"Her Majesty's Ship"
HMS 'VANGUARD' S-28 ssbn submarine
Introduced in 1994, the four “Vanguard” class SSBNs were the result of the decision to replace the previous “Resolution” class SSBNs, armed with the old Polaris SLBM with the Trident D-5. The class includes HMS Vanguard (S28), commissioned in 1993; HMS Victorious (S29), commissioned in 1995; HMS Vigilant (S30), commissioned in 1996; and HMS Vengeance (S31), commissioned in 1999. All were built by Vickers Shipbuilding and Engineering Ltd. at Barrow-in-Furness between 1986 and 1999, and are now based at HMS Neptune), 25 miles west of Glasgow, Scotland.
In 1998, all WE.177 free-fall nuclear bombs and all other nuclear weapons were removed from the British Army, the Royal Air Force, and all surface ships of the Royal Navy, with the result that the Vanguard/Trident SLBM system is the sole nuclear weapon system for the UK. Each Vanguard carries 16 Trident-II D5 missiles, each equipped with eight MIRV warheads, with a yield of 100-120 kilotons.
The ships were designed as unlimited-range nuclear powered ballistic missile submarines, unlike the Resolution class which had been adapted from the earlier Valiant class and American Lafayette class of nuclear powered SSBNs. They are the third largest submarines ever built - with a length of 492 ft, and a by displacement of 15,730 tons submerged displacement when surfaced - after the Russian Typhoon and American Ohio classes, and are roughly twice the size of the Resolution. This increase in size is due to the much larger size of the Trident D-5 missile as compared to Polaris.
HMS Vanguard arrived at Devonport Naval Base in February 2002, to begin a two year refit including a new reactor core, which was completed in January 2005. Following sea trials, which included test launching of Trident II D5 ballistic missiles, the vessel has returned to the fleet.