The 10 biggest nuclear submarines in the world

Le Terrible is the most recent of France's four Le Triomphant class SSBNs (ballistic missile submarines). It was commissioned in September 2010.

The UK has four SSBNs, making up a class known as Vanguard. The most recent, HMS Vengeance, entered service in November 1999. Each UK SSBN carries 40 nuclear warheads.

The UK Ministry of Defence is planning to invest no less than £31 billion to develop a fleet of next-generation SSBNs. The Deadnought class, officially announced in 2016, is intended to take over from the Vanguard class, whose submarines date from the 1990s. The first of the four new submersibles is due to enter service in 2028. HMS Dreadnought will weigh 17,000 tonnes and will be equipped with 'innovative new lighting that will allow the crew to simulate night and day,' explains BAE Systems, the company in charge of the construction.

The Delta III class K-44 Ryazan was commissioned by Russia in January 1982. Weighing just over 13,000 tons when submerged, it can accommodate 130 crew members.

Commissioned between 1984 and 1990, the seven Delta IV class submarines each weigh just over 18,000 tonnes. They can operate at depths of between 320 and 400 metres. The submersibles carry RSM-54 Makeyev missiles, which have a maximum range of 8 300 kilometres.

With four submersibles, the Borei class represents the second largest Russian fleet of SSBNs, after the Delta class. These submarines were the first built by Russia after the fall of the Soviet Union. Launched between 2008 and 2017, they are distributed between the Barents Sea and the Pacific Ocean. They reach 24,000 tonnes when submerged and can operate at a depth of 480 metres.

The Ohio class was the largest submarines ever built by the United States when it was launched in 1981. Today, 14 submersibles make up this class; the latest, the USS Louisiana, was commissioned in September 1997. Each carries 24 Trident nuclear-tipped sea-to-ground ballistic missiles with a range of 7,400 kilometres.

Like the British, the US is also planning to replace its Ohio submarines, which are reaching the end of their lives. The Columbia class will consist of 12 SSBNs, each weighing around 21 000 tons when submerged. Construction of the first submersible is due to start this year, with commissioning scheduled for 2031.

The Dimitri Donskoi sea monster is the last representative of the Typhoon class, which included six submersibles. In service since the end of December 1981, this SSBN weighing nearly 27,000 tons when submerged can count on a power of 100,000 horsepower. It can embark up to 160 men over a period of 120 days in the depths.

The K-329 Belgorod is not an SSBN but a nuclear submarine cruiser, which can also carry six Poseidon nuclear torpedoes. When it is commissioned this year, it will officially become the world's longest submarine at 184 metres. It is ten metres longer than its distant cousin, the Dimitri Donskoi, although the latter is wider.

Under construction since 1992, it will be able to spend up to four months in the depths of the oceans.