Valiant-class submarine
The Valiant-class was the first fully British nuclear fleet submarine, as the first nuclear submarine, HMS Dreadnought, used an American nuclear reactor. There were only two boats of the class, the first boat, Valiant (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, but were enlarged by twenty feet (6 m) and had an increased dived displacement of 4900 tons compared to 4000 tons. They were more polished than Dreadnought in the sense that they ran significantly quieter under main power, and also had a Paxman diesel-electric generator that could be used for silent running in emergencies. In most other respects (outside the power plant), 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 primary to secondary cooling system. The Valiants were very successful and served as the template for the Resolution-class ballistic submarine and subsequent Churchill-class fleet submarines.