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 It was superseded by the fully automatic 3.7 cm FlaK 43 late in the war.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 semi-automatic anti-aircraft gun (ie; after firing each round, the breech opened and the spent cartridge casing was automatically expelled, ready for the next round to be loaded), and it was hand-loaded one round at a time. This mechanism gave the weapon an effective, sustained, firing rate of 30 rounds per minute. Whilst not uncompetitive with contemporary and earlier designs of semi-automatic light gun, it was far inferior to the 120 rpm cyclic firing rate of its (slightly later-designed) wartime contemporary, the fully automatic Bofors 40 mm anti-aircraft gun. The C/30's muzzle velocity was, on the other hand, about 12-15% higher than the Bofors; this 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:


 * Admiral Hipper-class cruisers
 * Bismarck-class battleships
 * Chamois-class minesweeping sloops
 * Deutschland-class battleships
 * Deutschland-class cruisers
 * Elbing-class torpedo boats
 * F-class escort ships
 * German Type IXA submarines
 * German Type XIV submarines
 * Graf Zeppelin-class aircraft carriers
 * Königsberg-class cruisers
 * Leipzig-class cruisers
 * M-class minesweepers
 * PA-class patrol ships
 * R boats
 * Sperrbrecher
 * Scharnhorst-class battleships
 * Type 1934A-class destroyers
 * Type 1936-class destroyers
 * Type 1936A-class destroyers
 * Type 1936B destroyers
 * Type 35 torpedo boats
 * Type 37 torpedo boats

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 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 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 1.78 kg.