STRATEGIC DETERRENT - VANGUARD CLASS SUBMARINES

The United Kingdom's Strategic Deterrent is undertaken by the Royal Navy and submarine launched ballistic missiles (SLBM) have been installed in Royal Naval submarines since the late 1960s. Operational patrols commenced in 1969 with US Polaris missiles embarked.

VANGUARD CLASS
 

The first class of UK SSBN (Nuclear Powered Ballistic Missile Submarine) was the Resolution Class with four boats - this class has now been replaced by the larger Vanguard class armed with 16 x US Trident II D5 missiles.


Each missile has the capability of carrying up to 12 x MIRV (Multiple Independently Targeted Re-entry Vehicles) warheads, making a possible total of 192 warheads per submarine.


The UK is believed to have purchased 58 x Trident 2D-5 missile bodies from the United States and the range of the missile is believed to be in excess of 9,000 km with a CEP (Circular Error of Probability) of about 100 metres. It is believed that in UK service the Trident II D5 carry eight warheads per missile.

These large submarines displace over 16,000 tonnes and have a length of 150 metres. The three decks offer accommodation for the crew of 130 which is unusually spacious for a submarine. Good domestic facilities are provided for the crew and the air purification system enables them to remain submerged for long periods without any outside support. Each submarine has two crews known as Port and Starboard - when one crew is away on patrol the other crew is training or taking leave.

Following the 1998 Strategic Defence Review (SDR), the UK MoD revealed that it was no longer necessary to have a stockpile of 300 warheads and that the stockpile was being reduced to 200 operationally available warheads. In addition, the 58 missile bodies already purchased would be sufficient to maintain a credible deterrent. The MoD confirmed that there would be one SSBN on patrol at any one time but carrying a reduced load of 48 warheads.

In order to ensure one ship of a class to be available for operations, it is normally reckoned that three should be in service �?one in repair or refit, one preparing for operations or working up and one fully operational. Four submarines provide a guarantee of one operational at all times.
 

VANGUARD CLASS SUBMARINE Specifications
Length	149.9m
Beam	12.8m
Draught	12m
Displacement	15,980 tons dived
Propulsion	1 x Rolls Royce pressurised water-cooled reactor supplying steam to two sets of General Electric  geared turbines delivering 27,500 shp to one shaft
Performance	Speed 25 knots
Complement	135
Torpedoes	4 torpedo tubes capable of firing Spearfish Torpedoes
Missiles	16 Missile Tubes capable of firing Trident D5 missiles

In October 2005 HMS Vanguard successfully launched an unarmed Trident II D5 ballistic missile during a naval exercise in the Atlantic Ocean. HMS Vanguard had completed a period of routine maintenance and this test launch was the final part of the trials package prior to her return to operational service. HMS Vanguard is the first of the Royal Navy's Trident class submarines to complete a Long Overhaul Period.

This was the 8th occasion on which a Royal Navy submarine has test-fired a Trident II D5 missile, and the first for a Trident boat on completion of a Long Overhaul Period. The firing marks the final stage of the re-qualification of the submarine crew, and provides reliability and accuracy data which confirms the effectiveness of the strategic weapon system.

In January 2005 the Secretary of State for Defence stated that the total cost of the Trident programme (with payments already made expressed at the prices and exchange rates actually incurred and future spend at the current financial year exchange rate) was £9,8 billion.

Details of the replacement for the current strategic deterrent are up for debate and as yet (March 2006) no decision has been taken. However, a recent announcement by the UK MoD has confirmed that the service life of HMS Vanguard has been extended to 2024-25. We would assume that the service life for the other three submarines will be similarly extended.