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.
Swiftsure Class submarines
Swiftsure Class submarine – Image: seaforces.org
In 1971 the first of the UK’s Swiftsure class of second-generation SSNs was launched at the Vickers shipyard at Barrow-in-Furness. This HMS Swiftsure introduced a hull form shorter and fuller than that of the Valiant class in order to provide greater volume and create a stronger pressure hull for operation at greater depths and speeds than the previous class. The fin is smaller and the retractable diving planes are located below the water line. The Swiftsure was followed by five sister ships, HMS Sovereign, HMS Superb, HMS Sceptre, HMS Spartan and HMS Splendid. The submarines are currently used both in the ASW screening role for task forces, and in the independent anti-ship and ASW roles because of the quieter machinery used. Their sonar fit is basically the same as that of the Valiant class, and all had the Type 2020 fitted as the Type 2001 replacement during normal refits. The armament is reduced by one tube and seven torpedoes, but this reduction is balanced by the fact that it takes only 15 seconds to reload individual tubes. Emergency power is provided by the same 112-cell electric battery and associated diesel generator and electric motor as fitted in the Valiant and Churchill classes.
In 1976 the Sovereign demonstrated the Royal Navy’s ability to conduct ASW operations under the ice pack when it undertook a trip to the North Pole, the operational aspects being combined with a successful scientific voyage.
The Spartan and Splendid were both involved in the Falklands War. At the end of 2002 four of the submarines were still in service with the Royal Navy, the Swiftsure have been decommissioned in 1992 after cracks were found in its reactor during a refit. HMS Splendid followed in 2004, while the HMS Spartan was decommissioned in 2006. In 1998 two boats of the class, that were still in service, have been armed with Tomahawk cruise missiles.
All Swiftsure class boats were eventually retired by 2010.
|Diving depth (operational)||400 m|
|Diving depth (maximum)||600 m|
|Dimensions and displacement|
|Surfaced displacement||4 200 tons|
|Submerged displacement||4 900 tons|
|Propulsion and speed|
|Surfaced speed||20 knots|
|Submerged speed||30 knots|
|Nuclear reactors||1 x ?|
|Steam turbines||2 x ?|
|Missiles||Tomahawk Block III cruise missiles, 5 x UGM-84B Sub-Harpoon anti ship missiles|
|Torpedoes||5 x 533-mm bow tubes for 20 Mk 8 or Mk 24 Tigerfish torpedoes|
|Other||50 x Stonefish or Sea Urchin mines in place of torpedoes|
Swiftsure Class data military-today.com
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.
Trafalgar Class submarines
Essentially an improved Swiftsure class design, the Trafalgar class constitutes the third generation of British SSNs built at the Vickers shipyard in Barrow-in-Fumess. The lead boat, HMS Trafalgar, was launched in 1981 and commissioned into the Royal Navy in March 1983, serving with the Swiftsure class boats at the Devonport naval base. The class total of seven boats also includes HMS Talent, HMS Tireless, HMS Torbay, HMS Trenchant, HMS Triumph and HMS Turbulent.
The major improvements over the Swiftsure class include several features to reduce the underwater radiated noise. These comprise a new reactor system, a pumpjet propulsion system rather than a conventional propeller, and the covering of the pressure hull and outer surfaces with anechoic tiles to give the same type of protection as afforded by the Soviet Clusterguard coating in reducing noise.
The Trafalgar was the first boat to be fitted with the Type 2020 sonar, and was used as the development test platform for the system. According to other reports there has also been a rearrangement of the internal compartments to allow a rationalization and centralization of the operations, sound and ESM/radar rooms. The remaining systems, the armament and the sonars are the same as fitted to the Swiftsure class boats, although a thermal imaging periscope is now carried as part of the search and attack periscope fit, and Type 197 sonar is no longer carried. The fin, like those of the earlier British SSNs, houses an SHF DF antenna, communications antennae, and snort induction, radar and ESM masts. Underwater communications are believed to be conducted via a towed buoy and/of a floating antenna.
The primary mission of the Trafalgar class submarines all of which remain in service with the Royal Navy, is anti-submarine warfare, with anti-surface ship warfare as a secondary role. The boats can launch the Tomahawk Block IIIC cruise missile.
|Diving depth (operational)||400 m|
|Diving depth (maximum)||600 m|
|Dimensions and displacement|
|Surfaced displacement||4 800 tons|
|Submerged displacement||5 300 tons|
|Propulsion and speed|
|Surfaced speed||20 knots|
|Submerged speed||29 knots|
|Nuclear reactors||1 x ?|
|Steam turbines||2 x ?|
|Missiles||Tomahawk Block IIIC cruise missiles; 5 x UGM-84B Sub-Harpoon missiles in place of torpedoes|
|Torpedoes||5 x 533-mm bow tubes for 20 Spearfish and Mk 24 Tigerfish torpedoes|
|Other||50 x Stonewall and Sea Urchin mines in place of torpedoes|
Trafalgar class data military-today.com
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.
HMS Astute arrives at its base at Faslane, Scotland, in 2009
Royal Navy’s attack submarine development history
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.
Astute Class – Image @i26.tinypic.com
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.
View Raw Image” width=”685″ height=”514″ />Astute Class – Image @tinypic.com
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.
Boats of the class
|Name||Boat||Pennant No.||Builder||Laid down||Launched||Commissioned||Status|
|Astute||1||S119||BAE Systems Maritime – Submarines, Barrow-in-Furness||31 January 2001||8 June 2007||27 August 2010||In active service|
|Ambush||2||S120||22 October 2003||6 January 2011||1 March 2013||In active service|
|Artful||3||S121||11 March 2005||17 May 2014||18 March 2016 ||In active service|
|Audacious||4||S122||24 March 2009||28 April 2017||Expected 2018||Under construction|
|Anson||5||S123||13 October 2011||Expected 2020||Under construction|
|Agamemnon||6||S124||18 July 2013||Expected 2022||Under construction|
|Ajax||7||S125||Expected 2024||Confirmed, steel cut|
Royal Navy orders 6th Astute class submarine for £1.4 Billion: Here
The Ministry of Defence has agreed a new £1.4 billion contract for the Royal Navy’s new attack submarine.
Agamemnon is the sixth out of seven in the Astute class fleet and will protect the UK’s nuclear deterrent and new aircraft carriers.
The class of submarines are being built by BAE Systems.
Construction of the 7,400 tonne, 97-metre long Agamemnon began in 2012, alongside Anson, the fifth boat of the fleet, and the currently unnamed ‘Boat 7’.
Fourth British Astute-class attack submarine Audacious launched: Here
HMS Astute Shows Off SBS Minisub Dry Dock
updated image: HMS Astute returning to HMNB Clyde in Jan. 2015 following her maiden 8 month deployment, with Special Forces payload bay fitted. MOD photo LA(Phot) Pepe Logan / POA(Phot) Nick Tryon | © Crown copyright 2015
The minisub that is transported in such a dry dock is one of a new batch, that replace the 3 MK8 Mod 1 designs used previously. Its believed that the new minisubs, known as the shallow water combat submersible (SWCS), can accommodate 8 fully equipped SBS commandos. Unlike the previous design, the new minisub features a periscope, doppler sonar array and advanced navigation systems which means the craft will be able to carry out its missions without surfacing to take GPS bearings. Quiet electronic motors, passive sonar and a sound-absorbing fibre-glass hull will give the vessels a degree of stealthiness.
The miniature submarine births in the Astute class boat’s dry dock shelter and can be transported, submerged and undetected, for thousands of miles. To be launched, the minisub’s ‘mother’ sub rises to a relatively shallow depth before the minisub exits the dry dock and begins its mission. Recovery of the minisub back into the dry dock is just as simple. The dry dock can be fixed to whichever Astute class submarine is required for a given SBS operation. Even without a minisub present, SBS frogmen can still swim out of the dock, perhaps carrying inflatable craft up to the surface. This dry dock facility was developed under the code name of ‘Project Chalfont’ and is known as the Special Forces payload bay. Source eliteukforces.info
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.
Command and control room
Astute Command and control room – Image @defenseindustrydaily.comAstute Class Submarine Cutaway – Midships – Image @invisiblethemepark.com
45 – Port Side Communications Office
60 – Control Room Consoles
62 – Senior Ratings Bunks
58 – Senior Ratings Bathrooms
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.
The control room, in which up to 15 crew work. The planesman steers and dives the sub from here Greg White – Image @wired.co.ukTechnology: Leading engineering technician Andrew Gee tests out the sub’s steering system in the control room HMS Ambush – Image @vpinternational.ca
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).
Astute Command and control room – Image @naval.com.br
Northrop Grumman Sperry Marine was selected in March 2008 to provide the platform management system for the fourth of class, HMS Audacious.
HMS Artful uses new “brain” to fire torpedo: Here
The Royal Navy’s latest and most advanced nuclear submarine, HMS Artful, has successfully fired its first test torpedo using a state-of-the-art “brain.” According to the British Ministry of Defence, the 7,400-tonne (8,157 ton) hunter-killer used the new Command Combat System (CCS) to integrate data from its suite of sensors to track and hit the moving target with an unarmed practice weapon. The Artful is the third of the Astute class submarines and is the first to have the CCS installed.
It wasn’t that long ago when the most sophisticated computer aboard a submarine was the Apple II in the Paymaster’s office. Now, the likes of the RN’s Sonar 2076 alone has the processing capacity 60,000 present-day PCs. This and other sophisticated digital systems mean that today’s submarine captains need equally sophisticated command systems to turn all that data into meaningful action.
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.
Astute bow section – Image @forumimage.ru
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.
Inside: The weapons room of the £1billion sub. Many details of her weapons system remain top secret – Image @vpinternational.ca
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 Block IV
The TERCOM radar uses a stored map reference to compare with the actual terrain to determine the missile’s position – Image @fas.org
The Tomahawk land-attack cruise missile has been used to attack a variety of fixed targets, including air defense and communications sites, often in high-threat environments. The land attack version of Tomahawk has inertial and terrain contour matching (TERCOM) radar guidance. The TERCOM radar uses a stored map reference to compare with the actual terrain to determine the missile’s position. If necessary, a course correction is then made to place the missile on course to the target. Terminal guidance in the target area is provided by the optical Digital Scene Matching Area Correlation (DSMAC) system, which compares a stored image of target with the actual target image. Source fas.org
(GPS) guidance capability – Image @ryot.org
Primary Function: Long-range subsonic cruise missile
Prime Contractor: Raytheon Co.
Propulsion: Williams International F107-WR-402 turbofan engine with ARC/CSD solid-fuel booster
Length: 18 ft 3 in (5.56 m); with booster: 20.5 ft (6.25 m)
Diameter: 20.4 in (51.81 cm)
Wingspan: 8 ft 9 in (2.67 m)
Weight: 2,900 lbs (1,315 kg); 3,500 lbs (1,588 kg) with booster
Speed: 550 mph (880 km/h)
Range: Block II TLAM-A: 1,350 nm/1,500 miles (2,500 km)
Block III TLAM-C: 900 nm/1,000 miles (1,600 km)
Block III TLAM-D: 700 nm/800 miles (1,250 km)
Block IV TLAM-E: 900 nm/1,000 miles (1,600 km)
Guidance System: Block II TLAM-A: INS and TERCOM (Terrain Contour Matching);
Block III TLAM-C, TLAM-D & Block IV TLAM-E: INS, TERCOM (Terrain Contour Matching),
DSMAC (Digital Scene Matching Area Correlation), and GPS
Warhead: Block II TLAM-N: W80 nuclear warhead;
Block III TLAM-C & Block IV TLAM-E: 1,000-pound class unitary warhead;
Block III TLAM-D: Conventional submunitions dispenser with combined effect bomblets
Price/Unit Cost: $1,101,000 (in FY 2014)
Deployed: Block II TLAM-A: IOC 1984; Block III: IOC 1994; Block IV: IOC 2004
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.
BGM-109 Tomahawk – Image @fas.org
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.
Spearfish Heavyweight Torpedo
Spearfish torpedoe – Image @forces.tv
Spearfish Heavyweight Torpedo
The Spearfish advanced heavy weight torpedo from BAE Systems is effective against submarine and surface threats in oceanic and coastal waters. The 1.85t torpedo is in service with the submarine fleet of the UK Royal Navy.
The Spearfish carries Aluminised PBX explosive warhead of 300kg and is directed towards the target by high-capacity guide wire system and passive and active sonar.
Its power plant is composed of a gas turbine engine using Otto Fuel as a liquid monopropellant, and Hydroxyl Ammonium Perchlorate (HAP) as oxidant. The propulsion system allows the Spearfish to engage targets within 48km at low speed. Source naval-technology.com
Spearfish Heavyweight Torpedo power plant
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.
The immediate future of Thales Underwater Systems’ Sonar 2076 appears solely linked the U.K. Royal Navy’s Astute-class submarine. The Sonar 2076, or Type 2076, is a fully integrated passive/active search-and-attack sonar suite installed on the Astute class and as part of the midlife update of Trafalgar class submarines. A total of four Sonar 2076 systems have reportedly been produced for Trafalgar class submarines, and seven have been ordered for the first batch of Astute class submarines.
The Royal Navy’s planned inventory for a nuclear submarine fleet is eight boats: seven Astute class and one Trafalgar class. However, by the time the seventh and final Astute boat is commissioned, the remaining Trafalgar class boat will be long overdue for replacement.
It is still unclear whether the last of the Trafalgar class submarines will be retired without replacement, replaced by an eighth Astute-class submarine, or replaced by the lead ship in a new class of nuclear submarine. Source blog.forecastinternational.com
|Type: Hull Sonar, Active/Passive||Altitude Max: 0 m|
|Range Max: 74.1 km||Altitude Min: 0 m|
|Range Min: 0 km||Generation: Late 2000s|
|Sensors / EW:|
|Type 2079 [Type 2076 Suite] – (Astute) Hull Sonar, Active/Passive
Role: Hull Sonar, Active/Passive Search
Max Range: 74.1 km
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.
Passive-Only Towed Array Sonar System
|Type: TASS, Passive-Only Towed Array Sonar System||Altitude Max: 0 m|
|Range Max: 185.2 km||Altitude Min: 0 m|
|Range Min: 0 km||Generation: Late 1990s|
|Sensors / EW:|
|Type 2065 [Type 2076 Suite] – TASS, Passive-Only Towed Array Sonar System
Role: TASS, Passive-Only Towed Array Sonar System
Max Range: 185.2 km
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.
iXSea MARINS inertial navigation systems for HMS Audacious: Here
Military Fibre Optic Gyroscope Technology, Navigation Sensor Systems
IXSEA is a world leader in Fibre-Optic Gyroscope (FOG) and underwater acoustics technologies for the military sector, combining excellence in innovative design and technology with the ability to execute and maintain a complete range of gyroscopes/inertial navigation systems for naval and land based applications. More than 300 IXSEA FOG based systems are installed onboard military vessels and land based systems around the globe, successfully performing in varying applications.
The IXSEA product portfolio includes four main ranges:
- Marine Inertial Navigation Systems (INS) and Attitude and Heading Reference System (AHRS)
- Land Inertial Navigation Systems (INS) and Attitude and Heading Reference System (AHRS)
- Pre-calibrated Underwater Tracking systems (USBL)
- Seabed Mapping Solutions
CM010 optronic masts
CM010 optronic masts – Image @military-meshes.com
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.
CM010 optronic masts – Image @gizmag.com
The optronic masts, which will be powered by Wind River VxWorks’ mission-critical real-time operating system, are the result of a ten year, multi-million pound program, and will be installed in the Royal Navy’s Astute-class submarines.
Traditional submarines are vulnerable to detection when the periscope is used – however, the optronic mast uses a non-hull breaching design, in which the Sensor Head Unit extends from the submarine fin and rapidly captures a 360 degree scan, sending the image to the console screens in the sub’s operation center. The image can be then be analyzed at the leisure of the commander, with a reduced risk of detection. The optronics masts also incorporate multi-function antenna arrays, which monitor the radar environment, provide command and situational awareness of other radar equipped platforms, and enable a submarine to take early evasive action.
The Wind River VxWorks mission-critical real-time operating system runs on Thales’ quad PowerPC AltiVec COTS boards and AdaCore GNAT Pro. It powers the stabilization system, a high-performance 3 axis to sub-pixel accuracies; video and thermal camera control; communication with the in-hull systems; and the mechanisms and motors in the SHU. The SHU is a pressure proof, electro-optical assembly that contains high-performance cameras, optics, environmental sensors and stabilization mechanisms. It is can function in temperatures ranging from -15 degrees Celsius to 60 degrees Celsius, and can withstand a nearby explosion.
RemoteReality day/night 360-degree advanced periscope camera system – Image @gizmag.com
The Mast Control Unit uses two processors to control the mast raising equipment, control the stabilization system, and communicate with the submarine’s tactical, data and combat systems. The stabilization system is designed to compensate for the movement of the sub and the water, providing a clear image for analysis.
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.
UK nuclear submarine layout – Image @world-nuclear.org
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.
A dummy Cruise missile inside Astute – Image @BBC UKFeeding the crew: The submarine’s kitchen will be staffed by five chefs providing food 24-hours a day for her officers and crew HMS Ambush – Image @vpinternational.caThe crew’s quarter (left) – there are a maximum of 22 bunks per cabin, each man has a bunk, a locker and a curtain. The only man to have his own cabin the captain, Cmdr Peter Green (right), pictured on his seat in the control room. – Image @telegraph.co.uk
Source: naval-technology.com/vpinternational.ca/navyrecognition.com/military-today.com/from the net
Updated Jan 18, 2018