Type 23 frigate
|Name:||Type 23 class|
|Builders:||Yarrow Shipbuilders and Swan Hunter|
|Operators:|| Royal Navy
|Preceded by:||Type 22 frigate
Condell class frigate (Chile)
|Succeeded by:||Global Combat Ship|
|In commission:||24 November 1987|
|Active:||13 Royal Navy
3 Chilean Navy
|Class & type:||Frigate|
|Displacement:||4,900 t (4,800 long tons; 5,400 short tons)|
|Length:||133 m (436 ft 4 in)|
|Beam:||16.1 m (52 ft 10 in)|
|Draught:||7.3 m (23 ft 9 in)|
|Propulsion:||CODLAG with four 1510 kW (2,025 shp) Paxman Valenta 12CM diesel generators powering two GEC electric motors delivering 2980kW (4000 shp) and two Rolls-Royce Spey SM1A replaced by updated SM1C delivering 23,190 kW (31,100 shp) to two shafts|
|Speed:||28 knots, HMS Sutherland achieved 34.4 knots during high-speed trials (November 2008)|
|Range:||14,485 km (9,000 miles) at 15 knots|
|Aircraft carried:||1×Lynx HMA8, armed with;
1×Westland Merlin HM1, armed with;
The Type 23 frigate or Duke-class is a class of frigate built for the United Kingdom's Royal Navy. The ships are named after British Dukes, thus leading to the class being commonly known as the Duke-class. The first Type 23 was commissioned in 1989, and the sixteenth, HMS St Albans was commissioned in June 2002. They form the core of the Royal Navy's destroyer and frigate fleet and serve along side the Type 45 destroyers. Originally designed for anti-submarine warfare in the North Atlantic, the Royal Navy’s Type 23 frigate have proved their versatility in warfighting, peace-keeping and maritime security operations across the globe. Thirteen Type 23 frigates remain in service with the Royal Navy, with three vessels having been sold to Chile and handed over to the Chilean Navy.
The Royal Navy’s current Type 23 frigates will be replaced by the Global Combat Ship starting from 2021. As of 2012[update] it is planned that HMS Argyll will be the first Type 23 to retire from the Royal Navy in 2023 while HMS St Albans will be the last, in 2036.
When first conceived in the late 1970s, the Type 23 was intended to be a light anti-submarine frigate to counter Soviet nuclear submarines operating in the North Atlantic. The Type 23 would be replacing the Leander class frigates (which had entered service in 1960s) and the Type 21 frigate (a general purpose design that recently entered service) as "the backbone of the Royal Navy's surface ship anti-submarine force". Although not intended to replace the Type 22 frigate, reductions in the size of the Navy due to the 1998 Strategic Defence Review led to HMS St Albans replacing HMS Coventry, a Type 22 frigate.
The ships were intended to carry a towed array sonar to detect Soviet submarines in the North Atlantic and carry a Westland Lynx or EHI Merlin helicopter to attack them. It was initially proposed that the frigates would not mount defensive armament. Instead the Sea Wolf missile system was to be carried by Fort Victoria class replenishment oilers, one of which was to support typically four Type 23s. The Fort class oilers would also provide servicing facilities for the force's helicopters; the Type 23 would have facilities only for rearming and refuelling them.
As a result of lessons learned from the Falklands War, the design grew in size and complexity to encompass the Vertical Launch Sea Wolf (VLS) system with an extra tracking system as a defence against low-flying aircraft and sea-skimming anti-ship missiles such as Exocet. With the addition of Harpoon surface-to-surface missiles and a medium calibre gun for naval gunfire support, the Type 23 had evolved into a more complex and balanced vessel optimised for general warfare, which introduced a host of new technologies and concepts to the Royal Navy. These included extensive radar cross section reduction design measures, automation to substantially reduce crew size, a Combined diesel-electric and gas (CODLAG) propulsion system providing very quiet running for anti-submarine operations along with excellent range, vertical launch missile technology and a fully distributed combat management system.
The Vertical Launch Sea Wolf surface-to-air missile system was designed for and first deployed on the Type 23. Unlike conventional Sea Wolf, the missile is boosted vertically until it clears the ship's superstructure and then turns to fly directly to the target. Consequently, the ship's structure does not cause no-fire zones that would delay or inhibit missile firing in a conventionally launched system.
Although the Type 23 is officially the "Duke" class, and includes such famous names as HMS Iron Duke, (which had been the name of the battleship HMS Iron Duke, Admiral Jellicoe's flagship at the Battle of Jutland), five of the names had previously been used on classes known as the "County class": Kent and Norfolk were names given both to 1960s guided missile destroyers and Second World War-era County class heavy cruisers, while Monmouth, Lancaster, Kent and Argyll revived names carried by First World War-era Monmouth class armoured cruisers. This use of Ducal and County names broke a tradition of alphabetical names for escort ships which had run in two – not unbroken – cycles from the L-class destroyers of 1913 to the Daring-class destroyers of 1950; this progression was revived with the Amazon-class Type 21 frigates of 1972–75, and continued with B and C names for most of the Type 22 frigates of 1976–89. However, the D names have since been used for the new Type 45 Daring-class destroyers now entering service from 2009.
It is stated that: "Type 23 frigates achieved approximately 85–89 per cent average availability for operational service in each of the last five years with the exception of 1996 when the figure dropped to just over 80 per cent due to a number of ships experiencing a particular defect. This discounts time spent in planned maintenance."
Programme costs 
Prior to the Falklands War the cost of the Type 23 frigates was estimated at £75 million (September 1980 prices) Changes following the experiences in the Falklands, including improved damage control and fire precautions led to an increased cost estimated at £110 million (1984–85 prices) By 2001, the Ministry of Defence said the cost of HMS Norfolk was £135.449 million and the remaining ships would have a final cost between £60 million and £96 million each The Ministry of Defence said in 1998 that the Merlin ASW helicopter was costing them £97M each (this was for an order for 44 airframes), and that this was 57% of the cost of Type 23. From this it can be calculated that the cost of Type 23 was £ 170.1M each. The Government's declared policy for construction contracts for Type 23 was "...competition, the aim being to secure best value for money for the defence budget." while maintaining "sufficient warship-building capacity to meet likely future defence requirements and a competitive base"
Sale to Chile 
On 21 July 2004, in the Delivering Security in a Changing World review of defence spending, Defence Secretary Geoff Hoon announced that HMS Norfolk, Marlborough and Grafton were to be paid off. In 2005 it was announced that these three vessels would be sold to the Chilean Navy, to be delivered in 2008. In September 2005 BAE Systems was awarded a £134 million GBP contract to prepare the frigates for transfer. The Marlborough, Norfolk and Grafton were sold to Chile for a total of £134 million. The letter of intent for purchase was signed in December 2004, followed by a formal contract on 7 September 2005. The Norfolk was handed over by the Defence Logistics Organisation and BAE Systems and commissioned into the Chilean Navy on 22 November 2006, and named Almirante Cochrane (FF-05) (after Lord Cochrane, a naval hero to both the British and Chileans). The Grafton was delivered to Chilean Navy on 28 March 2007 at Portsmouth and renamed Almirante Lynch (FF-07). The Marlborough was delivered to Chilean Navy on 28 May 2008 at Portsmouth and renamed Almirante Condell (FF-06).
Upgrades and future technologies 
Mid-life refit 
The class are currently going through mid-life refits which last 12–18 months and cost £15-20m. Aside from refurbishment of the mess decks and drive train, the ships are being fitted with a transom flap which can add up to 1 knot to the top speed and reduce fuel consumption by 13%, and Intersleek anti-fouling paint which added 2 knots to the top speed of Ark Royal. Although the top speed of the Duke class is commonly quoted as 28 knots, the caption of an official Navy photo suggests that Lancaster was capable of 32 knots even before her mid-life refit; The Sea Wolf Mid Life Update (SWMLU) improves the sensors and guidance of the missiles, point defences are further improved with new remotely-operated 30mm guns, and Mod 1 of the Mk8 main gun has an all-electric loading system and a smaller radar cross-section. The communications and command systems are also upgraded.
Sonar 2087 
Sonar 2087 is described by its manufacturer as "a towed-array system that enables Type 23 frigates to hunt the latest submarines at considerable distances and locate them beyond the range at which they [submarines] can launch an attack." Sonar 2087 was fitted to eight Type 23 frigates in mid-life refits between 2004 and 2012; the five oldest Type 23 frigates, HMS Montrose, Monmouth, Iron Duke, Lancaster and Argyll are not scheduled to receive Sonar 2087. These ships will instead continue to be employed across the normal range of standing Royal Navy deployments.
Artisan 3D radar 
The Type 23's medium range radar will be replaced by BAE Systems Insyte Type 997 Artisan 3D radar. It is a medium range radar designed to be extremely modular and highly configurable to provide a cost-effective high-performance radar, capable of operating effectively in littoral zones and improving air-defence, anti-surface (anti-ship) and air traffic management capabilities of the Type 23 frigates. Protection measures are also added to maintain detection ranges even when attacked by complex jammers. HMS Iron Duke will be the first Type 23 frigate to receive the Type 997 Artisan 3D radar during her refit in 2012-13. It will be fitted to all T23's as well as the assault platforms (LPD) - HMS Albion & HMS Bulwark, the Helicopter Platform (LPH) - HMS Ocean and the two future Queen Elizabeth class aircraft carriers are also planned to be equipped with the same radar. The project was worth £100 Million and the contract was announced in 4 August 2008.
HMS Iron Duke received her new Type 997 Artisan 3D radar in 2013. It is claimed the radar is 5 times more capable than the Type 996 radar it replaces.
Common Anti-Air Modular Missile 
The CAMM(M) variant of the Common Anti-Air Modular Missile is intended to replace the current Sea Wolf missile currently equipped on the Type 23 frigates starting from 2016. CAMM(M) has a longer range of 1–25+ km compared to the 1–10 km offered by the Sea Wolf missile. An option exists to give the missile a surface-attack capability, though it is currently understood the Royal Navy will not take that option, due to budget reasons. Like Sea Wolf, CAMM(M) will be VLS launched, however due to its design, CAMM(M) can be packed much more tightly into the VLS, with up to four CAMM(M) fitting into the space occupied by one Sea Wolf missile. CAMM(M) is known as Sea Ceptor in Royal Navy service.
Weapons, countermeasures, capabilities and sensors 
- Anti-air warfare
- A BAE Systems Type 996 Mod 1, 3D surveillance and target indication radar.
- Two Marconi Electronic Systems Type 911 fire control radars.
- Sea Wolf missiles (range 1–10 km)
The Type 996 Mod 1, 3D surveillance and target indication radar is being replaced on all Type 23 frigates by the more capable Type 997 Artisan 3D radar.
- Anti-ship warfare
- 2× 4 Harpoon anti-ship missile launchers for a total of 8 Harpoon anti-ship missiles.
- 1× BAE Systems 4.5 inch Mark 8 naval gun has an anti-ship role.
- Up-to one embarked Westland Lynx helicopter can be equipped with 4× Sea Skua anti-ship missiles.
- Anti-submarine warfare
- A Thales Underwater Systems Type 2050 bow sonar.
- A Ultra Electronics Type 2031Z towed sonar on five of the Type 23 frigates.
- A Type 2087 towed sonar on eight of the Type 23 frigate.
- 2× twin 12.75 in (324 mm) tubes for anti-submarine Sting Ray torpedoes. The tubes are magazine reloaded.
- Up-to one embarked Westland Lynx or one AgustaWestland EH101 helicopter can be equipped with 2-4× anti-submarine Sting Ray torpedoes respectively.
- 1× BAE Systems 4.5 inch Mark 8 naval gun.
- 2× 30mm DS30M Mark 2 Automated Small Calibre Guns or 30mm DS30B guns.
- 2× Miniguns.
- 4× General-purpose machine guns.
- The Seagnat decoy system allows for the seduction and distraction of radar guided weapons, through active and passive means.
- Type 182 towed torpedo decoys.
- Type 2070 towed torpedo decoy system.
- Thales defence Scorpion Electronic Counter Measures/UAF-1 ESM Jammer. Used to confuse or block enemy radar making the Type 23 frigate harder to detect and or locked onto by enemy radar/sonar guided weapons.
- Electronic Systems
- Navigation: Kelvin Hughes Radar Type 1007 and Racal Decca Type 1008.
- fire-control system: Sperry Sea Archer 30 optronic surveillance/director'
- Combat Management System: BAE Systems Command System DNA(1)'
- Additional capabilities
- The Type 23 frigates have sufficient space to embark a small detachment of Royal Marines and their equipment.
Ships of the class 
Construction programme 
The costs in the table below are in two columns:
- Original hull cost. "Other costs, such as those for Government furnished equipment, are not held centrally for each ship and could be provided only at disproportionate cost."
- Estimated building cost. This is a phrase used in Defence Estimates, and before that in Navy Estimates. It does not include the armament, or government furnished equipment.
|Pennant||Name||(a) Hull builder||Ordered||Laid down||Launched||Accepted into service||Commissioned||Original hull cost||Estimated building cost|
|F230||Norfolk||Yarrow Shipbuilders Ltd.||29 October 1984||14 December 1985||10 July 1987||1 June 1990||£112.03M||£142M
|F231||Argyll||Yarrow Shipbuilders Ltd.||1 September 1986||20 March 1987||8 April 1989||17 April 1991||31 May 1991||£118.95M|
|F229 (ex-F232)||Lancaster||Yarrow Shipbuilders Ltd.||1 September 1986||18 December 1987||24 May 1990||1 May 1992||£119.71M|
|F233||Marlborough||Swan Hunter.||1 September 1986||22 October 1987||21 January 1989||7 March 1991||14 June 1991||£118.43M||£120M|
|F234||Iron Duke||Yarrow Shipbuilders Ltd.||11 July 1988||12 December 1988||2 March 1991||20 May 1993||£109.77M|
|F235||Monmouth||Yarrow Shipbuilders Ltd.||11 July 1988||1 June 1989||23 November 1991||24 September 1993||£111.66M|
|F236||Montrose||Yarrow Shipbuilders Ltd.||11 July 1988||1 November 1989||31 July 1992||2 June 1994||£117.29M|
|F237||Westminster||Swan Hunter.||December 1989||18 January 1991||4 February 1992||13 May 1994||£112.68M|
|F238||Northumberland||Swan Hunter.||December 1989||4 April 1991||4 April 1992||29 November 1994||£114.73M|
|F239||Richmond||Swan Hunter.||December 1989||16 February 1992||6 April 1993||22 June 1995||£116.2M|
|F82||Somerset||Yarrow Shipbuilders Ltd.||January 1992||12 October 1992||25 June 1994||20 September 1996||£114.14M|
|F80||Grafton||Yarrow Shipbuilders Ltd.||January 1992||13 May 1993||5 November 1994||29 May 1997||£115.56M||£79M|
|F81||Sutherland||Yarrow Shipbuilders Ltd.||January 1992||14 October 1993||9 March 1996||4 July 1997||£143.58M|
|F78||Kent||Yarrow Shipbuilders Ltd.||February 1996||16 April 1997||27 May 1998||8 June 2000||£108.42M|
|F79||Portland||Marconi Marine. [Formerly Yarrow.]||February 1996||14 January 1998||15 May 1999||15 December 2000||3 May 2001||£92.06M|
|F83||St Albans||BAE Systems Marine. [Formerly Yarrow.]||February 1996||18 April 1999||6 May 2000||6 June 2002||£106.82M|
Running costs 
|Date||Running cost||What is included||Citation|
|1987–88||£3.6 million||Estimate of the annual running costs for a type 23 frigate. These costs include personnel, fuel, spares and so on, and administrative support services, but exclude new construction, capital equipment, and refit-repair costs.|||
|2001–02||£10.3 million||"Average annual operating costs, based on historic costs over the last two full financial years are given in the table. The figures include manpower, maintenance, fuel, stores and other costs (such as harbour dues), but exclude depreciation and cost of capital."|||
|2007-08||£26.18 million||"The Type 23 Class of Frigates, comprising 13 vessels, has a combined annual operating cost of £340.3M." "This is based on information primarily from Financial Year 07/08 the last year for which this information is available, and includes typical day-to-day costs such as fuel and manpower and general support costs covering maintenance, repair and equipment spares. Costs for equipment spares are also included, although these are based on Financial Year 08/09 information as this is the most recent information available. Costs for weapon system support are not included as they could only be provided at disproportionate cost."|||
|2009-10||£24.14 million||The average running cost per class for Type 23 was £313.8 million. "These figures, based on the expenditure incurred by the Ministry of Defence in 2009-10, include maintenance, safety certification, military upgrades, manpower, inventory, satellite communication, fuel costs and depreciation."|||
- Refits completed since 1997
|HM Ship||Refit dates||Approx. duration||Contracted price||Final cost||Source|
|Argyll||Jun 2003 – Nov 2003||24 weeks||£5.6 million||£5.6 million|||
|Lancaster||May 2004 – Dec 2004||32 weeks||£7.6 million||£7.6 million|||
|Somerset||May 2006 – Jun 2007||56 weeks||£11.9 million||£11.9 million|||
|Portland||May 2006 – Jan 2007||44 weeks||£8.7 million||£8.7 million|||
|Richmond||Aug 2005 – Sep 2006||56 weeks||£9.4 million||£9.4 million|||
|Kent||Jan 2005 – Jun 2005||24 weeks||£5.8 million||£5.8 million|||
- Contracts placed under the SSS Programme
|HM Ship||Refit dates||Duration||Contracted price incl. profit and growth||Out-turn cost excl. profit||Final cost (£m)||Source|
|Iron Duke||Feb 2007 – Nov 2007||40 weeks||£10.8 million|||
|St Albans||May 2007 – Jul 2008||60 weeks||£15.4 million|||
|Name||RN Home port||Out-of-service date
(as planned in 2006)
(as announced in 2009)
|Actual out-of-service date||Name after sale abroad||New home port||Commissioned by foreign navy||Status|
|HMS Norfolk||Devonport||FY2005-06||Almirante Cochrane FF-05||Valparaiso||22 November 2006||Active Chilean Navy|
|HMS Marlborough||Portsmouth||FY2005-06||Almirante Condell FF-06||Valparaiso||2008||Active Chilean Navy|
|HMS Grafton||Portsmouth||Non-operational from 31 March 2006.||Almirante Lynch FF-07||Valparaiso||28 March 2007||Active Chilean Navy|
|HMS Argyll||Devonport||2019||2023||Active RN|
|HMS Lancaster||Portsmouth||2019||2024||Active RN|
|HMS Iron Duke||Portsmouth||2020||2025||Active RN|
|HMS Monmouth||Devonport||2021||2026||Active RN|
|HMS Montrose||Devonport||2021||2027||Active RN|
|HMS Westminster||Portsmouth||2028||Active RN|
|HMS Northumberland||Devonport||2029||Active RN|
|HMS Richmond||Portsmouth||2030||Active RN|
|HMS Somerset||Devonport||2031||Active RN|
|HMS Sutherland||Devonport||2033||Active RN|
|HMS Kent||Portsmouth||2034||Active RN|
|HMS Portland||Devonport||2035||Active RN|
|HMS St. Albans||Portsmouth||2036||Active RN|
Type 23 frigates in fiction 
- HMS Westminster was used for the Type 23 interior shots in the James Bond film Tomorrow Never Dies in three different roles as HMS Chester, HMS Devonshire and HMS Bedford. For the exterior shots a Type 23 model was constructed.
- The ITV series Making Waves was set aboard the Type 23 frigate HMS Suffolk (which was portrayed by HMS Grafton).
- HMS Montrose and HMS Monmouth were used to portray the interior and exterior shots of the fictional HMS Monarch for the film Command Approved which is the centre piece of Action Stations at Portsmouth Historic Dockyard, Portsmouth, England.
- The fictional HMS Beaufort is the centrepiece of British author Mike Lunnon-Wood's novel King's Shilling. In it, HMS Beaufort is tasked to evacuate the British embassy and citizens in the Liberian capital Monrovia during the 1990s civil war.
See also 
- Royal Navy - Frigates
- "Type 26". Royal Navy.
- "Daily Hansard - Written Answers to Questions". UK Parliament. 6 September 2012.
- "Navy unveils latest design of future frigate". Royal Navy. 20 August 2012.
- Hansard 5 Jul 2001: Column: 245W Questions to the Secretary of State for Defence, 5 July 2001.
- Hansard 11 Jul 2000: Column: 449W Question to the Secretary of State for Defence when he planned to withdraw the Type 22 Batch II frigates from service. His answer was:
- "HMS Sheffield 2012 – to be superseded by a T45 Destroyer
- HMS Coventry 2001 – to be superseded by HMS St. Albans, a T23 Frigate".
- "Defence;Where's the cache?". The Economist. 10 July 1982. p. 21.
- Hansard 10 Feb 1998: Column: 195, 10 Feb 1998 : Column: 196 Questions to the Secretary of State for Defence about the manning and availability of warships, 10 February 1998.
- Hansard 17 Mar 2011, Column 511W
- HC Deb 11 January 1985 vol 70 c561W Questions to the Secretary of State for Defence about Type 23 frigates, 11 January 1985.
- Hansard HC Deb 19 July 1983 vol 46 cc179-263
- Warship World, Spring 1998, pub Maritime Books, page 13. This figure of £97 million each included research and development costs.
- Hansard HC Deb 2 November 1989 vol 159 cc333-4W Questions to Secretary of State for Defence, 2 November 1989.
- "House of Commons Hansard Written Answers for 5 Jul 2001". Hansard (Official Report). HM Government. 5 July 2001. Retrieved 23 July 2007.
- Hansard 24 May 2007 : Column 1388W—continued Question to the Secretary of State for Defence which naval vessels have been sold by the Royal Navy in the last five years; what the (a) vessel type, (b) service cost and (c) destination country was in each case; and if he will estimate the (i) original costs of each vessel and (ii) financial gains accrued to public funds as a result of each sale, 24 May 2007.
- Saunders, Stephen Jane's Fighting Ships 2008–2009, pub Jane's Information Group, 2008, ISBN 978-0-7106-2845-9-page 111.
- "A Forth for good". Navy News. September 2008. p. 6.
- "The Royal Navy's Fleet". Royal Navy Matters (Royal Navy). 2010. p. 52. Retrieved 16 October 2011.
- http://www.defenceimagedatabase.mod.uk/ image 45139105.jpg (taken 12 September 1999) is captioned "DUKE CLASS TYPE 23 FRIGATE F229 HMS LANCASTER STEAMING AT 32 KNOTS."
- "HMS Sutherland - More About The Ship". Royal Navy. Retrieved 16 October 2011.
- Hansard 17 July 2006: Column 220W Question to the Secretary of State for Defence about the five Type 23 frigates which are not to be fitted with Sonar 2087, 17 July 2006.
- "New Royal Navy Type 997 radar is put through its paces on the Isle of Wight". 13 September 2011. Retrieved 16 October 2011.
- http://www.royalnavy.mod.uk/server/show/ConWebDoc.13459/changeNav/6568 Royal Navy News and Events:Navy to Get New Radar
- Navy's new Type 23 frigate radar 'five times more efficient
- "Press Information - CAMM". MBDA Systems. June 2011. Retrieved 16 October 2011.
- Sweetman, Bill (23 May 2011). "CAMM On Path To Replace Seawolf". Retrieved 16 October 2011.
- Hansard 13 March 2008: Column 667W Question to the Secretary of State for Defence about the outturn cost of each Type 23 frigate, 13 March 2008.
- "Unit cost, i.e. excluding cost of certain items (e.g. aircraft, First Outfits)." – Text from Defences Estimates
"They do not include other costs, such as those for Government Furnished Equipment (GFE)—as they are not held centrally for each ship and could be provided only at disproportionate cost." Bob Ainsworth, Minister of State for the Armed Forces, 16 July 2008.
- The term used in Navy Estimates and Defence Estimates is "accepted into service". Hansard has used the term acceptance date. Leo Marriott in his various books uses the term "completed", as does Jane's Fighting Ships. These terms all mean the same thing: the date the Navy accepts the vessel from the builder. This date is important because maintenance cycles, etc. are generally calculated from the acceptance date.
- Hansard HC Deb 23 October 1989 vol 158 cc358-61W Question to the Secretary of State for Defence asking him to list the Royal Navy vessels built in each of the past 15 years, showing the cost of each and the yards in which they were constructed.
- Saunders, Stephen Jane's Fighting Ships 2002–2003, pub Jane's Information group, 2002, ISBN 0-7106-2432-8-page 776.
- Gardiner, Robert Conway's All the World's Fighting Ships 1947–1995, pub Conway Maritime Press, 1995, ISBN 0-85177-605-1-page 525.
- Saunders, Stephen Jane's Fighting Ships 2008–2009, pub Jane's Information Group, 2008, ISBN 978-0-7106-2845-9-page 862.
- Hansard HC 23 May 1991 Questions to the Secretary of State for Defence about building programme for Type 23, 23 May 1991.
- "HMS Portland". Type 23 Frigates. royalnavy.mod.uk. 2009. Retrieved 7 January 2010.
- Hansard HC Deb 10 March 1989 vol 148 c44W Question to the Secretary of State for Defence about the annual running costs for different classes of frigate and destroyer.
- Hansard HC Deb 9 September 2003 vol 410 cc346-7W Question to the Secretary of State for Defence ab out the average operating cost of(a) batch 3 type 22, (b) type 23 and (c) type 42 destroyers, 9 September 2003.
- Hansard 9 Sep 2009, Column 2001W
- Hansard 24 November 2010 Written Answers.
- Out-turn cost data are not required for completed contracts as the price is agreed as part of the contract negotiations.
- 25 Nov 2008 : Column WA280
- Hansard 10 Jan 2006: Column 505W—continued Question to the Secretary of State for Defence how many helicopters are carried by each of the Type 23 frigates, broken down by type of helicopter, 10 January 2006.
- Hansard 3 Mar 2009 : Column 1446W—continued Question to the Secretary of State for Defence what the (a) in-service dates and (b) current out-of-service dates are for each (i) submarine, (ii) frigate and (iii) destroyer in the Royal Navy, 3 March 2009.
- The Encyclopedia of Warships, From World War Two to the Present Day, General Editor Robert Jackson
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