{"id":17203,"date":"2025-03-14T04:25:22","date_gmt":"2025-03-14T04:25:22","guid":{"rendered":"https:\/\/nuclearcompanion.com\/?post_type=dataposts&p=17203"},"modified":"2025-04-28T20:52:05","modified_gmt":"2025-04-28T20:52:05","slug":"vanguard-class-of-ballistic-missile-submarines","status":"publish","type":"dataposts","link":"https:\/\/nuclearcompanion.com\/data\/vanguard-class-of-ballistic-missile-submarines\/","title":{"rendered":"Vanguard Class of Ballistic Missile Submarines"},"content":{"rendered":"\n

Introduction<\/strong><\/h2>\n\n\n\n

The Vanguard-class<\/strong> submarines form the backbone of the United Kingdom\u2019s nuclear deterrent. Following the retirement of airborne nuclear weapons in 1998, Britain\u2019s strategic deterrence relies entirely on its four Trident-armed SSBNs<\/strong>.<\/p>\n\n\n\n

Commissioned between 1993 and 2001<\/strong>, the class includes HMS Vanguard<\/a>, HMS Victorious<\/a>, HMS <\/strong>Vigilant<\/a>, and HMS <\/strong>Vengeance<\/a><\/strong>.<\/p>\n\n\n\n

Each displaces 16,000 tons<\/strong> submerged and measures 150 meters in length<\/strong>, making them the largest submarines ever built for the Royal Navy<\/strong>. They are powered by the Rolls-Royce PWR2 reactor<\/strong> and are armed with 16 Trident II D5 submarine-launched ballistic missiles (SLBMs)<\/a><\/strong>, each capable of carrying up to eight warheads. Additionally, they are equipped with four 21-inch torpedo tubes<\/strong> for Spearfish torpedoes<\/strong>.<\/p>\n\n\n\n\n\n\n\t\n\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t
Vanguard Class SPECIFICATIONS<\/th><\/td>\n<\/tr>\n<\/thead>\n
Length:<\/td>149.9 m (491.8 ft)<\/td>\n<\/tr>\n
Height:<\/td>36 ft 3 in (11 m)<\/td>\n<\/tr>\n
Width:<\/td>12,8 m (42 ft)<\/td>\n<\/tr>\n
Weight:<\/td>14,000 tons surfaced
\n15,980 tons submerged<\/td>\n<\/tr>\n
Armament:<\/td>16 launch tubes for Trident missiles and four 21 inch
\ntorpedo tubes<\/td>\n<\/tr>\n
Speed:<\/td>18 knots on the surface
\n25 knots submerged<\/td>\n<\/tr>\n
Powerplant:<\/td>Rolls-Royce PWR-2 pressurized water nuclear reactor<\/td>\n<\/tr>\n
Crew complement:<\/td>135 (14 officers)<\/td>\n<\/tr>\n
Contractor:<\/td>Vickers Shipbuilding & Engineering, Barrow-in-Furness<\/td>\n<\/tr>\n
Names of submarines:<\/td>VANGUARD (S28), VICTORIOUS (S29), VIGILANT (S30), VENGEANCE (S31)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n

These submarines operate from Faslane Naval Base in Scotland<\/strong> and maintain a continuous at-sea deterrence (CASD)<\/strong> posture, ensuring that at least one is always on patrol. Britain\u2019s single deterrent capability<\/strong> ensures a rapid response, with at least two additional submarines available for deployment while the fourth undergoes maintenance. <\/p>\n\n\n\n

Description<\/strong><\/h2>\n\n\n\n

Design<\/strong><\/h3>\n\n\n
\n
\"Bow
Bow view of HMS Victorious. (Source <\/a>\u00a9 Crown copyright\/OGL v3.0<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n

The Vanguard-class<\/strong> was originally conceived as an evolution of the Trafalgar-class<\/strong>, but the integration of the PWR2 nuclear reactor<\/strong> required a larger and more complex design<\/strong>. Unlike the Resolution-class<\/strong>, which was adapted from existing designs, the Vanguard-class<\/strong> was purpose-built as a ballistic missile submarine (SSBN)<\/strong>, incorporating successful features from previous British nuclear submarines<\/strong>.<\/p>\n\n\n

\n
\"Rear
Rear view of HMS Vanguard as she leaves HMNB Clyde in Scotland. (Source <\/a>\u00a9 Crown copyright\/OGL v3.0<\/a> link<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n

At 149.9 meters in length<\/strong>, with a 13-meter beam<\/strong> and a submerged displacement of 15,980 tons<\/strong>, the Vanguard-class<\/strong> is nearly twice the size of the Resolution-class<\/strong>, primarily due to the 16-tube Trident D5 missile compartment<\/strong>. The increased size allowed for a fourth deck<\/strong>, providing spacious living quarters and improved working conditions<\/strong> for the crew. <\/p>\n\n\n\n

Despite this, space was limited<\/strong> due to the need to constrain length within existing dockyard facilities. To accommodate this, ballast tanks were wrapped around the ends of the pressure hull<\/strong> instead of maintaining a constant-diameter design<\/strong>, as seen in the U.S. Ohio-class SSBNs<\/a><\/strong>. While this solution controlled the submarine\u2019s size, it resulted in a cramped engine room<\/strong>, which later presented operational challenges.<\/p>\n\n\n

\n
\"Starboard
Starboard view of HMS Vengeance as she departs for Devonport prior to re-fit.<\/em> link<\/a> (Source <\/a>\u00a9 Crown copyright 2025. MOD Crown Copyright News \/ Editorial Licence<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n

The Vanguard-class<\/strong> was the last British submarine designed by the Royal Corps of Naval Constructors<\/strong>, as the Astute-class<\/strong> that followed was designed by the shipbuilders. Each submarine features an anechoic noise-reduction coating<\/strong> on the outer hull to minimize acoustic detection. <\/p>\n\n\n\n

Crew<\/strong><\/h3>\n\n\n\n

Each Vanguard-class submarine<\/strong> operates with two separate crews, known as Port<\/strong> and Starboard<\/strong>. While one crew undertakes patrol duties<\/strong> beneath the ocean, the other conducts training exercises<\/strong> or takes leave<\/strong> ashore. Training includes seamanship<\/strong>, weapons handling<\/strong>, and sonar operation<\/strong> at the Faslane naval base<\/strong>.<\/p>\n\n\n

\n
\"Officers
Officers of the watch aboard HMS Vanguard. (Source<\/a> \u00a9 Crown copyright\/OGL v3.0<\/a> link<\/a>))<\/figcaption><\/figure>\n<\/div>\n\n\n

A Vanguard submarine accommodates a crew of up to 130 sailors<\/strong>. They live across three decks<\/strong> spanning the vessel’s 150-metre length<\/strong>. The living spaces aboard are unusually spacious<\/strong> compared to earlier submarines. Enhanced domestic facilities<\/strong> and improved food quality<\/strong> help maintain crew morale<\/strong> during extended submerged operations. <\/p>\n\n\n\n

The submarine’s advanced air purification system<\/strong> and freshwater production<\/strong> from its nuclear plant<\/strong> further ensure comfort and health<\/strong> during patrols. Despite these comforts, the crew experiences strict limitations on communication<\/strong>, with telephone<\/strong> and internet access<\/strong> significantly restricted to maintain secrecy<\/strong>.<\/p>\n\n\n

\n
\"\"
Interior of HMS Victorious. (Source<\/a> \u00a9 Crown copyright\/OGL v3.0<\/a> link<\/a>))<\/figcaption><\/figure>\n<\/div>\n\n\n

Initial operational plans reportedly aimed to keep three submarines<\/strong> in active service simultaneously, supported by a total of five crews<\/strong>, rather than the expected six.<\/p>\n\n\n\n

In 1998, the Labour government announced plans to move from double crews to a single-crew system, aiming to reduce costs and ease recruitment pressures. In May of that year, HMS Vanguard temporarily operated with one enhanced crew of 200 sailors<\/strong>, instead of the usual 135. However, this single-crewing experiment was short-lived, and the double-crew system ultimately remained in place.<\/p>\n\n\n\n

Missiles<\/strong><\/h3>\n\n\n\n

Each Vanguard-class<\/strong> submarine carries 16 U.S.-made Trident II (D5) submarine-launched ballistic missiles (SLBMs)<\/strong>. These three-stage, rocket-propelled<\/strong> missiles are 44 feet long, weigh 130,000 pounds<\/strong>, and have a range of 4,000 nautical miles<\/strong>. <\/p>\n\n\n\n

Each missile can be armed with up to three multiple independently targetable reentry vehicles (MIRVs)<\/strong>, meaning a single submarine can carry up to 48 nuclear warheads<\/strong>. The warheads are a British variation of the U.S. W76 design<\/a><\/strong>, enclosed in a U.S. Mk-4 reentry vehicle<\/strong>.<\/p>\n\n\n

\n
\"A
A Trident II D5 Missile launch from HMS Vanguard during a DASO in 2005. (Source <\/a>\u00a9 Crown copyright\/OGL v3.0<\/a> link<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n

The United Kingdom does not own the Trident missiles outright<\/strong> but leases them from a pool of 58 SLBMs<\/strong> shared with the United States Navy<\/strong> at the Strategic Weapons Facility Atlantic (SWFLANT), Kings Bay, Georgia<\/strong>. Missiles used by a British SSBN<\/strong> may later be assigned to a U.S. Navy SSBN<\/strong>, and vice versa. After receiving their missiles in Kings Bay<\/strong>, British submarines sail to the Royal Naval Armaments Depot at Coulport<\/strong>, where the UK-designed and UK-manufactured warheads<\/strong> are fitted.<\/p>\n\n\n

\n
\"Missile
Missile compartment interior of HMS Victorious. These missile tubes contain Trident II missiles. (Source <\/a>\u00a9 Crown copyright\/OGL v3.0<\/a> link<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n

British SSBNs conduct their missile flight tests<\/strong> at the U.S. Eastern Test Range<\/strong> off the coast of Florida<\/strong>. The UK\u2019s Trident warheads, known as Holbrooke Mark 4s<\/strong>, were tested three times at the Nevada Test Site<\/strong>.<\/p>\n\n\n\n

Since the 2010 Strategic Defense and Security Review (SDSR)<\/strong>, British submarines on patrol carry no more than eight operational Trident missiles<\/strong>, armed with a total of 40 nuclear warheads<\/strong>. These missiles remain in a detargeted mode<\/strong>, meaning targeting data must be loaded before launch<\/strong>, reducing their alert status to several days’ notice<\/strong> instead of immediate readiness.<\/p>\n\n\n\n

Sonar and Electronics<\/strong><\/h3>\n\n\n\n

The Vanguard-class<\/strong> was the first Royal Navy submarine<\/strong> equipped with an advanced computerized Submarine Command System (SMCS)<\/strong>. This multi-screen command system employs eleven highly advanced computers connected by a high-capacity fibre-optic link. SMCS provides over twenty times the processing power of earlier systems, improving cost efficiency and reliability. The class also features the Sonar 2054<\/strong>, a unique system employing hydrophone and transducer arrays twice as large as any previously operated by the Royal Navy.<\/p>\n\n\n

\n
\"HMS
HMS Vanguard leaving HMNB Devonport in 2023 after refit. (Source <\/a>\u00a9 Crown copyright\/OGL v3.0<\/a> link<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n

The Type 2054 sonar<\/strong> comprises three elements initially designated separately: the Type 2043 active\/passive bow sonar<\/strong>, the Type 2044 reelable towed array<\/strong>, and the Type 2045 intercept sonar<\/strong>. These elements are integrated into a fully federated system. <\/p>\n\n\n\n

Signal processing is entirely digital, converting signals into digital form before transmission to the beam-former. The sonar suite features five consoles, each equipped with two 17-inch display screens and touch-sensitive plasma control panels. Plessey<\/strong> (now part of Marconi) supplied the bow sonar, beam-former, and signal processor; Marconi<\/strong> provided the intercept sonar, and Ameeco<\/strong> supplied the towed array.<\/p>\n\n\n\n

Navigation systems include the Ship’s Inertial Navigation System (SINS) Mk 2<\/strong> and the Navigation radar utilizes the Kelvin Hughes Type 1007 (I-band)<\/strong> radar.<\/p>\n\n\n

\n
\"\"
Officer of the watch aboard HMS Vanguard next to a Type 1007 navigation radar. (Source<\/a> \u00a9 Crown copyright\/OGL v3.0<\/a> link<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n

Additionally, the class introduced the first British submarine use of optronic masts<\/strong>, allowing relocation of the operations room to a more spacious lower deck. It is equipped with Pilkington Optronics CK 51<\/strong> search periscope and Pilkington Optronics CH 91<\/strong> attack periscope.<\/p>\n\n\n\n

Combat data management is handled by the BAE Systems SMCS NG<\/strong>, and weapon control employs the Ultra Electronics Outfit SWIM 2<\/strong>. Physical countermeasures include External Launched Countermeasures (SCAD 101)<\/strong> and three SSE Mk 10 launchers<\/strong>. Electronic support measures feature the Thales UAA4 intercept system<\/strong>. <\/p>\n\n\n\n

Propulsion<\/strong><\/h3>\n\n\n\n

The Vanguard-class submarines<\/strong> are powered by the PWR2 reactor<\/strong>, a pressurized water reactor developed in the United Kingdom specifically for ballistic missile submarines. Designed and built by Rolls-Royce<\/strong>, the PWR2 generates 145 MWt<\/strong> of thermal power and drives two GEC steam turbines<\/strong>, which in turn power a single pump-jet propulsion system delivering 20.5 MW<\/strong> of propulsive power.<\/p>\n\n\n\n

Compared to its predecessor, the PWR1<\/strong>, the PWR2 offers 50% more power<\/strong> and 50% longer operational life<\/strong>, significantly extending the submarines\u2019 time between refits and refueling. <\/p>\n\n\n

\n
\"Port
Port quarter view of HMS Victorious leaving Plymouth in 2008<\/em>. (Source <\/a>\u00a9 Crown copyright 2025. MOD Crown Copyright News \/ Editorial Licence<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n

The PWR2<\/strong> also enhances stealth capabilities. It uses natural circulation at low power, reducing noise levels compared to earlier reactors. This, combined with improved power distribution, makes the Vanguard-class submarines inherently quieter and more survivable in hostile environments.<\/p>\n\n\n\n

Initially, the Core G reactor core<\/strong> used in the Vanguard-class submarines provided nearly three times the lifespan of the earlier Core A<\/strong>, which was utilized in the previous Resolution-class SSBNs<\/strong>. This ensured these submarines to require refueling only every 8 to 9 years, allowing the Royal Navy to maintain three boats in active service at all times with fewer crews. <\/p>\n\n\n

\n
\"The
The crew of HMS Victorious on deck as she leaves her home port of HM Naval Base Clyde. (Source<\/a> \u00a9 Crown copyright 2025. MOD Crown Copyright News \/ Editorial Licence<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n

However, during their first overhaul, all four Vanguard-class submarines were fitted with a new long-life reactor core known as Core H<\/strong>. Core H was specifically designed to last for the remainder of the submarines’ service life without requiring refueling.<\/p>\n\n\n\n

Torpedoes<\/strong><\/h3>\n\n\n\n

In addition to their Trident II D5 ballistic missiles<\/strong>, the Vanguard-class submarines<\/strong> are equipped with four 21-inch (533 mm) torpedo tubes<\/strong> for Marconi Spearfish heavyweight torpedoes<\/strong>. These torpedoes provide anti-submarine<\/strong> and anti-surface warfare capabilities<\/strong>, ensuring the submarines can defend themselves against enemy warships and submarines.<\/p>\n\n\n

\n
\"Computer
Computer generated image of a Spearfish torpedo. (Source <\/a>\u00a9 Crown copyright 2025. MOD Crown Copyright News \/ Editorial Licence<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n

The Spearfish<\/strong> is the Royal Navy\u2019s primary heavyweight torpedo<\/strong>, designed to counter high-speed, deep-diving submarines and large surface vessels. It features dual guidance<\/strong>, using both wire guidance<\/strong> and active-passive sonar homing<\/strong>.<\/p>\n\n\n\n

Its speed and range vary depending on operational needs, reaching 65 knots<\/strong> with a range of 26 km<\/strong> or 50 knots<\/strong> with a range of 31.5 km<\/strong>. At its maximum, it can travel at 60 knots<\/strong> for 35 nautical miles<\/strong>. Powered by a HAP-Otto fuel-powered Sundstrand 21TP01 gas turbine engine<\/strong>, it uses a pump-jet propulsion system<\/strong> for high-speed maneuverability.<\/p>\n\n\n

\n
\"A
A Spearfish torpedo being loaded into a Royal Navy submarine. (Source <\/a>\u00a9 Crown copyright 2025. MOD Crown Copyright News \/ Editorial Licence<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n

The Spearfish torpedo<\/strong> carries a 300 kg directed-charge warhead<\/strong> capable of breaking the keel of a 50,000-ton ship<\/strong> by creating an underwater gas bubble explosion<\/strong> beneath the target. Weighing approximately two tons<\/strong>, it delivers firepower equivalent to a 550 lb bomb<\/strong>. These torpedoes ensure that the Vanguard-class submarines<\/strong> remain a formidable threat in underwater combat, even though their primary mission is nuclear deterrence<\/strong>.<\/p>\n\n\n\n

Construction<\/strong><\/h2>\n\n\n\n

The Vanguard-class submarine program<\/strong> was the largest, most complex, and most expensive military construction effort in Western Europe at the time. It was initiated after the British government decided on 15 July 1980<\/strong> to procure the US Trident I (C4) missile system<\/a><\/strong>. However, on 11 March 1982<\/strong>, this was upgraded to the more advanced Trident II D5<\/strong> system. These missiles would be deployed aboard a fleet of four submarines<\/strong>, with construction beginning in the mid-1980s.<\/p>\n\n\n

\n
\"HMS
HMS Vanguard<\/em> launch ceremony in March 1992<\/em>. (Crown Copyright \/ OGL<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n

All four submarines were built at Barrow-in-Furness<\/strong>, in a purpose-built indoor shipbuilding facility\u2014the largest in Europe\u2014located at the Devonshire Dock<\/strong>. The project\u2019s estimated cost was $19.8 billion<\/strong>. Lord Chalfont<\/strong>, Chairman of Vickers<\/strong>, compared the Vanguard-class to the engineering challenge of landing a man on the Moon<\/strong>, emphasizing the advanced technology involved.<\/p>\n\n\n\n\n\n\n\t\n\n\t\n\t\n\t\n\t
No.<\/th>Name<\/th>Builder<\/th>Keel Down<\/th>Launched<\/th>Comm.<\/th>\n<\/tr>\n<\/thead>\n
S28<\/td>Vanguard<\/td>Vickers Shipbuilding & Engineering, Barrow-in-Furness<\/td>3 Sep 1986<\/td>4 Mar 1992<\/td>1 4 Aug 1993<\/td>\n<\/tr>\n
S29<\/td>Victorious<\/td>Vickers Shipbuilding & Engineering, Barrow-in-Furness<\/td>3 Dec 1987<\/td>29 Sep 1993<\/td>7 Jan 1995<\/td>\n<\/tr>\n
S30<\/td>Vigilant<\/td>Vickers Shipbuilding & Engineering, Barrow-in-Furness<\/td>1 6 Feb 1991<\/td>15 Oct 1995<\/td>2 Nov 1996<\/td>\n<\/tr>\n
S31<\/td>Vengeance<\/td>Vickers Shipbuilding & Engineering, Barrow-in-Furness<\/td>1 Feb 1993<\/td>19 Sep 1998<\/td>27 Nov 1999<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n

The first submarine, HMS Vanguard<\/strong>, was ordered on 30 April 1986<\/strong>, and its keel was laid in September 1986<\/strong> in a ceremony attended by the Prime Minister<\/strong>. The second, HMS Victorious<\/strong>, was ordered on 6 October 1987<\/strong>, followed by HMS Vigilant<\/strong> on 13 November 1990<\/strong>. A decision on the fourth boat was delayed until after the 1992 general election<\/strong>, with HMS Vengeance<\/strong> finally ordered on 7 July 1992<\/strong>. Its keel was laid in February 1993<\/strong>.<\/p>\n\n\n\n

Operative Service<\/strong><\/h2>\n\n\n\n

The Vanguard-class submarines<\/strong> entered service in the mid-1990s, forming the backbone of the United Kingdom\u2019s strategic nuclear deterrent<\/strong>. <\/p>\n\n\n\n

HMS Vanguard<\/strong> was commissioned in August 1993<\/strong>, followed by HMS Victorious<\/strong> in January 1995<\/strong>, HMS Vigilant<\/strong> in November 1996<\/strong>, and HMS Vengeance<\/strong> in November 1999<\/strong>. All four submarines became part of the 1st Submarine Squadron (SM1)<\/a><\/strong>, based at the Clyde Submarine Base, Faslane<\/strong>. The first Trident patrol<\/strong> began in December 1994<\/strong>, while the last Polaris submarine<\/strong>, HMS Resolution<\/strong>, was decommissioned in August 1996<\/strong>, completing the transition to Trident.<\/p>\n\n\n

\n
\"HMS
HMS Vigilant at Faslane Naval Base, after a successful operational patrol. (Source<\/a> \u00a9 Crown copyright\/OGL v3.0<\/a> link<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n

In November 1998<\/strong>, HMS Vanguard<\/strong> became the first Royal Navy SSBN<\/strong> to visit Gibraltar<\/strong>, demonstrating expanded operational capabilities. On 4 February 2009<\/strong>, HMS Vanguard<\/strong> was involved in a collision with the French SSBN Le Triomphant<\/strong>, sustaining superficial damage.<\/p>\n\n\n\n

On 3 April 2013<\/strong>, the Prime Minister<\/strong> visited HMS Victorious<\/strong> by Royal Navy helicopter<\/strong> as it returned up the Firth of Clyde<\/strong>, commemorating the completion of the Royal Navy’s 100th Vanguard deterrent patrol<\/strong>.<\/p>\n\n\n\n

Demonstration and Shakedown Operations (DASO)<\/strong><\/h3>\n\n\n\n

Before entering operational service and after major overhauls, each Vanguard-class SSBN<\/strong> conducts Demonstration and Shakedown Operations (DASO)<\/strong> to verify system integrity. The Royal Navy has conducted twelve DASO firings of Trident II D5 missiles<\/strong>, ensuring certification for deployment:<\/p>\n\n\n\n\n\n\n\t\n\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t
#<\/th>Date<\/th>Submarine<\/th>Missile<\/th>Status<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>26 May 1994<\/td>HMS Vanguard<\/td>Trident D5<\/td>Successfull<\/td>\n<\/tr>\n
2<\/td>19 June 1994<\/td>HMS Vanguard<\/td>Trident D5<\/td>Successfull<\/td>\n<\/tr>\n
3<\/td>24 July 1995<\/td>HMS Victorious<\/td>Trident D5<\/td>Successfull<\/td>\n<\/tr>\n
4<\/td>22 August 1995<\/td>HMS Victorious<\/td>Trident D5<\/td>Successfull<\/td>\n<\/tr>\n
5<\/td>10 October 1997<\/td>HMS Vigilant<\/td>Trident D5<\/td>Successfull<\/td>\n<\/tr>\n
6<\/td>10 October 1997<\/td>HMS Vigilant<\/td>Trident D5<\/td>Successfull<\/td>\n<\/tr>\n
7<\/td>21 September 2000<\/td>HMS Vengeance<\/td>Trident D5<\/td>Successfull<\/td>\n<\/tr>\n
8<\/td>10 October 2005<\/td>HMS Vanguard<\/td>Trident D5<\/td>Successfull<\/td>\n<\/tr>\n
9<\/td>26 May 2009<\/td>HMS Victorious<\/td>Trident D5<\/td>Successfull<\/td>\n<\/tr>\n
10<\/td>23 October 2012<\/td>HMS Vigilant<\/td>Trident D5<\/td>Successfull<\/td>\n<\/tr>\n
11<\/td>20 June 2016<\/td>HMS Vengeance<\/td>Trident D5<\/td>Failure<\/td>\n<\/tr>\n
12<\/td>30 January 2024<\/td>HMS Vanguard<\/td>Trident D5<\/td>Failure<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n

These tests confirm the submarines’ combat readiness<\/strong> before they return to patrol duty.<\/p>\n\n\n\n

Maintenance, Upgrades, and Extended Service Life<\/strong><\/h3>\n\n\n\n

Each submarine undergoes a Long Overhaul Period and Refuel (LOP(R))<\/strong> approximately every 10\u201312 years<\/strong> at Devonport Dockyard<\/strong>, incorporating reactor refueling, sonar upgrades, and electronic warfare enhancements<\/strong>:<\/p>\n\n\n\n\n\n\n\t\n\n\t\n\t\n\t\n\t\n\t\n\t
Location<\/th>Submarine<\/th>Start<\/th>End<\/th>Comments<\/th>\n<\/tr>\n<\/thead>\n
HM Naval Base Devonport<\/td>HMS Vanguard<\/td>Feb 2002<\/td>Jun 2005<\/td>Long Overhaul Period and Refuel (LOP(R))<\/td>\n<\/tr>\n
HM Naval Base Devonport<\/td>HMS Victorious<\/td>April 2005<\/td>May 2008<\/td>Long Overhaul Period and Refuel (LOP(R))<\/td>\n<\/tr>\n
HM Naval Base Devonport<\/td>HMS Vigilant<\/td>October 2008<\/td>March 2012 <\/td>Long Overhaul Period and Refuel (LOP(R))<\/td>\n<\/tr>\n
HM Naval Base Devonport<\/td>HMS Vengeance<\/td>March 2012<\/td>December 2015 <\/td>Long Overhaul Period and Refuel (LOP(R))<\/td>\n<\/tr>\n
HM Naval Base Devonport<\/td>HMS Vanguard<\/td>December 2015 <\/td>May 2023<\/td> Life-extension (LIFEX) <\/td>\n<\/tr>\n
HM Naval Base Devonport<\/td>HMS Victorious<\/td>May 2023<\/td>-<\/td> Life-extension (LIFEX) <\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n

During their first overhaul, all submarines were fitted with a new long-life reactor core (Core H<\/strong>) at the newly constructed D154 refuelling and defuelling facility<\/strong> at Devonport. <\/p>\n\n\n\n

The sonar system modernization included an open architecture upgrade comparable to the US Navy\u2019s Acoustic Rapid COTS Insertion (ARCI)<\/strong> program. <\/p>\n\n\n\n

Additional upgrades included the installation of the Submarine Acoustic Warfare Control System (SAWCS)<\/strong> and enhancements to the UAP-3 radar electronic support measures (ESM)<\/strong>.<\/p>\n\n\n\n

Originally, Vanguard was scheduled for retirement in 2022<\/strong>, but instead, the class will receive additional refits<\/strong>, extending service for 5 to 10 more years<\/strong> until the Dreadnought-class SSBNs<\/strong> replace them.<\/p>\n\n\n\n

Vanguard Replacement<\/strong><\/h2>\n\n\n\n

The Vanguard-class<\/strong> submarines will be replaced by the Dreadnought-class<\/strong>, the United Kingdom\u2019s largest and most expensive defense project<\/strong>, with an estimated cost of \u00a341 billion (US$52.5 billion)<\/strong>. <\/p>\n\n\n\n

The Dreadnought program<\/strong> was first announced on 4 December 2006<\/strong>, and by February 2011<\/strong>, the UK government confirmed that four new submarines<\/strong> would be built. On 18 July 2016<\/strong>, the House of Commons formally authorized the program, and the first steel was cut on 6 October 2016<\/strong>.<\/p>\n\n\n

\n
\"Artist's
Artist’s impression of the Dreadnought-class submarine. (Crown Copyright \/ OGL<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n

The Dreadnought-class<\/strong> will continue the Continuous At-Sea Deterrence (CASD)<\/strong> mission, carrying Trident II D5 SLBMs<\/strong>, in cooperation with the U.S. Navy\u2019s Columbia-class SSBN program<\/strong>. <\/p>\n\n\n\n

Unlike the Vanguard-class<\/strong>, which carries 16 missile tubes<\/strong>, the Dreadnought-class<\/strong> will have 12 missile tubes<\/strong> but a larger displacement of 16,900 tons<\/strong> due to advanced silencing measures. <\/p>\n\n\n\n

It will be powered by the new PWR3 reactor<\/strong>, likely a natural circulation type<\/strong>, and will use a turbo-electric drive with a pump-jet propulsion system<\/strong> for increased stealth.<\/p>\n\n\n

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Infographic of the new Dreadnought Class. (Source <\/a>\u00a9 Crown copyright 2025. MOD Crown Copyright News \/ Editorial Licence<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n

The program entered Delivery Phase 3 in March 2022<\/strong>, with a budget of \u00a310 billion (US$12.5 billion)<\/strong>. This phase includes the completion of HMS Dreadnought<\/strong>, the first boat in the class, and the start of sea trials in the late 2020s<\/strong>. <\/p>\n\n\n\n

Most of Dreadnought\u2019s major components, including its 12 missile tubes<\/strong>, have been manufactured, and hull sections are now being assembled at BAE Systems\u2019 Devonshire Dock Hall in Barrow-in-Furness<\/strong>.<\/p>\n\n\n

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A section of HMS Dreadnought being transported. (\u00a9 Crown copyright 2025. MOD Crown Copyright News \/ Editorial Licence<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n

Construction of the second submarine, HMS Valiant<\/strong>, is well underway, while work on the third, HMS Warspite<\/strong>, began on 9 February 2023<\/strong>. The final boat, HMS King George VI<\/strong>, will follow. <\/p>\n\n\n\n

Efforts are also underway to develop support infrastructure<\/strong> to ensure a smooth transition when the Dreadnought-class<\/strong> enters service, replacing the Vanguard-class<\/strong> in the 2030s<\/strong>.<\/p>\n\n\n\n

Further Reading<\/strong><\/h2>\n\n\n\n