were definitely far better at producing (particularly interlocked) plate armour than any other combatant, and this served them well throughout, particularly on the Panther/Tiger series. One only has to look at the beautifully trunkated pyramid shape of the Pz.Jg.38 for a seminal illustration of the ability of German interlocked armour designers and fabricators.

Finally, the Israelis hired many ex-German slave labour armour technicians in the 1950s to help them with their newly-setup plate armour welding facility. And what the Israelis don't know about armour performance in combat isn't worth knowing.

And German industry DID use plenty of castings. What about all the myriad of topfblende mantlet variants for inst? Or MG34 Kügelblendes? Maybe you need to relook at your sources.

Ron
Ron, I know that rolled armour is slightly better, assuming similar quality steel. But, my main convcern was ease of production. From what can be interpreted from Spielberger and Jentz, Germans did have bottlenecks in supplying some thicknesses of rolled armour plate. Another consideration is that if an entire turret, for example, is cast vs. rolled+welded, considerable savings in production man-hours is achieved. And as far as I know, not a single German tank had either a cast turret or cast hull.

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Joined: August 3rd, 2005, 6:52 pm

May 8th, 2012, 4:19 pm #7

To add to Ron's comments, the superstructure front of the Jagdtiger was a single casting, of considerable size.

Rob
There's nothing cushy about life in the Women's Auxiliary Balloon Corps
I stand corrected on the Jagdtiger, a vehicle which I don't know much of. But speaking of tanks, as far as I know, no German cast hull or cast turret tanks.
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Joined: November 18th, 2009, 10:04 am

May 8th, 2012, 4:59 pm #8

Ron, I know that rolled armour is slightly better, assuming similar quality steel. But, my main convcern was ease of production. From what can be interpreted from Spielberger and Jentz, Germans did have bottlenecks in supplying some thicknesses of rolled armour plate. Another consideration is that if an entire turret, for example, is cast vs. rolled+welded, considerable savings in production man-hours is achieved. And as far as I know, not a single German tank had either a cast turret or cast hull.
Hi Jukka

You seem to be open-minded on the issue (if that's the word), so I'll just mention that any discussion such as this is probably a much more complex one than merely one manufacturing process vs. another. For instance, the whole first-in-first-out (US) vs. first-in-last-out (German) approaches were SO different in every way, the German method being decidedly inferior and of course resulting in bottlenecks, plus their difficulties with materials and slave-labour resulting in substandard results latewar. One only needs to look at 40,00 Shermans vs. 6,000 Tigers and Panthers to see the American system produced more tanks. But better tanks? I don't think many US tank crews would agree the Sherman was a better tank than the Panther. Even the Pershing wasn't as good. More is not better.

I am merely trying to illustrate the prewar industrial backcloth of German industrial design and process had led to them taking path A rather than path B, rather than any particular right or wrong way.

Ron
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Joined: November 18th, 2009, 10:04 am

May 8th, 2012, 5:09 pm #9

I had the impression for a long time, and more so after reading the report that was available here some months ago, that the interlocking of german armour plate was made as a solution to the cracked butt welds that were marring german hulls and turrets, specially from mid-war on, due to a mix of poor workmanship, poor materials and poor quality control. More so, I've been in a couple of shipyards for weeks due to a contract with my company, and have talked a lot (well, I blasted them with questions) with the engineering staff about all things related to metal construction, including this one. As a cracked weld would develope all along it's length, they agreed a posible way to prevent that at war could very well be interlocking, as it gets out a lot of the linear stress of the weld.

As for the comment that cast-hull M4A1s were avoided by some US units, just the same can be said from others crews that didn't like the welded ones, I think that has more to do with the tankers "ballistic mythology" than with objective reasons.

Javier de Luelmo - Diesel

http://dieselwerk.blogspot.com/
Javier, of course it was "ballistic mythology", I was merely alluding to the fact that one cannot badly state that cast is better than welded (or vice-versa), the reality is much more complex. Opinions ebb and flow on the subject in each successive generation of tanks.

Name possibly (definitely imo) the greatest lineage of great modern MBT tank turret influence: T-34 (cast), Panther (welded), Centurion (cast), Chieftain (cast), Chieftain 90 / Vickers MBT (welded/layered), Shir / Challenger 1 and 2 (welded/layered). New generations thinking in new ways.

Ron
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Joined: November 18th, 2009, 10:04 am

May 8th, 2012, 5:12 pm #10

How long did it take to pump out a M4A1 upper hull and turret compared to a Pz.Kpfw. IV upper hull and turret? Also could you state your sources for the units actively avoiding the cast hulled tanks because they thought their armour was inferior to the welded hull tanks. I actually thought they thought the opposite but many prefered the welded hull tanks because they were roomier but I am always willing to further my education.

Roy
...No. I don't like your hostile tone, so do your own research. By 'pump out' I presume you mean 'produce'? So what has productivity got to do with excellence? Answer, it hasn't. Unless you're one of those chosen few that actually believe a Sherman beats a Panther, or some other fantasyland.
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