View source for Type 21 frigate

{{Short description|Class of general purpose frigates built for Royal Navy}}
{{Use dmy dates|date=October 2020}}
{|{{Infobox ship begin}}
{{Infobox ship image
|Ship image=HMS Arrow (F173) underway c1982.jpg
|Ship caption=The [[Royal Navy]] frigate {{HMS|Arrow|F173|6}} underway (circa 1982)
}}
{{Infobox ship class overview
|Name=Type 21 ''Amazon''
|Builders=*[[Yarrow Shipbuilders]],
*[[Vosper Thornycroft]]
|Operators= * {{navy|United Kingdom}} <small>(historical)</small>
* {{navy|Pakistan}}
|Class before=[[Leander-class frigate|Type 12I ''Leander'']]
|Class after=[[Type 22 frigate|Type 22 ''Broadsword'']]
|Subclasses=*{{sclass|Niteroi|frigate|4}}
*{{sclass|Alvand|frigate|4}}
*{{sclass|Tariq|destroyer|4}}
|Cost=
|Built range=6 November 1969-20 November 1975
|In service range=
|In commission range=11 May 1974
|Total ships building= 
|Total ships planned=
|Total ships completed=8
|Total ships cancelled=
|Total ships active=0
|Total ships laid up=
|Total ships lost=2
|Total ships retired=6
|Total ships preserved=
}}
{{Infobox ship characteristics
|Hide header=
|Header caption=
|Ship type=[[Frigate]]
|Ship displacement=
*As built:
**2,750 [[long ton|tons]] (standard)
**3,250 tons (full load)
*After strengthening:
**2,860 tons (standard)
**3,360 tons (full load)
|Ship length=*{{convert|360|ft|abbr=on}} ([[Length at the waterline|waterline]])
*{{convert|384|ft|abbr=on}} ([[Length overall|overall]])
|Ship beam={{convert|41.8|ft|abbr=on}}
|Ship height=
|Ship draught={{convert|19|ft|abbr=on}}
|Ship draft=
|Ship power=
|Ship propulsion=*[[COGOG]]&nbsp;on 2 shafts;
*2 × [[Rolls-Royce Tyne|Tyne]] cruise turbines: {{convert|8500|shp|abbr=on}}
*2 × [[Rolls-Royce Olympus|Olympus]] boost turbines: {{convert|50000|shp|abbr=on}}
|Ship speed=*{{convert|32|kn}} 37 knots burst speed (Olympus)
*{{convert|18|kn}} (Tyne)
|Ship range=*{{convert|4000|nmi|lk=in|abbr=on}} at {{convert|17|kn}}
*{{convert|3500|nmi|abbr=on}} at {{convert|18|kn}}
*{{convert|1200|nmi|abbr=on}} at {{convert|30|kn}}
|Ship endurance=
|Ship complement=13 officers, 164 ratings
|Ship time to activate=
|Ship sensors=*1 × Radar Type 992Q low-level search
*1 × Radar Type 978 navigation
*2 × Radar Type 912 fire-control
*Sonar Type 184M and 162M
|Ship EW=
|Ship armament=
*1 × [[4.5-inch (114 mm) Mark 8 naval gun|4.5 in (114 mm) Vickers Mark 8 gun]]
*2 × [[Oerlikon 20 mm cannon|20 mm Oerlikon gun]]s (later 4)
*1 × 4-rail launcher for GWS-24 [[Seacat (missile)|Sea Cat]]
*2 × 8-barrelled Knebworth Corvus countermeasures launchers
*Later additions:
*4 × launchers for MM38 [[Exocet]] surface-surface missiles
*2 × {{convert|12.75|in|mm|abbr=on}} 3-tube STWS-1 anti-submarine [[torpedo]] launchers
*'''Pakistani modifications:'''
*[[MASS (decoy system)|TKWA/MASS (Multi Ammunition Softkill System)]]
*2 x 4-cell [[Harpoon (missile)|Harpoon]] missile launchers (3 ships)
*''or'' 
*1 x 6-cell [[LY-60 / FD-60 / PL10|LY-60N Hunting Eagle]] [[surface-to-air missile|SAM]] launcher (3 ships)
*1 × [[Phalanx CIWS|Vulcan Phalanx 20mm CIWS]]
|Ship armour=
|Ship armor=
|Ship aircraft=1 × [[Westland Wasp|Wasp]] or [[Westland Lynx|Lynx]]
|Ship aircraft facilities=Flight deck and hangar
|Ship notes=
}}
|}
[[File:HMS Amazon (F 169) during Exercise RIMPAC 86.jpg|thumb|{{HMS|Amazon|F169|6}} during Exercise RIMPAC 86]]
The '''Type 21 frigate''', or '''''Amazon''-class frigate''', was a British [[Royal Navy]] general-purpose escort that was designed in the late 1960s, built in the 1970s and served throughout the 1980s into the 1990s.<ref name="Marriott" />

==Development==
In the mid-1960s, the Royal Navy (RN) had a requirement for a replacement for the diesel-powered {{sclass|Leopard|frigate|0}} (Type 41) anti-aircraft frigates and {{sclass|Salisbury|frigate|0}} (Type 61) air direction frigates. While the Royal Navy's warships were traditionally designed by the [[Ministry of Defence (United Kingdom)|Ministry of Defence]]'s Ship Department based at [[Bath, Somerset|Bath]], private [[shipyard]]s (in particular [[VT Group|Vosper Thorneycroft]]) campaigned for the right to design and build a ship to meet this requirement. Vospers claimed that, by ignoring what they claimed to be the conservative design practices followed by the MoD team at Bath, they could deliver the new frigate at a significantly lower price (£3.5 million compared with the £5 million price of the contemporary {{sclass|Leander|frigate|4}}), while being attractive to export customers.<ref name="Conways47 p522">Gardiner and Chumbley 1995, p. 522.</ref><ref name="worst p171">Preston 2002, p. 171.</ref>

The class was ordered under political and Treasury pressure for a relatively cheap, yet modern, general purpose escort vessel which would be attractive to governments and officers of South America and [[Australasia]]: the traditional export markets of British shipyards. It was also envisaged as an out-of-area RN gunboat that would retain UK presence in those areas, as well as the [[Caribbean]] and the [[Persian Gulf]]; essentially replacing the diesel-powered Type 41s and Type 61s and the [[combined steam and gas]]-powered  [[Tribal-class frigate|Type 81]] frigates with smaller crewed vessels. The RN staff disliked the idea and would have preferred to continue to develop steam types – in the RN's case, the Type 12I ''Leander'' class, which was regarded as a successful and quiet anti-submarine hunter, but was seen by the politicians as dated and by the Treasury and export-oriented shipyards as too expensive to market.{{citation needed|date=April 2022}}

The development of Vosper's own export designs, the Mk 5 for Iran and the Mk 7 for Libya, increased the pressure on the Admiralty to accept this line of naval development, which seemed to offer a cheap export frigate with a range of {{convert|6000|nmi|lk=in}}, a top speed of {{convert|37|kn|lk=in}}, a superficially good armament of the new [[4.5-inch Mark 8 naval gun|Mark 8 4.5-inch (113 mm) gun]], facilities for a [[Westland Wasp]] helicopter, [[anti-ship missile]]s and two triple lightweight [[Seacat (missile)|Seacat missile]] launchers. When plans for the new {{ship|Libyan frigate|Dat Assawari}} were finalised in 1968, the Admiralty board accepted that its paper specifications were unanswerable<ref>{{citation |first=N. |last=Friedman |date=2006 |title=British Destroyers and Frigates. Second World War & After |publisher= Chatham  |location=London |pages= 275, 292}}</ref> and they would have to allow the shipyards to develop a low cost fill in [[anti-submarine warfare]] and general purpose version for the RN that would be stretched and fully gas turbine-powered rather than [[combined diesel and gas]] like the Mk 5 and Mk 7. In reality, it was a much more difficult design, with the lack of heavy propulsion machinery low in the hull to balance the top weight of bulky superstructure. The fitting of Tyne gas turbines for cruising, instead of the diesels used in the Iranian and Libyan versions, meant fuel consumption and cost would be high, which was a tremendous problem for the Royal Navy in the early 1980s when the austerity of early [[Thatcherism]] cut the Royal Navy fuel allowance and meant that most frigates spent more time tied up, rather than at sea in 1980–1981; and despite the smaller crew, running costs of the Type 21 were ten percent higher than those of the ''Leander''s.{{citation needed|date=April 2022}}

The Type 21 would provide the shipyards with experience in building fully gas turbine powered ships and provide them with useful work for the shipyards while the [[Type 42 destroyer]] and [[Type 22 frigate]] would not be ready until the mid-to-late 1970s. As the [[Admiralty design board]] were busy with the latter, the Type 21 project was given to the private shipyards of Vosper Thornycroft and [[Yarrow Shipbuilders Ltd|Yarrow]]. The unmistakably [[yacht]]-like and rakish lines were indicative of their commercial design.{{citation needed|date=April 2022}}

At one stage, it was hoped to build a joint design that would meet both the Royal Navy's requirement for a low-cost Patrol Frigate and Australia's General Purpose Escort requirement, with discussions between the two navies beginning in 1967,<ref name="Fried p292-4">Friedman 2008, pp. 292–294.</ref> with Australia, who hoped to build a series of Type 21s in Australian shipyards, part-funding design work on the proposal.<ref name="Conways47 p522"/> The requirements of the two navies were significantly different, with Australia wanting higher speeds ({{convert|35|kn}} rather than the {{convert|32|kn|adj=on}} requirement of the Royal Navy) and American armament (including [[Sea Sparrow]] missiles and a [[5"/54 caliber Mark 45 gun|{{convert|5|in|mm|adj=on|0}} Mark 45 gun]]).  Australia pulled out of the project in November 1968, later refining its requirements into the [[Australian light destroyer project]].<ref name="Fried p294-5">Friedman 2008, pp. 294–295.</ref> After the [[Royal Australian Navy]] (RAN) DDL was cancelled the RAN and [[Royal New Zealand Navy]] (RNZN) reconsidered the Type 21 but still found it too expensive,<ref>A. Preston. (2002) 'Type 21 Anti Sub Frigate' in ''The World's Worst Warships''  p. 172.</ref> and considered the UK gun and radar inferior to the [[United States Navy]] options.<ref>{{citation |first=M. |last=Briggs |contribution=DDL. The Australian Light Destroyer |title= Warship 2016 |publisher=Conway |date=2016 |location=London |page= 54}}</ref> Australia ordered the US {{sclass|Oliver Hazard Perry|frigate|0}} design in 1976.

A contract for detailed design of the new frigate to meet Royal Navy requirements and to build the first example was placed in March 1969. By this time cost had crept up to £7.3 million, more than ''Leander''-class frigates.<ref name="Fried p295">Friedman 2008, p. 295.</ref>

Attempts continued to sell frigates derived from the Type 21 to export customers, including Argentina.<ref name="Conways47 p522"/> A broad-beam derivative armed with vertical-launch [[Sea Wolf (missile)|Sea Wolf]] surface-to-air missiles was offered to Pakistan in 1985.<ref name="cf86 p372">Couhat and Baker 1986, p. 372.</ref>

The first of the eight built, {{HMS|Amazon|F169|2}}, entered service in May 1974.

==Design==
These ships were the Royal Navy's first privately designed warships for many years.<ref name="Marriott" /> They were also the first design to enter service with the Royal Navy to be solely powered by [[gas-turbine]] engines, with two [[Rolls-Royce Tyne]]s for cruising and two [[Rolls-Royce Olympus]] for high speeds arranged in a [[combined gas or gas]] (COGOG) arrangement.<ref name="Conways47 p522"/> The design had a large superstructure in relation to the volume of the main hull (below No 1 Deck) and made use of large amounts of [[aluminium alloy]] in the superstructure with the aim of reducing the topweight. However the design team miscalculated the weight of the ‘Outfit’ in and on the superstructure.  The height of the superstructure exacerbated the error. Worries later surfaced about aluminium’s resilience to fire, particularly following a major fire on ''Amazon'' in 1977 during which aluminium ladders distorted, preventing fire-fighting teams from reaching the blaze, and its ability to withstand blast damage. Later British warships avoided aluminium for superstructure and load-bearing structure, and reverted to steel. <ref name="worst p171,5-6">Preston 2002, pp. 171, 175–176.</ref>

As delivered, the Type 21s were armed with a single [[4.5 inch Mark 8 naval gun]] forward, and a four-round launcher for the SeaCat [[surface-to-air missile]] aft. The Italian Selenia Orion-10X lightweight fire control [[radar]] was adopted to control both the gun and the SeaCat missile (as the GWS-24 system) in an effort to save weight. A Type 992Q air/surface radar was fitted, but a long-range air-search radar was not provided. A [[hangar]] and [[flight deck]] were provided for a single helicopter, at first the [[Westland Wasp]]. The CAAIS was provided to integrate the ship's weapons and sensor systems and provide the crew with all the relevant information they required to fight the ship, as and when they needed it.<ref name="Conways47 p522"/><ref name="cf86 p193-4">pp. 193–194, Couhat, J.L., Baker III, A.D.  'Combat Fleets of the World 1986-1987', {{ISBN|978-0870-211-560}}, US Naval Institute Press, 1986</ref>

In terms of automation, systems integration and habitability, they were well in advance of many of the ships that they replaced, such as the [[Type 81 frigate|Type 81 (Tribal-class) frigate]] and Type 12M {{sclass|Rothesay|frigate|1}} - the latter's basic design could be traced back to 1945.

===Modifications===
MoD discovered the error in weight and Vertical Centre of Gravity about 6 months after the first of class was launched.   When they entered service, the Type 21s were criticised for being under-armed in relation to their size and cost.<ref name="Marriott" /> A programme was put in hand to increase their firepower by fitting four French-built MM38 [[Exocet]] anti-ship missiles. These were sited in front of the bridge screen aft of the forecastle, displacing the [[Corvus chaff launchers|Corvus]] countermeasure launchers to amidships. This improvement was quickly carried out to all ships of the class during their build period except ''Amazon, Antelope'' and ''Ambuscade''; Amazon and Ambuscade were fitted with Exocet in 1984/85. The Exocets were located in two pairs and the missiles would deploy across the ship and clear the opposite side of the vessel to their launchers in flight.

The design error in weight and stability had more than wiped out the margins that had been intended for replacing Seacat by the more capable Seawolf and the Type 2016 bow sonar.<ref name="A. Preston 1982 p21">A. Preston. Sea Combat off the Falklands. Willow Collins (1982) London, p. 21.</ref> The ships lacked the margins of weight and space customary to in-house Royal Navy warship designs for major modernization.<ref name="A. Preston 1982 p21"/><ref name="A. Preston 2002 p172">A. Preston. Type 21 Anti Submarine Frigates in The World's Worst Warships. Conway Maritime Press (2002) London, p. 172.</ref>

Five modernisation proposals for the Type 21s were considered by the Royal Navy<ref name="A. Preston 1982 p21"/> but rejected by 1979, when it was 'reluctantly' decided not to modernize the class,<ref name="A. Preston 1982 p21"/> and it was estimated that they would be laid up by 1988.<ref>A. Preston. Sea Combat off the Falklands (1982) pp. 12–13.</ref>

The small Wasp helicopter was replaced by the vastly more capable [[Westland Lynx]] when it became available. Compared to the Wasp, the Lynx was faster and carried its own sensors, plus more and better weapons. As and when ships came in for refit, ship-launched anti-submarine torpedoes were also fitted (though not in ''Amazon''<ref name="Lippiett 1990">R.J. Lippiett. Type 21 - Modern Combat Ships 5. Ian Allan (1990), pp.95</ref>), in the form of two STWS-1 triple-tube launchers capable of firing United States USN/NATO-standard [[Mark 44 torpedo|Mark 44]] or [[Mark 46 torpedo]]es. After the Falklands War, two more 20&nbsp;mm Oerlikon guns were mounted on some ships of the class, one each side of the hangar, to provide extra close-in armament. The first of these guns was actually salvaged from the wreck of ''[[HMS Antelope (F170)|Antelope]]'' by divers, and was fitted to ''[[HMS Avenger (F185)|Avenger]]'', where it carried the slogan 'Antelope's Avenger' on its gunshield.<ref>Lippiett 1990, pp.91</ref>

===Analysis===
Criticism was levelled at the performance of the type in the Falklands conflict.<ref name="Marriott" /> The ships developed cracks in their decks due to the different strength and fatigue properties of steel and aluminium. This was a vulnerability particularly demonstrated under the severe weather conditions that they encountered in the [[Atlantic (ocean)|South Atlantic]]. Steel reinforcing plates were eventually fitted down the sides of the ships and on No. 1 Deck. Although built to a tight budget and design specification (and carrying insufficient anti-aircraft weaponry) they distinguished themselves in a theatre for which they had not been designed. As shore bombardment platforms and in lethal, accurate gunfire support for the [[Royal Marines]] and [[British Army]] landing at [[San Carlos, Falkland Islands|San Carlos]], they were superb, pinning down any possibility of Argentine army counterattack,<ref>F. Southby-Tailyour. Reasons in writing. A Commando's view of the Falklands War. Leo Cooper (1993) London, pp. 207–208</ref> but they remained shallow water surface fighting ships, designed for Vosper's export market to provide nations like Libya and Iran with the firepower to replace the United States/UK as western supporting stabilisers under the [[Henry Kissinger|Kissinger]]/[[Denis Healey|Healy]] strategy. The lack of margin to accept the Type 2031 towed array sealed the fate of the class.<ref>N. Friedman. British Destroyers & Frigates. (2006) p. 296.</ref>

The class was criticised for being overcrowded: at {{convert|384|ft|m|0}}, they had 177 crewmen compared to {{convert|436|ft|m}} and 185 crewmen for the [[Type 23 frigate]]. This was important at a time when the Royal Navy was facing a manpower shortage. However the standard of accommodation for the officers was better than the RN average and the senior [[Naval rating|ratings]] enjoyed separate cabins – unlike the [[petty officer]]s of the [[Type 42 destroyer]] of the same era, who slept in bunk rooms. The ratings' accommodation was also improved, with four-man sleeping berths leading off from the communal mess deck; again, far better than those of the Type 42 destroyer. In essence, the standard of accommodation and fitting were better, especially for officers, because it was a design intended to attract export orders. Higher automation and the new Mk 8 4.5-inch automatic gun combined with an electronic fit meant that the Type 21 was in some ways simpler than that of the ''Leander''s or Type 42. The Type 21 class lacked both the long range [[Type 965 radar]]<ref>A. Preston. Sea Combat off the Falklands. Willow (1982) London, pp. 20–21.</ref> carried by most UK warships and the [[Limbo (weapon)|Limbo]] mortar with its associated sonar.

==Service==
Except for [[HMS Amazon (F169)|HMS ''Amazon'']],<ref name="Marriott">pp. 105–114, Marriott, Leo, 'Royal Navy Frigates Since 1945', Second Edition, {{ISBN|0-7110-1915-0}}, Published by Ian Allan Ltd (Surrey, UK), 1990</ref> all the class took part in the 1982 [[Falklands War]] as the [[4th Frigate Squadron (United Kingdom)|4th Frigate Squadron]].<ref name="Adm White Obituary">{{cite news|url=https://www.telegraph.co.uk/news/obituaries/10889508/Admiral-Sir-Hugo-White-obituary.html|title=Admiral Sir Hugo White - obituary|work=Daily Telegraph|date=10 June 2014|access-date=11 June 2014}}</ref> They were heavily involved, performing extensive shore-bombardment missions and providing anti-submarine and anti-aircraft duties for the task force. On 10 May, [[HMS Alacrity (F174)|HMS ''Alacrity'']] and ''Arrow'' probed through [[Falkland Sound]] at night searching for minefields that might have impeded landings and operations, almost as expendable hulls{{Citation needed|date=April 2022}}. ''Alacrity'' engaged and sank an Argentine naval supply vessel in the Sound. On exiting the Sound at daybreak, they were attacked by the [[ARA San Luis (S-32)|Argentine submarine ''San Luis'']], which fired two torpedoes; one hit ''Arrow''{{'}}s submarine towed decoy (as intended) and the other bounced off her hull, having failed to arm itself. Two ships were lost: {{HMS|Ardent|F184|2}} was hit by bombs dropped by Argentine aircraft on 21 May and consumed by fire; {{HMS|Antelope|F170|2}} was hit by bombs on 23 May, one of which detonated while a [[bomb disposal]] team was attempting to defuse it on 24 May. The ship caught fire and set off her [[Magazine (artillery)#Naval magazines|magazines]], resulting in her breaking her back and sinking.

===Sale to Pakistan===
The six surviving Type 21 frigates were sold to Pakistan in 1993&ndash;1994 for 60 million US dollars. The Exocet and Seacat were removed before the sale and the frigates were given a basic refit at [[Karachi]] with US Harpoon anti-ship missile. Three of them were fitted with [[Phalanx CIWS]], the others with 40mm Bofors L70 guns. The class was renamed by the [[Pakistan Navy]] as the {{sclass|Tariq|frigate|4}},  after the  first vessel that was acquired, ''Tariq'', formerly {{HMS|Ambuscade|F172|2}}. Only two of the six remain in service: ''Badr'' and ''Babur'' were both [[Ship decommissioning|decommissioned]] in 2014, while ''Tippu Sultan'' and ''Shah Jahan'' were sunk as [[Target ship|targets]] in 2020 and 2021 respectively.<ref name="Defense Brief, 2020">{{cite web |last1=Editorial |first1=Defense Brief |title=Pakistan sinks former Royal Navy frigate in missile firing drill |url=https://defbrief.com/2020/04/28/pakistan-sinks-former-royal-navy-frigate-in-missile-firing-drill/ |website=Defense Brief |access-date=19 September 2020 |date=28 April 2020}}</ref><ref name="defbrief">{{cite web |title=Pakistan sinks another former Royal Navy frigate in live-fire drill |url=https://defbrief.com/2021/01/12/pakistan-sinks-another-former-royal-navy-frigate-in-live-fire-drill/ |website=defbrief.com |date=12 January 2021 |access-date=14 January 2021}}</ref> By the closing years of the class the Harpoon was generally seen as slow and obsolete and in 2008 Harpoon was removed. The Pakistan frigates were given the Chinese 6-cell [[LY-60 / FD-60 / PL10|LY-60N]] Hunting Eagle surface-to-air missile system.<ref>[http://www.globalsecurity.org/military/world/pakistan/d-tariq.htm Global Security.Org Article on 'Tariq Class (UK Amazon Type 21)'  (Retrieved 9 March 2016)]</ref>

==Ships==
<!--"A contract was awarded to Vosper Thornycroft on 27 February 1968 for the design of a patrol frigate to be prepared in full collaboration with Yarrow Ltd."<ref name=Janes82>Moore, John ''Jane's Fighting Ships, 1982-83'', pub Jane's Publishing Co Ltd, 1982, {{ISBN|0-7106-0742-3}} page 554.</ref> They were "designed to replace the ''Leopard''- and ''Salisbury''-class frigates. Initial cost was to be £3.5 million but ''Amazon'' actually cost £16.8 million."<ref>[http://www.ambuscade.org.uk/Ambus_Stats02-2.htm HMS ''Ambuscade'' Facts and Figures], which contains a common internet site error and quotes the cost of ''Antelope'' as the cost of ''Amazon''. Figures for costs of Type 21 frigates are in: [https://api.parliament.uk/historic-hansard/written-answers/1989/oct/23/research-establishments#S6CV0158P0_19891023_CWA_517 Hansard: HC Deb 23 October 1989 vol 158 cc357-8W 357W] Question to the Secretary of State for Defence regarding warship costs, 23 October 1989.</ref> -->
{|class="wikitable" style="font-size:100%;"
|-valign=top
!  [[Pennant number|Pennant]]
! Name
! Hull builder
! Ordered
! Laid down
! Launched
! Accepted into service{{efn|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 that the Navy accepts the vessel from the builder. This date is important because maintenance cycles, etc. are generally calculated from the acceptance date.}}
! Commissioned
! Est. building cost{{efn|"Unit cost, i.e. excluding cost of certain items (e.g. aircraft, First Outfits)."<ref>{{citation |title=Defences Estimates |quote=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 |author=[[Bob Ainsworth]], [[Minister of State for the Armed Forces]] |date= 16 July 2008 |work=Hansard }}</ref> }}
! | Fate
|-valign=top
|| F169
|| [[HMS Amazon (F169)|''Amazon'']]
|| [[Vosper Thornycroft]], [[Woolston, Hampshire|Woolston]]
|| 26 March 1969 <ref name=MCS5p16>Lippiett, John ''Modern Combat Ships 5, Type 21'', pub Ian Allan, 1990, {{ISBN|0-7110-1903-7}} page 16.</ref>
|| 6 November 1969 <ref name=MCS5p16/>
|| 26 April 1971 <ref name=MCS5p16/>
|| 19 July 1974 <ref name=Hansard23Oct89pt1/>
|| 11 May 1974 <ref name=MCS5p16/>
|| £16.8M <ref name=Hansard23Oct89pt1>{{citation |url=https://api.parliament.uk/historic-hansard/written-answers/1989/oct/23/research-establishments#S6CV0158P0_19891023_CWA_517 |work=[[Hansard|Parliamentary Debates (Hansard)]] |date=23 October 1989 |volume= 158 |at=cc357-8W 357W |title= Question to the Secretary of State for Defence regarding warship costs, 23 October 1989 }}<!-- This section is mislabelled - it is the first part of the table that is continued on [https://api.parliament.uk/historic-hansard/written-answers/1989/oct/23/navy-vessels Hansard: HC Deb 23 October 1989 vol 158 c360W ].--></ref>
|| To Pakistan as PNS ''Babur''. Decommissioned in December 2014.
|-valign=top
|| F170
|| [[HMS Antelope (F170)|''Antelope'']]
|| Vosper Thornycroft
|| 11 May 1970 <ref name=MCS5p16/>
|| 23 March 1971 <ref name=MCS5p16/>
|| 16 March 1972 <ref name=MCS5p16/>
|| 30 June 1975 <ref name=Hansard23Oct89pt1/>
|| 16 July 1975 <ref name=MCS5p16/>
|| £14.4M <ref><br>{{citation |url=https://api.parliament.uk/historic-hansard/written-answers/1982/may/27/royal-navy-ships-replacement-costs#S6CV0024P0-08145 |work= [[Hansard|Parliamentary Debates (Hansard)]] |date= 27 May 1982 |volume= 24 |at=c397W |title=Royal Navy Ships (Replacement Costs)}}.<br>[https://api.parliament.uk/historic-hansard/written-answers/1989/oct/23/research-establishments#S6CV0158P0_19891023_CWA_517 Hansard: HC Deb 23 October 1989 vol 158 cc357-8W 357W] Question to the Secretary of State for Defence regarding warship costs, 23 October 1989.<br>Moore, John ''Jane's Fighting Ships, 1982-83'', pub Jane's Publishing Co Ltd, 1982, {{ISBN|0-7106-0742-3}} page 554.</ref>
|| Bombed by [[Argentinian Air Force]] [[Douglas A-4 Skyhawk]]s on 23 May 1982 and sank following day in [[San Carlos Water]]
|-valign=top
|| F171
|| [[HMS Active (F171)|''Active'']]
|| Vosper Thornycroft
|| 11 May 1970 <ref name=MCS5p16/>
|| 21 July 1971 <ref name=MCS5p16/>
|| 23 November 1972 <ref name=MCS5p16/>
|| 2 June 1977 <ref name=Hansard23Oct89pt1/>
|| 17 June 1977 <ref name=MCS5p16/>
|| £24.1M <ref name=Hansard23Oct89pt1/>
|| To Pakistan as PNS ''Shah Jahan''. Decommissioned and sunk as a target in January 2021.<ref name="defbrief"/>
|-valign=top
|| F172
|| [[HMS Ambuscade (F172)|''Ambuscade'']]
|| [[Yarrow Shipbuilders]], [[Scotstoun]]
|| {{nowrap|11 November}} 1971 <ref name=MCS5p16/>
|| 1 September 1971 <ref name=MCS5p16/>
|| 18 January 1973 <ref name=MCS5p16/>
|| 23 August 1975 <ref name=Hansard23Oct89pt1/>
|| 5 September 1975 <ref name=MCS5p16/>
|| £16.5M <ref name=Hansard23Oct89pt1/>
|| To Pakistan as PNS ''Tariq''
|-valign=top
|| F173
|| [[HMS Arrow (F173)|''Arrow'']]
|| YSL
|| 11 November 1971 <ref name=MCS5p16/>
|| {{nowrap|28 September}} 1972 <ref name=MCS5p16/>
|| 5 February 1974 <ref name=MCS5p16/>
|| 16 May 1976 <ref name=Hansard23Oct89pt1/>
|| 29 July 1976 <ref name=MCS5p16/>
|| £20.2M <ref name=Hansard23Oct89pt1/>
|| To Pakistan as PNS ''Khaibar''. Decommissioned and Sunk as a target during SEASPARK-2022 naval exercise
|-valign=top
|| F174
|| [[HMS Alacrity (F174)|''Alacrity'']]
|| YSL
|| 11 November 1971 <ref name=MCS5p16/>
|| 5 March 1973 <ref name=MCS5p16/>
|| {{nowrap|18 September}} 1974 <ref name=MCS5p16/>
|| 2 April 1977 <ref name=Hansard23Oct89pt1/>
|| 2 July 1977 <ref name=MCS5p16/>
|| £23.8M <ref name=Hansard23Oct89pt1/>
|| To Pakistan as PNS ''Badr''. Decommissioned in 2014.<ref name=dnua>{{cite news|last=Ansari|first=Usman|title=Reports: Increase in Pakistan Defense and Nuclear Budgets Likely|url=http://www.defensenews.com/article/20140519/DEFREG03/305190021/Reports-Increase-Pakistan-Defense-Nuclear-Budgets-Likely|archive-url=https://wayback.archive-it.org/all/20140524134442/http://www.defensenews.com/article/20140519/DEFREG03/305190021/Reports-Increase-Pakistan-Defense-Nuclear-Budgets-Likely|url-status=dead|archive-date=24 May 2014|access-date=20 May 2014|newspaper=Defense News|date=19 May 2014}}</ref>
|-valign=top
|| F184
|| [[HMS Ardent (F184)|''Ardent'']]
|| YSL
|| 11 November 1971 <ref name=MCS5p16/>
|| 26 February 1974 <ref name=MCS5p16/>
|| 9 May 1975 <ref name=MCS5p16/>
|| 10 September 1977 <ref name=Hansard23Oct89pt1/>
|| 14 October 1977 <ref name=MCS5p16/>
|| £26.3M <ref name=Hansard23Oct89pt1/>
|| Bombed by Argentine A-4 Skyhawks on 21 May 1982 in [[San Carlos Water]] and sank following day in [[Grantham Sound]]
|-valign=top
|| F185
|| [[HMS Avenger (F185)|''Avenger'']]
|| YSL
|| 11 November 1971 <ref name=MCS5p16/>
|| 30 October 1974 <ref name=MCS5p16/>
|| 20 November 1975 <ref name=MCS5p16/>
|| 15 April 1978 <ref name=Hansard23Oct89pt1/>
|| 15 April 1978 <ref name=MCS5p16/>
|| £27.7M <ref>[https://api.parliament.uk/historic-hansard/written-answers/1989/oct/23/research-establishments#S6CV0158P0_19891023_CWA_517 Hansard: HC Deb 23 October 1989 vol 158 cc357-8W 357W] Question to the Secretary of State for Defence regarding warship costs, 23 October 1989 says £27.7 million.<br>Moore, John ''Jane's Fighting Ships, 1982-83'', pub Jane's Publishing Co Ltd, 1982, {{ISBN|0-7106-0742-3}} page 554 says £28.3 million.</ref>
|| To Pakistan as PNS ''Tippu Sultan''. Decommissioned and sunk as a target in 2020.
|}

==Running costs==
{|class="wikitable" 
|-valign=top
! Date
!{{nowrap|Running cost}}
! What is included
|-valign=top
| {{nowrap|1981-82}}
| £6.5 million
| Average annual running cost of Type 21s at average 1981–82 prices and including associated aircraft costs, but excluding the costs of major refits.<ref>{{citation |url=https://api.parliament.uk/historic-hansard/written-answers/1982/jul/16/naval-vessels-operating-costs#S6CV0027P0-09171|work=[[Hansard|Parliamentary Debates (Hansard)]] |date= 16 July 1982 |volume= 27 |at=cc485-6W |title=Naval Vessels (Operating Costs) }}.</ref>
|-valign=top
| 1985-86
| £7 million
| The average cost of running and maintaining a type 21 frigate for one year.<ref>{{citation |url=https://api.parliament.uk/historic-hansard/written-answers/1987/jan/22/ships-operating-costs#S6CV0108P0-10356 |work= House of Commons Debate |date= 22 January 1987 |volume= 108 |at=c730W |title=Ships (Operating Costs) }}.</ref>
|-valign=top
|| 1987-88
|| £3.8 million
|The average annual operating costs, at financial year 1987-88 prices of a type 21 frigate. These costs include personnel, fuel, spares and so on, and administrative support services, but exclude new construction, capital equipment, and refit-repair costs.<ref>{{citation |url=https://api.parliament.uk/historic-hansard/written-answers/1989/mar/10/warships#S6CV0148P0-04574 |work=[[Hansard|Parliamentary Debates (Hansard)]] |date= 10 March 1989 |volume= 148 |at=c44W |title= Warships}}.</ref>
|}

== The Type 21 Club ==
In 2010, like-minded former crew members decided that an association should be formed for former shipmates and officers who ever served on these frigates. It also includes Pakistan Naval crew members of the frigates now part of the Pakistan navy.<ref>{{Cite web|url=http://www.type21club.org|title=Type 21 Club Association|website=Type 21 Club Association|language=en-UK|access-date=2016-06-08}}</ref>

==See also==
*[[List of naval ship classes in service]]

==Notes==
{{notelist}}

==Citations== 
{{reflist}}

==Bibliography==
{{Commons}}

*{{Cite Colledge2006}}
* Couhat, Jean Labayle and A.D. Baker. ''Combat Fleets of the World 1986/87''. Annapolis, Maryland, USA: Naval Institute Press, 1986. {{ISBN|0-85368-860-5}}.
* Friedman, Norman. ''British Destroyers & Frigates: The Second World War and After''. Barnsley, UK: Seaforth Publishing, 2008. {{ISBN|978-1-84832-015-4}}.
* Gardiner, Robert and Stephen Chumbley. ''Conway's All The World's Fighting Ships 1947–1995''. Annapolis, Maryland, USA: Naval Institute Press, 1995. {{ISBN|1-55750-132-7}}.
* Marriott, Leo. ''Royal Navy Frigates 1945-1983'' Ian Allan, 1983 {{ISBN|0-7110-1322-5}}.
* Moore, John E. ''Warships of the Royal Navy; New Edition'', Jane's Publishing, 1981 {{ISBN|0-7106-0105-0}}.
* Preston, Antony. ''The World's Worst Warships''. London: Conway Maritime Press, 2002. {{ISBN|0-85177-754-6}}.
* Lippiett, Capt. R.J. ''Type 21 - Modern Combat Ships 5'' Ian Allan, 1990 {{ISBN|0-7110-1903-7}}.

{{Type 21 frigate}}
{{Authority control}}

{{DEFAULTSORT:Type 21 Frigate}}
[[Category:Frigate classes]]
[[Category:Ship classes of the Royal Navy]]
[[Category:Type 21 frigates| ]]