Soryu Class Submarines

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.

Zuiryu (SS-505) Soryu Class diesel-electric submarine  – Image:

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:

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

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:

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.

JS_Souryu_Class_SS_X-shape_of_the_tail_planes Kawasaki HI Kobe 2013Close-up view of the X rudder. Photo : Wikipedia

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

D1 Mar 10 2016.pngImage:

Control room

BlackDragon06_zpsbaf40ceeSoryu Class submarine control room – Image: forum.lowyat.netBlackDragon07_zps6eadaa01Soryu Class submarine control room – Image: forum.lowyat.netBlackDragon08_zpsc940f3cdSoryu Class submarine control room – Image: forum.lowyat.netBlackDragon10_zps6070275fSoryu Class submarine control room – Image:

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

BlackDragon11_zps4c81962cSoryu Class submarine crew cabin – Image: Class submarine – Image: forum.lowyat.netBlackDragon13_zpscdcc4046Soryu Class submarine – Image:

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 ) 


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.

BlackDragon16_zps913b4c96Soryu Class submarine torpedo room – Image:

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.

Ship Class Used On Submarines Date Of Design 1989 Date In Service 1992 WeightN/AOverall LengthN/AExplosive 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  PowerN/ANotes:  The standard heavy submarine torpedo, roughly equivalent to the USA’s Mark 48.  Formerly the GRX-2. Source

Type 89 wire-guided torpedo

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


UGM-84 Harpoon anti-ship missile Photo: Boeing

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

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



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

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 (example)


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.

BlackDragon14_zps05929517Soryu class submarine engine room – Image:

4 x Kockums V4-275R Stirling engines

Kockums V4-275R Stirling engines – Image:
“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

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: Here


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.

“At this moment Japanese submarines use lead-acid batteries as a source of power, but submarines being produced since the fiscal year 2015 will use lithium-ion batteries instead,” said the company.

SS-501 Soryu ( そうりゅう, in kanji 蒼竜 ) Blue Dragon
SS-502 Unryu ( うんりゅう, in kanji 雲竜 ) Cloud Dragon
SS-503 Hakuryu ( はくりゅう, in kanji 白竜) White Dragon
SS-504 Kenryu ( けんりゅう, in kanji 剣竜) Sword Dragon
SS-505 Zuiryu ( ずいりゅう, in kanji 瑞竜) Auspicious Dragon
SS-506 Kokuryu ( こくりゅう, in kanji 黒竜) Black Dragon
SS-507 Jinryu ( じんりゅう, in kanji 仁竜) Humane Dragon
SS-508 Sekiryu ( せきりゅう, in kanji 赤竜 ) Red Dragon  ( named on 2nd Nov 2015 )

SS-509 is under construction and yet to be named. SS-510 and SS-511 are planned. Source


Source of main material:

Entered service 2009
Crew 65 men
Diving depth (operational) ~ 250 m
Diving depth (maximum) ~ 500 m
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 ?
Missiles UGM-84 Sub-Harpoon launched form torpedo tubes
Torpedoes 6 x 533-mm torpedo tubes for Type 89 torpedoes and missiles



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