British Nuclear Submarine Fleet at Devonport, Plymouth

The Royal Navy operates two main classes of nuclear-powered submarines:

Vanguard-class (SSBNs) – Armed with Trident II D5 ballistic missiles, these submarines provide the UK’s continuous at-sea nuclear deterrent. The four vessels—HMS Vanguard, HMS Victorious, HMS Vigilant, and HMS Vengeance—undergo deep maintenance and refueling at Devonport.

Astute-class (SSNs) – The latest generation of nuclear-powered attack submarines, used for intelligence gathering, anti-ship, and land-attack missions.

These are gradually replacing the older Trafalgar-class submarines, the last of which, HMS Triumph, is based at Devonport.

Devonport is responsible for the maintenance, refitting, and eventual decommissioning of these submarines.

This includes reactor refueling, system upgrades, and dismantling of retired vessels.

In the 1960s, as the UK developed its nuclear deterrent, Devonport was adapted to support nuclear-powered submarines.

British Nuclear Submarine Fleet at Devonport, Plymouth

By the 1980s, it became a key refit center, particularly as the Vanguard-class SSBNs entered service in the 1990s.

In 2002, Devonport was designated the sole facility for the refit and defueling of the UK’s nuclear submarine fleet, after Rosyth Dockyard ceased operations in this capacity.

Since then, Devonport has hosted decommissioned nuclear submarines awaiting dismantling, a process that has faced delays due to funding and regulatory challenges.

Ongoing investments aim to modernize the facility for future classes of nuclear-powered submarines, ensuring Devonport remains integral to the UK’s naval capabilities.