3.7 cm Flak M42

3.7 cm/69 Flak M42[1]
A single 3.7 cm Flak M42U gun on the LM 42U mount.
Type	Anti-aircraft gun
Place of origin	Nazi Germany
Service history
In service	1943–1945
Used by	Kriegsmarine
Wars	World War II
Production history
Designed	1942
Manufacturer	Rheinmetal-Borsig
Produced	1943–1945
Specifications (3.7 cm Flak M42)
Mass	109 kg (240 lb)
Barrel length	2.56 cm (1.01 in) bore (69 calibers)
Crew	3–4
Shell	37 × 249R
Shell weight	635–700 g (1.400–1.543 lb)
Caliber	37 mm (1.5 in)
Action	Recoil-operated
Breech	sliding breech block
Elevation	-10° to +90°
Traverse	360°
Rate of fire	250 rounds per minute (cyclic)
Muzzle velocity	815–865 m/s (2,670–2,840 ft/s)
Effective firing range	4,800 m (5,200 yd) at 85° elevation 6,400 m (7,000 yd) at 45° elevation
Feed system	5-round clips

The 3.7 cm Flak M42 was the marine version of the 3.7-centimetre (1.5 in) Flak 36/37 and used by the Kriegsmarine on surface ships and as the M42U on Type VII and Type IX U-boats. The 3.7 cm Flak M42U used several types of mounts and entered service in autumn 1943.^[2]