3.7 cm SK C/30

The 3.7 cm SK C/30 was the German Kriegsmarine's primary 3.7 cm anti-aircraft gun during the Second World War. It was superseded by the fully automatic 3.7 cm FlaK 43 late in the war.

Description
The C/30 was a single-shot, semi-automatic anti-aircraft gun that was loaded one round at a time which dropped its effective rate of fire to a mere 30 rounds per minute, far inferior to the 80-100 rounds per minute of its contemporary, the Bofors 40 mm anti-aircraft gun. The SK C/30U gun was modified for use by submarines. All mountings were suitable for use against both air and sea targets.

Mountings
The Dopp LC/30 was a twin mount with each gun in a separate cradle. It had a six-man crew on the mount itself plus additional ammunition handlers. The mounting was manually traversed and elevated and was gyro-stabilized up to a limit of 19.5° degrees to counteract the roll and pitch of the ship. Most German ships, fleet torpedo boat or larger, carried at least one Dopp LC/30 mounting. The Einheitslafette C/34 (universal mounting model 34) was a single gun mounted on a pedestal with a two-man crew. Some mounts were fitted with a 8 mm gun shield. It was used on the smaller Kriegsmarine ships like the Schnellboot. A number were used on land to supplement the anti-aircraft defenses of ports. The Ubts LC/39 submarine mount used the SK C/30U gun. It was a simple pedestal mount with a two-man crew, one of whom trained the gun with the shoulder stirrup; the other used gears to elevate the gun.

Ammunition
The SK C/30 used two types of tracer rounds. The 3.7 cm Br Sprgr Patr 40 L/4.1 Lh 37M was a high-explosive round with an incendiary filling while the 3.7 cm Sprgr Patr 40 L/4.1 Lh 37 lacked the incendiary fill, but was otherwise identical. Tracers were available in red, yellow or white and were marked on the shell by a painted band of the appropriate color. A complete round weighed 1.78 kg.