Shimushu-class escort ship

The Shimushu-class escort ships (占守型海防艦) were a class of ships in the service of the Imperial Japanese Navy during World War II. The Japanese called these ships Kaibōkan, "ocean defence ships", (Kai = sea, ocean, Bo = defence, Kan = ship),  to denote a multi-purpose vessel. They were initially intended for patrol and fishery protection, minesweeping and as convoy escorts. The four ships of the Shimushu class would provide the foundation for the five following classes of 171 Japanese Kaibōkan-type escort ships.

The Shimushu class was initially armed with just twelve depth charges, but this was doubled in May 1942 when their minesweeping gear was removed. The ASW weaponry would later rise to 60 depth charges with a 8 cm trench mortar and six depth charge throwers. The number of AA machine guns was increased to 15.

Ships

 * JAPANESE ESCORT Shimushu (占守): Launched, 13 December 1939. Commissioned, 30 June 1940. Ceded to the Soviet Union, 5 July 1947. Decommissioned on May 16, 1959.


 * JAPANESE ESCORT Hachijo (八丈): Launched, 10 April 1940. Commissioned, 31 March 1941. Scrapped, 30 April 1948.


 * JAPANESE ESCORT Kunashiri (国後): Launched, 6 May 1940. Commissioned, 3 October 1940. Wrecked, 4 June 1946.


 * JAPANESE ESCORT Ishigaki (石垣): Launched, 14 September 1940. Commissioned, 15 February 1941. Torpedoed and sunk by submarine USS Herring (SS-233) on 31 May 1944.