Final Sōryū-Class

According to Naval News, Japan’s shipbuilder Kawasaki Heavy Industries (KHI) launched the 12th and final Sōryū-class diesel-electric attack submarine (SSK) for the Japan Maritime Self-Defense Force (JMSDF). JS Tōryū (SS-512) is the second submarine of the class to feature Li-Ion batteries.

Kawasaki Heavy Industries (KHI) launched the 12th and final Soryu-class diesel-electric attack submarine (SSK) for the JMSDF (KHI picture)

The launching ceremony was held today at the KHI shipyard in Chuo-ku, Kobe. About 380 people from Japan’s Ministry of Defense and KHI participated in the ceremony. As per tradition, Admiral Hiroshi Yamamura, Chief of Staff of the JMSDF, cut the rope which started the launch process and send the new submarine in the water for the first time.

JS Tōryū (SS-512) is the 12th and final Sōryū-class submarine produced for the JMSDF (the 6th built by Kawasaki Heavy Industries, the other 6 having been built by Mitsubishi Heavy Industries). Tōryū means Fighting Dragon. The name of Toryu is derived from the famous scenic dragon fighting in Kato City, Hyogo Prefecture, where the torrent of the Kako River flows between strangely shaped rocks.

JS Tōryū (SS-512)’s keel was laid in January 2017, and the submarine is set to be delivered to the JMSDF around March 2021.

The keel for the first submarine in the class, JS Sōryū (SS-501), was laid down in March 2005. It was launched in December 2007 and commissioned in March 2009. The latest Sōryū-class SSK joint the fleet is JS Shōryū (SS-510) which was commissioned on March 18, 2019.

Twelve Sōryū-class submarines are currently planned for the JMSDF. The design features improved underwater endurance thanks to lithium-ion batteries from the eleventh submarine in the class. Previous submarines use Lead-acid batteries. Designed by GS Yuasa, the high-performance Li-Ion batteries are said to store about double the power. The last two submarines of the class, fitted with the new battery technology, will probably serve as test-bed for the next generation of Japanese SSK.

The Sōryū-class is an improved version of the Oyashio-class submarine. Sōryū-class submarines are the world’s largest conventionally powered submarines. All submarines of the class are named after dragons: Sōryū means Blue Dragon, Hakuryū (2nd in the class) White Dragon, Sekiryū (8th in the class) Red Dragon, Shōryū (10th in the class) means Soaring Dragon, Tōryū (12th in the class) means Fighting Dragon.


Main characteristics

Length 84 m/275.6 feet
Width 9.1 m/29.9 feet
Depth 10.3 m/33.8 feet
Draft 8.4 m/27.6 feet
Displacement 2,950 tons
Engine Kawasaki 12V 25/25SB type diesel engine 2 groups
Kawasaki Kokkamusu V4-275R Stirling engine four
Propulsion motor 1
Number of propellers 1
Speed 20 knots/23 mph/37 km/h


Kawasaki Launched The 12th & Final Sōryū-Class JS Tōryū (SS-512) – 2nd Li-Ion Submarine For JMSDF