HMS Vengeance Returns To The Seas

The nuclear-powered ballistic missile submarine HMS Vengeance has put to sea for the first time in almost four years.

The 15,900 tonne boat sailed from the shipyards of Devonport following a refit and a refuel of her nuclear reactor.

Her place in the repair dock will be taken by a worn-looking HMS Vanguard, the boat due to have her nuclear core replaced as a cautionary measure following the discovery of low levels of radioactivity in the cooling waters of a test reactor.

Comment: Trident - The Question No One Is Willing To Ask 

HMS Vengeance, one of the Royal Navy submarines that provides the UK's nuclear deterrent, also received new missile launch and computer systems.

The cost for the refit and refuel for the Trident boat is £350 million but will help keep her in service into the 2030s.

Having been towed into open waters off the south coast of England, HMS Vengeance will now undergo sea trials before returning to fleet duties.

The Nuclear Promise: Letters of Last Resort 

HMS Vanguard, the first of the submarines of her class to be built at Barrow-in-Furness, will also get new sonar equipment as well as computer and communication system upgrades before returning to sea in 2019.

The Royal Navy has four Vanguard-class submarines, they're among the biggest in the world at 150 metres long and carrying 135 officers and crew. Powered by Rolls Royce PWR2 nuclear reactors the length of time they can spend stealthily patrolling underwater is only determined by provisions and maintenance.

Carrying up to 16 Lockhead Trident II missiles, each boasting 8 nuclear warheads and backed up by Spearfish torpedoes their lethality is in no doubt.

More from Forces.tv: MoD Admit Royal Navy Submarine Snagged Fishing Boat