 Construction started in 1982 and was completed in 1986.The "Vanguard" class were designed in the early 1980s by Vickers Shipbuilding and Engineering (VSEL) based at Barrow-in-Furness, now BAE Systems Maritime – Submarines.They were designed from the outset as nuclear-powered ballistic missile submarines, able to accommodate the UGM-133 Trident II missiles.