Dreadnought-class

The Dreadnought class is the future replacement for the Vanguard class of ballistic missile submarines. Like their predecessors, they will carry Trident II D-5 missiles. The Vanguard submarines entered service in the United Kingdom in the 1990s with an intended service life of 25 years. Their replacement is necessary if the Royal Navy is to maintain a continuous at-sea deterrent (CASD), the principle of operation behind the Trident system.