HMS Warspite
Valiant-class
General Characteristics
Displacement:	4,200 tons surfaced, 4,900 tons dived
Length:	285.7 ft (87 m)
Beam:	33.3 ft (10.1 m)
Draught:	27 ft (8.2 m)
Propulsion:	One Rolls Royce Pressurised Water Reactor (PWR), two English Electric steam turbines, one shaft, 15000 hp (11 MW), one Paxman diesel-electric generator
Speed:	20 knots (37 km/h) surfaced, 28 knots (52 km/h) dived
Range:
Complement:	116
Armament:	6 x 21 in (533 mm) torpedo tubes (All located at the bow. 24 torpedoes in total) Was later equipped with Harpoon

The Valiant-class were the first fully British nuclear fleet submarine, as the first nuclear submarine, HMS Dreadnought, actually used an American nuclear reactor. There were only two boats of the class, the first boat, the nameship being commissioned just three years after Dreadnought in 1966, while Warspite commissioned the following year. Both were built by Vickers at Barrow-in-Furness.

The class were based on Dreadnought though were enlarged to twenty feet (6 m) and had an increased dived displacement of 4900 tons compared to 4000 tons. They were significantly quieter as compared to Dreadnought and thus were a more polished class compared to Dreadnought, and unlike Dreadnought, the two Valiants had a Paxman diesel-electric generator that would be used for silent running in emergencies. In nearly every other aspect, the Valiants were identical to Dreadnought.

The Valiants were primarily used in the anti-submarine role, a role that was prominent in the Royal Navy (RN) during the Cold War. In 1967, Valiant set a then RN record of sailing 12,000 miles (19,312 km) submerged in twenty-eight days, from Singapore to the UK. Both boats received a number of refits during their service in the RN, including the capability to use the Harpoon missile. HMS Valiant took part in the Falklands War, one of a number of nuclear fleet submarines to do so.

The Valiants had long careers with the Royal Navy, with Warspite being decommissioned in 1991. The nameship, Valiant, was decommissioned in 1994 due to cracks being discovered in her reactor core. The Valiants were very successful and served as the template for the Resolution-class ballistic submarine and subsequent fleet submarines.