The ''Sōryū''-class submarines (''16SS'') are diesel-electric

attack submarine An attack submarine or hunter-killer submarine is a submarine specifically designed for the purpose of attacking and sinking other submarines, surface combatants and merchant vessels. In the Soviet and Russian navies they were and are called "mul ...

s. The first boat in the class entered service with the

Japan Maritime Self-Defense Force , abbreviated , also simply known as the Japanese Navy, is the maritime warfare branch of the Japan Self-Defense Forces, tasked with the naval defense of Japan. The JMSDF was formed following the dissolution of the Imperial Japanese Navy (IJN) ...

in 2009. The design is an evolution of the , from which it can most easily be distinguished by its X-shaped stern combination

diving plane Diving planes, also known as hydroplanes, are control surfaces found on a submarine which allow the vessel to pitch its bow and stern up or down to assist in the process of submerging or surfacing the boat, as well as controlling depth when subm ...

s and

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally aircraft, air or watercraft, water). On an aircraft the rudder is used primarily to ...

s. The ''Sōryūs'' have the largest

displacement Displacement may refer to: Physical sciences Mathematics and Physics *Displacement (geometry), is the difference between the final and initial position of a point trajectory (for instance, the center of mass of a moving object). The actual path ...

of any submarine used by post-war Japan. It is Japan's first

air-independent propulsion Air-independent propulsion (AIP), or air-independent power, is any marine propulsion technology that allows a non-nuclear submarine to operate without access to atmospheric oxygen (by surfacing or using a snorkel). AIP can augment or replace the ...

submarine. From ''Sōryū'' to ''Shōryū'' are fitted with

Kockums Naval Solutions Saab Kockums AB is a shipyard headquartered in Malmö, Sweden, owned by the Swedish defence company Saab Group. Saab Kockums AB is further operational in Muskö, Docksta, and Karlskrona. While having a history of civil vessel construction, Kock ...

Stirling engine A Stirling engine is a heat engine that is operated by the cyclic compression and expansion of air or other gas (the ''working fluid'') between different temperatures, resulting in a net conversion of heat energy to mechanical work. More specif ...

s license-built by

Kawasaki Heavy Industries (or simply Kawasaki) is a Japanese Public company, public multinational corporation manufacturer of motorcycles, engines, Heavy equipment (construction), heavy equipment, aerospace and Military, defense equipment, rolling stock and ships, headq ...

, allowing them to stay submerged for longer periods of time. Furthermore, ''Ōryū'' is the world's first

lithium-ion battery A lithium-ion or Li-ion battery is a type of rechargeable battery which uses the reversible reduction of lithium ions to store energy. It is the predominant battery type used in portable consumer electronics and electric vehicles. It also se ...

submarine. The cost of the sixth submarine (''Kokuryū'') was estimated at 540 million USD. In 2019, the replacement to the ''Sōryū''s, the

Taigei-class submarine The ''Taigei''-class submarines (''29SS'') is a new class of attack submarines after 2022, developed for the Japan Maritime Self-Defense Force. It is the successor to the . The ''Taigei'' class is equipped with a large amount of lithium-ion bat ...

, entered the planning phase.

Naming convention

Japanese submarines since World War II were named after

ocean currents An ocean current is a continuous, directed movement of sea water generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature and salinity differences. Depth contours, s ...

. The JMSDF changed its

naming convention A naming convention is a convention (generally agreed scheme) for naming things. Conventions differ in their intents, which may include to: * Allow useful information to be deduced from the names based on regularities. For instance, in Manhatta ...

with the ''Sōryū'', and submarines will now be named after mythological creatures. ''Sōryū'' (そうりゅう) means

blue dragon Blue Dragon may refer to: Biology * '' Glaucus atlanticus'', a shell-less marine gastropod mollusc in the family Glaucidae * '' Glaucus marginatus'', a shell-less marine gastropod mollusc in the family Glaucidae * '' Pteraeolidia ianthina'', a she ...

in Japanese and shares its name with the World War II aircraft carrier , sunk during the

Battle of Midway The Battle of Midway was a major naval battle in the Pacific Theater of World War II that took place on 4–7 June 1942, six months after Japan's attack on Pearl Harbor and one month after the Battle of the Coral Sea. The U.S. Navy under Adm ...

Variants

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 under the 2015 Japanese Defense Budget.

Lithium-ion batteries A lithium-ion or Li-ion battery is a type of rechargeable battery which uses the reversible reduction of lithium ions to store energy. It is the predominant battery type used in portable consumer electronics and electric vehicles. It also se ...

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.

Exports

Japan offered ''Sōryū''-class submarines to Australia as replacements for the

Royal Australian Navy The Royal Australian Navy (RAN) is the principal naval force of the Australian Defence Force (ADF). The professional head of the RAN is Chief of Navy (CN) Vice Admiral Mark Hammond AM, RAN. CN is also jointly responsible to the Minister of ...

's s, as part of the . On 9 April 2014, then-Australian

Minister for Defence {{unsourced, date=February 2021 A ministry of defence or defense (see spelling differences), also known as a department of defence or defense, is an often-used name for the part of a government responsible for matters of defence, found in states ...

David Johnston David Lloyd Johnston (born June 28, 1941) is a Canadian academic, author, and statesman who served from 2010 to 2017 as Governor General of Canada, the 28th since Canadian Confederation. He is the commissioner of the Leaders' Debates Commis ...

, described the ''Sōryū'' class as "extremely impressive" while discussing Australia's future submarine options. On 26 April 2016, Australian

Prime Minister A prime minister, premier or chief of cabinet is the head of the cabinet and the leader of the ministers in the executive branch of government, often in a parliamentary or semi-presidential system. Under those systems, a prime minister is not ...

Malcolm Turnbull Malcolm Bligh Turnbull (born 24 October 1954) is an Australian former politician and businessman who served as the 29th prime minister of Australia from 2015 to 2018. He held office as leader of the Liberal Party of Australia. Turnbull grad ...

announced that the Australian contract had been awarded to the French-designed Shortfin Barracuda, though this deal was eventually rescinded.

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to ...

Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

, and

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the nort ...

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 Manohar Parrikar (born Manohar Gopalkrishna Prabhu Parrikar; 13 December 1955 – 17 March 2019) was an Indian politician and leader of the Bharatiya Janata Party who served as Chief Minister of Goa from 14 March 2017 until his death. Previous ...

, invited the Japanese government to participate in their USD$8.1 billion

Project 75I-class submarine The Project 75 (India)-class submarines, or P-75I, for short, are a planned class of diesel-electric submarines, which are to be built for the Indian Navy. The P-75I class is a follow-on of the P-75 class submarines of the Indian Navy. Under ...

procurement program. JS zuiryu（SS-505）

Boats

References

External links