Article Posted on : - Jun 27, 2012

The Vanguard Class submarine. A UK Navy photo

CLYDE (BNS): HMS Vigilant, one of the UK Royal Navy's Vanguard Class nuclear submarines, has returned to its home base at Clyde after undergoing a three-year overhaul.

The submarine was officially handed over to the UK Navy for operational use on June 21.

The vessel was retrofitted under a £350 million contract with Babcock Marine at Devonport Dockyard in Plymouth. Work carried out included installation of improved strategic weapons equipment and integration of the tactical weapons submarine command systems.

A new reactor core - which provides power for the 15,000 tonne vessel - was also refitted meaning that HMS Vigilant will be able to function until the end of her operational life without ever having to refuel again, the Navy said.

The refurbishing work began in 2008, with refuelling completed in November 2010. Since then the vessel has undergone thorough testing and sea trials.

HMS Vigilant will now complete final preparations for Demonstration and Shakedown Operations (DASO) where it will fire a dummy Trident missile down the US test range before returning to the operational Deterrent Patrol cycle, the Navy said.

The four Vanguard-class nuclear ballistic missile submarines (SSBNs), known as the Royal Navy's 'bombers', form the UK's strategic nuclear deterrent force. Each vessel has 16 missile tubes and is armed with Trident 2 D5 nuclear missiles.

Based at Clyde Naval Base in Scotland, the submarines are deceptively big and operate with a crew of 135 personnel.