Trident-II D-5
The Trident D5 missile is a three-stage solid-fuel rocket approximately 13 metres long, over two metres in diameter and weighing 60 tonnes. It has a range of over 6,000 kilometres. Each missile is technically capable of carrying up to twelve warheads and delivering them on to different targets with an accuracy that can be measured in metres. The advanced capabilities of the system enable it to carry out both the strategic and sub-strategic roles.
On 11 March 1982, agreement was reached between the U.K. and the U.S. to purchase the TRIDENT II missile system. The procurement of D5's replaced the U.K.'s original request of 10 July 1980 to procure C4's.
Although the Trident missiles are being bought from the United States, their warheads and the submarines that carry them are British designed and built. The warheads are designed by the Atomic Weapons Establishment at Aldermaston and assembled at Aldermaston and Burghfield.
The Vanguard Class submarines are larger than the Resolution Class mainly because of the need to accommodate the Trident D5 missile. The 16-tube missile compartment is based on the design of the 24-tube system used by the United States Navy's Ohio Class Trident submarines. Although each Vanguard Class submarine is capable of carrying 192 warheads, the boats will deploy with no more than 96, and possibly with significantly fewer.
