NPP

Name/Type	Launchers /SSBNs	First Deployed	Range (km)	Warheads x yield (kt)	Deployable Warheads
SLBMs
Trident II/D5	64	1994	7400	1-3 x 100 kt	200
TOTAL				55.5 MT	200

Sources:

British Nuclear Forces, 2005 Bulletin of the Atomic Scientists, November/December 2005

Federation of American Scientists."Text of UK Strategic Defense Review, July 1998."

Arkin, William and Robert Norris. "NRDC Nuclear Notebook: British Nuclear Forces, 1999." Bulletin of the Atomic Scientists, July/August 1999.

"French and British Nuclear Forces, 2000," Nuclear Notebook, Bulletin of the Atomic Scientists, September/October 2000.

Additional Resources

"Global nuclear stockpiles, 1945–2002," Bulletin of the Atomic Scientists)
British Nuclear Forces, 2001
(Bulletin of the Atomic Scientists)
French and British Nuclear Forces, 2000 (Bulletin of the Atomic Scientists)
British Nuclear Forces, 1999 (Bulletin of the Atomic Scientists)
UK Strategic Defense Review, 1998

Recent Developments

Britain's current nuclear force consists of four Vanguard-class SSBNs, each of which can carry 16 Trident II D-5 SLBMs per boat. The first Vanguard went on patrol in December 1994. Each Trident II SLBM can carry up to 8 multiple independent reentry vehicles (MIRVed warheads), for a maximum of 128 warheads per boat. The actual force loadings, however, are lower than this because of the 1998 Strategic Defense Review, which stipulated that all Tridents would be down-loaded to 3 MIRVs (48 warheads/boat). Because the UK plans to produce only enough warheads for three SSBNs, its total warhead inventory will be approximately 185 for the foreseeable future. Furthermore, only one SSBN, armed with no more than 48 warheads, is on active patrol at any given time.

UK Strategic Defense Review

The UK Strategic Defense Review, released in July of 1998, markedly changed the face of Britain's nuclear forces. By mid-1998, a previous decision to eliminate all of the UK's tactical nuclear weapons had been completed, leaving only the sea leg of the nuclear force structure intact. The Strategic Defense Review stipulated the following:

The new nuclear force structure would include only four Vanguard-class SSBNs (the fourth of which is expected to enter active service in late 2000 or early 2001), only one of which is to be on active patrol duty at any one time.

The load of Trident II warheads carried by each submarine was reduced from 96 to 48.

Overall, Britain's operational warhead stockpile was reduced to less than 200 warheads, a 30% reduction.

The UK's SSBNs "will routinely be at a 'notice to fire' measured in days rather than the few minutes quick reaction alert that [was] sustained throughout the Cold War," effectively de-alerting those forces.

Nonproliferation

United Kingdom

Nuclear Forces, 2005