Uzushio-class submarine

The Uzushio-class submarine was a series of seven submarines in service with Japanese Maritime Self Defense Force during the Cold War between 1972 and the mid-1990s. They were the first generation of the teardrop type submarine that valued the underwater performance against that of the preceding conventional-hull type Asashio class. Many were converted to training submarines (ATSS) towards the end of their lives.

Uzushio (SS-566)
Class overview
Name	Uzushio
Builders	Kawasaki Shipbuilding Corporation, Mitsubishi Heavy Industries
Operators	Japan Maritime Self-Defense Force
Preceded by	Asashio class
Succeeded by	Yūshio class
Built	1968–1978
In commission	1971–1996
Planned	8
Completed	7
Cancelled	1
Retired	7
General characteristics
Type	Submarine
Displacement	1,850 t (1,820 long tons) standard 3,600 t (3,500 long tons) submerged
Length	72.0 m (236 ft 3 in) pp
Beam	9.9 m (32 ft 6 in)
Draught	7.5 m (24 ft 7 in) max
Propulsion	1-shaft diesel-electric 2 × Kawasaki-MAN V8V24/30AMTL diesel engines 3,400 bhp (2,500 kW) (surfaced) 7,200 shp (5,400 kW) (submerged)
Speed	12 knots (22 km/h; 14 mph) surfaced 20 knots (37 km/h; 23 mph) submerged
Test depth	200 m (660 ft)
Complement	80
Sensors and processing systems	ZPS-4 surface search radar ZQQ-1, ZQQ-2, ZQQ-3 passive sonar SQS-4, SQS-36J active sonar
Electronic warfare & decoys	ZLA-5 ESM
Armament	6 × 533 mm (21 in) torpedo tubes Type 89 torpedoes

General characteristics

The Uzushio class was the first Japan Maritime Self-Defense Force submarine design to incorporate the teardrop hull. The Uzushios had a double hull construction which used NS-63 high-tensile steel to allow for a deeper diving depth of 200 metres (660 ft). The submarines measured 72.0 metres (236 ft 3 in) long between perpendiculars and 9.9 m (32 ft 6 in) at the beam. They had a maximum draught of 7.5 m (24 ft 7 in) and had a standard displacement of 1,850 tonnes (1,820 long tons) and a 3,600 t (3,500 long tons) displacement when submerged.^[1][2][a]

The submarines were powered by a diesel-electric system composed of two Kawasaki-MAN V8V24/30AMTL diesel engines and two electric motors turning one shaft creating 3,400 brake horsepower (2,500 kW) surfaced and 7,200 shaft horsepower (5,400 kW) submerged.^[1][b] This gave the boats a maximum speed of 12 knots (22 km/h; 14 mph) surfaced and 20 knots (37 km/h; 23 mph) dived.^[1][2] The submarines incorporated a separate emergency blowing system to all the vessels to surface rapidly and had a 3D automatic steering system which combined automatic depth and automatic direction maintenance systems.^[1]

The Uzushios were armed with Japanese Type 89 torpedoes fired from six 533-millimetre (21 in) torpedo tubes located amidships.^[3] The submarines had their sonar array located in the bow which was composed of a ZPS-4 surface search sonar, a ZQQ-2, ZQQ-3, or ZQQ-4 passive/active search sonar suite and a SQS-36J^[2][3] or SQS-4 active sonar.^[3]

Boats

Project no.	Building no.	Pennant no.	Name	Laid down	Launched	Commissioned	Note
S118	8081	SS-566	Uzushio (うずしお)	25 September 1968	11 March 1970	21 January 1971	Decommissioned 24 March 1987, scrapped
	8082	SS-567	Makishio (まきしお)	21 June 1969	27 January 1971	2 February 1972	Decommissioned 11 March 1988, scrapped
S119	8083	SS-568/ ATSS-8001	Isoshio (いそしお)	9 July 1970	18 March 1972	25 November 1972	Converted to auxiliary training submarine (ATSS-8001) on 24 March 1989, decommissioned 25 March 1992, sunk as target off Izu Ōshima August 1994
	8084	SS-569/ ATSS-8002	Narushio (なるしお)	8 May 1971	22 November 1972	28 September 1973	Converted to auxiliary training submarine (ATSS-8002) on 8 June 1990, decommissioned 15 March 1993, scrapped
	8085	SS-570/ ATSS-8003	Kuroshio (くろしお)	5 July 1972	22 February 1974	27 November 1974	Converted to auxiliary training submarine (ATSS-8003) on 20 March 1991, decommissioned 1 March 1994, scrapped
S119A	8086	SS-571/ ATSS-8004	Takashio (たかしお)	6 July 1973	30 June 1975	30 January 1976	Converted to auxiliary training submarine (ATSS-8004) on 6 June 1992, decommissioned 26 July 1995, scrapped
	8087	SS-572/ ATSS-8005	Yaeshio (やえしお)	14 April 1975	19 May 1977	7 March 1978	Converted to auxiliary training submarine (ATSS-8005) on 14 August 1994, decommissioned 1 August 1996, scrapped
	~	One hull canceled because of the 1973 oil crisis, naval budget was used for the Chikugo-class destroyer escort and others.

Notes

1. Sharpe has the tonnages as 1,850 t (1,820 long tons) standard, 1,900 t (1,900 long tons) surfaced and 2,430 t (2,390 long tons) submerged.^[3]
2. Sharpe has the submarines with only a single electric motor.^[3]