Dreadnought-class submarine

The Dreadnought class is a programme of four ballistic missile submarines (SSBNs) being built by BAE Systems Submarines at Barrow-in-Furness for the United Kingdom's Royal Navy. The class will replace the four ageing Vanguard-class boats and is designed to sustain the UK's policy of Continuous At-Sea Deterrence (CASD), under which at least one British SSBN has been on patrol with nuclear-armed missiles since April 1969.

The boats — named Dreadnought, Valiant, Warspite and King George VI — will carry Trident II D5 submarine-launched ballistic missiles drawn from a shared pool with the US Navy under the 1963 Polaris Sales Agreement, as amended for Trident. Each submarine is planned to deploy with a reduced load of missile tubes compared with the Vanguard class and is being built around the Common Missile Compartment developed jointly with the United States, which is also used on the US Columbia-class SSBN programme.

Construction of the lead boat began in 2016 after the UK Parliament voted in July 2016 to renew the deterrent. The Ministry of Defence has stated the first boat is expected to enter service in the early 2030s. The programme is one of the largest defence procurements in UK history; cost estimates have risen over time and are reported regularly to Parliament in the UK Nuclear Enterprise updates by the National Audit Office.

For IR and Model UN purposes, the Dreadnought programme is frequently cited in debates over:

• NPT Article VI disarmament obligations and recognised nuclear-weapon-state modernisation.
• The credibility of minimum credible deterrence postures.
• UK–US nuclear cooperation under the 1958 Mutual Defence Agreement.
• Scottish political debate over basing at HMNB Clyde (Faslane).

The class should not be confused with HMS Dreadnought (S101), the UK's first nuclear-powered submarine, commissioned in 1963 and decommissioned in 1980.