Vanguard Class Submarine .\rbr\rbrVanguard Class Submarine . Vanguard Class Submarine . Vanguard Class Submarine . DEFENCE SECRETARY ANNOUNCES FURTHER £350M FOR .\rbr\rbrFourteen years to design and build and costing around a billion pounds, nuclear submarine the Astute is one of the most technologically advanced and .\rbr\rbrThe Royal Navy Vanguard class SSBN, HMS Vigilant, successfully test launches a UGM-133 Trident II nuclear submarine-launched ballistic missile.