The was a bombing target ship class of the Imperial Japanese Navy (IJN), serving during World War II. 5 vessels were planned under the Kai-Maru 5 Programme (Ship #5411–5415), however, only the lead ship Ōhama was completed.
Design and construction Project number J36. In 1941, the IJN had decided to build the bombing target ship , with a speed under . However, what the IJN required was target ship which could emulate the higher speed of the s and s. The class specification given was therefore 33 knots, use of a destroyer hull, equipped with the machinery, enabled this to be achieved and able to withstand a 10 kilogram bomb dropped from meters. Her armament consisted initially of only four anti-aircraft machine guns. However, the significant loss of destroyers between 1942 and 1944 together with delays in mass production of the Kaibōkan-escort ships caused Ōhama to be converted. Thus rearmed for this escort role with many anti-aircraft arms and anti-submarine weapons, the lead ship Ōhama was completed on 10 January 1945. The ships were named after capes of Japan.
Service
Ōhama was assigned to the Combined Fleet on 10 January 1945. However, she did not take up any target ship duties, due to the significant losses resulting from the Battle of the Philippine Sea and Battle of Leyte Gulf. She was deployed instead to convoy escort duties in the Yokosuka area. In August 1945, she was dispatched to Onagawa Local Defense Squadron, shortly after, on 9 August 1945 she sunk by carrier aircraft. Construction on the second ship laid down, Ōsashi, stopped in 1945. Whilst three other class vessels were cancelled in 1944.
Ships in class Ship # Ship Builder Laid down Launched Completed Fate 5411 Mitsubishi, Yokohama shipyard 2 October 1943 29 March 1944 10 January 1945 Sunk by air raid at Onagawa on 9 August 1945; struck off 15 September 1945; salvaged and scrapped postwar. 5412 Mitsubishi, Yokohama shipyard 7 January 1944 16 February 1945 95% complete; construction stopped on 23 June 1945. Collided with army oiler and sank in shallow water on 6 March 1946;The Maru Special No.38 (1980), p.64Shizuo Fukui (1994), third separate volume, p.31 later salvaged and scrapped. 541354145415 Cancelled on 5 May 1944.Senshi Sōsho Vol.88 (1975), p.95
Footnotes
Bibliography Ships of the World No.522, Auxiliary Vessels of the Imperial Japanese Navy, , (Japan), March 1997 The Maru Special, Japanese Naval Vessels No.34 Japanese auxiliary vessels, Ushio Shobō (Japan), December 1979 The Maru Special, Japanese Naval Vessels No.38 Japanese aircraft carriers II, Ushio Shobō (Japan), March 1980 Senshi Sōsho Vol.88, Naval armaments and war preparation (2), "And after the outbreak of war", Asagumo Simbun (Japan), October 1975 (SNAJ), Histories of shipbuilding in Shōwa period (1), (Japan), September 1977 Shizuo Fukui, FUKUI SHIZUO COLLECTION "Japanese Naval Vessels 1869–1945", KK Bestsellers (Japan), December 1994