Dreadnought-class submarine

{{Main|Trident (UK nuclear programme)}}

Since the retirement of the last Royal Air Force WE.177 nuclear bomb in 1998, the British nuclear arsenal has been wholly submarine-based. It is intended to deter a potential enemy because they cannot ensure eliminating the entire stockpile in a first strike if a ballistic missile submarine remains undetected. Trident missiles are currently equipped with Holbrook warheads, thought to be technically similar to the American W76. There are plans to replace this with the Astraea A21/Mk7.{{Cite web |last=Cullen |first=David |date=August 2022 |title=Extreme circumstances - The UK’s new nuclear warhead in context |url=https://www.nuclearinfo.org/wp-content/uploads/2022/08/Extreme-Circumstances-print-version.pdf |website=Nuclear Information Service}}

Since the Strategic Defence Review (SDR), the UK has maintained a stockpile of around 215 warheads, with around 120 active (usable). Under the continuous at sea deterrence policy, at least one {{sclass |Vanguard|submarine|0}} SSBN is kept on patrol with up to 16 Trident missiles sharing up to 48 warheads from the stockpile at any given time. The SDR considered this was the minimum number of warheads adequate for deterrence. It is collectively known as the Trident system.{{cite web|url= http://www.parliament.the-stationery-office.co.uk/pa/cm200506/cmselect/cmdfence/986/986.pdf |title= The Future of the UK's Strategic Nuclear Deterrent|date=30 June 2006|publisher=House of Commons Defence Committee |access-date=2006-12-01 |archive-url=https://web.archive.org/web/20070206143013/http://www.parliament.the-stationery-office.co.uk/pa/cm200506/cmselect/cmdfence/986/986.pdf|archive-date= 6 February 2007}} The majority of this system is based in Scotland at HMNB Clyde (HMS Neptune), which includes the Faslane home of the Vanguard submarines, and at RNAD Coulport on Loch Long. The oldest Vanguard-class submarine had been expected to remain in service until 2019 without a refit.{{cite web|url= https://publications.parliament.uk/pa/cm200607/cmselect/cmdfence/225/225i.pdf |title= The Future of the UK's Strategic Nuclear Deterrent: the White Paper |date= 7 March 2007 |publisher= House of Commons Defence Committee | access-date = 2007-03-15}} Since 1998, the system has also provided the Government with the option of a lower-yield, "sub-strategic" nuclear strike capability.{{cite web | url= https://publications.parliament.uk/pa/cm200506/cmselect/cmdfence/986/986we12.htm | title=Annex A: Making Trident more usable and more threatening | via = House of Commons | work=Select Committee on Defence Written Evidence | date= 20 June 2006 | access-date= 2 June 2012 | publisher = Greenpeace}} Under both the Strategic Defence and Security Review 2010 and the Strategic Defence and Security Review 2015, the total number of warheads for the submarine on patrol would be 40 and the maximum total number of ballistic missiles would be 8.{{cite news |title= National Security Strategy and Strategic Defence and Security Review 2015 A Secure and Prosperous United Kingdom|url= https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/478933/52309_Cm_9161_NSS_SD_Review_web_only.pdf |access-date= 17 November 2018|agency=gov.uk|date=23 November 2015}}{{cite web|url= https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/62482/strategic-defence-security-review.pdf |title= Securing Britain in an Age of Uncertainty: The Strategic Defence and Security Review |date=19 October 2010 |publisher=HM Government |access-date=17 November 2018}} The 2021 Integrated Review announced, however, along with a lift on the cap on warheads to no more than 260 (from 180 planned in previous reviews), any numbers or information on deployed missiles and warheads will no longer be provided, under a policy of "deliberate ambiguity".{{Cite web |last=Mills |first=Claire |date=2023-05-03 |title=Nuclear weapons at a glance: United Kingdom |url=https://researchbriefings.files.parliament.uk/documents/CBP-9077/CBP-9077.pdf |url-status=live |archive-url=https://web.archive.org/web/20231227005341/https://researchbriefings.files.parliament.uk/documents/CBP-9077/CBP-9077.pdf |archive-date=2023-12-27 |access-date=2024-01-06 |website=House of Commons Library}}

File:Successor SSBN infographic.jpg

In May 2011 the government approved the initial assessment phase for the new submarines and authorised the purchase of long lead-time items including steel for the hulls. In May 2015 the Conservative Party won the UK General Election on a manifesto which included a commitment to maintaining a CASD with four Successor submarines.{{cite web | url=http://static.guim.co.uk/ni/1429010009028/Conservative-Manifesto-2015.pdf | title=Conservative Party Manifesto 2015 | publisher=Conservative Party | access-date=16 May 2015 | pages=77}} The final decision to commit to the Successor programme was approved on 18 July 2016 when the House of Commons voted to renew Trident by 472 votes to 117.{{cite web |author=Mills, Claire |date=10 March 2015 |title=The Trident Successor Programme: an update |url=https://researchbriefings.files.parliament.uk/documents/SN06526/SN06526.pdf |access-date=26 December 2023 |work=Standard Notes |publisher=House of Commons Library}}

Successor generated controversy because of its cost,{{cite news |url=http://uk.reuters.com/article/uk-britain-defence-trident-idUKKCN0SZ2IC20151110 |archive-url=https://web.archive.org/web/20160721152622/http://uk.reuters.com/article/uk-britain-defence-trident-idUKKCN0SZ2IC20151110 |url-status=dead |archive-date=21 July 2016 |title=Britain denies report nuclear deterrent to cost 167 billion pounds |work=Reuters |date=10 November 2015 |access-date=7 March 2018}} and because some political parties and campaign groups such as the Campaign for Nuclear Disarmament (CND) and Trident Ploughshares oppose the retention of CASD or any nuclear weapons by the UK on moral or financial grounds.{{cite news|url=http://news.bbc.co.uk/2/hi/uk_news/6050336.stm|title= Trident debate to top CND agenda|date=14 October 2006|work=BBC News| access-date = 2006-12-01}}{{cite news|url=http://news.bbc.co.uk/2/hi/uk_news/politics/5342812.stm|title= Unions oppose replacing Trident|date=13 September 2006|work=BBC News| access-date = 2006-12-01}}

The programme is managed by a new Submarine Delivery Agency (SDA), established on 3 April 2017 within the Ministry of Defence (MOD) Defence Equipment and Support (DE&S) organisation. BAE Systems and Rolls Royce are the programme's Tier One industrial partners.{{cite web |url=https://researchbriefings.files.parliament.uk/documents/CBP-8010/CBP-8010.pdf |title=Replacing the UK's strategic nuclear deterrent: Progress of the Dreadnought class |last=Mills |first=Claire |publisher=UK Parliament |work=House of Commons Library |id=CBP-8010 |date=3 May 2023 |access-date=24 July 2023}}

In 2011, the programme's Initial Gate report estimated costs at £25 billion. In 2015, the programme was estimated to cost £31 billion including estimated future defence inflation, design, testing and construction of the US-UK Common Missile Compartment and modernisation of shipyard facilities in Barrow, with £10 billion of additional contingency set aside. In March 2023, £2 billion of the contingency fund had been accessed to reprofile spending and bring construction forward. These costs do not include the related Trident missile renewal, new infrastructure projects at the re-nationalised Atomic Weapons Establishment, and new nuclear fuel production facilities at Rolls-Royce.

Once in service, annual in-service costs are expected to be approximately 6% of the defence budget (about £3 billion).

Studies by the Nuclear Information Service and the Campaign for Nuclear Disarmament have suggested that the MOD cost presentation is under-estimating replacement programme costs. Including all related costs, including new infrastructure investment and decommissioning costs, and 30 years of in-service costs, they estimate a cost in the region of £172 to £205 billion. Crispin Blunt, Chair of the Foreign Affairs Select Committee, estimated in July 2016 that the renewed deterrent lifetime cost would be £179 billion.{{cite web |url=https://ukdefencejournal.org.uk/british-parliament-votes-renew-trident-nuclear-weapons/ |title=British parliament votes to renew Trident |last1=Allison |first1=George |date=18 July 2016 |publisher=UK Defence Journal |access-date=20 July 2016 |archive-date=9 August 2016 |archive-url=https://web.archive.org/web/20160809020646/https://ukdefencejournal.org.uk/british-parliament-votes-renew-trident-nuclear-weapons/ |url-status=live}}

A January 2018, the National Audit Office expressed concern about the programme's spending profile, including that it was "unaffordable in the early years of the project" within the MOD allocated budget.{{cite news |url=https://www.telegraph.co.uk/business/2018/05/21/spending-watchdog-warns-6bn-risk-britains-nuclear-submarine/ |title=Royal Navy's nuclear submarines face £6bn black hole |last=Tovey |first=Alan |newspaper=The Daily Telegraph |date=22 May 2018 |access-date=22 May 2018 |archive-date=21 May 2018 |archive-url=https://web.archive.org/web/20180521231516/https://www.telegraph.co.uk/business/2018/05/21/spending-watchdog-warns-6bn-risk-britains-nuclear-submarine/ |url-status=live}} Subsequently the MOD moved £300 million into the Dreadnought programme from elsewhere, and later the 2018 budget added £1 billion to the defence budget, 40% of which went to the Dreadnought programme. The 2020 Spending Review allocated an extra £16.5 billion to the defence budget over 2020 to 2025, in part to "continue the renewal of the UK's nuclear deterrent".

The submarines have an intended service life of around 35 to 40 years, an increase of around 50% over the previous class.{{cite report |url=https://publications.parliament.uk/pa/cm201719/cmselect/cmpubacc/1028/1028.pdf |title=Ministry of Defence nuclear programme |date=10 September 2018 |publisher=UK Parliament |id=HC 1028 |access-date=21 September 2018 |work=Committee of Public Accounts}} The submarines will each have a crew of 130, including three chefs and a doctor. There will be separate female quarters,{{Cite web |title=Dreadnought Class |url=https://www.royalnavy.mod.uk/equipment/submarine/dreadnought-class |access-date=25 January 2025 |publisher=Royal Navy }} a gym space, classroom and a lighting system simulating the time of day on board.{{Cite news |date=10 December 2020 |title=Progress on the Royal Navy’s Dreadnought class submarine programme |url=https://www.navylookout.com/progress-on-the-royal-navy-dreadnought-class-submarine-programme/ |access-date=10 March 2025 |newspaper=Navy Lookout }} They will be powered by Rolls-Royce's PWR3 (Pressurised Water Reactor 3), compared to the PWR2 used on Vanguard- and Astute-class submarines. Although PWR2 and PWR2b (a derivative with improvements) designs were considered, the PWR3 was chosen for easier operations, longer service life and reduced maintenance costs, with 30% fewer parts.{{Cite news |title=Dreadnought-Class Nuclear-Powered Ballistic Missile Submarines |url=https://www.naval-technology.com/projects/dreadnought-class-nuclear-powered-ballistic-missile-submarines/ |access-date=25 January 2025 |newspaper=Naval Technology }}{{cite web |date=2016 |title=Nuclear – Engineering Excellence |url=https://www.rolls-royce.com/~/media/Files/R/Rolls-Royce/documents/investors/capital-markets-day/nuclear-excellence.pdf |access-date=10 March 2025 |publisher=Rolls-Royce}} They will be equipped with X-rudders, in a first on British submarines, to reduce noise, especially at high speeds, in front of the pumpjet.{{Cite news |date=22 November 2023 |title=Deep dive into the Dreadnought-class Trident nuclear submarines |url=https://www.forcesnews.com/services/navy/deep-dive-dreadnought-class-trident-nuclear-submarines |newspaper=Forces News |access-date=10 March 2025}} Unlike Vanguard-class submarines, control of movement will use "fly-by-wire" technology, with the Active Vehicle Control Management (AVCM) system from BAE Systems.{{Cite web |date=28 March 2021 |title=Flight control technology set to dive underwater for marine mobility |url=https://www.baesystems.com/en-uk/article/flight-control-technology-set-to-dive-underwater-for-marine-mobility |access-date=10 March 2025 |publisher=BAE Systems}}{{Cite web |date=1 April 2021 |title=Dreadnought-class submarines to get 'fly-by-wire' technology |url=https://www.royalnavy.mod.uk/news/2021/april/01/210401-dreadnought-fly-by-wire |access-date=10 March 2025 |publisher=Royal Navy }} As in Astute-class and Trafalgar-class submarines, they will be equipped with the Sonar 2076 system from Thales.{{Cite web |date=28 February 2020 |title=Thales to deliver next-generation sonar systems for the Royal Navy’s Dreadnought submarines {{!}} Thales Group |url=https://www.thalesgroup.com/en/united-kingdom/news/thales-deliver-next-generation-sonar-systems-royal-navys-dreadnought-submarines |access-date=10 March 2025 |publisher=Thales Group }} They will each have three missile compartments with four missile tubes each (quad packs), for a total of twelve missile tubes. These share a common design with those on American {{sclass|Columbia|submarine|2}}, as part of the "Common Missile Compartment" (CMC) scheme. There will be five deck levels.

Construction started in late 2016 at the Barrow-in-Furness shipyard operated by BAE Systems Submarines, when the first submarine was provisionally expected to enter service in 2028.{{cite news | url=https://www.bbc.co.uk/news/uk-26559534 | title=Successor submarine shipyard gets £300m investment |publisher=BBC News | date=13 March 2014 | access-date=21 June 2014}} The start of construction of the second phase was announced in May 2018.{{cite web|title=Defence Secretary announces massive £2.5bn investment in UK nuclear submarines|url=https://www.gov.uk/government/news/defence-secretary-announces-massive-25bn-investment-in-uk-nuclear-submarines|website=Gov.UK|date=14 May 2018 |access-date=15 May 2018}}

In October 2018, Cammell Laird was awarded a contract to manufacture 29 non-pressure hull sections in Birkenhead. The MOD said in December 2018 that construction of the first submarine was on schedule and within budget.{{Cite web|url=https://www.janes.com/article/85436/uk-dreadnought-submarine-programme-within-budget-and-on-track-says-latest-mod-report|title=UK Dreadnought submarine programme within budget and on track, says latest MoD report|publisher=Janes |archive-url=https://web.archive.org/web/20190417183626/https://www.janes.com/article/85436/uk-dreadnought-submarine-programme-within-budget-and-on-track-says-latest-mod-report |archive-date=17 April 2019}} In April 2021, The Sunday Times reported that delays on the {{sclass|Astute|submarine}}s may impact the Dreadnought class, which will be built in the same dock hall. Related concerns are a 19 month delay to an extension of the Barrow facility and a five year delay to a Rolls-Royce factory which will build the nuclear reactors.{{Cite news|last=Collingridge|first=John|date=25 April 2021|title=Are Britain's nuclear subs slipping below the waves?; First they were due in 2024, then 2028, then 'the 2030s'. Doubts are mounting over the new Trident boats.|newspaper=The Sunday Times |url=https://www.thetimes.com/article/are-britains-nuclear-subs-slipping-below-the-waves-3zt7658zq |access-date=10 March 2025}} However, the MOD commented that "the Dreadnought programme remains on track to deliver to schedule, with the first in class expected to enter service in the early 2030s."

Thales Glasgow was awarded a £193 million contract in July 2023, to provide optronic masts, similar to those in use on Astute class.{{Cite web |date=13 July 2023 |title=Scope for success as historic Glasgow firm wins £169m contract for Dreadnought 'periscopes' |url=https://www.royalnavy.mod.uk/news/2023/july/13/20230713-scope-for-success-as-historic-glasgow-firm-wins-169m-contract-for-dreadnought-periscopes |access-date=10 March 2025 |publisher=Royal Navy }} General Dynamics Mission Systems is to provide and maintain fire control systems for both Dreadnought- and American {{sclass|Columbia|submarine}}s.{{Cite news |last=Hill |first=John |date=23 January 2024 |title=General Dynamics remains integral to US and UK submarine ecosystem |url=https://www.naval-technology.com/news/general-dynamics-remains-integral-to-us-and-uk-submarine-ecosystem/ |publisher=Naval Technology |access-date=10 March 2025}} Seventy-five missile tube assemblies for Dreadnought- and Columbia-class submarines will be manufactured by Babcock in Rosyth and Bristol.{{Cite web |date=2 June 2020 |title=Babcock awarded multimillion pound missile tube contract extension by Electric Boat |url=https://www.babcockinternational.com/news/babcock-awarded-multimillion-pound-missile-tube-contract-extension-by-electric-boat/ |access-date=10 March 2025 |publisher=Babcock International Group }} Northrop Grumman will provide the launcher subsystem hardware for the common missile compartments in both platforms, under a $458 million contract in June 2022. In January 2025, Rolls Royce was awarded a £9 billion contract by the MOD, covering research, design, manufacture and support of all nuclear reactors in Royal Navy submarines. The contract, named "Unity", covers a period of 8 years, and will continue to support the delivery of the reactors for Dreadnought-class submarines. Defence Secretary John Healey said "This investment in Britain’s defence will deliver a long-term boost to British business, jobs and national security."{{cite news |url=https://www.neimagazine.com/news/rolls-royce-signs-9bn-uk-mod-deal-for-submarine-reactor/ |title=Rolls-Royce signs £9bn UK MoD deal for submarine reactor support |publisher=Nuclear Engineering International |date=27 January 2025 |access-date=28 January 2025}}{{Cite web |date=24 January 2025 |title=Rolls-Royce signs landmark Unity contract with UK Ministry of Defence |url=https://www.rolls-royce.com/media/press-releases/2025/24-01-2025-rolls-royce-signs-landmark-unity-contract-with-uk-ministry-of-defence.aspx |access-date=10 March 2025 |publisher=Rolls-Royce }}

{{Portal|United Kingdom}}

• Future of the Royal Navy
• List of submarine classes of the Royal Navy
• Nuclear weapons and the United Kingdom
• Royal Navy Submarine Service
• United Kingdom and weapons of mass destruction

{{Reflist|30em}}

• UK House of Commons, Select Committee on Defence [https://publications.parliament.uk/pa/cm200607/cmselect/cmdfence/225/22502.htm The Future of the UK's Strategic Nuclear Deterrent: the White Paper: Ninth Report of Session 2006-07], House of Commons Papers, HC 225 [2005-2007]
• UK House of Commons, Select Committee on Defence [https://publications.parliament.uk/pa/cm200607/cmselect/cmdfence/59/5902.htm The Future of the UK's Strategic Nuclear Deterrent: the Manufacturing and Skills Base: Fourth Report of Session 2006–07], House of Commons Papers, HC 59 [2005-2007]
• {{Cite report |url=http://www.nao.org.uk/pn/07-08/07081115.htm |title=Ministry of Defence: The United Kingdom's Future Nuclear Deterrent Capability |date=5 November 2008 |publisher=National Audit Office |isbn=978-0-10-295436-4 |access-date=2008-11-09 |archive-date=13 November 2008 |archive-url=https://web.archive.org/web/20081113214639/http://www.nao.org.uk/pn/07-08/07081115.htm }}
• [https://ukdefencejournal.org.uk/guide-dreadnought-class-nuclear-submarine/ Dreadnought Class Guide] - 21 October 2016
• [https://ukdefencejournal.org.uk/meet-the-dreadnought-class-new-nuclear-submarines-named/ Meet the Dreadnought class, new nuclear submarines named] - 16 December 2016

• {{Official website}}
• [http://www.mod.uk/NR/rdonlyres/AC00DD79-76D6-4FE3-91A1-6A56B03C092F/0/DefenceWhitePaper2006_Cm6994.pdf Government White Paper Cm 6994 The Future of the United Kingdom's Nuclear Deterrent (December 2006)]

{{UK submarine classes after 1945}}

{{Strategic nuclear weapon systems of the United Kingdom}}

Category:United Kingdom defence procurement

Category:2000s in the United Kingdom

Category:2010s in the United Kingdom

Category:Trident (UK nuclear programme)

Category:Nuclear submarines of the Royal Navy

Category:Submarine classes

Category:Ballistic missile submarines