# 3.7 cm SK C/30

The 3.7 cm SK C/30 was the German Kriegsmarine's primary 3.7 cm (1.5 in) 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 It was superseded by the fully automatic 3.7 cm FlaK 43 late in the war.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-millimetre (0.31 in) 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.
| Mounting | weight | elevation |
| Dopp L C/30 | 3,670 kg (8,090 lb) | -9° to +85° |
| Einh L C/34 | 1,860–2,020 kg (4,100–4,450 lb) | -10° to +80° |
| Ubts L C/39 | 1,450 kg (3,200 lb) | -10° to +90° |

### 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 kilograms (3.9 lb).

### Comparison of anti-aircraft guns

| Country | Gun Model | RPM | Projectile Weight | Weight of fire |
| Nazi Germany | 3.7 cm SK C/30 | 30 | .74 kg (1.6 lb) | 22.2 kg (49 lb) |
| France | Canon de 37 mm Modèle 1925 | 15–21 | .72 kg (1.6 lb) | 10.8–15.12 kg (23.8–33.3 lb) |
| Italy | Cannone-Mitragliera da 37/54 (Breda) | 60–120 | .82 kg (1.8 lb) | 49.2–98.4 kg (108–217 lb) |
| United States | 37 mm Gun M1 | 120 | .87 kg (1.9 lb) | 104.4 kg (230 lb) |
| Nazi Germany | 3.7 cm Flak 18/36/37/43 | 150 | .64 kg (1.4 lb) | 96 kg (212 lb) |
| Soviet Union | 37 mm automatic air defense gun M1939 (61-K) | 80 | .73 kg (1.6 lb) | 58.4 kg (129 lb) |
| United Kingdom | QF 2-pounder naval gun | 115 | .91 kg (2.0 lb) | 104.6 kg (231 lb) |
| Sweden | Bofors 40 mm gun | 120 | .9 kg (2.0 lb) | 108 kg (238 lb) |

## Footnotes

* ↑ SK - Schnelladekanone (quick loading cannon); C - Construktionsjahr (year of design)

## Citations

* ↑ Campbell, p. 256
* ↑ "German 3.7 cm/L83 (1.5") SK C/30 3.7 cm/L83 (1.5") SK C/30U". 23 March 2009. Retrieved 11 June 2009.
* ↑ Hogg, p. 223
* ↑ DiGiulian, Tony. "Germany 3.7 cm/83 SK C/30 - NavWeaps". www.navweaps.com. Retrieved 7 June 2017.
* ↑ DiGiulian, Tony. "France 37 mm/50 (1.46") Model 1925 and CAIL Model 1933 - NavWeaps". www.navweaps.com. Retrieved 7 June 2017.
* ↑ DiGiulian, Tony. "Italy 37 mm/54 (1.5") Models 1932, 1938 and 1939 - NavWeaps". www.navweaps.com. Retrieved 7 June 2017.
* ↑ DiGiulian, Tony. "Germany 3.7 cm/57 (1.5") Flak M43 - NavWeaps". www.navweaps.com. Retrieved 7 June 2017.
* ↑ Foss, Christopher (1977). Jane's pocket book of towed artillery. New York: Collier. p. 229. ISBN 0020806000. OCLC 911907988.
* ↑ DiGiulian, Tony. "Russia / USSR 37 mm/67 (1.5") 70-K - NavWeaps". www.navweaps.com. Retrieved 7 June 2017.
* ↑ DiGiulian, Tony. "United Kingdom / Britain 2-pdr QF Mark VIII - NavWeaps". www.navweaps.com. Retrieved 7 June 2017.
* ↑ DiGiulian, Tony. "USA Bofors 40 mm/60 Model 1936 - NavWeaps". www.navweaps.com. Retrieved 7 June 2017.