The crew of one of Britain’s most powerful military machines gathered in the cavernous dry dock housing her to mark the next stage in the £560m regeneration of HMS Victorious.

The 16,000-tonne submarine – one of four which conducts nuclear deterrent patrols to safeguard the nation’s security – is now out of the water at the impressive refit complex in Devonport Naval Base.

The boat is undergoing an extensive overhaul – the official designation is Deep Maintenance Period – to allow her to conduct deterrent patrols into the next decade when the next generation of Dreadnought-class submarines begins taking over the UK military’s No.1 mission.

Crew, plus staff of the Submarine Delivery Agency and employees of Babcock Marine, clambered down to the bottom of  Devonport’s 9 Dock, which has been specially upgraded for the work to be carried out on Victorious.

While awaiting the dock to be readied, the V-boat underwent the first phase of her maintenance still afloat in Devonport’s 5 Basin, where the combined efforts of the Royal Navy and Babcock teams made significant progress.

“The afloat phase has seen some extremely innovative engineering solutions and several in-water firsts for a ballistic missile submarine, including reactor de-pressurisation and removal of missile tube muzzle hatches which has only been achieved by working together as one team,” said Commander Simon ‘Bob’ Church, HMS Victorious’ Commanding Officer.

“While there have been some initial challenges, the dedication and professionalism of our crew and our Babcock partners, has ensured that we are making every effort to maintain momentum.”

The maintenance period is a highly complex engineering task which combines significant capability upgrades with the revalidation of safety-critical systems. The scale of the operation requires close coordination between the Royal Navy, Babcock, and the Ministry of Defence.

“Everyone in the Defence Nuclear Enterprise recognises the importance of this maintenance period to the UK’s national security and that is why our work to ensure HMS Victorious returns to operations as soon as possible matters,” explained Captain Ben Stafford, Superintendent Submarines.