A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. Submarines are referred to as “boats” rather than “ships” irrespective of their size. Submarines can work at greater depths than are survivable or practical for human divers., and can remain submerged for months. Submarines were first widely used during World War I (1914-1918), and are now used in many navies large and small.
Military uses include attacking enemy surface ships (merchant and military), or other submarines, aircraft carrier protection, blockade running, ballistic missile submarines as part of a nuclear strike force, reconnaissance, conventional land attack (for example using a cruise missile), and covert insertion of special forces. Civilian uses for submarines include marine science, salvage, exploration, facility inspection and maintenance, undersea cable repair, tourism and undersea archaeology.
Here are the top 10 largest submarines in the world.
Submerged displacement: 48,000 tonnes
The Typhoon class,Soviet designation Project 941 Akula, is a class of nuclear-powered ballistic missile submarines designed and built by the Soviet Union for the Soviet Navy. They are currently in service with the Russian Navy. With a submerged displacement of 48,000 tonnes, the Typhoons are the largest submarines ever built, able to accommodate comfortable living facilities for the crew of 160 when submerged, comfortably living aboard for as long as 120 days.
Typhoon class submarine has a length of 175m, a 23m beam and a 12m draught. It’s powered by two nuclear water reactors, two 50,000hp steam turbines and four 3,200KW turbogenerators. It can sail at a speed of 22.2kt on the surface and 27kt below water. The submarine carries 20 RSM-52 intercontinental three-stage solid propellant ballistic missiles capable of holding 100kt of nuclear warheads each. It’s also equipped with six 533mm (21in) torpedo tubes and type 53 torpedoes.
2. Borei-class submarine
Submerged displacement: 24,000 tonnes
The Borei class, alternate transliteration Borey, Russian designation Project 955 Borei and Project 955A Borei-A, also referred to as Dolgorukiy class, are series of nuclear-powered ballistic missile submarines constructed by Sevmash for the Russian Navy. The 170m-long Borei class has a 13.5m beam and a 10m draught. Its power plant consists of an OK-650 nuclear reactor, one steam turbine, and one shaft and propeller.
It sails at a speed of 15kt on the surface and 29kt when submerged. The submerged endurance is dependent on the availability of food stores. The submarine carries 16 missiles and 45t Bulava submarine-launched ballistic missile (SLBM). The armoury also includes six multiple independently targetable re-entry vehicle warheads, six 533mm torpedo tubes and RPK-2 Viyuga cruise missiles.
3. Oscar II-class submarine
Submerged displacement: 24,000 tonnes
The Oscar II class, Soviet designations Project 949A Antey, are a series of nuclear-powered cruise missile submarines designed in the Soviet Union for the Soviet Navy. They are currently in service with the Russian Navy. It measures 155m long and 18m wide. The Project 949A submarine is armed with 24 P-700 Granit anti-ship cruise missiles and six torpedo tubes while the 949AM submarine can carry 3M54 Kalibr supersonic cruise missiles. The Oscar II Class is powered by two pressurised water-cooled reactors and two steam turbines. The propulsion system ensures a surface speed of 15kt and a maximum speed of 32kt when submerged.
4. Ohio-class submarine
Submerged displacement: 18,750 tonnes
The Ohio class of nuclear-powered submarines includes the United States Navy’s 14 ballistic missile submarines (SSBNs) and its four cruise missile submarines (SSGNs). Each displacing 18,750 tons submerged, the Ohio-class boats are the largest submarines ever built for the U.S. Navy. Each Ohio class submarine has a length of 170m, a 13m beam and a 10.8m draught.
The gliding speed on the surface is 12kt and underwater is 20kt. The submarine class includes one S8G pressurised water reactor, two geared turbines, one auxiliary 242kW diesel motor and one shaft with a seven-bladed screw. The submarine is capable of carrying 24 Trident missiles. The armament also includes four 53cm Mark 48 torpedo tubes.
5. Delta-class submarine
Submerged displacement: 18,200 tonnes
The Delta class, Soviet designations Project 667B Murena (Delta I), Project 667BD Murena-M (Delta II), Project 667BDR Kalmar (Delta III), Project 667BDRM Delfin (Delta IV), are a series of nuclear-powered ballistic missile submarines, designed and built in the Soviet Union, which formed the backbone of the Soviet and Russian strategic submarine fleet since their introduction in 1973. It carries nuclear ballistic missiles of the R-29 Vysota family.
The submarine has a length of 166m, a beam of 12.3m and draught of 8.8m. The power plant includes two pressurised water-cooled reactors and two steam turbines driving two five-bladed fixed-pitched shrouded propellers. The submerged speed of the submarines is 24kt. The armoury includes D-9D launch tubes for 16 R-29D SLBMs, four 533mm and two 400mm torpedo tubes.
6. Vanguard-class submarine
Submerged displacement: 15,900 tonnes
The Vanguard class is a class of nuclear-powered ballistic missile submarines (SSBNs) in service with the Royal Navy. The class was introduced in 1994 as part of the Trident nuclear programme, and includes four boats: Vanguard, Victorious, Vigilant and Vengeance. The nuclear-powered ballistic missile submarine is in service with the UK’s Royal Navy. The Vanguard class submarines are 149.9m-long and have a beam of 12.8m and a draught of 12m.
Its main machinery includes one pressurised water reactor supplied by Rolls-Royce, two 20.5MW turbines manufactured by GEC, two auxiliary retractable propulsion motors and one shaft pump jet propulsor. Two turbo generators and two diesel alternators are also installed aboard. The submarine is armed with 16 Trident II missiles and four 533mm torpedo tubes. It has a submerged speed of 25kt.
7. Triomphant-class submarine
Submerged displacement: 14,335 tonnes
The Triomphant class of ballistic missile submarines of the French Navy and is part of the French Navy’s nuclear deterrent strike force. The class includes four submarines, namely Le Triomphant, Téméraire, Vigilant and Terrible. Each submarine has a length of 138m, a beam of 12.50m and a draught of 10.60m. The surface speed is 25kt.
The propulsion system includes a pressurised water K15 nuclear reactor, two SEMT Pielstick diesel-alternators, a turbo reductor system and 8PA4V200 SM auxiliary motors. The submarine is armed with 16 M45 intermediate-range missiles. The weaponry also includes TN 75-tipped missiles, four 533mm torpedo tubes and F17 torpedoes.
8. Akula-class submarine
Submerged displacement: 13,800 tonnes
The Akula class, Soviet designation Project 971 Shchuka-B, are a series of nuclear-powered attack submarines (SSNs) first deployed by the Soviet Navy in 1986. It includes ten submarines, of which nine are in the Russian Navy’s service and one in the Indian Navy’ service. The submarine features a double hull composed of an inner pressure hull and an outer light hull. It is 110m in length, has a beam of 13.6m and draught of 9.7m. The surface speed of the sub is 10kt, while the submerged speed is 35kt. The submerged endurance is 100 days.
It’s main machinery includes one pressurised water nuclear reactor, one steam turbine and two turbo generators rated at 2,000KW. The propulsion system includes one seven-bladed propeller and one retractable electric propulsor for reduced speed cruising. The submarine can be armed with up to 12 submarine-launched cruise missiles capable of carrying nuclear warheads up to a range of 3,000 km. The armament also includes four 533mm torpedo tubes and four 650mm torpedo tubes.
9. Yasen-class submarine
Submerged displacement: 13,800 tonnes
The Yasen class, Russian designations Project 885 Yasen and Project 885M Yasen-M, also referred to as Graney class, are a series of nuclear-powered cruise missile submarines constructed by Sevmash for the Russian Navy. The Yasen class features a single hull made of low magnetic steel, which reduces magnetic signature. The submarine has a length and beam of 139m and 15m respectively.
The weapon systems aboard the submarine include submarine-launched cruise missiles (SLCM), long-range supersonic anti-ship missiles (ASM), anti-submarine missiles, torpedoes, anti-submarine rockets and mines. Powered by a KPM type pressurised water reactor and a steam turbine, the Yasen class submarine attains a maximum submerged speed of 35kt and a surface speed of 20kt.
10. Sierra-class submarine
Submerged displacement: 10,400 tonnes
The Sierra class, Soviet designations Project 945 Barrakuda (Sierra I) and Project 945A Kondor (Sierra II), are series of nuclear-powered attack submarines intended for the Soviet Navy and currently in service with the Russian Navy. The class is unique due to its light and strong titanium pressure hull which enables the submarines of the class to dive to greater depths, reduce the level of radiated noise and increase resistance to torpedo attacks.
It is powered by a single OK-650 pressurized water reactor. The submarine has a length of 111m and beam of 14.2m. The main equipment includes one pressurised water nuclear reactor, two emergency motors, one shaft and two spinners. The submerged speed is 32kt. The assault equipment includes four 650mm torpedo tubes, four 530mm torpedo tubes, SS-N-21 Sampson SLCM, SS-N-15 Starfish anti-submarine weapon, SS-N-16 Stallion and 42 mines.