The current system
Trident is Britain’s nuclear weapon system. It consists of four nuclear-armed submarines, one of which is on operational patrol, under the seas, at all times. Each Trident submarine carries up to 48 nuclear warheads, each of which can be sent to a different target. Each warhead has an explosive power of up to 100 kilotons, the equivalent of 100,000 tons of conventional high explosive. This is 8 times the power of the atomic bomb that was dropped on Hiroshima in 1945, killing an estimated 140,000 people.
There are three parts to the system: the warheads – which are the explosive ‘bombs’, the missiles which carry them and the submarines which carry the missiles. The submarines are made in Britain at Barrow-in-Furness, refitted at Devonport, and maintained at Faslane, Scotland. The missiles are leased from the US. The warheads are made at the Atomic Weapons Establishment (AWE) Aldermaston and are stored at Faslane.
Britain has been nuclear armed since 1952, buying into the US nuclear weapons system Polaris from 1968 to 1996 and Trident from 1994.
The current Trident submarines will begin to reach the end of their service life in 2024. In 2007 the government suffered its biggest rebellion on domestic policy since Labour came to power in 1997. Only the Iraq war rebellion has been greater. 161 MPs voted against the government’s motion calling for a replacement to go ahead, and 167 voted for an amendment stating that the case for Trident replacement has not been proven.