Ōhama-class target ship

The Ōhama-class target ship (大濱型標的艦, Ōhama-gata hyōtekikan) 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.

Class overview
Name	Ōhama-class target ship
Builders	Mitsubishi Heavy Industries
Operators	Imperial Japanese Navy
Preceded by	Hakachi
Cost	10,064,000 JPY[1]
Built	1943–1945
In commission	1945
Planned	5
Completed	1
Cancelled	4
Lost	2
General characteristics [2]
Type	Target ship
Displacement	2,580 long tons (2,621 t) standard
Length	116.00 m (380 ft 7 in) overall 112.00 m (367 ft 5 in) Lpp
Beam	11.55 m (37 ft 11 in)
Draught	4.10 m (13 ft 5 in)
Propulsion	3 × Kampon water-tube boilers 2 × Kampon geared turbines, 2 shafts, 52,000 shp
Speed	33 knots (38 mph; 61 km/h)
Range	4,000 nmi (7,400 km) at 18 kn (21 mph; 33 km/h)
Endurance	Fuel: 500 tons oil
Complement	173
Sensors & processing systems	1 × Type 13 radar (mast) 1 × Type 93 active sonar
Armament	in plan[3] 4 × Type 93 13 mm AA guns as built 4 × 120 mm (4.7 in) L/45 AA guns 32 × Type 96 25 mm AA guns 36 × depth charges
Armour	Deck: 16 to 22 mm (0.63 to 0.87 in) Gun shields: 25 mm (0.98 in) Conning tower and Superstructure: 16 to 22 mm (0.63 to 0.87 in)

Design and construction

Project number J36. In 1941, the IJN had decided to build the bombing target ship Hakachi, with a speed under 20 knots (37 km/h). However, what the IJN required was target ship which could emulate the higher speed of the Essex-class aircraft carriers and Iowa-class battleships. The class specification given was therefore 33 knots, use of a destroyer hull, equipped with the Akizuki-class machinery, enabled this to be achieved and able to withstand a 10 kilogram bomb dropped from 4,000 m (13,000 ft) meters. Her armament consisted initially of only four anti-aircraft machine guns.^[3] 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

Wreck of Ōsashi (left) and Yamashio Maru in the port of Yokohama, 1946

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	Ōhama (大濱)	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	Ōsashi (大指)	Mitsubishi, Yokohama shipyard	7 January 1944	16 February 1945		95% complete; construction stopped on 23 June 1945. Collided with army oiler Yamashio Maru and sank in shallow water on 6 March 1946;[4][5] later salvaged and scrapped.
5413 5414 5415	Yagoshi (矢越) Anori (安乗) Ōbatake (大畠)					Cancelled on 5 May 1944.[6]