Guidance

Dreadnought submarine programme: factsheet

Updated 16 March 2021

Government and parliament

• the protection and defence of the United Kingdom is the primary responsibility of His Majesty’s government
• the government is committed to maintaining the minimum continuous at sea deterrence to deter the most extreme threats to the UK and to protect our vital interests; it was elected in May 2015 on a clear manifesto to build 4 new nuclear armed submarines, the first of which was named Dreadnought, to replace the current 4 Vanguard class submarines
• Parliament has voted in support of the government’s plans 4 times, in March 2007, in January 2015, in November 2015 and most recently in July 2016
• the government has considered alternative systems but concluded a ‘4 boat system’ is the most cost effective way to deliver continuous deterrence, see the Trident alternatives review

Context

• the UK’s independent nuclear deterrent remains essential to our security

• our independent nuclear deterrent exists to deter the most extreme threats to our national security and way of life, helping to guarantee our security and that of our allies

• since the end of the Cold War there remain substantial nuclear arsenals in the world; the number of nuclear-armed states has increased and potential adversaries are modernising their conventional and nuclear forces. The continuing risk of the further proliferation of nuclear weapons remains

• recent changes in the international security context remind us that we cannot relax our guard and we cannot rule out further shifts, which would put us and our NATO allies under grave threat; it would be irresponsible to assume that the UK will not in the foreseeable future be confronted with the kinds of extreme threat to our security or way of life which nuclear weapons seek to deter

• continued retention of our independent nuclear deterrent is required to deter any aggressor; a minimum, credible, independent nuclear deterrent, based on continuous at sea deterrence, and assigned to NATO, remains vital; we are therefore making the necessary investment to sustain continuous at sea deterrence with the Dreadnought programme

• how the government will meet this commitment is set out in the Strategic Defence and Security Review (SDSR)

Continuous at sea deterrence

• the United Kingdom has been protected 24 hours a day by a continuous at sea deterrent (CASD) known as Operation Relentless, since April 1969
• CASD is the minimal, credible and independent deterrent against aggression towards the United Kingdom
• the nuclear deterrent’s command and control system is fully independent; decision making and use of the system remains entirely sovereign to the UK and under political control
• the UK has declared our nuclear deterrent to the defence of the NATO Alliance since 1962, thereby contributing to the ultimate guarantee of collective Euro-Atlantic security
• 4 Resolution Class submarines operated between 1969 and 1996, carrying the Polaris nuclear missile system
• The first of the 4 Vanguard Class submarines became operational from 1992. They will continue serving into the 2030s and carry the Trident strategic nuclear armed missile system
• 4 submarines guarantee that one is deployed operationally at any given time

What is the Dreadnought programme?

• Dreadnought is the British programme to replace the 4 Vanguard class submarines, which have provided CASD since 1992, with 4 new submarines that will be built in the UK
• the 4 Dreadnought submarines will be introduced, on current plans from the 2030s onwards and have a lifespan of at least 30 years

The Trident missile

• the Dreadnought submarines will carry the Trident Missile System; Dreadnought will be armed with existing Trident missile stocks which will not need replacing until the 2040s

Costs

• our latest estimate is that manufacturing the 4 Dreadnought submarines is likely to cost a total of £31 billion (including inflation over the lifetime of the programme); we have also set a contingency of £10 billion

• this is a prudent estimate based on past experience of large, complex projects, such as the 2012 Olympics, Crossrail or High Speed 2.

Related information

• UK nuclear deterrence policy
• UK nuclear deterrence (CASD)
• Dreadnought submarine programme
• Defence Nuclear Organisation.