Each submarine carries 16 Trident II D-5 missiles, which can each carry
up to twelve warheads (i.e. a potential of 192 warheads). However, the British
government announced in 1998 that each submarine would carry only 48 warheads
(halving the limit specified by the previous government), which is an average
of three per missile. However one or two missiles per submarine are probably
armed with fewer warheads for "sub-strategic" use causing others
to be armed with more.
The British-designed warheads are thought to be selectable between 0.3
kt, 5-10 kt and 100 kt; the yields obtained using either the unboosted
primary, the boosted primary, or the entire "physics package".
The United Kingdom has purchased the rights to 58 missiles under the Polaris
Sales Agreement (modifed for Trident) from a jointly maintained "pool".
These missiles are fitted with UK-built warheads and are exchanged when
requiring maintenance. Under the terms of the agreement the United States
does not have any veto on the use of British nuclear weapons.
History
Name |
Launched |
Commissioned |
Test launch 1 |
Test launch 2 |
Maiden patrol |
HMS Vanguard (S28) |
March 1992 |
August 1993 |
May 26, 1994 |
June 20, 1994 |
December 1994 |
HMS Victorious (S29) |
September 1993 |
January 1995 |
July 24, 1995 |
August 22, 1995 |
December 1995 |
HMS Vigilant (S30) |
October 1995 |
November 1996 |
October 10, 1997 |
October 10, 1997 |
June 1998 |
HMS Vengeance (S31) |
September 1998 |
November 1999 |
September 21, 2000 |
|
February 2001 |
Table 1 Vanguard class ? significant dates
The Trident missile agreement was reached in 1982 as a modification of
the Polaris Sales Agreement. At the time it was envisaged the entire project;
four submarines, the missiles, new facilites at Coulport and Faslane and
a 5% contribution to Trident research and development, would cost �5 billion.
The option for a fifth submarine was discussed at the time.
The submarines were built in specially constructed facilites at Vickers
Shipbuilding and Engineering Ltd, subsequently GEC Marine (VSEL) and BAE
Systems Marine (VSEL), Barrow-in-Furness, Cumbria. The Trident II D-5
achieved an initial operational capability with the U.S. Navy in March
1990. Following launch and commissioning the vessels deployed on Demonstration
and Shakedown Operations (DASOs). The major part of this was the test
firing of Trident missiles at the United States' SLBM Launch Area, Eastern
Test Range, Cape Canaveral, off the coast of Florida (see table above).
In the Strategic Defence Review published in July 1998, the British Government
stated that once the Vanguard submarines became fully operational (the
fourth and final one, Vengeance, entered service on 27 November 1999),
it would "maintain a stockpile of fewer than 200 operationally available
warheads". The Stockholm International Peace Research Institute has
estimated the figure as 185.
At the same time, the British Government indicated that warheads "required
to provide a necessary processing margin and for technical surveillance
purposes" were not included in the "fewer than 200" figure.
Many estimates for the total number of warheads are around 200; for instance
the Natural Resources Defense Council believes that this figure is accurate
to within a few tens. The World Almanac suggests the number is between
200 and 300.
General characteristics
- Displacement: 15,900 tons submerged
- Length: 149.9 meters
- Beam: 12.8 meters
- Draught: 12 meters
- Complement: 14 officers, 121 ratings
- Propulsion: PWR2 reactor
- Armament
- 16 missile tubes capable of firing Trident II (D5) missiles
- four torpedo tubes capable of firing Spearfish torpedoes
- Sensors:
- sonar (bow array, active intercept, and towed arrays)
- periscopes: (attack and two search periscopes)
- c collision avoidance radar
USS Nautilus SSN 571
USS SEAWOLF
USS ARCHERFISH, SSN 678
USS PENNSYLVANIA SSBN736
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