An SSN is a nuclear-powered general-purpose

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 Navy, Soviet and Russian Navy, Russian navies ...

. ''SSN'' is the

US Navy hull classification symbol US or Us most often refers to: * ''Us'' (pronoun), the objective case of the English first-person plural pronoun ''we'' * US, an abbreviation for the United States US, U.S., Us, us, or u.s. may also refer to: Arts and entertainment Albums * ...

for such vessels; the ''SS'' (as 'Ship Submersible') denotes a

submarine A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited underwater capability.) The term "submarine" is also sometimes used historically or infor ...

and the ''N'' denotes

nuclear power Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced by ...

. The designation SSN is used for interoperability throughout

NATO The North Atlantic Treaty Organization (NATO ; , OTAN), also called the North Atlantic Alliance, is an intergovernmental organization, intergovernmental Transnationalism, transnational military alliance of 32 Member states of NATO, member s ...

under STANAG 1166, though navies use other terms.

History

The first nuclear-powered attack submarine was the US Navy's , operational from 1954. This was followed by the four submarines of the entering service in 1957. The Royal Navy's first nuclear fleet submarine was which by using an American reactor entered service in 1963. The first all-British nuclear submarines were the two s. The USN submarine fleet has been all-nuclear powered for over three decades. The last Barbel-class diesel-electric attack submarine, , was decommissioned in 1990. The bulk of the USN's SSN fleet has been the ''Los Angeles''-class attack submarine. Designed during the

Cold War The Cold War was a period of global Geopolitics, geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 unt ...

the ''Los Angeles''-class boats ''raison d'etre'' was to protect USN carrier battle groups and to hunt

Soviet Navy The Soviet Navy was the naval warfare Military, uniform service branch of the Soviet Armed Forces. Often referred to as the Red Fleet, the Soviet Navy made up a large part of the Soviet Union's strategic planning in the event of a conflict with t ...

SSBNs before they could launch a first strike against the United States. The first ever major combat action involving an SSN was during the 1982

Falklands War The Falklands War () was a ten-week undeclared war between Argentina and the United Kingdom in 1982 over two British Overseas Territories, British dependent territories in the South Atlantic: the Falkland Islands and Falkland Islands Dependenci ...

. An Argentinian cruiser, was sunk by torpedoes fired by the Royal Navy fleet submarine . After that incident, the Argentinian Navy was effectively confined to port. Since the end of the Cold War, SSNs have evolved into multi-mission submarines. Their roles include submarine-launched

cruise missile A cruise missile is an unmanned self-propelled guided missile that sustains flight through aerodynamic lift for most of its flight path. Cruise missiles are designed to deliver a large payload over long distances with high precision. Modern cru ...

platforms, intelligence gathering platforms, insertion and exfiltration of

special forces Special forces or special operations forces (SOF) are military units trained to conduct special operations. NATO has defined special operations as "military activities conducted by specially designated, organized, selected, trained and equip ...

teams in addition to traditional hunter-killer SSN roles. The advantages of an SSN over a conventionally powered SSK are much longer endurance (limited more by the crew than the boat, a nuclear submarine can stay submerged for months and does not need refueling in their 25-year lifespans), and higher speed. Unlike most SSKs, SSNs do not have to surface periodically for air, which would compromise their stealth. Some of the newest conventional submarines approach these advantages:

Stirling engine A Stirling engine is a heat engine that is operated by the cyclic expansion and contraction of air or other gas (the ''working fluid'') by exposing it to different temperatures, resulting in a net conversion of heat energy to mechanical Work (ph ...

powered vessels can cruise underwater for up to two weeks and, like diesel/electric vessels (and in theory LOX powered vessels), are significantly quieter than nuclear submarines, since they do not need to run the powerful (and noisy) pumps associated with the cooling circuits of pressurized water reactors. The main disadvantages of an SSN are the technological challenges and expenses of building and maintaining a

plant. Nuclear submarines can have political downsides, as some countries refuse to accept nuclear-powered vessels as a matter of policy. Furthermore, decommissioned nuclear submarines require costly dismantling and long term storage of the

radioactive waste Radioactive waste is a type of hazardous waste that contains radioactive material. It is a result of many activities, including nuclear medicine, nuclear research, nuclear power generation, nuclear decommissioning, rare-earth mining, and nuclear ...

Active SSN classes

;

United States Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...

(50 in service) * – 23 in service, 39 retired * – 3 in service * – 24 in service, 16 ordered * SSN(X)-class submarine – under development ; Russian Navy (21 in service) *

Victor-class submarine The Victor class, Soviet designations Project 671 ''Yorsh'', Project 671RT ''Syomga'' and Project 671RTM/RTMK ''Shchuka'', (List of NATO reporting names for submarines, NATO reporting names Victor I, Victor II and Victor III, respectively), are ...

– 2 in service, 46 retired * Sierra-class submarine – 4 in service * – 10 in service, 4 retired * – 5 in service, 7 ordered ; People's Liberation Army Navy (9 in service) * – 3 in service, 2 retired * – 6 in service, 4 ordered * – 5 ordered ;

Royal Navy The Royal Navy (RN) is the naval warfare force of the United Kingdom. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King of the United Kingdom, King. Although warships were used by Kingdom ...

(6 in service) Astute2cropped

* – 1 in service, 6 retired * – 5 in service, 2 ordered * SSN-AUKUS – under development (12 planned) ;

French Navy The French Navy (, , ), informally (, ), is the Navy, maritime arm of the French Armed Forces and one of the four military service branches of History of France, France. It is among the largest and most powerful List of navies, naval forces i ...

(5 in service) * – 2 in service, 4 retired * ''Suffren''-class submarine – 3 in service, 3 ordered ;

Royal Australian Navy The Royal Australian Navy (RAN) is the navy, naval branch of the Australian Defence Force (ADF). The professional head of the RAN is Chief of Navy (Australia), Chief of Navy (CN) Vice admiral (Australia), Vice Admiral Mark Hammond (admiral), Ma ...

(0 in service) * – 3 ordered * SSN-AUKUS – under development (5 planned) ; Brazilian Navy (0 in service) * Álvaro Alberto – 1 ordered ;

Indian Navy The Indian Navy (IN) (ISO 15919, ISO: ) is the Navy, maritime and Amphibious warfare, amphibious branch of the Indian Armed Forces. The President of India is the Supreme Commander of the Indian Navy. The Chief of the Naval Staff (India), Chief ...

(0 in service) * – 1 ordered * Project 77-class submarine – under development (6 planned)

Retired SSN classes

;

(75 retired, 2 lost) * – (1954-1980) * – (1957-1987) * – 4 in service (1957-1989) * – 6 in service, 1 lost (1959-1990) * – (1959-1969) * – (1960-1976) * – (1960-1988) * – 14 in service, 1 lost (1961-1996) * – 37 in service (1967-2004) * – (1969-1999) * – (1974-1990) ;

Soviet The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

/ Russian Navy (20 retired, 2 lost) * November-class submarine – 14 in service, 1 lost (1959-1991) * Alfa-class submarine – 7 in service (1971-1996) * K-278 ''Komsomolets'' – lost (1983-1989) ;

(12 retired) * – (1963-1980) * – 2 in service (1966-1994) * – 3 in service (1970- 1992) * – 6 in service (1973-2010) ;

(0 retired, 2 returned) * was formerly the ''K-43'' leased in 1987 from Russia and returned in 1991. * was formerly the ''Nerpa'' leased from Russia in 2011 and returned in June 2021.

References

{{DEFAULTSORT:Ssn (Hull Classification Symbol) Attack submarines

History

Active SSN classes

Retired SSN classes

See also

References