UK Trident Programme - Replacement

Replacement

The Vanguard-class submarines were built with a 25-year life expectancy, taking them into the 2020s. The Trident II D-5 missiles are expected to continue in service until at least 2042 following an upgrade.

The government has begun planning a new submarine-based system, and has announced its intention to replace the four vessels as they reach the age of 25 (possibly to be extended to 30) years. Costs are uncertain, depending on whether the replacement programme buys new-design boats, modifies the design of the existing Astute class SSN to carry ballistic missiles, or simply acquires new Vanguard-class submarines. A final decision to proceed with the replacement has not yet been taken.

It is also uncertain whether the replacement programme will buy three submarines or four. Four submarines would guarantee "continuous at-sea deterrence". Three submarines would present a risk that continuity could be stretched. The proposed British replacement of Trident is a programme replacing the existing Trident weapons system based on four Vanguard class submarines each armed with 16 Trident II submarine-launched ballistic missiles.

The US are extending the life of their Trident submarines to 30–40 years and Professor Richard Garwin, a US nuclear weapons expert and advisor to three US presidents, has advised British MPs that the same could be done in the UK saving £5 billion and allowing time for a rethink of British nuclear strategy.

There is some opposition to the replacement programme - both from those who want to take the opportunity for full nuclear disarmament and those, such as the Liberal Democrats who would prefer a less costly alternative. Initial proposals to replace the Trident system were passed by the House of Commons by a majority of 248 on 14 March 2007.