Sōryū-class submarine

The Sōryū-class submarines (16SS) are diesel-electric attack submarines. The first boat in the class entered service with the Japan Maritime Self-Defense Force in 2009. The design is an evolution of the Oyashio-class submarine, from which it can most easily be distinguished by its X-shaped stern combination diving planes and rudders. The Sōryūs have the largest displacement of any submarine used by post-war Japan.[2]

Soryu class submarine.svg
Soryu-class profile
JS Hakuryu (SS-503) arrives at Joint Base Pearl Harbor-Hickam for a scheduled port visit, -6 Feb. 2013 (YP255-023).jpg
Hakuryū (SS-503) visits Pearl Harbor, Feb 2013
Class overview
Operators Japan Maritime Self-Defense Force
Preceded by Oyashio-class submarine
Succeeded by Taigei-class submarine
Built2005 – Present
In commission2009 – Present
General characteristics
TypeAttack submarine
  • Surfaced: 2,900 tonnes (2,854 long tons)
  • Submerged: 4,200 t (4,134 long tons)
Length84.0 m (275 ftin)
Beam9.1 m (29 ft 10 in)
Draught8.5 m (27 ft 11 in)
  • 1-shaft 2× Kawasaki 12V 25/25 SB-type diesel engines diesel-electric
  • 4× Kawasaki Kockums V4-275R Stirling engines - up to Shōryū
  • 3,900 hp (2,900 kW) surfaced
  • 8,000 hp (6,000 kW) submerged
  • Surfaced: 13 kn (24 km/h; 15 mph)
  • Submerged: 20 kn (37 km/h; 23 mph)[1]
RangeAIP endurance (est.): 6100 nautical miles (11297.2 km; 7060.75 miles) at 6.5 knots (12 km/h; 7.48 mp/h)[1]
Complement65 (9 officers, 56 enlisted)
Sensors and
processing systems
Electronic warfare
& decoys

It is Japan's first air-independent propulsion submarine. From Sōryū to Shōryū are fitted with Kockums Naval Solutions Stirling engines license-built by Kawasaki Heavy Industries, allowing them to stay submerged for longer periods of time. Furthermore, Ōryū is the world's first lithium-ion battery submarine.[3] The cost of the sixth submarine (Kokuryū) was estimated at 540 million USD.[4]

In 2019, the replacement to the Sōryūs, the Taigei-class submarine,[5] entered the planning phase.[6]

Naming conventionEdit

Japanese submarines since World War II were named after ocean currents. The JMSDF changed its naming convention with the Sōryū,[7] and submarines will now be named after mythological creatures. Sōryū (そうりゅう) means blue dragon in Japanese and shares its name with the World War II aircraft carrier Sōryū, sunk during the Battle of Midway.


The eleventh Sōryū-class submarine (Ōryū) is the first Japanese submarine in the fleet to mount lithium-ion batteries. The JS Ōryū was given a budget of ¥64.3 billion (equivalent to ¥65.55 billion or US$601.3 million in 2019)[8] under the 2015 Japanese Defense Budget.[9] Lithium-ion batteries have almost double the electric storage capacity of traditional lead-acid batteries, and by not only replacing them in the existing battery storage areas but adding to the already large battery capacity by also filling the huge space (several hundred tons displacement) inside the hull previously occupied by the AIP Stirling engines and their fuel tanks with these new batteries, the amount of (more powerful) batteries carried overall is massive. This has improved the underwater endurance significantly and is felt will be an advantage over the slow recharge capability of the AIP system. In any event, JMSDF believes that lithium-ion is the way forward and intends to 'trial' this new system and compare it to the previous AIP system for operational effectiveness.


Japan offered Sōryū-class submarines to Australia as replacements for the Royal Australian Navy's Collins-class submarines, as part of the Collins-class submarine replacement project.[10] On 9 April 2014, then-Australian Minister for Defence, David Johnston, described the Sōryū class as “extremely impressive”[11] while discussing Australia's future submarine options. On 26 April 2016, Australian Prime Minister Malcolm Turnbull announced that the Australian contract had been awarded to the French-designed Shortfin Barracuda.[12]

India, Morocco, Norway, Netherlands, and Taiwan have also approached Japan, and expressed an interest in buying Sōryū-class submarines. During a visit to Japan, India's then-Union Minister of Defence, Manohar Parrikar, invited the Japanese government to participate in their USD$8.1 billion Project 75I-class submarine procurement program.[13]

Zuiryū (SS-505) under construction.
Hakuryū (SS-503) visiting Guam in 2013.


Project no. Building no. Pennant no. Name/namesake Laid down Launched Commissioned Home port Notes
S131 8116 SS-501 Sōryū そうりゅう
Blue Dragon
31 March 2005 5 December 2007 30 March 2009 Kure
8117 SS-502 Unryū (うんりゅう)
Cloud Dragon
31 March 2006 15 October 2008 25 March 2010[14] Kure These five submarines are equipped with a new sonar ZQQ-7B.
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
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
8122 SS-507 Jinryū (じんりゅう)
Benevolent Dragon
14 February 2012 8 October 2014 7 March 2016 Kure This submarine is equipped with a new sonar ZQQ-7B and a new satellite communication device.
8123 SS-508 Sekiryū (せきりゅう)
Red Dragon
15 March 2013 2 November 2015 13 March 2017[15] Kure This submarine is equipped with a new sonar ZQQ-7B, a new satellite communication device and new torpedo counter measures.
8124 SS-509 Seiryū (せいりゅう)
Pure Dragon
22 October 2013 12 October 2016 12 March 2018 Yokosuka
8125 SS-510 Shōryū (しょうりゅう)
Soaring Dragon 
28 January 2015 6 November 2017 18 March 2019 Kure
8126 SS-511 Ōryū (おうりゅう)
Phoenix Dragon
16 November 2015 4 October 2018 5 March 2020 Kure These two submarines utilize Li-ion battery propulsion technology
8127 SS-512 Tōryū (とうりゅう)
Fighting Dragon
27 January 2017 6 November 2019 24 March 2021 Yokosuka

See alsoEdit


  1. ^ a b Pike, John. "SS-501 Soryu / 16SS / SS 2,900 ton Class". www.globalsecurity.org. Archived from the original on 2016-03-05. Retrieved 2012-07-11.
  2. ^ "SS Soryu Class Submarines". Naval Technology. 2017-09-03. Archived from the original on 2018-07-19. Retrieved 2018-07-19.
  3. ^ Japan commissions first Soryu-class submarine equipped with lithium-ion batteries Jane's, 05 March 2020
  4. ^ "Japan launches newest submarine Kokuryu amid party atmosphere". The Japan Daily Press. 2013-11-04. Archived from the original on 2013-11-08. Retrieved 2013-12-14.
  5. ^ Mizokami, Kyle (2019-06-25). "Taking a Closer Look at Japan's Futuristic Attack Submarine". Popular Mechanics. Hearst Digital Media.
  6. ^ Roblin, Sebastien (2019-11-07). "Meet the 29SS: Japan's New Stealth Submarine". The National Interest.
  7. ^ 海上自衛隊訓令第30号 Archived 2011-07-22 at the Wayback Machine, Japan Maritime Self Defense Force
  8. ^ 1868 to 1938: Williamson J., Nominal Wage, Cost of Living, Real Wage and Land Rent Data for Japan 1831-1938, 1939 to 1945: Bank of Japan Historical Statistics Afterwards, Japanese Historical Consumer Price Index numbers based on data available from the Japanese Statistics Bureau. Japan Historical Consumer Price Index (CPI) – 1970 to 2014 Retrieved 30 July 2014. For between 1946 and 1970, from "昭和戦後史". Retrieved 2015-01-24.
  9. ^ "Japanese Ministry of Defense website, 2015 Defense Budget" (PDF). Archived (PDF) from the original on 2016-03-04. Retrieved 2015-05-09.
  10. ^ "Japanese Media Now Openly Talking about Japan-Australia Soryu Deal". Asia Security Watch. Archived from the original on 25 February 2013. Retrieved 15 May 2016.
  11. ^ "Government struggling to find replacement design for Collins Class subs: Defence Minister". ABC News. Archived from the original on 23 March 2016. Retrieved 15 May 2016.
  12. ^ "France wins $50b contract to help build Australia's new submarines". The Age. Archived from the original on 31 May 2016. Retrieved 15 May 2016.
  13. ^ "Archived copy". Archived from the original on 2015-01-31. Retrieved 2015-04-03.CS1 maint: archived copy as title (link)
  14. ^ "Submarine Unryu Delivered". Kawasaki Heavy Industries, Ltd. 2010-03-25. Retrieved 2010-02-14.[dead link]
  15. ^ Japan receives Soryu-class attack submarine Archived 2017-04-24 at the Wayback Machine, Brahmand.com, 2017-03-16, accessed 2017-04-24

External linksEdit