German 37mm PaK vs T34 Armor

[rexford]

During early 1942, the Germans produced T34 like armor with same composition, and hardened to same level (about 450 Brinell). 37mm and 50mm anti-tank guns were fired at an assumed range of 100m, which was the standard for penetration tests.

Following results were obtained for 37mm AP and indicate the angle at which complete penetration is not likely ("sicher" criteria):

40.6mm plate, 40.0 degrees from vertical

40.9mm plate, 40.5 degrees

42.1mm plate, 40.0 degrees

43.2mm plate, 34.5 degrees

45.8mm plate, 21.0 degrees

47.1mm plate, 19.0 degrees

47.2mm plate, 20.0 degrees

51.9mm plate, 10.5 degrees

53.0mm plate, 09.0 degrees

53.3mm plate, 09.0 degrees

Complete penetration would occur a few degrees below the "sicher" angle presented above.

Against T34 high hardness 45mm plates, 37mm AP will not penetrate armor sloped at 30 or 40 degrees at 100m, will penetrate 45mm of vertical plate.

If 37mm AP is uncapped (no ballistic windscreen), a trajectory spreadsheet estimates velocity vs range profile as:

745 m/s at 0m

708 m/s at 100m

651 m/s at 250m

561 m/s at 500m

This suggests that the thicknesses needed for protection against complete penetration ("sicher" criteria) would decrease by following factors relative to 100m figure:

100m, 100%

250m, 88%

500m, 72%

At 100m, 250m and 500m range, 21 degree impacts by 37mm AP would be defeated by 45.8mm, 40.4mm and 33.0mm.

The maximum penetration of 45.8mm plate by 37mm AP occurred at an angle of 16 degrees from vertical during tests, with failure at 21 degrees. This suggests that 100m successes against 45mm would be restricted to a small angle range, 0 to 18 degrees from armor perpendicular, and the range would shrink very quickly as distance to armor increased.

If 45.8mm can be penetrated at an angle of 16 degrees at 100m, penetration at 0 degrees would be expected at a maximum range of about 200m.

So 37mm AP might not be expected to penetrate a 45mm high hardness plate above 200m, if the round is uncapped.

Miles Krogfus provided the report which contained the data used in this post.

[ February 01, 2003, 03:36 AM: Message edited by: rexford ]

[rexford]

Paul Lakowski posted the following on the Yahoo! Tankers forum for a thread regarding whether the Germans trained crews to use aimed fire. I am attempting to obtain a reference:

"I was reading an account of a squadron of Pz-35t encountering a troop of KV heavy tanks..the CO orders them to concentrate fire on the turret ring and sure enough two tanks get there turrets jammed while the other runs away!Not one of the puny Cz tanks are hit....it did happen! Although for obvious reasons it would be preferable to penetrate the target."

[rexford]

Did German 37mm AP have a ballistic windscreen cap to reduce air resistance?

Thanks.

[Darryl60]

It also came with a little battery operated windshield whiper.

[Bastables]

Originally posted by rexford:

Did German 37mm AP have a ballistic windscreen cap to reduce air resistance?

Thanks.

Does not look like it

Taken from Tony WILLIAMS' AMMUNITION PHOTO GALLERY.

3,7cm AP shell is the one on the left. Seems Pzgr 39 (APCBC) is not available until the 5cm L/60 cartridges.

Might be a good idea to contact him at Tony.Williams@quarry.nildram.co.uk

He's the author of Rapid Fire: The development of automatic cannon, heavy machine guns and their ammunition for armies, navies and air forces

[ February 01, 2003, 07:02 AM: Message edited by: Bastables ]

[rexford]

Thanks for looking into 37mm cap question.

[Bastables]

You're welcome.