Type 90 torpedo

• Name — 61 cm Type 90 torpedo • Origin — Empire of Japan • Type — Torpedo • Is Ranged — yes • Is Explosive — yes • Is Missile — yes • Is Uk — yes • Service — 1933–1945 • Used By — Imperial Japanese Navy • Wars — Second World War • Design Date — 1928–1932 • Manufacturer — Kure, Yokosuka and Sasebo Naval Arsenals • Weight — 2.54 t • Length — 8.485 m • Diameter — 60.9 cm • Range — 7000 m (at 46 knots) • Max Range — 15000 m (at 35 knots) • Filling — Type 97 (60% TNT, 40% HND) • Filling Weight — 400 kg • Engine — 2-cylinder double-action • Speed — 46 kn

The torpedo was based on a newly developed British 46 kn 21 in Whitehead torpedo. This weapon used a new double-action two-cylinder engine rather than the four-cylinder radial engine used by World War I-era British torpedoes. It was significantly faster (8 -), although it had a much shorter range (only 10000 m) than the Japanese 6th and 8th Year torpedoes. Twenty of these were bought with training warheads in 1926 for ¥30,000 each; the British allowed Japanese technicians to observe the manufacturing process and launch trials. Japan bought a manufacturing license in 1928 for ¥150,000. The Japanese did not actually manufacture any of these torpedoes, but combined their technology with the results of independent Japanese research to produce the 61 cm Type 90. Testing of the prototypes was prolonged by the need to correct a number of design errors and manufacturing defects, but two prototypes were turned over to the Underwater School in 1931 for practical use. It was informally adopted for use in 1932, but not officially accepted until 15 November 1933. Production initially began at the Kure Naval Arsenal, but the Yokosuka and Sasebo Naval Arsenals began production later.

Despite the invention of the more modern and famous type 93 "long lance" torpedo, they were only introduced for the Shiratsuyu class destroyers and following designs, and the Mutsuki, Fubuki, Akatsuki, and Hatsuharu class destroyers were still loaded with type 90 torpedoes between the start of the war to mid 1943, and thus the torpedo saw some good use during the first year of the war. List of ships sunk or damaged by type 90 torpedoes HMAS Perth: Australian light cruiser sunk partly by torpedoes from the destroyers Murakumo and Shirakumo, battle of Sunda Strait, 1 March 1942 USS Houston: A crippled American heavy cruiser finished off by a torpedo from the destroyer Shikinami, battle of Sunda Strait, 1 March 1942 HMS Exeter: An already sinking British heavy cruiser hit by torpedoes from the destroyer Inazuma, battle of the Java Sea, 1 March 1942 SS Dardanus; British passenger ship sunk partly by torpedoes from the destroyer Amagiri, Indian Ocean Raid, 6 April 1942 SS Gandara: British steamship sunk partly by torpedoes from Amagiri, Indian Ocean Raid, 6 April 1942 USS Vincennes: American heavy cruiser sunk partly by a torpedo from the light cruiser Yūbari, battle of Savo Island, 9 August 1942 USS Atlanta: American light cruiser sunk primarily by a torpedo from the destroyer Ikazuchi, naval battle of Guadalcanal, 13 November 1942 USS Portland': American heavy cruiser badly damaged by a torpedo from the Inazuma, naval battle of Guadalcanal, 13 November 1942 USS Preston: American destroyer sunk partly by a torpedo from the destroyer Ayanami, naval battle of Guadalcanal, 15 November 1942 USS Benham: American destroyer sunk by a torpedo, possibly from the destroyer Shirayuki, naval battle of Guadalcanal, 15 November 1942

* • OCLC 77257764 • Masataka Chiyaka; Yasuo Abe (1972). Warship Profile 22; IJN Yukikaze/Destroyer/1939-1970. Profile Publications Ltd. • O'Hara, Vincent (2009). Struggle for the Middle Sea: The Great Navies at War in the Mediterranean Theater, 1940–1945. Annapolis, Maryland: Naval Institute Press.. • Hornfischer, James D. (2011). Neptune's Inferno: The U.S. Navy at Guadalcanal. New York: Bantam Books..