1966 - 1994: Valiant Class
The Valiant class was the first fully British nuclear fleet submarine, as the first nuclear submarine, HMS Dreadnought used an American nuclear reactor.
The class were based on Dreadnought, but enlarged by 20ft and with an increased dived displacement of 4,900 tons compared to 4,000 tons. They were more polished than Dreadnought and ran significantly quieter under main power. The boats also had a Paxman diesel-electric generator which could be used for silent running in emergencies. In most other respects the Valiants were identical to Dreadnought.
Although the name originally chosen for her was Inflexible, Britain's second nuclear submarine was commissioned as HMS Valiant on 18th July, 1966. Valiant's near-perfect streamlining gives maximum underwater efficiency, whilst her fin-like conning tower is intended to reduce 'drag' to a minimum.
As early as April 1967, Valiant set a record submerged passage for a British submarine when she completed the 12000 mile homeward voyage from Singapore in 28 days. Month long submerged voyages have since become routine.
Vickers third 'nuke', Warspite, was launched on 25th September 1965, and commissioned on 18th April 1967. Unfortunately, completion of the Valiant Class was held back to speed work on the Resolution Class Polaris submarines. However, as soon as Resolution was launched, no time was lost in completing the Valiant Class
The Valiants were primarily used in the anti-submarine role, a role that was prominent in the Royal Navy during the Cold War.