The were a class of rescue ship / tugboat of the Imperial Japanese Navy (IJN), serving during World War II. The IJN official designation for this class was for all vessels.
Background Under the Russo-Japanese War, the IJN purchased many steamships and converted them to salvage vessels. However, when they entered in 1930s, deterioration became remarkable. The IJN initially planned for the Tategami class to succeed them. The IJN was going to build the one by one for three years from fiscal year 1936. However, the plan came to an impasse due to budget shortages by the second year. The IJN postponed building of the second ship for two years, and built two cheap 600-ton ships instead: the Hashima (later renamed Kasashima) and Futakami.Editorial Committee of the Navy, p. 191
Ships in class Ship Builder Laid down Launched Completed Fate ex- Harima Zōsen 15 December 1937 8 March 1938 27 May 1938 as Hashima Renamed Kasashima on 25 October 1940;Cable layer Hatsushima was renamed Hashima on 25 October 1940, therefore, salvage tugboat Hashima was renamed Kasashima. The Maru Special (1981), p. 50 sunk by aircraft off Taipei on 25 January 1944.Shinshichirō Komamiya, p. 129 Harima Zōsen 21 October 1938 27 March 1939 30 April 1939 Survived war in Truk; decommissioned on 3 May 1947 (?); later scuttled off Tonowas.
Footnotes
Bibliography The Maru Special, Japanese Naval Vessels No. 47, "Japanese naval mine warfare crafts", (Japan), January 1981. Editorial Committee of the Navy, Navy Vol. 11, "Part of small vessels, auxiliary vessels, miscellaneous service ship and converted merchant ships", Seibunsha K.K. (Japan), August 1981. 50 year History of Harima Zōsen, Harima Zōsen Corporation, November 1960. Shinshichirō Komamiya, The Wartime Convoy Histories, (Japan), October 1987. , National Archives of Japan Reference code: C05110820900, [Data in English is under preparation] 第4890号 12．9．22 600屯救難船兼曳船缶用管間邪魔板製造の件. Reference code: C05110821000, [Data in English is under preparation] 第4891号 12．9．22 600屯救難船兼曳船缶用重油噴燃器及コ-ン製造の件. Monthly Ships of the World No. 500, Ships of the Imperial Japanese Navy", , (Japan), August 1995.