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Astute Class

Type Designation: Submarine Attack, Nuclear (SSN)


astute.jpg (51355 bytes)

(Above) A very early artist impression (in the now rare literal sense) from 1997
 of the Astute class submarine

(Above) Artists impressions (now computer generated images) perhaps dating
 to 1999 of the Astute class


(Above) An updated graphics dating to 2000 or early 2001.


(Above) These superb new graphics of the revised Astute design appeared in 2004. (Source: BAE Systems)


(Above) This graphic first appeared in January 2006. (Source: MOD)


(Above) Artist impressions of an Astute Class Submarine dived.. (Source: BAE Systems)


(Above) The first pressure hull modules for HMS Astute being assembled, September 2000. (Source: BAE Systems)


(Above) The forward pressure units of HMS Astute in October 2003 after work temporarily halted.  Internally they are largely empty space, with little fitting out due to the design problems. (Source: BAE Systems)


(Above) The Manoeuvring Room module is slid in to Hull Unit 4 of HMS Astute at the Barrow Devonshire Dock Hall in October 2004.


(Above) Aft section of HMS Astute at the Barrow Devonshire Dock Hall, probably taken late 2004.


(Above) Hull sections being assembled vertically.  (Source: BAE Systems)

(Above) An early 2005 view of the now busy Devonshire Dock Hall, HMS Astute to left, Ambush to the right.  (Source: BAE Systems)


(Above) This image from early 2007 that makes an interesting comparison to an image (above) from three years earlier - the sail (or fin) has been modified and enlarged - its is suspected that this is to better support operations by embarked special forces.  (Source: MOD(UK))



(Above) HMS Astute being prepared for her roll-out.  (Source: BAE Systems)


(Above)  HMS Astute emerging from the Devonshire Dock Hall for her naming ceremony by HRH The Duchess of Cornwall on 8 June 2007.  (Source: David Reid)


(Above) Two nice nice views of HMS Astute on the ship lift at Barrow, she did not actually touch water for several days (below), even more confusingly this picture is taken several days before her eventual official launch date of 15 June, when divers released her from the shiplift.   (Source: BAE Systems)


(Above) HMS Astute undergoing basin trials of her systems, June 2007.  The designs slight 'humpback' aft of the sail is obvious in this picture, perhaps exaggerated by her trimming. (Source: BAE Systems)


(Above) HMS Astute preparing for her first dive, 30 October 2007. (Source: BAE Systems)



Cut away diagram of the Astute design

(Above) Cut-away graphic of the Astute-class.  Click to enlarge.  (Source: BAE Systems)


Cut away diagram of the Astute design


How BAE Systems saw construction going in 2006.  (Source: BAE Systems)


(Source: The Times, April 2006)





Laid down [1]


ASTUTE S119 BAE Systems Submarines,  Barrow 31 Jan 2001 8 / 15 June 2007 [2] 27 August 2010
AMBUSH S120 BAE Systems Submarines,  Barrow 22 Oct 2003 6 January 2011 [2013]
ARTFUL S121 BAE Systems Submarines,  Barrow 11 March 2005   [2015]
AUDACIOUS S122 BAE Systems Submarines,  Barrow 24 March 2009   [2018]
ANSON S123 BAE Systems Submarines,  Barrow 13 October 2011   [2020]
AGAMEMNON S124 BAE Systems Submarines,  Barrow Long lead items ordered   [2022]
AJAX S125 BAE Systems Submarines,  Barrow Planned   [2024]



1. A purely ceremonial date of no other importance.
2. Her naming ceremony was performed on 8 June.  It had been expected that this would also be her launch day, but embarrassingly additional checks were required and the boat did not actually touch water until several days later.  Her official "launch" date is 15 June  - several days later again, this is likely to cause confusion in reference books for ever!

Displacement: 7,000 tonnes surfaced, 7,800 tonnes dived*
Dimensions, metres: 97.0 x 11.3 x 10.0
Main Machinery: 1 modified Rolls-Royce PWR-2 pressurized water reactor;  2 sets GEC-Alston geared turbine drive; 1 shaft with pump jet propulsion; 27,500 shp.  2 Paxman auxiliary diesels
Speed, knots: Officially 29+ knots dived, unofficially probably over 32 knots
Endurance: 70 days submerged
Dive Depth: Over 300m
Complement: 84 (qualified), accommodation for 12 officers, 97 enlisted

Missiles: SLCM: GDC/Hughes Tomahawk (TLAM-C Block III) land attack; Tercom aided inertial navigation system (TAINS) with GPS backup; range 1,700 km (918 n miles) at 0.7 Mach; altitude 15-100 m; 318 kg shaped charge warhead.
Torpedoes: 6-21 in (533 mm) tubes. Marconi Spearfish torpedoes; active/passive homing to 65 km (35 n miles) at up to 60 kt; directed energy warhead; depth to ? m (? ft).
A total of 38 weapons can be carried for tube-launch, for example: 14 Tomahawk missiles, 24 Spearfish torpedoes.
Mines: Can lay mines.

Sonar: Type 2076 integrated suite (with Type 2074 active/passive bow array); Type 2077 HF under-ice navigational active; type ?? towed passive array
EW: Racal Outfit UAP(4) intercept suite; launchers for SCAD 101 and SCAD 102 decoys and SCAD 200 sonar jammers
Radar: 1 Kelvin Hughes Type 1007 navigation/search

* Apparently increased from 6,500 and 7,200 tonnes respectively during the redesign work - a substantial amount for a submarine already in build.  A small part of the increase appears to have gone in to enlarging the sail.


Background Notes

Astute is the first of an advanced new class of nuclear-powered attack submarines which will replace the Swiftsure and Trafalgar classes in the Royal Navy (RN) of the United Kingdom. Many major technological advances have been incorporated into Astute, including reduced noise levels, an enhanced sonar suite, a 50% greater weapon load, new intelligence gathering capabilities and the ability to deploy special forces.

Originally intended as a relatively low-risk low-cost approach to providing a next generation SSN (Ship Submersible Nuclear), the Astute project has been plagued by serious design problems, delays and cost increases. However Astute is now at sea, spending 2010 undergoing an intensive trials, testing and commissioning programme. The RN’s Submarine Service is already delighted with the vastly improved capabilities that are being provided by its first new-build SSN to be commissioned since the last of the Trafalgar class (Triumph) in 1991. Defence Equipment and Support (DE&S) Director Submarines, Rear Admiral Simon Lister, describes Astute as being ‘A quantum leap in capability from the Trafalgar class.’

Astute is expected to finally become operational during 2012, about seven years later than the originally planned date of June 2005. 


Origin of the Astute class

Most classes of warship can demonstrate a complex origin as requirements change and ideas evolve, but the story of the Astute class is particularly convoluted.

In the mid-1980s it was proposed that the Trafalgar class submarines then being built would be succeeded in the RN’s shipbuilding programme by an all-new class. In 1987, Vickers Shipbuilding and Engineering Limited (VSEL) was awarded a contract by the UK's Ministry of Defence (MOD) to carry out design work for the W class (sometimes called SSN-20), with the aim of ordering the first-of-class in 1990 for commissioning in 1997. However, with the end of the Cold War, no order for the expensive W class was placed. Instead, in June 1991, it was decided to commence studies into a cheaper 'Batch 2 Trafalgar Class' (B2TC) submarine. In August 1991, VSEL was invited to develop a design based on the evolution, with minimum change, of the existing Trafalgar class. 

On 14 July 1994 the MOD issued an invitation to tender for the building of three of the new BT2C submarines, with an option for one or two more. Competitive bids were received in June 1995 from GEC and VSEL. GEC had never previously designed and built submarines but partially remedied this deficiency in the same month by purchasing VSEL, which then became called  Marconi Marine (VSEL) - part of the company's GEC-Marconi division.

GEC-Marconi was formally identified as the MOD's preferred bidder for the BT2C submarines in December 1995 and ‘no acceptable price, no contract’ (NAPNOC) negotiations began. With construction of the Vanguard class Trident missile submarines winding down, GEC-Marconi badly needed new work for the former VSEL shipyard at Barrow-at-Furness, which it now owned. However, it was not until 17 March 1997 that the company was awarded a fixed price contract worth nearly £2 billion for the design, build, and initial support of three submarines (Boats 1-3) to be called Astute, Ambush and Artful. The new submarines were now officially recognised as being of a new class - the Astute class – and it was planned that the first would enter service in June 2005. At that time, it was expected that five Astute boats would eventually be built to replace the five remaining Swiftsure class SSNs. The Astute class would then be succeeded in manufacture by an advanced new Future Attack Submarine (FASM), which would replace the seven Trafalgar class boats. 

 In 1999 British Aerospace purchased Marconi Electronic Systems (as GEC-Marconi had been renamed in 1998), thus becoming the prime contractor for construction of the new Astutes.  The merged company called itself BAE Systems and has since undergone several re-organisations. Responsibility for the Astute submarine programme currently lies with BAE Systems Submarine Solutions, with its head office at Barrow-in-Furness. From a government perspective, the Astute project is currently managed by the Submarine Production Team in the MOD's Defence Equipment and Support (DE&S) organisation.


Requirements and Capability

During the Cold War the Royals Navy's nuclear-powered attack submarines – or ‘fleet submarines’ in RN parlance - had just two primary roles: protecting the ballistic missile submarines that provided the UK's nuclear deterrent and conducting autonomous operations against enemy maritime forces. However since the end of the Cold War (c.1991) they have proven to be extremely adaptable and well suited to other tasks, resulting in the Naval Strategic Plan 2006 emphasising the need for a ‘future underwater capability to contribute to maritime strike, ISR (Intelligence, Surveillance, and Reconnaissance), theatre entry and security’.   Thus, despite their very high cost, SSN's have remained at the heart of the Royal Navy's current plans and future force structure.

 It's expected that the new Astute class will make a major maritime contribution to joint operations with other UK armed services, and with those of allied nations. This contribution may include covert delivery of special forces, surveillance, intelligence gathering, land attack with Tomahawk land attack missiles (TLAM), and close support of amphibious task groups, as well as continuing to conduct more traditional roles such as protecting the Vanguard class submarines and anti-ship and anti-submarine operations. They will be capable of deployment as an integrated layer of defence within a task force or task group, or of independent operation for extended periods.

 The Astute class submarines are thus required to perform a wide range of military tasks. These require a submarine platform that provides global reach, endurance, covertness, sustained high speed and the ability to conduct unsupported operations in hostile environments. The ability of the Astutes to meet these requirements is being measured using nine key performance measures (KPM), all of which will apparently be met according to a National Audit Office report published in 2009: 

  • KPM 01: Weapon system effectiveness

  • KPM 02: Sonar performance

  • KPM 03: Hull strength (survivability)

  • KPM 04: Top speed

  • KPM 05:  Endurance

  • KPM 06: Acoustic signature

  • KPM 07: Complement

  • KPM 08: Land attack capability

  • KPM 09: Special forces capability

 The definition of these high level KPMs is classified and it is only possible to speculate on such matters as Astutes top speed (KPM 04) and maximum diving depth (KPM 03).  



In origination, the design of the Astute class was closely related to that of the earlier Trafalgar Batch 1 boats. The intention was to install an updated version of the tactical weapon system already being developed for refit to the Swiftsure and Trafalgar submarines, utilise an enlarged hull to accommodate the Rolls-Royce Pressurised Water Reactor 2 (PWR2) that had been developed for the Vanguard class submarines and incorporate a few features from the recently built Upholder class of diesel-electric submarines, such as their bow design. However, this ‘pick and mix’ approach initially resulted in a design which had some basic flaws, for example in regards to the trim of the submarine. As the technical problems were resolved and the new design evolved, the result began to have little in common with the Trafalgar's – indeed about 75% of the final Astute design is either new or has been re-qualified.

One of the most notable features of Astute (frequently referred to as Boat 1) is her sheer size and weight compared to the previous Trafalgar class, which displace 5,200 tons submerged. Early versions of the Astute design were estimated at 6,800 tons submerged but this gradually grew to about 7,800 tons submerged in the final design. This displacement is similar to that of many Second World War cruisers.

At an early stage of the project a decision was made that the submarines would be built using fully modular construction techniques and this heavily influenced the Astute class design work. Prior to Astute, the standard method used in the UK to build submarines had been to assemble components inside the pressure hull after it had been completed: equipment was fed in through the hatches in a process that made the final fit-out very time-consuming. It was hoped that the use of the modular construction approach – which allowed the concurrent construction and fitting out of multiple modules – would cut Astute design time by 25% and production time by 30% compared to previous submarine projects (the smaller Trafalgar class had averaged six years to build). Although the modular construction of submarines had been proven by submarine builders in Sweden and Germany, the fact that it would be a new technique at Barrow-in-Furness (the sole remaining submarine yard in the UK by the mid-1990's) inevitably caused some controversy within BAE Systems and involved a calculated amount of risk. 

Another key early decision was to employ the latest computer-aided design (CAD) methods for the Astutes’ design and construction. It was hoped that this would allow concurrent engineering and enable the work of designers at several companies and at several sites to be fully integrated, reducing overall design time. 

The cost savings anticipated by using the modular approach permitted a decision to make the Astute pressure hull much larger than the Trafalgar class - partly to help reduce the risks associated with using the new construction technique. The 10.7m diameter adopted was essentially determined by the space needed to accommodate a PWR2 reactor. Early B2TC design studies examined bulging the hull only around the reactor, however it was found that this would be more complicated and costly than extending the widened diameter to the whole submarine and thus simplifying construction. Another benefit of the larger hull was that it created space for 50% more weaponry. 

The modular design of the hull allows it to be built in ring-like sections which are initially constructed and fitted out in a vertical orientation, with considerable advantages in terms of health and safety. Components can be assembled simultaneously and installed before the sections are welded together at the latest possible stage. The Astute design is actually broken down into nine hull sections and five main modules - the latter including a 178-ton Command Deck Module and the Main Propulsion Machinery Package.  The later has sophisticated 'raft' mountings to isolate it from shock, vibration and noise, and protection of varying levels is also provided to the nuclear reactor plant as well as to the command deck, accommodation and the other modules.  There is also 65-tons Bridge Fin and more than thirty mini-modules. After the hull modules have been finally welded together, the restricted access to the interior multiplies the time it takes to carry out further work. 

The final design features significant improvements over the preceding Trafalgar class submarines, including:

  • Reduced crew size

  • The latest, fully integrated submarine combat system

  • Significantly (50%) increased weapons load - including Spearfish torpedoes, Sub-Harpoon surface-to-surface missiles (now out of RN service) and Tomahawk land attack missiles

  • Two optronic periscopes with electronic displays to avoid hull penetrating masts

  • External actuation for all control surfaces to reduce hull penetrations and simplify aft end construction

  • A digital control and information system that minimises costly cabling

  • Extensive detailed improvements to avoid outdated equipment, improve operability and save cost

Reduced radiated noise. Anti-sonar coatings are applied to all outboard equipment, whilst the main body of the hull is covered by 39,000 acoustic tiles that help mask the submarine’s sonar signature.

Crew numbers are intended to be the minimum possible consistent with maintaining operability and skill levels. Crews will certainly be smaller than the 130 of the Trafalgar class and the prime contractor was originally incentivised to keep total numbers down to a maximum of eighty-four, excluding trainees and sea-riders. The final crew size of Astute is slightly larger at ninety-eight, but that is still small enough to avoid the need for 'hot bunking', i.e. assigning more than one crew member to a bed.


Equipment, Weapons & Systems

Rolls-Royce Marine Power Operations Limited is the technical authority responsible for the design, manufacture and supply of the PWR2 nuclear steam-raising plant for all of the Astute boats. Major sub-contracted components include the PWR2 reactor high pressure vessel from Doosan Babcock, main coolant pumps from Weir and protection and control instrumentation from Ultra Electronics PMES.  The reactor is designed to have a 25-year lifespan and Astute is fitted with a new long-life core (known as core H) which will allow her to circumnavigate the globe forty times. The core is expected to be able to power Astute for her whole service life, eliminating the need for costly reactor refuelling and associated long overhaul periods.   

 The other main items of machinery are two Alstom turbines, which drive a single shaft to Rolls-Royce pump jet propulsor that consists of moving rotor blades within a fixed duct. There are also two diesel alternators, one emergency drive motor and one auxiliary retractable propeller. CAE Electronics supplies the digital, integrated controls and instrumentation system for steering, diving, depth control and platform management. Rolls-Royce also provides secondary equipment such as Turbo Generators, whilst Wellman Defence supplies the fuel cell stacks for emergency electrical power.

 Strachan and Henshaw (now owned by Babcock International) provide the air turbines, discharge air and hydraulic systems. The company also manufactures the heavily automated weapon handling and launch system.

 Astute is the first RN submarine not to be fitted with a traditional periscope. Instead she is equipped with two CM010 optronic masts manufactured by Thales UK, with mast control units provided by MacTaggart Scott. These are non-hull-penetrating electro-optical devices which carry radio frequency, infra-red and optical (high definition colour television quality) sensors. The masts send collected data to systems and consoles inside the submarine. With a reduced acoustic, visual, radar and thermal signature, the CM010 masts are highly suited to covert intelligence gathering. 

The countermeasures suite fitted to Astute includes both decoys and electronic support measures (ESM). The ESM system is the Thales Sensors Outfit UAP(4), which has two multifunction antenna arrays mounted on the CM010 masts. Astute is also equipped with the Eddystone communications and electronic support measures (CESM) system. This was developed by DML in the UK and Argon ST in the USA; it provides advanced communications, signal intercept, recognition, direction-finding and monitoring capabilities. 

 EADS provides the external communications External Communications System (ECS) which enables Astute to communicate over all the frequency ranges used for tactical communications transmitting voice, data and imagery. ECS is installed on the submarine's command deck module and is controlled by a special software enabling system operation by a single person from a central workstation.

Undoubtedly the most important set of sensors fitted to Astute is Sonar 2076.  This is a very advanced, fully integrated, passive/active search and attack sonar suite supplied by Thales UK. Outboard, the suite comprises large flank arrays with smaller square passive ranging arrays positioned at each end, plus an additional square installed aft.  There is also a conformal passive/active bow array, a chin mine and obstacle avoidance array, and intercept arrays (one UHF intercept array under the chin, and probably one atop the fin). Small fore and aft domes on the fin cover cylindrical underwater telephone arrays. Mounted on deck forward is the Intercept Array Transducer Hull Outfit 51R; this is in a free-flooding, carbon fibre dome forward that closely resembles the prominent PARIS array fitted to many RN submarines over the last twenty year.  Outfit 51R is optimised to receive returns from active sonar transmission from other warships. The 2076 suite also has a 1,200 metre long fibre optic towed array with a 400 metre cable; the towed array is reelable.

 Inboard of Astute are all the processing cabinets and user consoles associated with Sonar 2076. Software is used to generate a sonar picture which can be displayed in the control room. Astute is currently fitted with the 2076 Stage 4 system but she will be upgraded with new hardware and software to the latest Stage 5 standard by 2011 - this essentially replaces legacy hardware with the latest commercial off-the-shelf components and utilises a more open architecture. Boat 4 (Audacious) will be fitted from build with 2076 Stage 5 and a new Thin Flank Array. The current flank array is the largest acoustic sensor fitted to any submarine in the world, but it's heavy and is costly to fit. Improvements in acoustic materials technology allow a significant reduction in the weight of the array without losing performance, and also a simplification of the installation process. It is intended that the same technology will be used to simplify the bow array fitted to Boat 5 onwards.

 Astute is currently fitted with the Astute Combat Management System (ACMS).  This has three sub-components: an upgraded version of the Submarine Command System (SMCS) originally designed for the Vanguard class submarines in the 1980's for tactical information and torpedo weapon control; a  command support system that can show the recognised maritime picture, and a command workstation which can receive periscope and other video. The three systems are interfaced over an Ethernet network, SCMS also connects to the Sonar 2076 suite and other important systems using the fibre optic based (FDDI) Tactical Weapons Systems (TWS) Highway. The ACMS layout includes seven multifunction consoles – six on the tactical side of the Control Room and one on the sonar side. Each console includes two 18-inch flat screen displays, a keyboard and mouse.

The introduction of ACMS and Sonar 2076 Stage 5 will be a major step towards deploying the future Common Combat System (CCS) later this decade. CCS is being developed by the Astute Innovative Combat System Rainbow Team led by BAE Systems Submarines Solutions; it also comprises Insyte, Thales, QinetiQ and SEA. It's expected that all of the Astute's will eventually be fitted with CCS.

In terms of weapons, Astute has six 21 inch torpedo tubes and capacity for thirty-eight full loads, such as fourteen Tomahawk missiles and twenty-four Spearfish torpedoes. These can be substituted by equivalent load-outs, for example two Sea Urchin mines can be carried instead of one torpedo.

The only missile currently likely to be carried by Astute is the Block IV version of the Tomahawk land attack missile, which is manufactured by the American company, Raytheon. The Royal Navy has purchased a tube launched version of TLAM, which can strike at targets up to 1,700 kilometres away.  Tomahawk targeting is not done through AMCS; instead a standalone missile control system equivalent to the US Navy’s ATWCS is used. Astute also carries Spearfish heavyweight torpedoes manufactured by BAE Systems Underwater Systems. Each is powered by an open-cycle, bi-propellant gas turbine engine, which provides the weapon with a high sprint speed (up to 80 knots) and high endurance (at least 40 kilometres – and up to 65 kilometres has been speculated). The torpedo is provided with a copper wire command data link to the launch platform but can also operate autonomously. It has an active/passive homing head and a directed energy warhead for use against both surface and deep-diving submarine targets. 

Whilst it has not been officially confirmed, Astute might also be able to carry a wire guided uninhabited underwater vehicle (UUV) for use in visual and sonar intelligence roles, as well as for remote satellite communications.

Finally, Astute can be fitted with a dry deck shelter (DDS) aft of the fin structure. This is connected to the submarine's after hatch to permit free passage between the submarine and the DDS while the submarine is underwater. With the submarine still submerged, Royal Marines from the Special Boat Service can exit the DDS and ascend to the surface, bringing with them equipment and rubber rafts. Alternatively, they can mount a swimmer deliver vehicle and travel several kilometres underwater to their objective.



All of the Astute class submarines will be assembled in the Devonshire Dock Hall (DDH) at Barrow-in-Furness; this is a huge shipbuilding construction complex which covers an area of 25,000m. Originally built to accommodate the massive Vanguard class Trident missile submarines – which displace nearly 16,000 tons submerged – three or four Astutes can be worked on at once with room to spare. Major hull sections are built in the nearby New Assembly Shop before being moved by road the one kilometre to the DDH. Equipment and components for the submarines arrive at the DDH from subcontractors all over the UK, Europe and further afield. Delays and changing schedules to the Astute programme have resulted in material and equipment being stored for years before it's finally fitted or used.

The first steel for Boat 1 (i.e. Astute) was cut in October 1999, although the keel (actually the first pressure hull unit) was not formally laid down at the DDH until 31 January 2001 in an act of purely ceremonial value. By early 2002 all the major components and systems for Astute had been delivered by sub-contractors to the Barrow shipyard. However during 2001 and 2002 shipyard workers found that the designs they were working to simply did not make sense, and that the equipment would not fit together as it was supposed to. Unassembled materials and equipment rapidly accumulated at Barrow, whilst delays lengthened as the designers tried to resolve the rapidly multiplying issues.

BAE Systems was unable to disguise from the MOD the increasingly obvious fact that it was making slower progress in the detailed design and in the build-up of production than had been anticipated. On 9 July 2002 Mr Lewis Moonie, Armed Forces Minister, stated in answer to a Parliamentary Question that the first of class, Astute, had been due to enter service in June 2005, but was ‘not now expected to enter service before late 2006, although this date has yet to be agreed with the contractor.’ With all the problems, in November 2002 the MOD put the expected 'Astute Second Buy' - an order expected to be for a further three boats at a cost of £1.7 billion - on hold. BAE Systems blamed the delays on ‘engineering complexities’ but this was overly simplistic. Part of the problem was the significant gap between the Vanguard class construction contract and the award of the Astute class deal, resulting in the loss of many experienced staff. Also, work on the new submarines was hampered by the diversion of management effort and skilled workers to meet a surge in orders for surface ships – the Barrow-in-Furness shipyard winning in rapid succession contracts for the construction of two Albion class amphibious assault ships, two Wave class fleet auxiliary tankers, and the reactivation of four Upholder class conventionally powered submarines for Canada. However, the fundamental source of most of the delays was massive difficulties arising from the introduction of a computer-aided design tool. The system chosen was CADDS5, made by the American software company, PTC. Although this was a proven piece of software, Astute was the first UK submarine to be designed in a three-dimensional computer model and the adopted system was simply overwhelmed by the size and complexity of the task.  Despite the best efforts of PTC to customise the product, it was just too slow and time consuming for designers to use for the production of 7,000 design drawings with over one million components, 160 kilometres of electrical cabling, and 23,000 pipes totalling more than 10 kilometres in length.

 In the face of increasing dissatisfaction from the MOD over its performance, on 11 December 2002 BAE Systems publicly admitted that ‘additional issues’ had arisen and that it had ‘become apparent that there are substantial schedule and cost implications.’


Project Restructuring and Recovery

The MOD was not prepared to protect BAE Systems from its failure to perform on the Astute project, but it did acknowledge that the original contract had made cost saving assumptions with regards to the use of computer aided design techniques that had proven difficult to realise on a programme of great complexity. Throughout January and February 2003 the MOD negotiated with BAE Systems on the basis that the introduction of CAD required more time and effort than had originally been anticipated. Agreement was reached on 19 February, with the MOD increasing funding by £430 million whilst BAE Systems contributed another £250 million. An amendment to the Boat 1 contract was signed in December 2003, with Boat 1 production continuing under a revised target cost incentive fee arrangement. Production work on Boats 2 and 3 was essentially suspended until the design had matured sufficiently for a new price for these two boats could be agreed.

Apparently at the MOD’s instigation, Mr Murray Easton – former head of BAE Naval Ships – returned from a short retirement to become MD of BAE Systems' Submarine division in June 2003, charged with sorting out the Astute project. A complete review of the Astute design began, with personnel from the US General Dynamics Electric Boat Division being brought in to reinforce the project team and allow them to benefit from Electric Boat's recent CAD experience with the Seawolf and Virginia class submarines for the US Navy. By April 2004, Electric Boat had thirteen staff at Barrow, and another fifty working on the project at Groton in the US. They provided design and production expertise; assisted with the development of computer aided design (CAD) tools and their use in submarine design and production processes; produced Astute class production drawings; and exchanged expertise on submarine construction techniques.  The American's continued to assist the project well into 2007, with an eventual value of over US$200 million.

On 24 November 2004 the then First Sea Lord Admiral, Sir Alan West, said of the Astute project ‘I think it is firmly back on track now ... they have started to master the computer-assisted design, which was a much bigger issue than anyone thought it would be, and I am very impressed that they are getting to grips with it.’ Other issues at the Barrow shipyard such as overhead costs, quality control, absenteeism and accident levels were also starting to show a positive trend and long lead items worth £70 million for a fourth boat were quietly ordered.

By early 2007 the recovery of the project seemed solid, with the MOD noting that ‘All the programme’s revised anchor milestones continue to be met.’ It was finally possible for the MOD and BAE Systems to reach agreement on the price of the second and third Astutes - this included a £580 million increase on previous agreements to reflect inflation and the Government's acceptance of a share of the responsibility – along with BAE Systems – for the underestimate of the required effort and the consequent design delays. Even better, on 23 May 2007, the MOD announced a £200m contract for BAE Systems Submarine Solutions to begin preparing for construction of Boat 4 (Audacious) at Barrow-in-Furness in Cumbria. The boat was fully contracted for in the following year.

However, the National Audit Office kept a perspective on the situation a few months later when its Major Projects Report 2009 revealed that costs for the first three Astutes had risen from the original approved budget of £2,578m to £3,933m, and that the in-service date of Astute herself (defined as safe operation and start of operational work up) had slipped from June 2005 to March 2010 - and the later date was not to be met.

It is currently expected that Boat 4 - which will be very similar to the first three - will cost as much as £1,589m to build. However BAE Systems Submarine Solutions and its suppliers have been working hard to identify modifications for Boats 5-7 that will help reduce costs. Consequently, it is anticipated that Boat 7 will cost at least 10% less than Audacious.


Completing Astute

A major landmark in the life of Astute was her rollout from the Devonshire Dock Hall on 8 June 2007.  She was then formally named by the Duchess of Cornwall  in front of a crowd of approximately 10,000 people. As is traditional for submarine launches at the Barrow-in-Furness, the ceremony was performed using a bottle of beer brewed by her crew!

A week later Astute was lowered on a shiplift in to the water. On completion of initial basin trials she returned to the Devonshire Dock Hall for final outfitting, which would include the installation of the reactor core. At this stage it was planned that she would be delivered by November 2009, and BAE Systems was publicly hoping for August 2009. But during 2008 several programme and technical problems arose - in particular serious damage to the vessel's propulsion system was accidentally caused by staff inexperienced in the testing and commissioning of nuclear submarines. The additional delay increased to nearly a year after a small fire broke out in the conning tower (fin) on 18 April.  Nevertheless, in July 2008 Astute passed a major milestone on her programme – the successful fuelling of her reactor core and she entered the final stages of the testing and commissioning of her reactor, propulsion and ships systems.

Under the command of Commander A L Coles, on 14 November 2009 Astute finally slipped her moorings and departed Barrow-in-Furness for six days of basic sea trials before arriving for the first time at her home port of Faslane on the River Clyde in Dunbartonshire. After a couple of months of defect resolution alongside at Faslane, Astute was given clearance to go back to sea for further sea trials, sailing on 16 February 2010 and returning on 26 February. A major milestone was reached on 18 February when she conducted her inaugural dive in open waters in the Scottish Exercise Areas, safeguarded by the Type 23 frigate HMS Montrose. Afterwards the Commanding Officer signalled that ‘the submarine has handled exceptionally well, and, with a few exceptions has stood up to the rigours of the sea trials very well.’  It had been planned that Astute would be delivered and commissioned during April, but this was delayed to the Summer because of technical problems rather more numerous and serious than the signal indicated.

In May 2010 Astute conducted her first deep dive (the depth is classified, but probably 300m) and full power trial. During full power testing, she reached her maximum speed (again classified – but believed to be in excess of 30 knots). Further extensive testing and training was then conducted under the guidance of a team of Flag Officer Sea Training’s (FOST) submarine safety experts before she commenced a short maintenance period in June 2010 to resolve outstanding technical issues.

A final package of sea trials is scheduled before Astute will be delivered by BAE Systems Submarine Solutions to the Ministry of Defence, and formally commissioned in to the Royal Navy - probably Summer 2010. HMS Astute (now officially 'Her Majesty's Ship') is then scheduled to carry out trials to test her war fighting capability before sailing to America to carry out procedural test firings of her Tomahawk missile and Spearfish torpedo weapon systems. Full operating capability should be declared in early 2011 following operational workup and agreement with BAE Systems on any outstanding requirements, defects or deficiencies.

The Future

In May 2001 the MOD effectively cancelled the increasingly unaffordable FASM project, deciding instead to order additional Astutes to replace the Trafalgar class.  Speculation that at least nine Astutes might be built proved ill founded as defence cuts continued to reduce the Royal Navy's SSN force. Indeed when the last of the Swiftsure class (Sceptre) retires in December 2010, the only nuclear-powered attack submarines left in RN service will be the six remaining Trafalgar class boats plus Astute herself, with the latter still undergoing her operational work-up

The Defence Industrial Strategy published in 2004 targeted a new submarine order every twenty-two months to ensure vital skills and capabilities were not lost to BAE and its supply chain.  By 2005 the expectation was that eight Astutes would be built, but senior officials then increasingly indicated that this was a ‘funding permitting’ target.  The MOD's 2007 Equipment Plan allowed for seven boats and this is likely to be the final total unless the Strategic Defence Review being undertaken by the UK's new Conservative-Liberal Democrat coalition government decides differently when it reports in late 2010. Possibly only six Astutes would be built but for the need to sustain the UK's capability to build submarines until the construction of the first of the Trident armed Successor submarines - Vanguard class replacements - is likely to begin, at the end of this decade.

In March 2008 the MOD removed £139m from the Astute Project for the financial years 2009/10 to 2012/13.  This deferment of expenditure has resulted in delays to the delivery of Boats 2-4 of about nine months, and also to the build start dates and the procurement of long lead items for Boats 5-7.  As a consequence of this short term economy, Astute project costs for seven boats will actually grow by another £539m, and BAE Systems Submarine Solutions has slowed the overall rate of construction of the Astute class submarines to roughly one per two years.  The cost of Astute project, including the build of the first four boats, is expected to be £5,551m.  The final total cost for seven boats is likely to be nearly £10 billion.

On 25 March 2010, the government announced that it had a made a contractual commitment with BAE Systems to proceed with the initial build of Astute Boat 5 and had also authorised the long lead procurement activities (in particular the ordering of the reactor) associated with Boat 6, at a total cost of over £300m. 

By June 2010, the second of class, Ambush, was essentially complete and she was undergoing testing work in preparation for a roll-out from the DDH during the summer of 2010. As regards Boat 3, Artful, during the first half of 2010 her command deck module was shipped in to the hull, the welding of hull sections had been almost completed and the fin fitted. Outfitting of Artful will now continue with a 2012 roll-out planned under the latest schedule.  Also during early 2010, the first hull sections of Audacious were moved to the DDH at Barrow, and fabrication work started in the nearby New Assembly Shop on Boat 5.

By 2010 it was being widely leaked that the names of Boats 5-7 would be Agamemnon, Anson and Ajax; and on 15 September 2011 the MOD officially announced that Boat 5 would be called Anson.



It seems likely that only seven Astutes will be built to replace the twelve SSN's that were in RN service as recently as 2004.  However Astute is undoubtedly a very capable submarine. Based on unclassified information the US Navy's Seawolf class probably remains unequalled, but Astute may be able to equal or even exceed the capabilities of the USN's later but lower cost Virginia class, for example in regards to the number of torpedo tubes and the versatility of her mast sensors. 

Astutes advanced systems, in particular the Sonar 2076 suite, would seem to make her far more capable than the best SSN's currently in service with the Russian (Project 0971A, Akula II), French (Améthyste class) and Chinese (Type 093 Shang class) navies. One comparison is that the flank sonar's of Astute are far superior to equivalent French systems in terms of channels, number of beams and tracking distances.

Because of her extraordinary versatility, combined with a patrol endurance of three months, Astute gives the UK government a nearly unique military capability. In a crisis she can sit discreetly off a coast gathering intelligence and then – if necessary – conduct devastating precision attacks on enemy land and sea targets.  Unfortunately the Astute Project has been badly affected by cost increases. Each Astute submarine will now cost the UK tax payer about £1.4bn (approximately US$2.1bn), rather than the £850m originally estimated. However, this is still less than the c. US$2.7bn of the broadly comparable Virginia




The Astute Class of submarines is the planned replacement for the Swiftsure and Trafalgar Class SSNs (Sub-Surface Nuclear), and was to start entering service from the middle of this decade.  Intended as a relatively low risk low cost approach to providing a next generation nuclear submarine for the Royal Navy, the Astute programme has unfortunately become one of the most troubled UK defence projects since the 1980's, matched only by the Nimrod 2000 programme.  Due to serious delays and problems encountered by the prime contractor BAE Systems, the first unit, HMS Astute, is now not expected to be delivered until November 2008 and will become fully operational in 2009 - four years later than forecast when ordered. Up to seven Astute's will be procured by about 2022, and it is possible that a modified variant may also eventually replace the Vanguard class SSBN's.  Unlike every previous class of British nuclear submarine since HMS Dreadnought in the early 1960's, a very significant foreign (American) content has been accepted in the design work after the failure of BAE Systems to complete the task in-house.

Nuclear powered hunter-killer submarines are at the heart of the Royal Navy force structure.  They have a wide variety of roles and, although conceived towards the end of the cold war, are proving extremely adaptable to a revised employment within the new world order.  The new Astute class will [eventually!] contribute fully to the Maritime Contribution to Joint Operations (MCJO), including covert delivery of Special Forces and close support of amphibious task groups, as well as conducting the more traditional roles of support to the nuclear deterrent and autonomous operations against maritime forces.  They will be capable of deployment either as an integrated layer of defence within a task force or independently in advance of such a force.

The Astute project is managed by the MOD's Defence Equipment and Support (DE&S) Attack Submarine (ASM) Integrated Project Team (IPT).

Click on the above picture to see a video of the Astute SSN in RealPlayer®  format

Early History

In the mid 1980's it was expected that the Trafalgar class of "hunter killer" submarines would be succeeded by an all-new class, and in 1987 VSEL (subsequently bought by GEC-Marconi who in turn were bought by British Aerospace, now BAE Systems) was awarded a contract to carry out design work for the "W class" (SSN20), with the aim of ordering the first of class in1990(!).  With the Trident missile armed Vanguard Class SSBN's being given higher priority, and many other pressures on the defence budget, no orders were placed.  Instead, in June 1991, approval to proceed with a programme of studies at an estimated cost of £6m (1991/92 prices) to define a Batch 2 Trafalgar Class Boat (now known as the Astute Class) was given. 

In August 1991 VSEL were invited to tender for a design "based on the development, with minimum change, of the existing Trafalgar class".  The first order was then expected in 1994 with an in-service date of 2001. This programme of studies led to the issue of an Invitation to Tender for the design and build of an initial batch of three Astute Class SSNs and a further approval of £2m (1992/93 prices) for contractor and Defence Research Agency support to MOD during the tendering exercise in 1994.

Invitations to tender for the first three submarines of the class were issued in July 1994, with competitive bids received in June 1995 from GEC Marconi and Vickers Shipbuilding and Engineering Limited.  As a result of concerns over the overall affordability of the programme, Minister (Defence Procurement) and the Treasury approved a further £23.5m (at 1993/94 prices) for risk reduction studies to be undertaken in parallel with the formal bid phase of the project. To maintain an effective competition, contracts for the risk reduction work were awarded to both bidders.

GEC-Marconi (now BAE SYSTEMS Astute Class Ltd) was identified as the MOD's preferred bidder in December 1995.  Following protracted negotiations, using the policy of No Acceptable Price No Contract (NAPNOC), a prime contract was placed and announced on 17 March 1997. The contract put in place the first whole boat, Prime Contract for UK nuclear powered submarines. The Prime Contract is for the design, build, and initial support of three submarines.  The support task will be undertaken by the Prime Contractor for a total of eight submarine years (4.5 calendar years). The Prime Contract required an integrated Tactical Weapons System with a performance at least as good as the Swiftsure & Trafalgar (S&T) Update Final Phase.  As a risk reduction measure, the former Departmental contracts for the Final Phase of the S&T Update have since been novated into the Prime Contract for Astute. 

The successful outcome of these studies led to EAC approval (the equivalent of Main Gate) in March 1997 to place a contract for the design, build and initial support of three Astute Class submarines with GEC Marconi, now BAE SYSTEMS.

The 1998 Strategic Defence Review decided that the SSN force level was to be reduced from the current 12 boats (itself a reduction from 15 at the start of the decade) to 10, and therefore two of the five remaining Swiftsure Class would not be replaced after all, but the additional two Astute units  would still be ordered in about 2002 in order to replace early Trafalgar Class units and maintain the new force level.  In August 2000 a sixth Astute was apparently provisionally added to the programme because of the ever lengthening financially driven delays to the FASM project, and the major and expensive serviceability problems being encountered with the older Trafalgar Class submarines - the third of which, HMS Talent, will be taken out of service in 2011, well before the first FASM could possibly enter service.

The Astute's will be an improved and enlarged version of the Trafalgar Class, and were originally intended to replace the remaining Swiftsure Class which were launched between 1973 and 1977 and are now approaching the end of their operational life.  With the effective cancellation of the FASM project and slow progress on the MUFC project, the Astute's will now eventually replace the Trafalgar Class as well.  The order for the first three Astute units (with an option for a further two) was placed with GEC-Marconi (now part of BAE Systems) on 17th March 1997 and the value of the contract was put at nearly £2 billion ($3.2 billion), including a Swiftsure and Trafalgar Final Phase Integration Task and Contractor Logistic Support for the first 4.5 years from the in-service date.  In January 2001 the MoD stated that the cost of each of the first three boats would be around £745m.  The total programme cost of the first three units was expected (November 2001, Major Projects Report 2001) to be £2,698m.  On 19 February 2003 it was announced that in the face of disastrous cost overruns that the government had agreed to increase its funding to BAE Systems by around £430m, while BAE would also  contribute (or rather write-off) £250m.  Under the terms of the renegotiated contract, the Design and Development phase of the programme is now separated from the Production phase. Design and Development will be completed under new Target Cost Incentive Fee (TCIF) arrangements. BAE Systems and the MoD have established new Target Costs and Fee levels for the programmes, up to the Target Cost level, cost saving will be shared by the MOD and BAE as an additional Incentive Fee for BAE.  Any cost overruns above the Target Cost will be shared by the customer and the company, up to the maximum level established for the company by the agreement.  Including government supplied equipment (e.g. sonars and the Tomahawk control system), the out-turn cost of the first three A's now seems set to reach £4 billion.

The Prime Contractor is BAE SYSTEMS Astute Class Limited, based at Frimley in Surrey.  The boats are actually being built at the BAE Systems Marine (VSEL) shipyard in Barrow-in-Furness, England.  First steel for HMS Astute was cut in October 1999 but the keel (actually the first hull section) was not formally laid down until 31 January 2001. 

Fabrication of the second submarine in the class, HMS Ambush, started in August 2001, although progress was very slow due to the design problems being experienced with HMS Astute, all fabrication work on her was suspended in February 2003 (see below), although her ceremonial lay down ceremony was conducted a few months later in October - an act of purely publicity value. 

On 31st January 2001 the Defence Procurement Minister, Baroness Symons, stated that "The MOD is considering plans for a second batch of up to three of these [Astute] submarines with a final decision being taken next year."  A joint BAE Systems/Defence Procurement Agency team was established to deliver an Astute Second Buy (A2B) proposal by March 2002.  This was intended to help inform the MOD's decision - then still planned for mid-2002 - on whether the order should be placed for two or three further submarines.  It was expected to lead to the MoD’s Main Gate decision soon after, with an award of contract around November of that year. 

In May 2001 the FASM project was replaced by the "Maritime Underwater Future Capability" with an expected in-service date of about 2020, but perhaps as late as 2030.  This made it seem likely that sufficient Astute's would eventually be ordered to complete the replacement all of the current Trafalgar and Swiftsure class SSNs, i.e. ten Astute's.  Although this was not officially confirmed, USNI Proceedings (March 2001 edition) reported that the MoD had decided at the end of 2000 to add a third batch of three Astute's (A3B) to the programme (i.e. for a total of 9 Astute's).  Official statements at the time of the 2002 SDR "New Chapter" confirmed that the projected size of the SSN force was now 9. 

By mid-2002 it was clear that the Astute programme was in severe difficulties and rather than placing an order the MOD instead informed BAE Systems in November 2002 that the Second Buy order would not be placed until it was satisfied that the all-to-evident design, engineering and management problems with the project had been overcome. 

Newspaper reports in early 2003 stated that due to pressure from the Treasury, the third A2B boat had been dropped and that the order, when finally placed, would again be for two boats - thus by 2015 the SSN force was likely to consist of 5 Astute Class plus the 4 Trafalgar Class boats that have undergone the Final Phase of the S&T Mid-life Update Programme. 

On 21 July 2004 it was announced in the Defence Command Paper (Cm 6269): Delivering Security in a Changing World: Future Capabilities that the Royal Navy's SSN force would be cut to 8 boats [from 2006], and it was presumed that in the long term these will eventually all be Astute's.  However, leaks in early 2005 indicated that the MOD in fact had a requirement for only 7 Astute's, and other sources have since confirmed this same.  By Autumn 2005, industry was pressing hard for the final four Astute's to be ordered in one batch, emphasising the industrial and financial advantages this would realise over ordering them in 1's and 2's.

The MOD's Defence Industrial Strategy published in December 2005 apparently confirmed the need for up to eight Astute's to be built, with a delivery "drumbeat" of every two years from 2010.  But senior MOD officials later hinted that eight was very much a funding permitting target and Equipment Plan 2007 (EP07) apparently included on seven.

During early 2006 it became apparent that there was still a large affordability gap between what the MOD was prepared to pay for additional Astute's and what BAE considered to be a fair "ticker price" for their manufacture after having resolving many of the projects problems at its own expense and with great effort.  Only  one Astute (Boat Four) was ordered in 2007.


Programme Problems

HMS Astute was officially laid down in February 2001, although first steel was cut long before that - in October 1999.  By early 2002 all major components and systems for HMS Astute had been delivered by sub-contractors to the Barrow yard, and material for HMS Ambush was also rapidly accumulating and some fabrication work began.  But BAE Systems was unable to disguise from the MOD the increasingly obvious fact that it was making slower progress in the detailed design and in the build up of production than had been anticipated, and that the approved ISD of June 2005 could not now be achieved.  BAE blamed the delays on "engineering complexities", although work on HMS Astute had also been delayed due to the diversion of skilled workers to the reactivation of the Upholder Class of SSK's for Canada.

The biggest headache came with the computer-aided design tools. The system chosen was CADDS5, made by the American software company PTC. Although it was a proven piece of software, it was overwhelmed by the size and complexity of Astute.  According to BAES's head of the submarine business, Murray Easton: “This was the first submarine designed in a three-dimensional computer model, and there wasn’t a system capable of doing it.  This has caused us a big delay. We have collaborated with PTC and customised the system extensively, but it is still not capable of doing what we want it to.”  John Hudson, Engineering Director, said the problems were made worse by a welter of work landing at the same time. As well as winning Astute, BAE Systems was awarded contracts for two large amphibious assault ships and a fleet of auxiliary oilers [the Wave Class]. ... All this happened within 18 months, and at the same time we were changing procurement methods and introducing new computer design technology.  ... The system (the computer design tools) would go to sleep for long periods, or take five minutes to update every time you did anything. That’s obviously time-consuming, but it also leads to a loss of concentration on the part of the designer.”

On 9 July 2002, Mr Lewis Moonie, Armed Forces Minister, announced in answer to a Parliamentary Question that the first of class, HMS Astute, had been due to enter service in June 2005, but "is not now expected to enter service before late 2006, although this date has yet to be agreed with the contractor".   It was still hoped at this point that Astute would be launched in 2004, be accepted from the contractor (safe operation and start of operational work-up) in June 2005 and be in-service (operationally available) by late 2006, after concluding about 18 months of trials and work-up.  

Work now focused on BAE Systems establishing a robust revised programme for Astute to which the MOD could agree.  But the problems came to a head in late 2002  when the frantic negotiations between BAE and the MoD on Astute and Nimrod, another problem contract, broke down.  In the face of increasingly public statements of dissatisfaction from the MOD over its performance on the Astute and Nimrod contracts, on 11 December 2002 BAE Systems had no choice but to tell the market about the problems — which had become something of an open secret in the shipbuilding industry in the preceding months.  It admitted that "additional issues" had arisen with the Astute [and the Nimrod MRA.4]  contract and that it had "become apparent that there are substantial schedule and cost implications. ...  The company and the MoD are continuing to discuss the extent to which these two contracts can be modified to the mutual benefit of the MoD and BAE Systems."   It also said that BAE Systems' Underwater Systems division was awaiting the award of various contracts, in the meantime, the firm said it was not able to find enough work to keep its staff busy.

As BAE Systems share price collapsed, the MOD and BAE Systems had to choose between renegotiate or cancel.  The contract was renegotiated. BAE and the MoD will now share the risk and reward, and Easton, who had quit BAE in October 2002 after only five months as boss of its naval shipyards, was brought back into the fold. Industry insiders said the MoD told BAE that Easton had to come back — a suggestion that the company declined to comment on.  Easton himself described his period away from the company as “my little break”.  His first priority was to “stabilise” the Astute schedule, something he now thinks has been achieved. “We have had a complete design review, with input from American experts, and we are on track for a November 2008 delivery,” he said.  The Americans in question were from General Dynamics, the company that has built most of the US Navy’s nuclear submarines. Some reports have suggested that General Dynamics has been brought in by the MoD in a project-management role, but Easton said it is mainly providing extra resources for the computer design task.  General Dynamics has 11 staff at Barrow, with others trained on the computer design system working from America. Easton has also launched an efficiency drive — 20% will be cut from the company’s costs in the next 15 months.

In an article published in the Sunday Times newspaper in November 2003, managers at Barrow were quoted as saying the Astute Project's problems went all the way back to the initial contract in March 1997:

“We had a contract that frankly was not working,” said Murray Easton, MD of BAE Systems' Submarine division.  GEC-Marconi, then the Barrow yard’s owner, promised to build the submarines for a fixed price. “It was one of a series of what the MoD called napnoc deals — no agreed price, no contract,” said Malcolm Christie, Astute Project Director.  Barrow was desperate for work. There had been “a significant gap” between the last Trident construction contract and the award of the Astute deal, said Easton, which not only spurred GEC’s determination to win the work, but also depleted the ranks of experienced staff.  The biggest headache came with the computer-aided design tools. The system chosen was CADDS5, made by the American software company PTC. Although it was a proven piece of software, it was overwhelmed by the size and complexity of Astute. “This was the first submarine designed in a three-dimensional computer model, and there wasn’t a system capable of doing it. This has caused us a big delay. We have collaborated with PTC and customised the system extensively, but it is still not capable of doing what we want it to,” said Easton.  John Hudson, engineering director, said the problems were made worse by a welter of work landing at the same time. As well as winning Astute, BAE Systems was awarded contracts for two large amphibious assault ships and a fleet of auxiliary oilers.  “All this happened within 18 months, and at the same time we were changing procurement methods and introducing new computer design technology.  The system (the computer design tools) would go to sleep for long periods, or take five minutes to update every time you did anything. That’s obviously time-consuming, but it also leads to a loss of concentration on the part of the designer,” said Hudson.

On 19 February 2003 the MOD and BAE Systems announced that they had reached agreement on the restructuring of the Astute contract.  As part of this agreement, all construction has been halted while design issues are resolved, and the first submarine will not enter service until at least 2008 (three years later than planned).   The cost of the Astute submarine programme - already running at over £2.5bn - is also to rise by almost £700m.

A BAE Systems press release dated 19 February 2003 stated:

In December 2002, the company announced that additional issues had arisen in relation to these programmes and that it had become apparent that there were substantial schedule and cost implications.

Under the terms of today's agreement, the current contracts for design, development, production and support on each of the two programmes will be revised. These revisions will separate the Design and Development phase of each programme from the Production phase. Design and Development will be completed under new Target Cost Incentive Fee (TCIF) arrangements. Both programmes will be placed on a firm footing for the delivery of the Astute and Nimrod capabilities into service.

BAE SYSTEMS and the MoD have established new Target Costs and Fee levels for both programmes, and have high levels of confidence of delivering the programmes within these new target levels. Up to the Target Cost level, cost saving will be shared by the customer and company as an additional Incentive Fee for the company. Any cost overruns above the Target Cost will be shared by the customer and the company, up to the maximum level established for the company by the agreement. These new arrangements will place a significant economic incentive on the company to perform. The company has reviewed its project management of these programmes, consistent with today's best practice, and is taking actions based on lessons learned.

Pricing of the Production phase of each programme will be concluded following achievement of sufficient risk mitigation from the Design and Development phase to enable production costs to be established with confidence.

The difficulties in the Astute programme stemmed principally from moving the design of the submarine to a fully electronic CAD (Computer Aided Design) design basis - a process that neither party understood would be as difficult as it has turned out to be.

Production work on the Astute Programme will only be resumed after design maturity has been established. Design and Development, which includes the build of the First of Class, HMS Astute, will be completed under new TCIF arrangements.

Pricing for the production of HMS Ambush and HMS Artful will be established once adequate design maturity has been achieved and progress has been made on the First of Class. In order to maintain progress on the programme, General Dynamics Electric Boat Division (GD) will provide design assistance to reinforce the project team. This will enable the Astute project team to take advantage of lessons GD learned in computer-aided design on major US submarine programmes.

An official government statement was simultaneously made by Defence Procurement Minister Lord Bach:

.... The original contract was based on a single source supplier, namely GEC-Marconi (which subsequently merged with British Aerospace to form BAE Systems) as the only UK provider of this unique defence capability. We sought to establish a fair price given the economic conditions and agreed joint assumptions on an open book basis at the time of contract signature in March 1997 on how the project would be delivered. These related, in part, to the benefits to be derived from the first comprehensive application of computer aided design (CAD) techniques to UK submarines.
This will deliver significant advantages in the future, but its benefits have proved more difficult to realise on a programme of this complexity than either we or the company had assumed. We now know that the introduction of CAD requires more time and effort than either of us had originally anticipated.
As a result, the Government has agreed to increase its funding by around £430M, subject to final negotiations, as against an increased contribution by the company of £250M which it has announced will be included as a provision in its preliminary results for 2002. These increases reflect the Government's acceptance of a share of the responsibility along with BAE Systems for the under estimate of the required effort and the consequent design delays. They also cover costs incurred through restructuring and other revisions to the project and will result in the first of class coming into service by 2008. In the light of what we now know about the costs and benefits of CAD, we are confident that the new deal represents a good deal for the taxpayer and will provide outstanding new generation attack submarines for the Royal Navy.

Road to Recovery

On 24 November 2004 the First Sea Lord Admiral Sir Alan West said of Astute “I think it is firmly back on track now, I think they have really gripped it, and some of the things like the welding practices there and the levels - almost no re-weld required at all - and the quality of that sort of thing; they have started to master the computer-assisted design, which was a much bigger issue than anyone thought it would be, and I am very impressed that they are getting to grips with it”.

The plan for future Astute buys will now be re-addressed in the light of the BAE's revised programme for the first buy of Astute, and the Main Gate submission for the "Astute Subsequent Procurement" (as A2B has been renamed) is expected in early 2006.

In April 2003 a leak of the contents of the MOD's "Equipment Plan 2003" indicated that the SSN fleet was to be reduced to just 7 boats, compared to current 12 and the SDR mandated 10 SSN's.  This report was confirmed by government sources, although emphasising that no final decision has been made.  In July 2004 the government stated that the SSN force would be reduced to 8 boats by December 2007, and it is suspected that in the long term these will be solely Astute Class boats.  However reports in early 2005 indicated that only 7 Astute's are planned, appearing to confirm EP03

EP07, approved March 2007 apparently included a total of 7 Astute's - this number was finally offically confirmed in in mid-2008, with the UK press already doubting that even seven would ever be ordered.

Possible road map for RN SSN force levels based on data available mid 2008
Year Submarine Event New number in fleet
2004 Splendid Decommissioned 11
2006 Sovereign Decommissioned 10
2006 Spartan Decommissioned 9
2008 Superb Decommissioned 8
2009 Trafalgar Decommissioned 7
2009 Astute Delivered & Commissioned* 8
2010 Sceptre Decommissioned 7
2010 Ambush Delivered 8
2011 Turbulent Decommissioned 7
2011 Artful Delivered 8
2013 Tireless Decommissioned 7
2013 Audacious Delivered 8
2015 Torbay Decommissioned 7
2015 A-05 Delivered 8
2017 Trenchant Decommissioned 7
2017 A-06 Delivered 8
2019 Talent Decommissioned 7
2019 A-07 Delivered 8
2022 Triumph Decommissioned 7
* Not equivalent to operational


Admiral Sir Alan West said on 24 November 2004  “When I have got the Astutes, then, with eight, I will be able to do all the things that  we need to do. ... The Defence Planning Guide, ….requires actually six SSNs, five or six (operational), depending on the circumstances, available for use .The current fleet has eight of these old ageing ones… Can I actually provide that?  When I have got the Astutes, then, with eight, I will be able to do all the things that I need to do, ...they are newer, they have got a different core, all of these sort of benefits…. I am convinced we need to keep them, ...I believe we need to keep building the Astutes, ...once I have got those my worry about the ageing fleet and my worry about having availability will go”. (Source: House of Commons Defence select Committee, 24 Nov. 2004)

According to Defense News (a leading and well informed news source) an early order for a fourth Astute is now expected in order to sustain the industrial base.  BAE Submarines supply chain coordination manager William Jones told Wavelength, a BAE SYSTEMS house magazine published in August 2004 that “Due to the timing of Boat 4 it is possible that some suppliers will have gone out of business, or have lost critical capacity or capability, before we are able to place orders for equipment”  The BAE magazine said that the MOD had sought special approval from the U.K. Treasury for advance procurement of major items from a small number of key suppliers, including Rolls-Royce Marine, which makes nuclear power plants, and Weir Strachan & Henshaw, which builds weapon discharge and handling systems.  More work was expected to go to other suppliers later this year, it said.  A Ministry of Defence (MoD) spokesman confirmed that the government so far has spent about 70 million pounds on long-lead items for Astute Boat 4.  A spokesman for Rolls-Royce Marine declined to give any details of their contract, saying any discussions with the MoD were private, but the firm spokesman did say, “We don’t see the business as fragile, although clearly there has been a slowdown in order flow from the MoD. This is a business we are in for the long term. Everybody understands the capacity situation: If we don’t have work, we have to adapt our resources accordingly.”HMS Astute being assembled, early 2006

Another factor that emerged in June 2004 is the possibility that the Maritime Underwater Future Capability (MUFC) studies currently being undertaken might result in a new multi-role nuclear submarine with an ISD as early as 2020 (rather than previous estimates of 2030) in order to allow it to replace the  Vanguard Class SSBN's.  MUFC would probably be improved Astute type design, but with 16 VLS tubes for cruise missiles or 4 more versatile Trident missile tubes.  The revised  ISD for MUFC would allow it to replace the last of the updated Trafalgar's. 

Work on the third boat, HMS Artful was due to commence in 2003, and the First Sea Lord, Admiral Sir Alan West finally performed the delayed keel-laying ceremony on 11 March 2005.

On 29 June 2005, Murray Easton, Managing Director of BAE Systems' Submarines Division said during a briefing for BAE staff that Astute project was likely to make a modest profit in 2005.  Mr Easton said: "We are not banging the drum and we are not shouting from the roof tops, but the word is getting out that this project is back on the right track.  A project that was demonstrably out of control is now in control. But we are only half way there. People have long memories. Astute is very sensitive so we need to be careful. Miss a target and it's 'here we go again'. So we have to avoid complacency."  

Astute was "the most complex engineering challenge in the UK, comparable to the United State's space programme," Mr Easton said, involving 7,000 design drawings and 23,000 pipes. Since October 2003, BAE's submarine yard in Barrow-in-Furness, Cumbria, has cut absenteeism among its 3,000 staff by two thirds to 3pc and halved sickness rates to 2.1pc of the workforce.  Reportable accidents resulting in staff being off work for more than three days were down 75pc in 2004 and 45pc in 2005.  Mr Easton attributed the success to using "lean manufacturing" tips from the car industry.  Overheads are down by 27pc over the past two years and staff are meeting and beating stretching deadlines, incentivised by a bonus scheme which could net them £5,000 each in total if they hit all deadlines by 2008.   Mr Easton has brought forward the completion date of HMS Astute to August 2008 to allow for any slippage when trials start at the end of the year without incurring penalties (this margin may be required due to the emergence of reactor commissioning problems)


Current Situation

HMS Astute's naming ceremony was performed on 8 June 2007 and she was floated a few days later.  She is expected to be completed and handed over by BAE Systems to the Royal Navy in August 2008.  After completing 12 months of extensive test, communication and weapons trials, checks and training.  Its hoped that she will be potentially available to the Fleet for limited operations by November 2008 (technically entering service) before these trials complete, but she won't be fully operational until late 2009.

An investment decision on the "Astute Subsequent Procurement" had been expected to be made in Q1 2006 but was delayed.  On 21 May 2007, the MOD finally announced an approximately £200 million order for the start of the construction of the fourth Astute-class nuclear powered attack submarine, which it named as HMS Audacious.   The contract runs to March 2008 and covers initial build work on the submarine. The MOD aims to contract for the whole boat by late 2008, and detailed terms and conditions will be agreed over the intervening period.  The final contract placed will cover all aspects of the construction and completion of the submarine. It comes on top of orders for long-lead items that have already been placed with industry both to prepare the way for the construction of Audacious and to support the industrial infrastructure.

BAE said that that about 35% by value of HMS Audacious had previously been contracted for under long lead contracts (presumably this had now increased to about 50%).  BAE also said that HMS Audacious  would be delivered in accordance with 22 month "drum beat" for the class - which would imply early 2014.  The Barrow yard had already completed preparations to cut first steel in the hull. 

In November 2007, the NAO's annual Major Projects Report 2007 revealed that the Ministry of Defence had agreed to BAE ordering “long lead items” including gear boxes and reactor components for three more submarines, making a total of seven in all.  However in early December 2007 there were press reports speculating that these three boats could be cancelled and that the Astute Class would be limited to just four boats - improbable but an indication of just how much strain the defence budget is under.



Development costs and production of the first three boats has been budgeted at 3.5 billion pounds ($6.5 billion).   It had been anticipated that an order for a further three Astute class submarines would be placed in late 2002 at an estimated cost is £1.7bn, but this order has now been delayed indefinitely and their cost will be re-assessed.  However, some long lead time items for the fourth Astute had been been ordered by mid-2004 to help sustain the industrial base. 

The pricing of Astute boats resulted in a number of questions for Sir Peter Spencer, Defence Procurement Agency chief, when he appeared 10 October 2006 before the parliamentary Defence Committee.  Despite the two boats being under construction, the MoD and BAE have yet to agree on a final price. That stems from a complicated renegotiation of the Astute contract in the wake of the design problems. Lack of a firm price was raising concerns, Spencer said.  “At the moment, we have unlimited financial liability for boats 2 and 3 because we have not managed to agree the prices. We know there have been problems in terms of rework and in terms of fragility of the supply chain. I am extremely keen to bring this to a conclusion, ideally before the end of this financial year,” he told the committee.

In October and November 2006 it also became public that significant efforts are being made to reduce the cost of the Astute Class.  Rear Adm. Andrew Mathews, the MoD’s director general nuclear, is said to have told BAE Systems and its suppliers that he wants cut the slash acquisition costs of the fourth boat in the program by 30 percent. By the sixth sub, he wants the reduction to amount to 45 percent. 

According to an article in BAE’s internal newspaper Wavelength in November 2006, the company and its suppliers already have substantially exceeded the targets set by the MoD.  “Measures identified exceed the challenge by 25 percent for boat 4 and 10 percent from boat 5 onwards”.   The internal newspaper says that BAE and others have a “design for cost reduction contract” with the MoD covering the whole of boat four.   The company reckons an industry team including Thales, QinetiQ and others will have cut the cost of the fourth boat by 55 percent when compared with the build-to-print system to be used on the third boat of the class.   BMT is also believed to have been brought in by the MOD to bring some radical thinking to the redesign effort.

Cost reduction efforts include more than 60 cost-saving measures for the redesigned combat system.  Among the changes are using commercially available processing rather than custom-made systems, and the adoption of common cabinets and multifunction consoles across the entire combat system.

One of the most significant innovations in the new combat system has been the use of commercial, off-the-shelf (COTS) systems, said Gavin Ireland, a researcher at the Royal United Services Institute.  “The extensive use of COTS on a submarine is a severe challenge, given the harsh operating environment and strict safety standards involved, and given the need to educate suppliers in how to engineer-in survivability without adding excessive cost,” he said. “Therefore, the COTS success being achieved in the combat system is of great significance, and is likely to lead the way for greater input of this sort of technology for Boat 4 and beyond.  BAE examined other options for reducing the combat capability of the boat to improve affordability, but the cost savings were insufficient to justify compromising the capability of a boat that is required to be even more flexible than its predecessors. Importantly, there is no capability reduction between the combat systems of boats 3 and 4, even with a substantial cost saving."

One of the aims of the combat system changes, according to Wavelength, is to link into MoD initiatives toward a common combat system with open architecture for the submarine fleet.  Capt. Paul Jagger, the MoD project leader for combat systems, was quoted saying that applying the initiative across Astute, the existing nuclear submarine flotilla and future boats has the potential to save “tens of millions of pounds.”

Ireland also said the MoD is facing significant financial challenges for its future nuclear-powered submarines, not only in terms of driving down the costs of individual hulls, particularly the fourth boat, but also in developing a more affordable acquisition architecture for future programs.  He warned, though, that the reduction target will be difficult to achieve if the fourth boat is ordered as an individual vessel, rather than part of a second batch.  “The real cost of boat 4 and beyond largely depends on how the MoD structures the procurement of further Astute-class submarines,” he said.

Ministry of Defence officials revealed on 27 February 2007 that government negotiators and BAE Submarine Solutions had agreed on a deal on the price of the second and third Astute's, but that it still required endorsement by the hierarchy of the two sides.  The formal order for the fourth boat was then expected to follow rapidly order.  BAE  Submarine Solutions reported that had completed preparations for manufacture of Boat 4 on 8 February 2007, and had begun procuring combat system equipment in the shape of a towed array handling system.

BAE Systems confirmed on 21 May 2007 that the first three Astute's were expected to cost £3.65 billion.

During 2007 the MOD and BAE Systems (Submarine Solutions) finally agreed a Target Cost Incentive Fee for Boat One, and a Target Cost Incentive Fee with Maximum Prices for Boats Two and Three, the current forecast cost for the three boats was £3,798 million, compared with £2578 million when ordered, the cost growth is despite economies - including capability reductions taken in Equipment Plan 2007 (EP07), approved March 2007.

The MoD has said the approval to build Boat 4 was sought on the basis of meeting a construction drumbeat that required a new submarine order every 22 months in order to ensure vital skills and capabilities were not lost to BAE and its supply chain.  However it is frequently emphasised that the MOD's ability to maintain the necessary stream of orders in face of its budgetary problems is dependent on BAE and key subcontractors meeting the cost targets being set by  Rear Adm. Andrew Mathews.


The Astute Class SSN's will all be based at Faslane on the Clyde. 

The implications of the Astute project delays for the SSN flotilla are currently being studied by DNRP involving CinC Fleet and WSA with input from the ASM IPT.  The ASM IPT continues to work closely with the WSA to ensure that the predicted in service dates are consistent with the programme for the jetty project at HMNB Clyde - construction work for which finally began in 2004.



A 30-year contract, worth about £300 million, to train crewmen for the Royal Navy's latest Astute class attack submarines was originally awarded by the Ministry of Defence in September 2001 to the UK-based FAST consortium. The FAST consortium is composed of AMS (a joint venture company owned by BAE Systems and Finmeccanica Spa of Italy), CAE Inc of Canada and Flagship (a joint venture company owned by BAE Systems, Vosper Thornycroft and Johnson Controls of the US).

AMS will provide the Command Team Trainer, Weapons Handling and Launch Trainer, Optronics trainer, other related training devices, and trainer maintenance support. CAE will provide the Manoeuvring Room Trainer, Submarine Control Trainer, Platform Management System Trainer, other related training devices, and trainer maintenance support. Flagship Training Limited will provide the building, facility management service, and the instructors.

The Astute Class Training Service (ACTS) contract is heavily dependent on accurate Astute design information being supplied from BAE Systems, and thus has been badly affected by the problems and delays experienced by the programme.   In light of the slippage to the submarine build contract, a submission for re-approval of ACTS via a Review Note is expected in early 2003.  Should further Astute class boats be ordered, the ACTS contract could be extended to run for 40 years.



In origination, the design and performance of the Astute Class closely relates to that of the earlier Trafalgar Batch 1, but updated tactical weapon systems and the enlarged hull required to accommodate the newer Rolls Royce Pressurised Water Reactor 2 (PWR2) which was originally developed for the Vanguard Class submarines.

In practice, the Astute Class is entering new waters by adopting the fully modular construction technique which it is hoped will significantly reduce cost and build time.  The decision to use the modular technique to build the Astute's involved not a little controversy within BAE Systems Marine (and between the engineers of its formally independent and competing constituents GEC Marconi, VSEL, British Aerospace, etc.), and a calculated amount of risk.  The standard method of submarine building in the UK is to assemble the components inside the pressure hull after it is completed.  Electronic equipment is fed in through the hatches and sometimes shoehorned into whatever space is available, making the final fit-out time-consuming.  Traditionally the attitude has been: 'We've got a huge amount of welding to do on this, so let's get on with it.''   Using these techniques it would take about 12 million staff hours to actually build three submarines of the size of the Astute Class, so the production phase is the obvious main target for reducing costs.  Building the boat in sections has been proven by submarine builders in Sweden and Germany as the best way to reduce production labour costs.  As late as May 2001 BAE engineers were publicly claiming that by adopting modular construction techniques, they could cut Astute design time by 25% and production time by 30%  compared to previous submarine projects.  BAE also said that it hoped to build the Astute's in an average of 6 years compared with the 8 years of the smaller Trafalgar Class.  Unfortunately these expectations soon proved to be badly mistaken.

The Astute's hull will be built in ring-like sections, rafts of components will be assembled simultaneously and installed before the sections are welded together at the latest possible stage.  When the hull modules are welded together, the restricted access to the interior will multiply the time it takes to carry out further work by many times.  The Astute design is actually broken down into nine hull sections and 11 main modules of equipment, including the reactor section, a 400-tonne command and control unit and more than 30 mini-modules.

MoD cost estimates are usually calculated in direct proportion to weight - hence the drive towards smaller vessels. It was hoped that the modular construction technique, with concurrent construction and fitting out of multiple modules saves time (and thus money) would allow BAE to build a larger hull for less than it cost to build the smaller Trafalgar class.  The cost savings anticipated by the modular approach led to a decision to make Astute hull as big as possible - 10.7m in diameter, determined by the space needed to accommodate the new PWR2 reactor - to reduce the risks of the new technique.  The larger hull also in turn created space for 50% more weaponry.  The previous plan had been for the hull to bulge around the reactor, but this would have been more complicated and costly than extending the whole sub's diameter and simplifying construction.

Bow section of HMS Ambush on a transporter, May 2006Rolls-Royce is supplying the PWR2 nuclear propulsion units for all the Astute boats. It has already delivered the first reactor pressure vessel to BAE Systems. As with earlier designs, the plant has a 25-year lifespan.  However, the Astute's will be fitted with a new long-life core (known as core H), which will power the boat for its full service term, eliminating the need for expensive and time-consuming refuelling.   

The latest computer-aided design (CAD) methods are being employed in the design and construction of the Astute's.  These supposedly allow full concurrent engineering and enable the work of designers in several companies and sites to be fully integrated, with regard to the performance and layout of all the individual elements of the submarine in a reduced overall design time.  Reduction in both build and support costs was a key objective of the design work.  Unfortunately the adopted CADDS5 system proved to be total disaster - despite BAE's expected input of significant expertise in this area given its advanced aerospace industry background - and this has been largely blamed for the enormous cost over-runs and multi-year delays that the Astute project has suffered.  During 2001 and 2002 shipyard workers found that the designs they were working to simply did not make sense, and equipment wouldn't fit together as it was supposed to, thus unassembled materials and equipment rapidly accumulated at Barrow, and delays lengthened as the designers tried to resolve the rapidly multiplying issues.  BAE's project management team also proved simply not up to the job of managing of a project as large and complex as Astute. 

In March 2003 it was announced that the American company - General Dynamics Electric Boat Division - would provide design assistance, and also help reinforce BAE's own Astute Project Team.  Under an agreement finalised in April 2003, up to 10 designers and engineers will be assigned to BAE SYSTEMS' Barrow-In-Furness shipyard for a period of approximately two years.  Additionally a number of American engineers and designers from EB will be familiarized on BAE Sustems' computer-aided design system and produce initial output drawings to support critical construction needs.  When they return to Groton USA, these employees will assist in familiarizing the main body of EB designers with BAE SYSTEMS' design system and methods. EB will provide the resources required by BAE SYSTEMS to complete timely, high-quality drawing outputs to support the production program of the Astute-class submarines.  On 23 October 2003 General Dynamics Electric Boat announced that it had received a $23 million contract modification to the contract initially announced in March 2003, which brings the total value of the work to $52.7 million. Under the contract, Electric Boat will provide the resources required to complete timely, high-quality drawing outputs to support the production program of the Astute-class submarines. Ninety percent of the work will be performed in Groton, USA; the remainder will be done in Barrow-in-Furness, Cumbria, UK.  By April 2004, EB had 13 staff at Barrow, and another 50 working on the Astute project at Groton, the two teams networked via a secure high-speed link. 

On 3 September 3 2004 it was announced (by the US DOD, not the MOD or BAE Systems) that  
Electric Boat Corp had been awarded a $144,848,826 cost-plus-fixed-fee modification to the previously awarded contract for Design Agent, Planning Yard and engineering and technical support for a foreign submarine program.  The contract provides services for the Astute-Class Submarine in the area of design support. The contract will provide for U.S. submarine design and production expertise; assisting with the development of computer aided design (CAD) tools and their use in submarine design and production processes; producing Astute-Class production drawings; and assisting/exchanging of expertise on submarine construction techniques.  Work will be performed in Groton, Conn. (90 percent) and Barrow-in-Furness, Cumbria U.K. (10 percent), and is expected to be completed by January 2007.

The failure of BAE to be able to successfully complete the design of the Astute's in-house, and its now all to public reliance on an American company to help complete the design, is a major failure.  Indeed, in May 2004 it seemed that BAE Systems was about to sell its Barrow facility to General Dynamics, but this was stopped when the MOD indicated that it would oppose the sale on national security grounds - the commercial logic of the deal for GD was based on it being able to transfer as much work as possible to its underutilised Electric Boat facilities in the USA and reducing Barrow to a minimal "metal bashing" facility for only the final assembly of RN boats . The loss of a UK national capability to design and upgrade submarines is not [yet] considered acceptable by the MOD, given that the UK's nuclear deterrent is still reliant on this.

Assuming that all the problems are eventually overcome, the final design will include the following significant improvements over the current Trafalgar Class submarines:

  • the latest, fully integrated submarine combat system;
  • significantly (50%) increased weapons load - including Spearfish, Sub-Harpoon and Tomahawk land attack missile;
  • two COM 10 "optronics" periscopes with electronic displays to avoid hull penetrating masts;
  • external actuation for all control surfaces to reduce hull penetrations and simplify aft end construction;
  • a digital control and information system for the submarine, to minimise costly cabling;
  • extensive detailed improvements to avoid outdated equipment's, improve operability and save cost.
  • reduced radiated noise.

During the redesign process, submerged displacement increased by 600 tonnes, from 7,200 to 7,800 tonnes.


Weapon Systems

Astute's combat system is an uplift of technology originally developed for the Final Phase update of the Swiftsure- and Trafalgar-class SSN tactical weapon system (TWS).  Its principal components are: the Astute Combat Management System, which ports existing Submarine Command System (SMCS) functionality onto a more open computing and display infrastructure; the Sonar 2076 integrated sonar suite (comprising bow, intercept, flank and towed arrays); the Outfit UAP(4) electronic support measures equipment; and the FDDI-based TWS Highway.  The Astute Class will have six 21 inch torpedo tubes and a capacity for a total of 38 torpedoes, missiles, mines and other weapons and systems. Contrary to some reports, a Vertical Launch System (VLS) will not be fitted.

Tomahawk Block III land attack missile

The Astute's will be equipped with the Tomahawk Block III cruise missile from Hughes Missiles Systems (became part of Raytheon Systems Company in December 1997).  The UK is also looking at developing a torpedo tube launched version of the successor to Tomahawk Block III in USN service, the Tactical Tomahawk ("TacTom").  This can currently only be fired from VLS tubes however a joint US/UK feasibility study established the integrity of an encapsulated version of Tactical Tomahawk suitable for torpedo tube launch, and early testing has been promising.

Sub- Harpoon

It is currently planned that the Astute Class will also have the capability to fire the Sub-Harpoon anti-surface warfare (ASuW) weapon developed by McDonnell Douglas Missile Systems Company (now part of Boeing).  Sub-Harpoon is an anti-ship sea-skimming missile with maximum velocity in excess of 0.8 mach and range in excess of 70 miles.  However, the existing Sub-Harpoon inventory is due to be withdrawn by the end of 2003 on the grounds that it is ill-suited to littoral operations and subject to restrictive rules of engagement.  It is still being considered whether RN submarines should retain a capability to fire the new Harpoon Block 2 missile which has increased capability.  

Loading Spearfish into a submarine

The Astute's will also carry Spearfish heavyweight  torpedoes, originally manufactured by Marconi - now part of BAE Systems.   Procured against Staff Requirement (Sea) 7525, Spearfish replaced the Mk 24 Mod 2 Tigerfish torpedo.  Spearfish is powered by a Sundstrand 21TP01 gas turbine (using HAP-Otto fuel) driving a shrouded pumpjet propulsor.  The Spearfish torpedo is an advanced wire-guided with an active/passive homing head and a directed energy warhead.  It's admitted range is 65km at 60 knots and it costs over over £2 million each!   A progressive programme of through-life technology insertion and capability enhancement is being developed under the Advanced Spearfish initiative.  

Spearfish packs a major punch in the ASuW role, but it is optimised against large targets and is an expensive weapon to expend against the small surface threats likely to be encountered in the littoral.

Given the costly "heavy weight" and frequently overkill limitations of Spearfish and Sub-Harpoon, there is growing interest from both FOSM staff and Director Equipment Capability (Under Water Battlespace) - DEC(UWB) - within the Ministry of Defence (MoD) in a shorter-range fibre optic-guided regional conflict weapon, such as the Triton submarine-launched weapon being developed by EADS LFK.

According to FOSM, such a regional conflict missile could offer universal application to influence the land battle ashore, provide precision ASuW against fast-attack craft and offer a self-protection capability against maritime patrol aircraft and anti-submarine helicopters.

Engineering mock up of the Astute Combat Management System (Source: BAE Systems)

In parallel, plans are being formulated to introduce TTWCS as part of a rolling programme of technology refresh planned for the RN Tomahawk during its lifecycle. UK mission planning facilities would also be the subject of a concomitant upgrade.

A wire guided Uninhabited Underwater Vehicle (UUV) will be carried for use in visual and sonar intelligence roles, and for remote SATCOM.  Approximately 15 nm of wire.

Finally, as part of very early studies in to the possible replacements of the Trident missile armed Vanguard class submarines in the nuclear deterrent role, consideration has been given to a dual role Astute variant.  BAE has considered a hull plug accommodating a silo of 16 Mk36 vertically launched cruise missiles (with nuclear or conventional warheads) forward, or 4 Trident D5 SLBM tubes incorporated in to an extended sail.   It appears that Prime Minister Blair authorised further studies in to a replacement of the UK's nuclear deterrent around May 2005, although no new system is needed until 2024 the lead times are very long. 



The names of the first 3 units will be HMS ASTUTE, HMS AMBUSH and HMS ARTFUL.


Web Links:

BAE Systems - Astute Class

Defence Procurement Agency  - Astute Class Submarine

Naval Technology SSN Astute Class Attack Submarine

Royal Navy - Astute Class Submarine



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 © 2004-13 Richard Beedall unless otherwise indicated.