SSN Astute Class Nuclear Submarine - Naval Technology Nuclear power for the Astute is provided by the Rolls-Royce PWR 2 pressurised water reactor. SSN Astute Class Nuclear Submarine, United Kingdom The Royal Navy's Astute Class submarine is a nuclear-powered attack submarine which will replace the five Swiftsure Class submarines, launched between 1973 and 1977 and approaching the end of their operational life. The initial order quantity was three, but the UK MoD has ordered an additional four, meaning seven submarines will be built as part of the Astute Class. The performance specification of the Astute is an extension of the performance of the Trafalgar Class batch 1 fleet of the Royal Navy's Second Submarine Squadron, based at Devonport. The Trafalgar batch 1 submarines are to be decommissioned by 2022, beginning with HMS Trafalgar, which was decommissioned in December 2009. The Astute Class submarines will be based at Faslane in Scotland.

Royal Navy's attack submarine development history "Trafalgar batch 1 submarines are to be decommissioned by 2022, beginning with HMS Trafalgar." BAE Systems Astute Class is the prime contractor for the project and the submarines are being built at the BAE Systems Marine Barrow shipyard. The first three Astute ships were named HMS Astute (S119), HMS Ambush (S120) and HMS Artful (S121). The fourth submarine was named HMS Audacious (S122). The fifth Astute Class submarine was named HMS Anson (S123) in September 2011. The sixth and seventh will be named as HMS Agamemnon (S124) and HMS Ajax (S125) respectively. The keel for the first-of-class HMS Astute was laid in January 2001 and it was launched on 8 June 2007. In October 2007, HMS Astute made her first dive, for an underwater systems test, at the 'dive hole' in Devonshire Dock, Barrow.

Also, in October, the vessel successfully carried out first firing trials from its torpedo tubes. HMS Astute was commissioned in August 2010. The keel of HMS Ambush was laid in October 2003. It was launched in December 2010. Ambush made its first voyage in January 2011. The initial dive test of the Ambush was completed in September 2011. The Ambush was commissioned in March 2013. The HMS Astute and HMS Ambush submarines were handed over to the Royal Navy in July 2013. The keel of HMS Artful was laid in March 2005. The submarine was launched in May 2014 and performed maiden dive in October 2014. It is expected to be commissioned by 2015. In May 2007, the UK MoD awarded BAE Systems a contract to build a fourth Astute Class submarine, HMS Audacious (S122), to enter service in 2018. The keel of Audacious was laid in March 2009.

In December 2012, BAE Systems received £1.2bn contract from the UK MoD for the design, construction, test and commissioning programme of Audacious. The fifth and sixth Astute Class submarines, HMS Anson (S123) and HMS Agamemnon (S124), were ordered in March 2010. The keel for Anson was laid in October 2011 while that of Agamemnon was laid in July 2013. These submarines are expected to be commissioned in 2020 and 2022 respectively. The seventh, HMS Ajax (S125), has been confirmed but the order is yet to be placed. Command and control systems on Astute Class submarines Astute combat management system (ACMS) is being supplied by BAE Systems Insyte (formerly Alenia Marconi Systems) and is a development of the submarine command system (SMCS) currently in service in all classes of UK submarines. ACMS receives data from the sonars and other sensors and, through advanced algorithms and data handling, displays real time images on the command consoles.

Factory acceptance of the operational software was received from the Astute Prime Contract Office in July 2002. EADS Defence & Security Systems and EADS Hagenuk Marinekommunikation were awarded the contract to provide the external communications systems for the Astute in August 2005. Strachan and Henshaw are to provide the weapon handling and launch system (WHLS). Northrop Grumman Sperry Marine was selected in March 2008 to provide the platform management system for the fourth of class, HMS Audacious. Astute Class Tomahawk missiles and torpedoes Astute is equipped with the Tomahawk Block IV (tactical tomahawk) cruise missile from Raytheon, fired from the 533mm torpedo tubes. Tomahawk is equipped with the TERCOM terrain contour mapping-assisted inertial navigation system. The terrain contour mapping for use over land combines onboard radar altimeter measurements with terrain mapping data installed in the missile. Block II added digital scene matching area correlation (DSMAC) guidance.

"Astute is equipped with the Tomahawk Block IV (tactical tomahawk) cruise missile from Raytheon." Block III improvements include an improved propulsion system and Navstar global positioning system (GPS) guidance capability. The GPS provides location and velocity data of the missile for precision targeting. Tomahawk has a range of up to 1,000 miles and a maximum velocity of 550mph. Block IV includes a two-way satellite link that allows reprogramming of the missile in flight and transmission of battle damage indication (BDI) imagery. Tomahawk Land Attack Missile (TLAM) Block IV entered service with the UK Royal Navy in April 2008, onboard Trafalgar batch I submarine, HMS Torbay. Astute has six 533mm torpedo tubes, and is equipped with Spearfish torpedoes and mines. There is capacity for a total of 36 torpedoes and missiles. The Spearfish torpedo from BAE Systems is wire-guided with an active / passive homing head. The range is 65km at 60kt. Spearfish is fitted with a directed-energy warhead.

Countermeasure technology and sensors The countermeasures suite includes decoys and electronic support measures (ESM). The ESM system is the Thales Sensors Outfit UAP(4). Outfit UAP(4) has two multifunction antenna arrays, which are mounted on the two non-hull penetrating optronics masts from Thales (formerly Pilkington) Optronics and McTaggart Scott. Astute Class submarines are fitted with the Royal Navy's new Eddystone Communications band Electronic Support Measures (CESM) system, also fitted to the Trafalgar Class submarines. The Eddystone system was developed by DML of Devonport UK, with Argon ST of the US. It provides advanced communications, signal intercept, recognition, direction-finding and monitoring capabilities. Sea trials of the system were completed in December 2007. Astute is fitted with I-band navigation radars. The sonar is the Thales Underwater Systems (formerly Thomson Marconi Sonar) 2076 integrated passive / active search and attack sonar suite with bow, intercept, flank and towed arrays.

Sonar 2076 has so far been fitted to Trafalgar Class submarines Torbay, Trenchant and Talent, entering service in February 2003. Astute is fitted with the latest version of the Thales S2076 integrated sonar suite. Atlas Hydrographic provided the DESO 25 high-precision echosounder, which are fitted on the Astute. DESO 25 is capable of precise depth measurements down to 10,000m. Astute has two non-hull-penetrating CM010 optronic masts developed by Thales Optronics. McTaggart Scott supplied the masts. The CM010 mast includes thermal imaging, low light TV and colour CCD TV sensors. Raytheon Systems was contracted to provide the Successor IFF (identification friend or foe) naval transponder system for the Astute Class. Propulsion, power and speed of the UK's nuclear submarines The nuclear power is provided by the Rolls-Royce PWR 2 pressurised water reactor. The long-life core fitted on the PWR 2 means refuelling will not be necessary in the service life of the submarine.

The other main items of machinery are two Alstom turbines and a single shaft with a Rolls-Royce pump jet propulsor, consisting of moving rotor blades within a fixed duct. There are two diesel alternators, one emergency drive motor and one auxiliary retractable propeller. CAE Electronics provided the digital, integrated controls and instrumentation system for steering, diving, depth control and platform management. The PWR 2 second-generation nuclear reactor was developed for the Vanguard Class Trident submarines. Current generations of PWR would allow submarines to circumnavigate the world about 20 times, whereas the latest development of PWR would allow circumnavigation 40 times without refuelling. The major equipment components in the development of PWR 2 were the reactor pressure vessels from Babcock Energy, main coolant pumps from GEC and from Weir and protection and control instrumentation from Siemens Plessey and Thorn Automation. Global Naval Submarines Market 2011-2021 This project forms part of our recent analysis and forecasts of the global naval submarines market available from our business information platform Strategic Defence Intelligence.

For more information click here or contact us: EMEA: +44 20 7936 6783; Americas: +1 415 439 4914; Asia Pacific: +61 2 9947 9709 or via email . Related content Royal Navy History Article 8 Footnotes History It is sometimes claimed that the United Kingdom was the last major maritime power to use submarines at the beginning of the 20th century, as the idea of submarine warfare was considered by many senior personnel in the Admiralty to be "Underhand, unfair and damned un-English" (Admiral Sir Arthur Wilson VC, 1901). However, those in favour of experimenting with submarine technology eventually won the argument, and the Royal Navy launched its first submarine, Holland 1, in 1901. The Submarine Service proved its worth in World War I, where it was awarded five of the Royal Navy's 14 Victoria Crosses of the war, the first by LieutenantNorman Holbrook, Commanding Officer of HMS B11.

During World War II the major operating arenas were the Norwegian waters; theMediterranean where a flotilla of submarines fought a successful battle against theAxis replenishment route to North Africa; and the Far East where Royal Navy submarines disrupted Japanese shipping operating in the Malacca Straits. The first British nuclear-powered submarine, HMS Dreadnought (S101) was launched in 1960 based around a US-built nuclear reactor. This was complemented by theValiant class from 1966, which featured the Rolls-Royce PWR1 reactor. Royal Navy submarines became an important part of the strategic nuclear deterrent with the introduction of the Resolution class ballistic missile submarines (SSBNs) from 1968. These carried US-built Polaris missiles and were later replaced by theVanguard class submarines and the Trident missile system from 1994. HMS Conqueror made history in 1982 during the Falklands War when she became the first nuclear-powered submarine to sink a surface ship, the ARA General Belgrano.

In May 1991 Oberon class submarines HMS Opossum and her sister HMS Otus returned to the submarine base HMS Dolphinin Gosport from patrol in the Persian Gulf flying Jolly Rogers (see below), the only indication that they had been involved in alleged SAS and SBS reconnaissance operations. In 1999 HMS Splendid participated in the Kosovo Conflict and became the first Royal Navy submarine to fire a cruise missile in anger. After Operation Veritas, the attack on Al-Qaeda and Taliban forces following the 9/11 attacks in the United States, it emerged that HMS Trafalgar was the first Royal Navy submarine to launch Tomahawk cruise missiles against Afghanistan. HMSTriumph was also involved in the initial strikes. On April 16, 2003 it was reported that HMS Turbulent, the first Royal Navy vessel to return home from the war against Iraq, had launched fourteen Tomahawk cruise missiles.

The Jolly Roger and the Submarine Service Admiral of the Fleet Sir Arthur Wilson VC, the Controller of the Royal Navy, summed up the opinion of many in the Admiralty at the time when he said in 1901 "[Submarines are] underhand, unfair, and damned un-English. ... treat all submarines as pirates in wartime ... and hang all crews." In response, Lieutenant Commander (later Admiral Sir) Max Horton first flew the Jolly Roger on return to port after sinking the German cruiser SMS Hela and the destroyer SMS S-116 in 1914 while in command of the E class submarine HMS E9. In World War II it became common practice for the submarines of the Royal Navy to fly the Jolly Roger on completion of a successful combat mission where some action had taken place, but as an indicator of bravado and stealth rather than of lawlessness. For example in 1982 returning from the Falklands conflict HMS Conqueror flew the Jolly Roger depicting one dagger for the SBS deployment to South Georgia and one torpedo for her sinking of the Argentinian Cruiser Belgrano. The Jolly Roger is now the emblem of the Royal Navy Submarine Service.

Perisher 'Perisher' (as the Submarine Command Course is better known) is a 24-week course all officers must take prior to serving as an Executive Officer on board a Royal Navy Submarine. It has been run twice a year since 1917, usually starting on 2 July and 14 November each year. It is widely regarded as one of the toughest command courses in the world, with an historical failure rate of 25%. If at any point during the training a candidate is withdrawn from training he will be nominated for boat transfer and kept occupied until the transfer. His bag is packed for him and he is notified of the failure when the boat arrives. On departure he is presented with a bottle of whisky. A failure on Perisher means that it is very unlikely the candidate will return to the Submarine Service. Since the Royal Navy no longer operates diesel-electric submarines, in 1995 the Royal Netherlands Navy has taken over the Perisher course for these boats from the British, and annually host a course that is attended by candidate submarine commanders from multiple navies around the world. Traditions Active submarines The Submarine Service has many traditions that are not found in the surface fleet.

These include slang unique to submariners (such as referring to the torpedo storage compartment as the Bomb Shop and the diesel engine room as the Donk Shop), a special communications code known as the Dolphin Code and the entitlement of a sailor to wear Dolphins upon entering the service. (Which were only awarded after completion of training and qualification in ships systems - on board first submarine posting (Part III training) The Submarine Service consists of two classes of Fleet submarines and one class ofBallistic Missile submarines. Fleet submarines There are seven fleet submarines on active duty - six Trafalgar class submarines and one Astute class submarine. They are all nuclear submarines and are classified asSSNs. These submarines are armed with the Spearfish torpedo for anti-submarine and anti-surface warfare. Some are also armed with Tomahawk cruise missiles for attacking targets on land. This capability was used by HMS Trafalgar against the Taliban in 2001 during Operation Veritas. The Fleet submarines are also capable of surveillanceand reconnaissance missions. Fleet submarines are sometimes referred to asattack or hunter-killer vessels.

Royal Navy Fleet submarines in active service Name Ballistic submarines Vanguard class submarine The four ballistic missile submarines (SSBN) of the Royal Navy are all of the Vanguard class. They were all built by Vickers Shipbuilding and Engineering Ltd, now BAE Systems Submarine Solutions. The SSBN flotilla or bomber 'fleet' tends to be almost a separate entity, for example it rarely uses pennant numbers preferring to use hull numbers, thus Vanguard 05, Victorious 06, Vigilant 07 and Vengeance 08. The four Vanguard class boats are responsible for the United Kingdom's nuclear deterrent, and use the Trident missile system. Each boat can carry up to 16 Trident II D5 Missiles, each of which may carry up to 12 nuclear warheads. It is UK Government policy to limit the actual number of warheads carried to 48 per boat. There has been at least one SSBN on patrol at all times for over 30 years, for a total of over 300 missions.

Royal Navy ballistic missile submarines in active service Name 1998 LR5 Submarine Rescue System The Royal Navy also operates the LR5 Submarine Rescue System, designed for retrieving sailors from stranded submarines. It is capable of rescuing 16 at a time. Future submarines Seven Astute-class submarines are planned, with the first in service, three under construction, the fifth ordered, and the procurement process started for the sixth. The first Astute class submarine, HMS Astute, entered service in August 2010. The second Astute class submarine, HMS Ambush, is expected to be replace HMS Turbulent in 2011. The Astute Class submarine is the largest nuclear Fleet submarine ever to serve with the Royal Navy, nearly 30% larger than its predecessors. Its powerplant is the Rolls Royce PWR2 reactor, developed for the Vanguard class SSBN. The armament of Astute class is to be 38 Spearfish torpedoes (the US equivalent is the Mk48 ADCAP torpedo), Tomahawk Block III/IV Cruise Missiles and submarine-launched mines. It is not known whether more Astute class submarines will be ordered.

Another development project is the Maritime Underwater Future Capability (MUFC). These will follow on from the Astute class, and possibly replace the Trafalgar class. Reports (e.g. in Defense News) have suggested that the MUFC studies may result in a single class of multi-role submarines to replace the Trafalgar class, Vanguard class SSBNs and eventually the Astute class. This would require a submarine capable of launching conventional land-attack missiles, some form of nuclear missile (ICBM or tactical nuclear missile) as well as conventional submarine munitions including mines and torpedoes. A new generation of ballistic missile submarines is also being planned, following a December 2006 Ministry of Defence white paper which recommended that the nuclear weapons should be maintained into the 2040s. It advocated the currently preferred submarine-based system, as it remained the cheapest and most secure deterrence option available. Britain's secret nuclear submarine plans Britain's secret nuclear submarine plans Britain's secret nuclear submarine plans Blackleaf #1Mar 6th, 2006 Britain's first three new Astute Class submarines will enter service over the course of the next few years. They will be called HMS Ambush, HMS Artful and HMS Astute.

They'll be the most powerful submarines ever operated by the Royal Navy. But the MoD is looking at having the futuristic Maritime Underwater Future Capability (MUFC) program to replace the Trafalgar Class submarines - Britain's secret nuclear submarine plans Reports say that Britain is secretly working on a replacement for its Trident nuclear missile submarines in a bid to maintain its status as one of the world's major nuclear powers. By Michael Fishpool for ISN Security Watch According to recent reports in The Scotsman and the US-based Defense News, Britain is secretly working on a replacement for its Royal Navy Trident ballistic missile submarines. The reports say that British Prime Minister Tony Blair is determined to have a replacement for the Trident-armed Vanguard class to maintain Britain as one of the worldï¿½s major nuclear powers. The Royal Navy currently operates four Vanguard-class Ship Submersible Ballistic Missile (SSBM) submarines ï¿½ HMS Vanguard, Victorious, Vigilant, and Vengeance - from the Clyde naval base at Faslane in Scotland.

Constructed by Vickers Shipbuilding & Engineering Limited (VSEL) at Barrow-in-Furness in Cumbria, the first Vanguard-class submarine (HMS Vanguard) entered service in 1994, with the last delivery in 2001 (HMS Vengeance). With each submarine capable of carrying up to 16 Trident D5 II submarine-launched nuclear ballistic missiles (SLBMs), each armed with up to 48 100-kiloton nuclear warheads, the Vanguard class is Britainï¿½s sole nuclear deterrent and cost some ï¿½9 billion (over US$16.5 billion) to develop. Meeting new international security requirements While the Vanguard class is due to be decommissioned in about 2020, it was designed during the Cold War, and there is now a greater requirement for cost-effective, multi-role military equipment in the post-Cold War international security environment.

As a result, it is believed that the British Ministry of Defence (MoD) is looking at enhancing the design for a new nuclear attack submarine, capable of firing both ballistic nuclear missiles and Tomahawk cruise missiles armed with conventional warheads, to fill the requirement for a successor to the Vanguard class. According to The Scotsman, the new submarine design could be based on the Maritime Underwater Future Capability (MUFC) program, which will involve major British defense companies like BAE Systems and Rolls-Royce. The MUFC, which was originally called the Future Attack Submarine (FASM) until 2001, is aimed at replacing the Royal Navyï¿½s four Trafalgar-class Ship Submersible Nuclear (SSN) submarines by 2016. It would also initially augment the Royal Navyï¿½s three Tomahawk-armed Astute-class SSN submarines - HMS Astute, Ambush, and Artful. These are currently being developed by BAE Systems at a cost of ï¿½2 billion to replace the Royal Navyï¿½s seven Swiftsure SSN submarines between 2006ï¿½2009.

Defense analysts believe that the MUFC could eventually replace the Astute class around 2030. Shrouded in secrecy There are presently few details available on the MUFC program, although it is believed that it has already entered the initial design stages. One of the main functions of the MUFC would be to undertake combat operations at long-range, using manned and remote-controlled undersea vehicles to attack the enemy. It is envisaged that the MUFC would fire vertical-launched missiles, rather than using the torpedo tubes as on the Astute, Swiftsure, and Trafalgar classes. The MUFC could also be equipped with mini-nuclear warheads to meet the requirements for a Vanguard-class successor. It has been widely speculated that Britain may already be involved in the research of mini-nuclear warheads with the US, which is looking to develop 1- to 5-kiloton mini-nuclear warheads capable of penetrating high-value underground military targets such as nuclear, biological, and chemical (NBC) weapons, as well as command and control facilities. Britain has a long history of close cooperation with the US on nuclear weapons development.

Both countries signed the Agreement For Cooperation on the Uses of Atomic Energy for Mutual Defense Purposes (also known as the Mutual Defense Agreement, MDA) in 1958, which was amended in 1994 and is due for renewal before the end of this year. The agreement allows Britain and the US to exchange nuclear information and technology, and to collaborate on nuclear projects. The British-built warhead for the Trident D5 II SLBM is based on the US W76, while the missile itself was purchased from the US in the early 1980s to replace the US-designed Polaris SLBM on British submarines. Money, the major stumbling block In June 2002, The Observer newspaper claimed that the MoD was planning to expand and modernize the Atomic Weapons Establishmentï¿½s (AWE) 270-acre Aldermaston site in Berkshire to undertake research and development of the new mini-nuclear weapons. An article in The Guardian four months earlier alleged that the government had already given the AWE approval to undertake small nuclear explosions at the Aldermaston site. The allegations were, however, denied by the MoD and the government.

Meanwhile, the New Scientist magazine reported in May 2003 that an AWE source had said that there were plans to increase staff at Aldermaston to cope with the new nuclear projects, while it was widely reported in December 2003 that the AWE had been given planning permission to construct a laser facility as part of the overall expansion of the Aldermaston site. The major stumbling block in the development of a new submarine to replace the Vanguard class is money. Many major defense projects for the British armed forces, such as the Astute-class SSN and the Eurofighter combat aircraft, have been criticized by the National Audit Office (NAO) for going over budget and taking too long to develop. The Royal Navy is particularly under scrutiny, with public money already being spent on the development of six Type 45 air defense destroyers and two 50ï¿½000-ton future aircraft carriers, being constructed by BAE Systems and due to enter service between 2007 and 2015. As a result, Tony Blairï¿½s government could face a backlash from Labour party members if it approves another ambitious and expensive defense project.

Other, less expensive options Defense analysts believe that a less expensive option would be to extend the service life of the Vanguard class as the US has done with its Trident-armed Ohio Class SSBM submarines. Indeed, the US Navyï¿½s Ohio class, which has been in service since the 1980s, has had its service-life extended from 30 to 45 years as part of the 2002 Nuclear Posture Review (NPR). Such an option would not be difficult to pursue as the Vanguard class has many design similarities to the Ohio class, although the submarineï¿½s core reactor would have to be replaced or modified. Significantly, the US is planning to order new and upgraded Trident D5A II SLBMs for some of its nuclear attack submarine fleet, replacing the D5 version, which is also used by the British. While Britain could purchase or lease the D5A missile from the US, it would have to either modify or replace the AWE-built warhead for the missile to continue in service.

The US is also planning to upgrade its W76 warheads, and it has been reported that additional updated W88 warheads are on order for use on its Trident SLBMs. Another option would be to allow the Royal Air Force (RAF) to again become responsible for providing Britainï¿½s nuclear deterrent. During the 1950s and the 1960s, the RAFï¿½s ï¿½V-Forceï¿½ bombers and 60 US-loaned Thor Intermediate-Range Ballistic Missiles (IRBMs) were responsible for Britainï¿½s nuclear deterrent until the Royal Navy was equipped with Polaris in 1966. The RAF continued to be equipped with the WE-177 free-fall nuclear bomb until they were withdrawn from service in 1998, leaving the Royal Navyï¿½s 200-odd Trident SLBMs as Britainï¿½s sole nuclear deterrent.

Defense analysts suggest that the Future Offensive Air System (FOAS), which will meet the RAFï¿½s requirement for a replacement for the Tornado GR4 fighter-bomber from 2017, would provide Britain with the ideal platform for an airborne nuclear capability. BAE Systems is currently considering a number of options for the aircraftï¿½s design, including long-range bomber versions of the Eurofighter and the Lockheed F-35 Joint Strike Fighter (JSF). The principal armament of the FOAS is likely to include the next generation of air-launched cruise missiles, which could be equipped with nuclear warheads if the government decides to allow the RAF to go nuclear again. Such a decision would also suit the submarineï¿½s future role in warfare, where it is expected to act more as a command and control centre to direct military operations rather than undertaking its traditional role of anti-submarine and anti-shipping warfare. This role would also suit the MoD by being cost-effective, allowing the MUFC to replace the Royal Navyï¿½s entire submarine fleet by the time the Astute Class comes to the end of its service life.

MoD remains tight-lipped Given the governmentï¿½s secrecy over its nuclear program, it is unlikely that much information will emerge during 2004 on the proposals for a replacement. The governmentï¿½s December 2003 defense white paper, Delivering Security in a Changing World, said that a decision on whether to replace Trident would not be made until after the next general election, due in 2006. In May 2004, the Royal Navyï¿½s First Sea Lord Admiral Alan West added to the speculation when he told a conference held by the London-based Royal United Services Institute (RUSI) that a decision was expected within the next two to three years. The MoD, however, has said that no decision has yet been made. Michael Fishpool is a London-based journalist and country analyst specializing in international security, defense, and EU affairs. He has written for a number of publications, including Jane's Security Sentinel and Nations of the World. He also runs the European Defence website ( (external - login to view)).

A speculative graphic from the Sunday Telegraph illustrating several possible MUFC vehicles Artist's impression of a Royal Navy "Future Underwater Vehicle (FUV)." (external - login to view) Trafalgar-class - encyclopedia article - Citizendium [ edit intro ] The Trafalgar-class is a type of British tactical submarine , the first of which, HMS Trafalgar , entered service in 1983. There are currently 6 Trafalgar-class submarines in service with the Royal Navy . All 7 Trafalgar-class submarines were built by Vickers Shipbuilding and Engineering in Barrow-in-Furness . Turbulent was the second to enter service, in 1984, followed by Tireless in 1985, Torbay in 1987, Trenchant in 1989, Talent in 1990 and Triumph in 1991. [1] HMS Trafalgar was decommissioned in 2009, [2] to be the first vessel replaced by the Astute-class . Four Trafalgars, however, will have a final systems upgrade, bringing many of their electronics to the Astute standard.

[3] The Trafalgar-class is a development of the Swiftsure-class and despite being slightly longer is internally almost identical in design. [4] Design All submarines face design tradeoffs. In Trafalgars, and the preceding Swiftsure-class , for a variety of reasons, small size was important. In the Cold War, this could limit the submarine's habitability, and other factors limiting it to European anti-submarine warfare — but that was precisely the NATO mission of Britain. Today, however, there is a role for small submarines in littoral warfare , in that they can operate in more confined waters than a submarine optimized for blue water operations. As demonstrated in the Falklands War , a submarine, moving ahead of the main task force, has a key mission of sea denial . The Royal Navy describes this submarine mission as The SSN is used to great effect when the submarine is deployed in advance of friendly forces in order to reduce the flexibility of an opposition force by denying the use of an area or region. This is known as regional sea denial. [5] Small submarines also have advantages for intelligence collection, both strategic and tactical, and for surveillance and reconnaissance as part of combined operations.

The Astute-class , which will replace both the Trafalgars and Swiftsure-classes , has grown in size, with sensors and silencing mentioned as factors. Greater automation, however, will allow a smaller crew, and thus greater habitability and range. [6] Still, the Astutes were originally called Trafalgar Batch 2, possibly a political compromise such as calling earlier Royal Navy aircraft carriers "through-deck cruisers" since "carrier" was equated to "high cost". The Astute designation came into use when images of the design showed a radically different look in the bow design. Specifications Displacement: 4,740 tons (surfaced), 5,208 tons (dived) Length: 85.4m Britain’s nuclear subs ‘potentially vulnerable’ to accidents – Channel 4 News Share on Twitter The MoD’s senior nuclear safety expert is warning that the safety of submarine reactors compares “poorly” with that of nuclear power stations, and there could be dangerous leaks of radioactivity. There was also a risk of “multiple fatalities” from submarines failing to surface, he says. Yet the reactors are currently being installed in a new £10 billion fleet of Astute submarines.

And they are still under consideration for the submarines due to replace those that carry Trident nuclear missiles from 2028. The report , released under Freedom of Information law and passed to Channel 4 News, also reveals that arguments over the reactor designs have delayed decisions on replacing Trident by 18 months, and added over £260 million to the bill. The report is a submission made to the Defence Board – a senior decision-making body within the MoD – in November 2009 about the status of the plans to replace Trident submarines. It includes a damning assessment of the safety of current submarine reactors by the MoD’s senior nuclear safety regulator, Commodore Andrew McFarlane. “A significant risk to life to those in close proximity and a public safety hazard out to 1.5km from the submarine.” Commodore McFarlane’s assessment of risk should there be a failure of the reactors. “Current UK practice falls significantly short of benchmarked relevant good practice,” he warns. The pressurised water reactors that run submarines are “potentially vulnerable to a structural failure of the primary circuit”.

This could cause “a release of highly radioactive fission products” and “a significant risk to life to those in close proximity and a public safety hazard out to 1.5km from the submarine”, says Commodore McFarlane. “Current designs of UK and global civil power plants have systems for safety injection of coolant into the reactor pressure vessel head and passive core cooling systems,” he adds. “UK submarines compare poorly with these benchmarks, with the ability to tolerate only a structural failure equivalent to a…” Unfortunately the rest of the sentence, along with most of the following two pages, are blacked out in the released document. McFarlane, who has retired as head of the MoD’s internal Defence Nuclear Safety Regulator since 2009, also suggests that reactor problems could prevent submarines from surfacing. There was a “risk of multiple fatalities resulting from loss of depth control”, he says. Submarine fleet The Royal Navy currently operates 11 nuclear-powered submarines , including six old Trafalgar class and four Vanguard class, which carry Trident missiles. It has also launched HMS Astute, the first of seven Astute class submarines being built at Barrow in Cumbria.

The Astute programme, which could end up costing over £10 billion, has been plagued with delays and cost overruns. HMS Astute itself suffered embarrassment last October when it accidently ran aground near the Isle of Skye during trials . The MoD is also trying to decide on the type of reactor to drive the submarines destined to replace the Vanguards. The declassified MoD document discloses that there are several options still under consideration. One – known as PWR2 – is “essentially” similar to the Astute class, while another – PWR2b – has “significantly modified systems to improve platform safety and survivability”. A third – PWR3 – is described as a “new propulsion plant based on a US design but using UK reactor technology”. Uncertainty over which reactor to choose has delayed a crucial investment decision about Trident, known as the “initial gate”, by at least 18 months. The decision was originally due to be made in September 2009, but has still not been announced by the MoD. The delay incurred “additional funding” of £260.89m, the document says.

It also meant that “substantial interest can be expected from Parliament and elements of the media”, which would require “presentational handling”. “All of our nuclear reactors meet the strict safety standards set by the Defence Nuclear Safety Regulator and we continuously look for areas of improvement.” Ministry of Defence John Large – the consulting nuclear engineer who helped oversee the salvage of the stricken Russian submarine, Kursk, after it sank in August 2000 – said the document revealed “very serious shortcomings” in the present generation of submarine reactors. “These include doubts about the survivability of the submarine after a nuclear reactor malfunction, lack of a passive shut down system, and strong hints that the reactor plant could fail when subject to what should be tolerable levels of hostile action.” John Ainslie, the coordinator of the Scottish Campaign for Nuclear Disarmament – who obtained the document from the MoD – called on the Government to scrap the Trident replacement programme. “There is a serious risk that there will be a nuclear accident which will expose the crew and members of the public to lethal levels of radiation,” he said. An MoD spokesman said: “The MoD takes nuclear safety very seriously.

All of our nuclear reactors meet the strict safety standards set by the Defence Nuclear Safety Regulator and we continuously look for areas of improvement.” *This story is due to be broadcast on Channel 4 News at 7pm this evening (10 March). The world's biggest submarines - Naval Technology Ambush, the second submarine of the Astute Class, was commissioned in 2013. The world's biggest submarines The Russian Navy's Typhoon Class submarine tops the list of the world's biggest submarines, closely followed by Russia's newest submarine the Borei Class and the enormous Ohio Class, the biggest submarine ever built for the US. Naval-technology.com profiles the world's biggest submarines based on submerged displacement. Typhoon Class, Russia The Typhoon, with a submerged displacement of more than 48,000t, is the world's biggest submarine class. It is a nuclear-powered submarine equipped with ballistic missiles. Dmitry Donskoy, the first of the six submarines in the class, was commissioned in 1981 and is still in active service with the Russian Navy. Typhoon Class submarines have a length of 175m, beam of 23m and draught of 12m.

It is powered by two nuclear water reactors, two 50,000hp steam turbines and four 3,200KW turbogenerators. It can sail at a speed of 22.2kt on the surface and 27kt below water. Multiple pressure hulls make the Typhoon wider than any other submarine. Crew members can comfortably live aboard for as long as 120 days. The submarine carries 20 RSM-52 intercontinental three-stage solid propellant ballistic missiles capable of holding 100kt of nuclear warheads each. It is also equipped with six 533mm (21in) torpedo tubes and type 53 torpedoes. Borei Class, Russia The Borei Class, which has a submerged displacement of 24,000t, ranks as the world's second biggest submarine. It is a nuclear-powered missile carrying submarine serving the strategic naval forces of Russia. The first Borei Class submarine, Yury Dolgoruky, was inducted into the pacific fleet of the Russian Navy in January 2013. It was designed by Rubin Design Bureau and constructed at a cost of $770m.

Two more Borei Class submarines named Vladimir Monomakh and Knyaz Vladimir are currently under development. Borei Class measures 170m long, has a beam of 13.5m and draught of 10m. Its power plant consists of a ??-650? nuclear reactor, one steam turbine, one shaft and propeller. It sails at 15kt speed on the surface and 29kt when submerged. The submerged endurance is dependent on the availability of food stores. The submarine carries 16 missiles and 45t Bulava submarine launched ballistic missile (SLBM). The armoury also includes six multiple independently targetable re-entry vehicle warheads, six 533mm torpedo tubes and RPK-2 Viyuga cruise missiles. Ohio Class, US The Ohio Class submarine is the third biggest in the world. The US Navy operates 18 Ohio class nuclear-powered submarines, which are the biggest submarines ever built for the US. Each sub has a submerged displacement of 18,750t. The first submarine of the class, USS Ohio was built by the Electric Boat Division of General Dynamics Corporation in Groton.

It was commissioned into service in November 1981. All the other submarines were given names of the US States, except USS Henry M. Jackson, which was named after a US senator. Each Ohio Class submarine has 170m length, 13m beam and 10.8m draught. The gliding speed on surface is 12kt and under the water is 20kt. The submarine class includes one S8G pressurised water reactor, two geared turbines, one auxiliary diesel motor with 242KW and one shaft with seven-bladed screw. The submarine is capable of carrying 24 Trident missiles. The armament also includes four 53cm Mark 48 torpedo tubes. Delta Class, Russia Delta Class, currently the fourth biggest submarine in the world, is a large ballistic missile submarine constructed by Severodvinsk. The Delta Class includes Delta I, II, III and IV sub-classes. The submerged displacement of the Delta IV submarine is 18,200t. The first Delta Class submarine was commissioned into service in 1976. Delta Class III and IV submarines are currently in operation with the Russian Navy.

Five Delta III and six Delta IV submarines are currently active. The submarine has a length of 166m, beam of 12.3m and draught of 8.8m. The power plant includes two pressurised water-cooled reactors and two steam turbines driving two five-bladed fixed-pitched shrouded propellers. The submerged speed of the submarine is 24kt. The armoury includes D-9D launch tubes for 16 R-29D SLBMs, four 533mm and two 400mm torpedo tubes. Vanguard Class, UK The Vanguard Class has a submerged displacement of 15,900t, making it the fifth biggest submarine in the world. The nuclear-powered ballistic missile submarine is in service with the UK's Royal Navy. The class consists of four submarines, namely Vanguard, Victorious, Vigilant and Vengeance. The submarines were built by Vickers Shipbuilding and Engineering. The first sub in the class, HMS Vanguard, was commissioned in 1993. All the submarines are based at HM Naval Base Clyde, which is located 40km west of Glasgow, in Scotland.

The Vanguard Class submarines are 149.9m long and have a beam of 12.8m and draught of 12m. Its main machinery includes one pressurised water reactor supplied by Rolls-Royce, two 20.5MW turbines manufactured by GEC, two auxiliary retractable propulsion motors and one shaft pump jet propulsor. In addition, two turbo generators and two diesel alternators are installed aboard. The submarine is armed with 16 Trident II missiles and four 533mm torpedo tubes. It has a submerged speed of 25kt. Triomphant Class, France The 14,335t (submerged displacement) Triomphant Class is currently the sixth biggest submarine in the world. The nuclear ballistic missile submarine serves the French Navy and is part of the French Navy's nuclear deterrent strike force. The class includes four submarines, namely Le Triomphant, Téméraire, Vigilant and Terrible. The lead submarine was commissioned into the French Navy in 1997. Each submarine has a length of 138m, beam of 12.50m and draught of 10.60m.

The propulsion system includes a pressurised water K15 nuclear reactor, two SEMT Pielstick diesel-alternators, a turboreductor system and 8PA4V200 SM auxiliary motors. The surface speed is 25kt. The submarine is armed with 16 M45 intermediate-range missiles. The weaponry also includes TN 75-tipped missiles, four 533mm torpedo tubes and F17 torpedoes. Akula Class The Akula Class is a nuclear-powered attack submarine with a submerged displacement of 13,800t. It includes ten submarines, of which nine are in the Russian Navy's service and one in the Indian Navy' service. The first sub in the class, Akula, was commissioned into the Soviet Navy in 1984. The submarine features a double hull composed of an inner pressure hull and an outer light hull. It is 110m in length, has a beam of 13.6m and draught of 9.7m. The surface speed of the sub is 10kt, while the submerged speed is 35kt. The submerged endurance is 100 days.

Its main machinery includes one pressurised water nuclear reactor, one steam turbine and two turbogenerators rated at 2,000KW. The propulsion system includes one seven-bladed propeller and one retractable electric propulsor for reduced speed cruising. The submarine can be armed with up to 12 submarine-launched cruise missiles capable of carrying nuclear warheads up to a range of 3,000km. The armament also includes four 533mm torpedo tubes and four 650mm torpedo tubes. Sierra Class, Russia The Sierra Class with a submerged displacement of 10,400t ranks as the world's eighth biggest submarine. Four Sierra submarines are currently in service with the Russian Navy. Sierra II, an improved version of the class, entered into service in 1990. The Sierra Class submarines are built with light and strong titanium pressure hull, which allows the submarine to reach greater depths and reduces the level of radiated noise. It also increases resistance to torpedo attacks. The submarine has a length of 111m and beam of 14.2m.

The main equipment includes one pressurised water nuclear reactor, two emergency motors, one shaft and two spinners. The submerged speed is 32kt. The assault equipment includes four 650mm torpedo tubes, four 530mm torpedo tubes, SS-N-21 Sampson SLCM, SS-N-15 Starfish anti submarine weapon, SS-N-16 Stallion and 42 mines. Seawolf Class, US The Seawolf Class of nuclear-powered fast attack submarines operated by the US Navy is the ninth biggest submarine class in the world. The submerged displacement of the class is 9,138t. The lead sub, Seawolf (SSN21), was inducted into service in July 1997. Seawolf Class is designed to combat the threat of advanced Soviet ballistic missile submarines. Three submarines of the class are currently in the service. The hull of the submarines is constructed using HY-100 steel. The length and beam of the Seawolf class are 107m and 12m respectively. The submarine is equipped with one pressurised water nuclear reactor, one secondary propulsion submerged motor, one shaft and one propeller.

The speed is 18kt on surface and 35kt when submerged. The submerged endurance is unlimited depending on food supplies. The armament fitted in the submarine includes eight 660mm torpedo tubes, 50 Tomahawk cruise missiles and Mk-48 torpedoes. Astute Class, UK The Astute Class is the tenth biggest submarine in the world. It has a submerged displacement of 7,400t. The nuclear-powered submarine class is in service with the British Royal Navy. It was constructed by BAE Systems Submarine Solutions. The class includes two submarines, both of which are currently active. The first submarine Astute was commissioned in August 2010 and the second submarine Ambush was commissioned in March 2013. The submarine has a length of 97m, beam of 11.3m and draught of 10m. It is equipped with two pressurised water reactors made by Rolls-Royce and MTU diesel generators of 600KW. It can operate at 30kt of speed under water.

The armament in the submarine includes six 533mm torpedo tubes, Tomahawk Block IV land-attack cruise missiles and Spearfish wire-guided heavyweight torpedoes. Related content #comments Royal Navy Submarine Service <div class="field field-name-field-image field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><a href=""><img class="adaptive-image" src="" alt="HMS Superb" title="HMS Superb" /></a></div></div></div><!-- google_ad_section_start --><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>The <strong>Royal Navy Submarine Service </strong>is sometimes known as the "<em>Silent Service</em>", on account of a submarine being required to operate quietly in order to remain undetected by enemy sonar. The service currently consists of seven fleet submarines (SSNs), of the <em>Trafalgar</em> and <em>Astute</em>classes, and four ballistic missile submarines (SSBN), of the <em>Vanguard </em>class.

It also operates the LR5 Submarine Rescue System. All the Royal Navy's submarines are now nuclear powered. The Royal Navy's use of submarines began in 1901, and for many years of the late 20th century was associated with HMS Dolphin in Hampshire. Flag Officer Submarines moved from <em>Dolphin</em> to the Northwood Headquarters in 1978. In the early 21st century Flag Officer Submarines lost his solely submarine role and is now Commander Operations on the staff of Commander-in-Chief Fleet.

The Submarine School is now at HMS Raleigh at Torpoint in Cornwall.</p> <table id="toc"><tbody><tr><td> <div id="toctitle"> <h2> Contents</h2> </div> <ul><li> 1 History <ul><li> 1.1 The Jolly Roger and the Submarine Service</li> </ul></li> <li> 2 Perisher</li> <li> 3 Traditions</li> <li> 4 Active submarines <ul><li> 4.1 Fleet submarines</li> <li> 4.2 Ballistic submarines</li> <li> 4.3 LR5 Submarine Rescue System</li> </ul></li> <li> 5 Future submarines</li> <li> 6 See also</li> <li> 7 Further reading</li> <li> 8 Footnotes</li> </ul></td> </tr></tbody></table><h2> History</h2> <p>It is sometimes claimed that the United Kingdom was the last major maritime power to use submarines at the beginning of the 20th century, as the idea of submarine warfare was

 considered by many senior personnel in the Admiralty to be "Underhand, unfair and damned un-English" (Admiral Sir Arthur Wilson VC, 1901).

However, those in favour of experimenting with submarine technology eventually won the argument, and the Royal Navy launched its first submarine, Holland 1, in 1901. The Submarine Service proved its worth in World War I, where it was awarded five of the Royal Navy's 14 Victoria Crosses of the war, the first by LieutenantNorman Holbrook, Commanding Officer of HMS <em>B11</em>. During World War II the major operating arenas were the Norwegian waters; theMediterranean where a flotilla of submarines fought a successful battle against theAxis replenishment route to North Africa; and the Far East where Royal Navy submarines disrupted Japanese shipping operating in the Malacca Straits. The first British nuclear-powered submarine, HMS Dreadnought (S101) was launched in 1960 based around a US-built nuclear reactor. This was complemented by theValiant class from 1966, which featured the Rolls-Royce PWR1 reactor. Royal Navy submarines became an important part of the strategic nuclear deterrent with the introduction of the Resolution class ballistic missile submarines (SSBNs) from 1968.

These carried US-built Polaris missiles and were later replaced by theVanguard class submarines and the Trident missile system from 1994. HMS <em>Conqueror</em> made history in 1982 during the Falklands War when she became the first nuclear-powered submarine to sink a surface ship, the ARA <em>General Belgrano</em>. In May 1991 Oberon class submarines HMS <em>Opossum</em> and her sister HMS <em>Otus</em> returned to the submarine base HMS <em>Dolphin</em>in Gosport from patrol in the Persian Gulf flying Jolly Rogers (see below), the only indication that they had been involved in alleged SAS and SBS reconnaissance operations. In 1999 HMS <em>Splendid</em> participated in the Kosovo Conflict and became the first Royal Navy submarine to fire a cruise missile in anger. After Operation Veritas, the attack on Al-Qaeda and Taliban forces following the 9/11 attacks in the United States, it emerged that HMS <em>Trafalgar</em> was the first Royal Navy submarine to launch Tomahawk cruise missiles against Afghanistan.

HMS<em>Triumph</em> was also involved in the initial strikes. On April 16, 2003 it was reported that HMS <em>Turbulent</em>, the first Royal Navy vessel to return home from the war against Iraq, had launched fourteen Tomahawk cruise missiles.</p> <h3> The Jolly Roger and the Submarine Service</h3> <h3> <span>Admiral of the Fleet Sir Arthur Wilson VC, the Controller of the Royal Navy, summed up the opinion of many in the Admiralty at the time when he said in 1901 "[Submarines are] underhand, unfair, and damned un-English. ... treat all submarines as pirates in wartime ...

and hang all crews." In response, Lieutenant Commander (later Admiral Sir) Max Horton first flew the Jolly Roger on return to port after sinking the German cruiser SMS <em>Hela</em> and the destroyer SMS <em>S-116</em> in 1914 while in command of the E class submarine HMS <em>E9</em>.</span></h3> <p>In World War II it became common practice for the submarines of the Royal Navy to fly the Jolly Roger on completion of a successful combat mission where some action had taken place, but as an indicator of bravado and stealth rather than of lawlessness. For example in 1982 returning from the Falklands conflict HMS Conqueror flew the Jolly Roger depicting one dagger for the SBS deployment to South Georgia and one torpedo for her sinking of the Argentinian Cruiser Belgrano.

The Jolly Roger is now the emblem of the <em>Royal Navy Submarine Service</em>.</p> <h2> Perisher</h2> <div> <span>'Perisher' (as the Submarine Command Course is better known) is a 24-week course all officers must take prior to serving as an Executive Officer on board a Royal Navy Submarine. It has been run twice a year since 1917, usually starting on 2 July and 14 November each year. It is widely regarded as one of the toughest command courses in the world, with an historical failure rate of 25%.</span></div> <p>If at any point during the training a candidate is withdrawn from training he will be nominated for boat transfer and kept occupied until the transfer. His bag is packed for him and he is notified of the failure when the boat arrives. On departure he is presented with a bottle of whisky. A failure on Perisher means that it is very unlikely the candidate will return to the Submarine Service.

Since the Royal Navy no longer operates diesel-electric submarines, in 1995 the Royal Netherlands Navy has taken over the Perisher course for these boats from the British, and annually host a course that is attended by candidate submarine commanders from multiple navies around the world.</p> <h2> Traditions</h2> <p><span>Active submarines </span> The Submarine Service has many traditions that are not found in the surface fleet. These include slang unique to submariners (such as referring to the torpedo storage compartment as the <em>Bomb Shop</em> and the diesel engine room as the <em>Donk Shop</em>), a special communications code known as the Dolphin Code and the entitlement of a sailor to wear Dolphins upon entering the service.

(Which were only awarded after completion of training and qualification in ships systems - on board first submarine posting (Part III training)</p> <div> <div> </div> </div> <p>The Submarine Service consists of two classes of <em>Fleet</em> submarines and one class of<em>Ballistic Missile</em> submarines.</p> <h3> Fleet submarines</h3> <div> <div> <div> <div> There are seven fleet submarines on active duty - six Trafalgar class submarines and one Astute class submarine. They are all nuclear submarines and are classified asSSNs. These submarines are armed with the Spearfish torpedo for anti-submarine and anti-surface warfare. Some are also armed with Tomahawk cruise missiles for attacking targets on land. This capability was used by HMS Trafalgar against the Taliban in 2001 during Operation Veritas. The Fleet submarines are also capable of surveillanceand reconnaissance missions.

Fleet submarines are sometimes referred to as<em>attack</em> or <em>hunter-killer</em> vessels.</div> </div> </div> </div> <table><caption> Royal Navy Fleet submarines in active service</caption> <tbody><tr><th> Name</th> <th> Class</th> <th> Pennant Number</th> <th> Launched</th> </tr><tr><td> HMS Turbulent</td> <td> Trafalgar</td> <td> S87</td> <td> 1982</td> </tr><tr><td> HMS Tireless</td> <td> Trafalgar</td> <td> S88</td> <td> 1984</td> </tr><tr><td> HMS Torbay</td> <td> Trafalgar</td> <td> S90</td> <td> 1985</td> </tr><tr><td> HMS Trenchant</td> <td> Trafalgar</td> <td> S91</td> <td> 1

986</td> </tr><tr><td> HMS Talent</td> <td> Trafalgar</td> <td> S92</td> <td> 1988</td> </tr><tr><td> HMS Triumph</td> <td> Trafalgar</td> <td> S93</td> <td> 1991</td> </tr><tr><td> HMS Astute</td> <td> Astute</td> <td> S119</td> <td> 2007</td> </tr></tbody></table><h3> Ballistic submarines</h3> <div> Vanguard class submarine</div> <p>The four ballistic missile submarines (SSBN) of the Royal Navy are all of the Vanguard class.

They were all built by Vickers Shipbuilding and Engineering Ltd, now BAE Systems Submarine Solutions. The SSBN flotilla or bomber 'fleet' tends to be almost a separate entity, for example it rarely uses pennant numbers preferring to use hull numbers, thus Vanguard 05, Victorious 06, Vigilant 07 and Vengeance 08. The four Vanguard class boats are responsible for the United Kingdom's nuclear deterrent, and use the Trident missile system. Each boat can carry up to 16 Trident II D5 Missiles, each of which may carry up to 12 nuclear warheads. It is UK Government policy to limit the actual number of warheads carried to 48 per boat.

There has been at least one SSBN on patrol at all times for over 30 years, for a total of over 300 missions.</p> <table><caption> Royal Navy ballistic missile submarines in active service</caption> <tbody><tr><th> Name</th> <th> Class</th> <th> Pennant Number</th> <th> Launched</th> </tr><tr><td> HMS Vanguard</td> <td> Vanguard</td> <td> S28</td> <td> 1992</td> </tr><tr><td> HMS Victorious</td> <td> Vanguard</td> <td> S29</td> <td> 1993</td> </tr><tr><td> HMS Vigilant</td> <td> Vanguard</td> <td> S30</td> <td> 1996</td> </tr><tr><td> HMS Vengeance</td> <td> Vanguard</td> <td> S31</td> <td> 1998</td> </tr></tbody></table><h3> LR5

 Submarine Rescue System</h3> <p>The Royal Navy also operates the LR5 Submarine Rescue System, designed for retrieving sailors from stranded submarines.

It is capable of rescuing 16 at a time.</p> <h2> Future submarines</h2> <p>Seven <em>Astute</em>-class submarines are planned, with the first in service, three under construction, the fifth ordered, and the procurement process started for the sixth.<span> </span> The first Astute class submarine, HMS <em>Astute</em>, entered service in August 2010. The second Astute class submarine, HMS <em>Ambush</em>, is expected to be replace HMS <em>Turbulent</em> in 2011. The Astute Class submarine is the largest nuclear Fleet submarine ever to serve with the Royal Navy, nearly 30% larger than its predecessors. Its powerplant is the Rolls Royce PWR2 reactor, developed for the Vanguard class SSBN. The armament of Astute class is to be 38 Spearfish torpedoes (the US equivalent is the Mk48 ADCAP torpedo), Tomahawk Block III/IV Cruise Missiles and submarine-launched mines. It is not known whether more Astute class submarines will be ordered.

Another development project is the Maritime Underwater Future Capability (MUFC). These will follow on from the Astute class, and possibly replace the Trafalgar class. Reports (e.g. in <em>Defense News</em>) have suggested that the MUFC studies may result in a single class of multi-role submarines to replace the Trafalgar class, Vanguard class SSBNs and eventually the Astute class. This would require a submarine capable of launching conventional land-attack missiles, some form of nuclear missile (ICBM or tactical nuclear missile) as well as conventional submarine munitions including mines and torpedoes. A new generation of ballistic missile submarines is also being planned, following a December 2006 Ministry of Defence white paper which recommended that the nuclear weapons should be maintained into the 2040s. It advocated the currently preferred submarine-based system, as it remained the cheapest and most secure deterrence option available.

</p> </div></div></div><!-- google_ad_section_end --><div class="field field-name-field-tags field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/25">Submarines</a></div><div class="field-item odd"><a href="/taxonomy/term/33">HMS Dolphin</a></div><div class="field-item even"><a href="/taxonomy/term/34">Admiralty</a></div></div></div><div class="field field-name-field-category field-type-taxonomy-term-reference field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/category/submarine">Submarine</a></div></div></div> Tue, 15 May 2012 11:15:59 +0000 admin

Question: Which class of submarines is currently being built at Vickers to replace Britain's "Trafalgar" class of submarines?
Answer: Astute