Hiburi-class escort ship

The Hiburi-class escort ship was a design development from the s of the Imperial Japanese Navy, serving during and after World War II.

Background

In the Rapid Naval Armaments Supplement Programme of 1941, the Imperial Japanese Navy ordered the construction of thirty escort vessels – designated as #310 to #339 of that Programme, to provide escort ships for the Navy. Fourteen of these were planned as of 860 tons standard displacement and sixteen as of 940 tons, although in the Budget they were all stated to be of 1,200 tons. However, three of the Mikura class were subsequently designated as to be built to the Hiburi design.
In the next year's Modified 5th Naval Armaments Supplement Programme, the IJN ordered the construction of another thirty-four ships to a modified version of the Type-B design; these were designated as #5251 to #5284 of that Programme. However, eight of these ship were subsequently designated to be built to the Hiburi design. Only six of the eight were so completed, with #5265 and #5266 being incomplete at the end of the Pacific War and broken up.
The eleven ships were all ordered from the Hitachi Zōsen shipbuilding concern at Sakurajima, which had also received other orders for ships completed to the Etorofu, Mikura and Ukuru designs. The Hiburi design used the same hull as the Ukuru class, but with different fittings. In 1943, the Japanese Navy General Staff (Gunreibu) promoted the building of Escort ship Type-A, the and Escort ship Type-B, the and. However, the Navy General Staff also noted that too many man-hours of work were needed for their building.

Design

The Navy Technical Department (Kampon) used the Ukuru's basic designs for the new drawings. It was a chimera of Mikura and Ukuru classes.
The new drawings had the following characteristic.
* Armaments and under waterline designs were same as Mikura.
* Everything else was same as in the Ukuru.
The Kampon estimated man-hours for building will be between 42,000 to 40,000.
The new drawing was sent to the Hitachi Zōsen Corporation, Sakurajima Shipyard. Those ships of the Mikura class and the Ukuru class that had not been started were converted to the Hiburi class. The Hitachi Zōsen built all of the Hiburi class vessels.

Ships in class

Of the nine ships completed, three were sunk by US submarines and two by naval mines.

Ship #	Ship	Laid down	Launched	Completed	Fate
#328	Japanese escort ship Hiburi	3 January 1944	10 April 1944	27 June 1944	Sunk by USS Harder at west of Manila, 22 August 1944.
#333	Japanese escort ship Daitō	17 April 1944	24 June 1944	7 August 1944	Sunk by naval mine at Tsushima Strait, 16 November 1945.
#339	Japanese escort ship Shōnan	23 February 1944	19 May 1944	13 July 1944	Sunk by USS Hoe at south of Hainan Island, 25 February 1945.
#5252	Japanese escort ship Kume	26 May 1944	15 August 1944	25 September 1944	Sunk by USS Spadefish at Yellow Sea, 28 January 1945.
#5254	Japanese escort ship Ikuna	30 June 1944	4 September 1944	15 October 1944	Decommissioned on 30 November 1945. Transferred to Meteorological Agency 26 December 1947, and renamed Ikuna-maru. Transferred to Maritime Safety Agency 1 January 1949, and renamed Ojika. Decommissioned on 25 May 1963.
#5257	Japanese escort ship Shisaka	21 August 1944	31 October 1944	15 December 1944	Decommissioned on 15 September 1945. Surrendered to Republic of China on 6 July 1947, and renamed Huian. Defected to People's Liberation Army 23 April 1949. Sunk by aircraft at Yanziji, 28 April 1949. Repairs were completed on 24 December 1953, and given the pennant number 218. Decommissioned in 1990.
#5259	Japanese escort ship Sakito	7 September 1944	29 November 1944	10 January 1945	Decommissioned on 20 November 1945. Scrapped January 1947.
#5263	Japanese escort ship Mokuto	5 November 1944	7 January 1945	19 February 1945	Sunk by naval mine at Kanmon Straits, 4 April 1945.
#5264	Japanese escort ship Habuto	3 December 1944	28 February 1945	7 April 1945	Decommissioned on 23 October 1945. Surrendered to United Kingdom on 16 July 1947, later scrapped.
#5265	Ōtsu	12 January 1945	10 May 1945		Not completed by the end of the war. Scrapped on 25 March 1948.
#5266	Tomoshiri	5 March 1945			Not completed by the end of the war. Scrapped on 23 October 1947.

Appendix

Classification of the Kaibōkan classes in IJN official documents
*The Shimushu, Etorofu, Mikura, Hiburi and Ukuru were classed in the Shimushu class.
*The IJN changed their classification on 5 June 1944, because the shipyards and commanders were confused.
*The Escort ship Type-B and Modified Type-B were combined to the Escort ship Type-A, and Type-Bs became extinct thereby.