15in Up Gunned Gneisenau v 1939 Modernized Renown

[Dave Saxton]

Actually we have US documetation that it was considered a major factor in the cases of yawing AP shells.

[lwd]

Actually we have US documetation that it was considered a major factor in the cases of yawing AP shells.

Mind stating what documentation?

[Dave Saxton]

Again? I gave you this a few months ago.

USN, Navy Dept. BoO, Correspondence with Carnegie Steel Corp, July 1941.


I'd hate to think how weak the deck protection of the fast BB's would have been without the upper deck yaw factor.

[Bgile]

Again? I gave you this a few months ago.

USN, Navy Dept. BoO, Correspondence with Carnegie Steel Corp, July 1941.


I'd hate to think how weak the deck protection of the fast BB's would have been without the upper deck yaw factor.

The British fast BB's don't have one, do they?

[Dave Saxton]

Nope, and neither did Jean Bart or Dunkerque.

Don't assume that 36mm + 88mm laminate = the British 5" single plate.

[dunmunro]

One of the things that the RN noted during the Baden trials was that shells fired at very low MVs from guns designed for higher MVs tended to develop yaw right from the muzzle, so this may have exacerbated the effects of yaw during firing tests.

[dunmunro]

Nope, and neither did Jean Bart or Dunkerque.

Don't assume that 36mm + 88mm laminate = the British 5" single plate.

Jean Bart has a 7mm WD. KGV has a 31mm (13+18mm IIRC) WD versus 36 -38mm in USN fast BBs. I don't if KGV's WD constitutes a "yaw deck", but it is certainly more substantial than Jean Bart's.

[tommy303]

One of the things that the RN noted during the Baden trials was that shells fired at very low MVs from guns designed for higher MVs tended to develop yaw right from the muzzle, so this may have exacerbated the effects of yaw during firing tests

Which might indicate that shells were understabilized; yaw can develop as a shell is in flight. If it does not have an optimum rate of spin that will maintain proper stabilization throughout its range, it may be stable at the muzzle, but further down range yaw can increase due to the effects of spin degradation as the shell slows down in flight. The reduced MV in the trials was to simulate performance at longer ranges, and it is possible that at longer ranges the shells would begin to yaw in flight in much the same way as noted in the tests..

[dunmunro]

Which might indicate that shells were understabilized; yaw can develop as a shell is in flight. If it does not have an optimum rate of spin that will maintain proper stabilization throughout its range, it may be stable at the muzzle, but further down range yaw can increase due to the effects of spin degradation as the shell slows down in flight. The reduced MV in the trials was to simulate performance at longer ranges, and it is possible that at longer ranges the shells would begin to yaw in flight in much the same way as noted in the tests..

That's possible. Later RN tests with WW2 era APC shells do not note yaw as a factor in reduced MV penetration tests.

[Bgile]

Nope, and neither did Jean Bart or Dunkerque.

Don't assume that 36mm + 88mm laminate = the British 5" single plate.

Not sure what US BB you are referring to, but NC was:

Weather deck: 1.45"
Second deck: 1.4" + 3.6" = 5.0"
Third deck: 0.62"
Total: 7.07"

the above is centerline; outboard is thicker. The other US Fast BBs had thicker armor than that. None of that is structural steel; it's all STS or armor plate. I think laminate is closer to a single plate than two separate plates in effective thickness, is it not? And US homogeneous armor plate is as good as anyone's.

[Karl Heidenreich]

Bgile,

It´s time to read Garzke and Dullin with a bit of Friedman and Raven & Roberts. That will refresh a lot of concepts that are simply being ignored.

Just a tip.

[lwd]

Again? I gave you this a few months ago.

USN, Navy Dept. BoO, Correspondence with Carnegie Steel Corp, July 1941.


I'd hate to think how weak the deck protection of the fast BB's would have been without the upper deck yaw factor.

Could you quote the relevant parts or suggest how one goes about getting a copy?

[Dave Saxton]

.... I think laminate is closer to a single plate than two separate plates in effective thickness, is it not? And US homogeneous armor plate is as good as anyone's.

Actually in British tests post war they found that laminates had less ballistic resistance than if the plates were spaced.

[Dave Saxton]

[
Could you quote the relevant parts or suggest how one goes about getting a copy?

I'll see if I can find time this weekend.

[lwd]

Thanks.