Mark 18 torpedo

Mark 18 torpedo
Mark 18 torpedo general profile as illustrated in its service manual, April 1943
Type	Anti-surface ship torpedo
Place of origin	United States
Service history
In service	1943–1950
Used by	United States Navy
Wars	World War II
Production history
Designer	Westinghouse Electric Electric Storage Battery Co.
Designed	1943
Manufacturer	Westinghouse Electric Naval Ordnance Station Forest Park
Produced	1943-1945
No. built	9000
Specifications
Weight	3154 pounds
Length	245 inches
Diameter	21 inches
Effective firing range	4000 yards
Warhead	Mod 0 Torpex, Mod 2 Torpex/HBX, Mod 3, HBX
Warhead weight	Mod 0 600 pounds, Mod 2 595 pounds, Mod 3 575 pounds
Detonation mechanism	Mk 8 contact exploder, Mk 9 contact/influence exploder
Engine	Electric motor
Speed	29 knots
Guidance system	Gyroscope
Launch platform	Submarines

The Mark 18 torpedo was an electric torpedo used by the United States Navy during World War II. The Mark 18 was the first electric storage battery torpedo manufactured for the US Navy and it was designed primarily for use as a submarine torpedo.

The Mark 18 was built in competition with the Bureau of Ordnance electric torpedoes, which had been in development at the Naval Torpedo Station (NTS), Newport, Rhode Island, since the 1920s, in particular the Mark 20, originated in 1941 in collaboration with General Electric and Electric Storage Battery Company.

In 1942, several German G7e electric torpedoes ran ashore, leading CNO, Admiral Ernest J. King, to prod BuOrd into building an electric torpedo for the U.S. Navy's own submarines. BuOrd told NTS to get the Mark 20 in shape, or drop it in favor of a copy, with the primary emphasis being speed of introduction. "Newport, typically, preferred its own finely machined project", but neither General Electric nor NTS had the facilities. As a result, BuOrd turned to Westinghouse Electric & Manufacturing Company, which on 10 March 1942 got all data and designs for electric torpedoes NTS had produced so far.

Westinghouse quickly decided to copy the G7e, and "went to work with a speed and fervor that was dazzling" (certainly in comparison to NTS's languid pace). Design was complete by mid-April, and a contract for 2,000 Mark 18s, 2,020 warheads, 543 exercise heads (for training shots), tools, spares, and workshop gear was issued 2 May. The first test models were delivered just 15 weeks after Westinghouse started work and the Mark 18 was promised to the Submarine Force by summer 1942.