Soryu Class

The Soryu class boats have larger displacement than any previous Japanese submarines since the WWII

The Soryu class is a new class of Japanese diesel-powered attack submarines. It evolved from Oyashio class design. The first boat, named after Japanese Imperial Navy aircraft carrier Soryu, will be commissioned in 2009. Translated from Japanese it means Blue Dragon. The JMSDF plans to operate at least five of these submarines.

The Soryu class boats are significantly larger than Oyashios. Furthermore these submarines have a larger displacement than any previous Japanese submarines since the World War II.

It can be distinguished from the Oyashio class by the X-shape rudders. Such rudder configuration was first used on the Swedish Gotland class. It is computer aided and provides the submarine with extreme maneuverability. It also enables to operate very close to seabed.

Submarines have hydrodynamic design and are fitted with anechoic coating. Interior also has sound isolation of loud components.

The Soryu class submarines are armed with six 533-mm torpedo tubes for the Type 89 torpedoes and UGM-84 Harpoon missiles. Boats have high automation in combat systems.

Theses vessels are powered by a Swedish Stirling air-independent propulsion system. The Soryu is significantly larger than Oyashio class boats, in order to incorporate this propulsion system. This system is license-produced by Kawasaki Heavy Industries. It allows to stay submerged for longer periods of time without surfacing to charge the batteries. Submerged endurance is increased from days to weeks. It also enhanced vessel's stealth and operational capabilities.

The AIPS develops 3 900 hp surfaced and 8 000 hp submerged. Power is delivered through one shaft.

Entered service	expected in 2009
Crew	65 men
Diving depth (operational)	?
Diving depth (maximum)	?
Sea endurance	?
Dimensions and displacement
Length	84 m
Beam	9.1 m
Draught	8.5 m
Surfaced displacement	2 900 tons
Submerged displacement	4 200 tons
Propulsion and speed
Surfaced speed	13 knots
Submerged speed	20 knots
Diesel engines	1 x 3 900 / 8 000 hp
Electric motors	?
Armament
Missiles	UGM-84 Harpoon launched form torpedo tubes
Torpedoes	6 x 533-mm torpedo tubes for Type 89 torpedoes

Source: Military-Today

Yuushio Class

The 10 boats of the Yuushio class have provided the backbone of the Maritime Self-Defense Force's submarine strength since the 1980s. Essentially an enlarged version of the preceding teardrop Uzushio class, the Yuushios differ primarily in having a deeper diving capability. The Uzushios were decommissioned in the 1990s as the new Harushio class was commissioned.

Of double-hull construction, these boats follow the US Navy nuclear attack submarine practice of having a bow sonar array with the torpedo tubes moved to amidships and angled outwards. The first of the class, Yuushio (SS573), entered service in 1980 with the Mochishio (SS574), Setoshio (SS575), Okishio (SS576), Nadashio (SS577), Hamashio (SS578), Akishio (SS579), Takeshio (SS580), Yukishio (SS581), and Sachishio (SS582) following at yearly intervals.

From the Nadashio onwards the class was fitted to carry and fire the American Sub-Harpoon anti-ship missile, a capability which was retrofitted to all of the earlier boats except for the Yuushio itself. All the boats carry the Type 89 dual-purpose, active-passive torpedoes which have a maximum speed of 55 kts (102km/h; 63 mph) and a maximum reduced speed range of 50 km (31 miles).

The electronics carried are of the latest design, and include the ZQQ-5 bow sonar (a modified American BQS-4) and the ZQR-1 towed array (similar to the American BQR-15). Yuushio was removed from front-line service to become a training boat in 1996.

The last of the Yuushios was commissioned in 1989. By that time, the first three boats of the follow-on Harushio class had been laid down, with the name-ship commissioning at the end of November 1990. Harushio was followed at yearly intervals by Natsushio, Hayashio, Arashio, Wakashio, Fuyushio, and by Asashio in 1997. As each entered service one of the Uzushio-class boats was paid off.

The Harushios follow the same basic design as the Yuushios, but are slightly larger in all dimensions. More attention has been paid to reducing noise internally, and all have anechoic material applied to the outer surfaces. A stronger pressure hull means that operational diving depth has been increased to some 300 m (1 150 ft).

Asashio, the last of the class, was completed to a modified design. Increased systems automation has allowed its crew to be reduced from 74 to 71.

The Last of the Yuushio class boat was retired in 2008.

Entered service	1980
Crew	75 men
Diving depth (operational)	275 m
Dimensions and displacement
Length	76 m
Beam	9.90 m
Draught	7.50 m
Surfaced displacement	2 200 tons
Submerged displacement	2 730 tons
Propulsion and speed
Surfaced speed	12 knots
Submerged speed	20 knots
Diesel engines	2 x 3 400 hp
Armament
Torpedoes	6 x 533-mm torpedo tubes for 18 - 20 torpedoes or anti-ship missiles

Source: Military Today

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The Harushio Japan

The Harushio is a Japanese diesel-electric submarine class operated by the JMSDF. The design is an evolution from the Yuushio class being slightly larger and with better noise reduction. The Asashio, has been modified to test Air-independent propulsion (AIP).

General characteristics
In Service: 1989
Complement: 75 (10 officers)
Displacement: 2,450 tonnes (surfaced)
2,750 tonnes (submerged)
Length: 77 m
Beam: 10 m
Draught: 7.7 m
Machinery: 1-shaft diesel-electric
Speed: 12 knots (surfaced)
20 knots (submerged)
Maximum depth: 350 m
Armament: 6 × 21 inch (533 mm) torpedo tubes for a total of 20 Type 89 torpedoes, or Type 80 ASW torpedoes, or Sub-Harpoon missiles
Electronics: Sonar: Hughes/Oki ZQQ 5B hull mounted sonar, ZQR 1 towed array.

Radar: JRC ZPS 6 I-band search radar

Source: Bluefame

The SS590 Oyashio Japan

The Oyashio is a class of Japanese diesel-electric submarine operated by the JMSDF. The submarines entered service in the late 1990s. The submarines are larger than the earlier Harushio class submarines, to make room for a flank sonar array.

General characteristics
Type: Oyashio class submarine
Displacement: 2,750 tonnes (surfaced)
4,000 tonnes (submerged)
Length: 81.7 m
Beam: 8.9 m
Draught: 7.4 m
Propulsion: 1-shaft diesel-electric
Speed: 12 knots (surfaced)
20 knots (submerged)
Complement: 70 (10 officers)
Sensors and
processing systems: Sonar: Hughes/Oki ZQQ 5B/6 hull-mounted sonar, flank arrays, 1 towed array.
Radar: JRC ZPS 6 I-band search radar.
Armament: 6 × 21 inch (533 mm) torpedo tubes for Type 89 torpedoes, or UGM-84 Harpoon

Source: Bluefame