The Soryu Class diesel-electric submarines are being built by Mitsubishi Heavy Industries and Kawasaki Shipbuilding Corporation for the Japan Maritime Self-Defense Force (JMSDF). Soryu Class is an improved version of the Oyashio Class submarine.

The keel for the first submarine in the class, Soryu (SS-501), was laid down in March 2005. It was launched in December 2007 and commissioned in March 2009. Unryu (SS-502) was laid down in March 2006, launched in October 2008 and commissioned in March 2010.

Hakuryu was laid down in February 2007 and launched in October 2009 for commissioning in March 2011. The fourth and fifth submarines under construction are scheduled to be commissioned in 2012 and 2013 respectively.

Soryu Class diesel-electric submarine – Image: seaforces.org

The class is also referred to as the SS 2,900t and the 16SS project. Soryu and Unryu have been named after the World War II aircraft carriers. Soryu was one of the carriers that participated in the Pearl Harbour attack. Both submarines are home-ported at Kure and operated by Subron 5, S-flotilla-1 of the JMSDF.

Soryu Class design and features

gentleseas.blogspot.com

The Soryu Class carries a hydrodynamic design based on the Oyashio class submarine. It has a larger displacement than any other submarine class in JMSDF’s service.

Soryu Class submarine – Image: seaforces.orgOyashio class submarine – Image: seaforces.org

The hull form is made of high tensile steel and is covered with anechoic coating to reduce the reflection of acoustic waves. Interiors of the submarine boast acoustic isolation of loud components.

Close-up view of the X rudder. Photo : Wikipedia 4.bp.blogspot.com

The submarine features computer-aided X control planes. The design incorporates highly automated systems.

Image: gentleseas.blogspot.com

Control room

Soryu Class submarine control room – Image: forum.lowyat.netSoryu Class submarine control room – Image: forum.lowyat.netSoryu Class submarine control room – Image: forum.lowyat.netSoryu Class submarine control room – Image: forum.lowyat.net

The submarine is equipped with Stirling engines for increased propulsion performance and underwater endurance. The engine supports superior submerged operations. The high-performance sonar onboard improves surveillance capabilities. The submarine also features stealth capabilities and enhanced safety measures such as snorkel equipment.

The submarine has an overall length of 84m, beam of 9.1m and depth of 10.3m. The normal draft of the sub is 8.4m. It has a surfaced displacement of 2,950t and submerged displacement of 4,200t. The Soryu Class can complement a crew of 65 including nine officers and 56 enlisted members.

Crew cabin & rest area

Soryu Class submarine crew cabin – Image: kaskus.co.idSoryu Class submarine – Image: forum.lowyat.netSoryu Class submarine – Image: kaskus.co.id

Range : Unpublished but estimated at 6100 nautical miles at 6.5knots with AIP

Operational Depth : Unpublished but estimated at 500m.

Complement : 65 ( 9 officers 56 enlisted )

Source daisetsuzan.blogspot.com

The submarine can sail at a surfaced speed of 13kt and submerged speed of 20kt. It has a maximum range of 6,100nm at 6.5kt speed.

Weapon systems

The Soryu Class is fitted with six HU-606 533mm torpedo tubes for Type 89 torpedoes and UGM-84 Harpoon anti-ship missiles. The Harpoon has a range of over 124km and speed of 864km/h.

Soryu Class submarine torpedo room – Image: kaskus.co.id

Type 89 is a wire-guided torpedo with active and passive homing modes. It has a maximum speed of 130km/h and can engage targets within the range of 50km. The torpedo can carry a warhead of 267kg.

Type 89 wire-guided torpedo

Type 89 torpedo being loaded onto Soryu Class submarine – Image: reddit.com

Ship Class Used On	Submarines
Date Of Design	1989
Date In Service	1992
Weight	N/A
Overall Length	N/A
Explosive Charge	589 lbs. (267 kg)
Range / Speed	about 54,000 yards (49,380 m) @ 40 knots about 42,000 yards (38,400 m) @ 55 knots Reported maximum speed is 70 knots
Power	N/A

The standard heavy submarine torpedo, roughly equivalent to the USA’s Mark 48. Formerly the GRX-2.

Source navweaps.com

Harpoon

In 1985 the Block 1C version of Harpoon was introduced, being designated AGM-84D, RGM-84D and UGM-84D. The Block 1C has increased range (AGM-84D maximum range is quoted to be 220 km (120 nm)) by using JP-10 instead of JP-6 jet fuel. The terminal attack mode of the xGM-84D is selectable (pop-up or sea-skimming), and the missile also has improved ECCM equipment. Ships equipped with the improved AN/SWG-1A Fire Control System can program several way-points into the flight path of the missile before launch. Using this feature, the RGM-84D will fly an indirect path to the target area, thereby concealing the position of the launching ship. As with the earlier versions, there are also ATM-84D, RTM-84D and UTM-84D training missiles. The CATM-84D is a captive-carry training missile. The CATM-84D-1s are converted older ATM-84As, and CATM-84D-2s are improved new-built missiles. Source designation-systems.net

Sensors / radars

The submarine is equipped with a ZPS-6F navigation or surface search radar. The sonar suite integrates four low frequency flank arrays, a bow-array and a towed array sonar.

Sensors : Hughs/Oki ZQQ-7B Sonar Suite with
1x Bow Array
4x Low Frequency Flank Array
1x Towed Array

Communications :

X-band High Speed Satellite Communications Device for SS-507 and later

Source daisetsuzan.blogspot.com

1 x J/ZQQ-7 Bow

General data:
Type: Hull Sonar, Active/Passive	Altitude Max: 0 m
Range Max: 74.1 km	Altitude Min: 0 m
Range Min: 0 km	Generation: Late 2000s

Sensors / EW:
J/ZQQ-7 Bow – Hull Sonar, Active/Passive Role: Hull Sonar, Active/Passive Search & Track Max Range: 74.1 km

Source cmano-db.com

4 x J/ZQQ-7 Flank Array

General data:
Type: Hull Sonar, Passive-Only	Altitude Max: 0 m
Range Max: 74.1 km	Altitude Min: 0 m
Range Min: 0 km	Generation: Late 2000s

Sensors / EW:
J/ZQQ-7 Flank Array – Hull Sonar, Passive-Only Role: Hull Sonar, Passive-Only Ranging Flank Array Search & Track Max Range: 74.1 km

Source cmano-db.com

ZPS-6F surface/low-level air search radar

General data:
Type: Radar	Altitude Max: 0 m
Range Max: 111.1 km	Altitude Min: 0 m
Range Min: 0.2 km	Generation: Early 1980s

Properties: Pulse-only Radar

Sensors / EW:
J/ZPS-6F – Radar Role: Radar, Surface Search & Navigation Max Range: 111.1 km

Source cmano-db.com

J/ZQQ-7 TASS Passive-Only Towed Array Sonar System

General data:
Type: TASS, Passive-Only Towed Array Sonar System	Altitude Max: 0 m
Range Max: 129.6 km	Altitude Min: 0 m
Range Min: 0 km	Generation: Late 2000s

Sensors / EW:
J/ZQQ-7 TASS – TASS, Passive-Only Towed Array Sonar System Role: TASS, Passive-Only Thin Line Towed Array Sonar System Max Range: 129.6 km

Source cmano-db.com

かこてつ

Countermeasures

Soryu features ZLR-3-6 electronic support measures (ESM) systems. There are two 3in underwater countermeasure launcher tubes installed for launching acoustic device countermeasures (ADCs).

ZLR-3-6 electronic support measures (ESM) system

2 x 3 inch Underwater Countermeasure Launcher Tubes for acoustic device countermeasures (ADCs).
Torpedo Countermeasure System (TCM) for SS-508 and later Source daisetsuzan.blogspot.com

ADC (Acoustic Device Countermeasure) MK 2

The ADC (Acoustic Device Countermeasure) MK 2 is a 3-inch diameter, expendable countermeasure device designed for launch from surface ships and submarines to counter torpedo threats. The ADC MK2 hovers vertically at a pre-selected depth, emitting an acoustic signal. The vertical depth is set prior to launch and maintained by a pressure-controlled motor driving a small, shrouded propeller in the tail of the decoy. Power for the motor and electronics is provided by a thermal battery. In the electronics section mounted below the acoustic projector section the signals are generated and amplified, while the uppermost acoustic projector section consists of ceramic transducers and impedance-matching networks. Variants include the MOD1, MOD3 and MOD4. Ultra Electronics Ocean Systems is proud to be the only manufacturer of these ADC MK2 variants for the USN and Foreign Military Sales (FMS). Source ultra-os.com (example)

Propulsion

Hayato Gaku YouTube

Soryu is powered by a diesel-electric propulsion system. Two Kawasaki 12V 25/25 SB-type diesel engines and four Kawasaki Kockums V4-275R Stirling engines provide a total power output of 2,900kW surfaced and 6,000kW submerged.

2 x Kawasaki 12Ｖ 25/25 SB-type diesel engines

Soryu class submarine engine room – Image: kaskus.co.id

4 x Kockums V4-275R Stirling engines

Kockums V4-275R Stirling engines – Image: saab.com

“Soryu features ZLR-3-6 electronic support measures systems.”

Soryu is the first submarine of the JMSDF to be equipped with Stirling engines manufactured by Sweden-based Kockums.

The AIPS develops 3,900 hp surfaced and 8,000 hp submerged. Power is delivered through one shaft. Source military-today.com

Stirling is a silent and vibration-free external combustion engine. The Kockums Stirling air independent propulsion system onboard reduces the need for frequent battery charging surfaced and thus increases the submerged endurance of the submarine.

The electric propulsion motor drives a propeller through a single shaft. The submarine is also fitted with an X rudder to provide high manoeuvrability to the submarine when operating very close to the seabed. This X rudder configuration was initially developed by Kockums for the Swedish Gotland class. The propulsion system provides a maximum speed of 20kt.

Japan to equip future Soryu-class submarines with lithium-ion batteries:

Japan will likely become the first country in the world to equip diesel-electric submarines with lithium-ion batteries. GS Yuasa, a Kyoto-based developer and manufacturer of battery systems, said in a 21 February press statement that such batteries will be mounted on two Soryu-class boats currently in build for the Japan Maritime Self-Defense Force (JMSDF).

According to Jane’s Fighting Ships , eight Soryu-class boats are currently in service with the JMSDF.

Four others are currently under construction, two of which, SS 511 and SS 512, are expected to be commissioned in 2020 and 2021 respectively, and will be fitted with lithium-ion batteries in place of lead-acid batteries and a Stirling air-independent propulsion (AIP) system. Source janes.com

Project no.	Building no.	Pennant no.	Name/namesake	Laid down	Launched	Commissioned	Home port
S131	8116	SS-501	Sōryū (そうりゅう) Blue Dragon	31 March 2005	5 December 2007	30 March 2009	Kure
S131^[13]	8117	SS-502	Unryū (うんりゅう) Cloud Dragon	31 March 2006	15 October 2008	25 March 2010^[14]	Kure
	8118	SS-503	Hakuryū (はくりゅう) White Dragon	6 February 2007	16 October 2009	14 March 2011	Kure
	8119	SS-504	Kenryū (けんりゅう) Sword Dragon, Stegosauria	31 March 2008	15 November 2010	16 March 2012	Kure
	8120	SS-505	Zuiryū (ずいりゅう) Auspicious Dragon	16 March 2009	20 October 2011	6 March 2013	Yokosuka
	8121	SS-506	Kokuryū (こくりゅう) Black Dragon	21 January 2011	31 October 2013	9 March 2015	Yokosuka
S131^[13]^[15]	8122	SS-507	Jinryū (じんりゅう) Benevolent Dragon	14 February 2012	8 October 2014	7 March 2016	Kure
S131^[13]^[15]^[16]	8123	SS-508	Sekiryū (せきりゅう) Red Dragon	15 March 2013	2 November 2015	13 March 2017^[17]	Kure
S131^[18]	8124	SS-509	Seiryū (せいりゅう) Green Dragon	22 October 2013	12 October 2016	12 March 2018	Yokosuka
S131^[19]	8125	SS-510	Shōryū (しょうりゅう) Soaring Dragon	28 January 2015	6 November 2017	(March 2019)	?
S131^[20]	8126	SS-511	?	16 November 2015	(2018)	(March 2020)	?
S131^[21]	8127	SS-512	?	27 January 2017	(2019)	(March 2021)	?
S131^[22]	8128	SS-513	?	30 December 2017	(2020)	(March 2022)	?
S131^[23]	8129	SS-514	?	(2018)	(2021)	(March 2023)	?