Mark 21 Mod 0 torpedo

The Mark 21 torpedo, designated Mark 21 Mod 0 was a passive acoustic homing torpedo designed in 1943 by Westinghouse Electric Corporation. The Mark 21 successfully passed launching tests in 1943, however, due to difficulties encountered by Westinghouse, the project was abandoned after a few development models had been built.^[1]

Mark 21 torpedo
Type	Anti-surface ship torpedo[1]
Place of origin	United States
Service history
In service	never in service[1]
Production history
Designer	Westinghouse Electric Corporation[1]
Designed	1943[1]
Variants	Mark 21 Mod 2 torpedo
Specifications
Mass	approx. 2,300 lb (1,000 kg)[1]
Length	161 in (4.1 m)[1]
Diameter	22.5 in (570 mm)[1]
Warhead	HBX[1]
Warhead weight	400 lb (180 kg)[1]
Detonation mechanism	Mark 8 contact exploder[1]
Engine	Electric[1]
Maximum speed	25 kn (29 mph; 46 km/h)[1]
Guidance system	passive acoustic homing[1]
Launch platform	Aircraft[1]

It was based on the widely used Mark 13 torpedo. Propulsion was switched to electric, but weight restrictions limited the speed available.

See also

• Mark 21 Mod 2 torpedo, a similar but more successful project, with homing developed by Bell Labs, and using a steam turbine.