3.7 cm SK C/30
The 3.7 cm SK C/30 was the German Kriegsmarine's primary 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 It was superseded by the fully automatic 3.7 cm FlaK 43 late in the war.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 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 120 rounds per minute of its contemporary, the Bofors 40 mm anti-aircraft gun. Its muzzle velocity was on the other hand slightly superior (about 12 -15% higher), which slightly eased the aiming. The "SK C/30U" gun was modified for use by submarines. All mountings were suitable for use against both air and soft surface targets. Ship classes that carried the 3.7 cm SK C/30 include: Mountings. The "Doppellafette C/30" (Dopp L C/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 L C/30" mounting. The "Einheitslafette C/34 (Einh L 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 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 L C/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 .