Type 21 (Amazon class) Frigate (1971)

8 frigates + exports 1969-78: Amazon, Antelope, Active,; Ambuscade, Arrow, Alacrity, Ardent, Avenger.

The Type 21 frigate or Amazon-class were Royal Navy general-purpose escorts designed to be budget-fiendly in the late 1960s, built in the 1970s. They were active in the 1980s and 1990s, but two were sunk during the Falkland wars (Antelope and Ardent) drawing a lot of criticism. The survivors were all sold to Pakistan. None remains in service today. They were also exported, for Brazil (Niteroi class) and a modified version was sold to Iran (The Alvand class).

Development

In the 1960s, the Royal Navy had an excellent ship class, the Type 12 and 12I Leander, that could perform all the missions required from them, chiefly ASW, but with AA escort capabilities as well. But in 1965, there was a requirement to replace older frigates, namely the Leopard-class (Type 41) anti-aircraft frigates and Salisbury-class (Type 61) air direction frigates. The new frigate would be a AA escort first frigate, if possible made on a budget. There was however a lot of agitation at the time converning shipbuilding. Traditional Royal yards were in charge of new warship construction given the tradition at the Ministry of Defence’s Ship Department based at Bath. Private Yards were eager to obtain contracts as well, and could count on local political support.

These yards started campaigning to obtain the construction of these new projected frigates, led by Vosper Thorneycroft. The latter argued that the MoD team at Bath kept conservative design practices that prevented cost-saving measures as seen in civilian and private years accostumed to export (like Vosper). The latter argued they could deliver, given their own design and construction practice, the new frigate at a significantly lower price of £3.5 million compared with £5 million for a Leander class, making them attractive at export as well. This hit a cord in the MoD in these budget-restricted times, secuded the treasury, and under political pressure to give work to these neglected yards as well.

Vosper described relatively cheap and yet modern general purpose escorts that could be sold in South America and Australasia, traditional export markets, and to create an out-of-area RN gunboat retaining UK presence “east of Suez” plus the Caribbean and Persian Gulf, replacing the diesel-powered Type 41s and Type 61s and Gas-powered Type 81 frigates, with smaller crews (thus cheaper to finance yearly as well). The new Frigate would be COGOG. The RN staff resisted this however, preferring to continue steam types like the successful Type 12I Leander class, still regarded as the apex, quiet anti-submarine hunter. In the end, politicians considered the design as dated and the Treasury seeing plenty of exports from these more efficient private shipyards defended the idea.

Vosper indeed did not started from scratch: They argued that the development of their own export designs, the projected Mk 5 for Iran and the Mk 7 for Libya (contracts just signed) made their design more relevant. Pressure on the Admiralty to accept this new type of ship capable of a range of 6,000 nautical miles with a top speed of 37 knots and superficially good armament (new Mark 8 4.5-inch gun) with air facilities (Westland Wasp) as well as anti-ship missiles and a lightweight Seacat SAM to round the package made them on paper useful indeed.

Vosper had plans for the new Libyan Dat Assawari class finalised in 1968, providing a set of plans for the Admiralty board to look at. The plan was accepted on paper specifications. The shipyards were entrusted to develop a low cost anti-submarine warfare and general purpose frigate, that the admiraklty wanted to be stretched out, but also preferred the turbine-powered option rather than combined diesel and gas as the export Mk 5 and Mk 7. For Vosper it seems however a more difficult design to pull out, notably for weight reasons: The propulsion machinery mounted low in the hull was not enough to balance top weight with a bulky superstructure.

Tyne gas turbines were agreed upon for cruising, instead of diesels and so immediately this rose fuel consumption and cost. This would be an issue in the 1980s especially when austerity cut down fuel allowance for the RN, immobilizing these gas-turbine frigates. Despite the smaller crew, running costs for the Type 21 would also en 10% higher than for the Leanders. However, the Type 21 were supposed to provide the shipyards with experience for ships with full gas turbine power, and just gave them work in the first place shipyards. The Type 42 destroyer and Type 22 frigate design meanshil was worked out to be ready by the late 1970s. So the Type 21 seems like a cheap stopgap. The Admiralty design board was entirely aborbed by the Type 42/22 so the Type 21 project management ended in he private shipyards, namely Vosper Thornycroft and Yarrow.

It was hoped to even further reduce the bills by having these a joint design meeting requirement for a low-cost Patrol Frigate wanted also by Australia as its “General Purpose Escort” and discussions between the two navies started in 1967. Australia hoped to build a Type 21s in Australia as well, and part-funded design work. Requirements were significantly different however as Australia wanted 35 knots rather than 32-knot for the Royal Navy. They also wanted an US American with Sea Sparrow an a 5-inch (127 mm) Mark 45 gun. Australia eventually pulled out of the project in November 1968 and continued developme t with the “light destroyer project”. The Royal New Zealand Navy (RNZN) reconsidered the Type 21 in the follow-up, but found it too expensive and preferred to acquire extra leander class vessels. They also considered the British gun and radar inferior to USN equivalents. Australia eventually cancelled its own program and instead ordered Oliver Hazard Perry-class ships in 1976.

The first contract for the Type 21, meeting Royal Navy requirements, was signed in March 1969 from Vosper. By this time however, cost rose up to £7.3 million which was more than a Leander-class frigate. Attempts to sell derivatives from the Type 21 including Argentina mostly failed, apart Brazil. A “broad-beam Amazon” with Sea Wolf SAMs was also offered to Pakistan in 1985, but the latter obtained second-hand regular Type 21s anyway. The yards in charge were the following:
Vosper Thornycroft, Woolston Amazon, Antelope, Active (1969-77)
Yarrow Shipbuilders, Scotstoun (YSL): Ambuscade, Arrow, Alacrity, Ardent, Avenger (1971-78).

Design of the class

The Type 21 were unlike any of the frigates built for the RN to that point. They were completely different animals compared to the Leander class for example, with none of the their design specifics. Instead, for example, their lines looked more than yachts, notably for their prow, with a knuckle, a beam-wide structure making the whole amidship section, a low panoramic, more conventional bridge, a main mast, aft mast and massive funnel. Technically they were flush deck vessel, as well. As the first privately designed warships for decades, they were the first solely powered by gas-turbine engines in a COGOG arrangement. The large superstructure in relation to the hull volume made them use a aluminium alloy in the superstructure, trying to reduce topweight. However in the end, since thety were better armed than export variants, the final “Outfit” added extra topweight, that the height of the superstructure only exacerbated.

It seems calculation errors were the cause of this extra topweight. The admiralty also expressed worries about aluminium’s resilience to fire. This became evident by seeing what happened in the USN, but also a major fire on Amazon in 1977. In this event, the distorted aluminium ladders blosked fire-fighting teams from reaching the blaze. The same issue was to their supposed lower tolerance to blast damage. The experience of the Type 21 led to avoid aluminium for superstructure and calculate with better care the load-bearing structure, back to steel. The final armament comprised a single 4.5 inch Mark 8 naval gun, launchers for the SeaCat SAM aft as a base line.

Unusually, it was the Italian Selenia Orion-10X lightweight fire control radar that was adopted for the gun and SeaCat as well as the GWS-24 system to save weight. The lighweight Type 992Q air/surface radar was also fitted, but she lacked a long-range air-search radar. The hangar and flight deck aft could accomodate a single helicopter, namely the Wasp, which in the late 1970s was now considered largely obsolete. There was however a modern CAAIS provided to integrate weapons and sensors. One of the selling point, a reduced crew, looked at a better automation, systems integration and habitability. The private design provided indeed the goods, the ship was most advanced, especally when compared to the Type 81 (Tribal-class) frigate and Type 12M Rothesay-class.

Hull and general design

The Type 21 original design was for a standard displacement of 2,750 tons and fully loaded, 3,250 tons (this changed massive after strenghening, see below). They measured 360 ft (110 m) at the waterline and 384 ft (117 m) overall and indeed were stretched out Mk 5/Mk 7. In beam was were relatively similar at 41.8 ft (12.7 m) for a draught of 19 ft (5.8 m). As for the design layout, they had a more pronounced clipper bow with a knuckle and seen from atop, yacht-like and rakish, fine lines, but with a constant beam past the bridge, and down to the flat transom stern. This maximized internal accomodation space. One other aspect that clearly made them different from the Type 12 frigate was their panoramic bridge, located atop a long beam-wide structure that supported the main superstructure. Later exocet missiles were mounted in front of the bridge, four canisters pointing up inwards (added before 1982). The foredeck supported a single automated Mark 8 Vickers naval gun.

The mainmast was immediately aft of the bridge, with all the main aerial, supporting the Type 1006 navigation radar mid-way on a platform, and the Type 992Q surveillance radar on top. The two 20mm Oerlikon AA guns were located immediately aft of the bridge. Then there was an utility deck, were the corvus chaff launchers were located. There was next the funnel block structure and satellite communication terminal in front. The funnel was rounded and had an IR-reduction system. The funnel structure ended with the type 912 fire control radar usable for the gun and Sea Cat. The latter was mounted atop the hangar. Abaft the hangar were located the two triple Mark 46 torpedo tubes (added later), the only ASW armament outside the Wasp helicopter. Past the helideck there was a down step with an opening for the Type 182 towed torpedo decoy. All in all, seen from the front or rear, the ship quite appeared tall with limited buoyancy.

Powerplant

The Type 21 innovated by their powerplant, COGOG on 2 shafts and composed of a pair of Tyne cruise turbines rated for a total of 8,500 shp (6,300 kW), then two Olympus “boost” turbines for a total of 50,000 shp (37,000 kW). Top speed was 32 knots (59 km/h; 37 mph) combined, with 37 knots burst speed with the Olympus. It was down to 18 knots (33 km/h; 21 mph) with the Tyne turbines for cruising. Range was 4,000 nmi (7,400 km; 4,600 mi) at 17 knots (31 km/h; 20 mph), then 3,500 nmi (6,500 km; 4,000 mi) at 18 knots (33 km/h; 21 mph) and utimately 1,200 nmi (2,200 km; 1,400 mi) at 30 knots (56 km/h; 35 mph).

Protection

Outside the usual suspect, NBC protection with air conditioning, external and internal sprinklers with halon fire extinguishers, or manual bottles, fire protection curtains and doors, blast protection hatches in the ammo compartments and quick filling cocks, the active protection was limited to one system, the two eight-barrelled Knebworth Corvus countermeasures launchers.

Armament

4.5 in (114 mm) Vickers Mark 8 gun

This was the Type 21 maina armament, quite diffrent from the twin barreled Mark 6 of the Leander class. This single gun, still produced today, is in short a British alternative to the OTO melara 3-in gun apart for its much larger caliber. The Mod 0 was developed by the Royal Armament Research and Development Establishment from 1965. It entered service in 1972, just in time for the Type 21 Frigates. The Mod 1 was developed later by the Royal Ordnance Defence. It was a 55-calibre barrel from Vickers Ltd Armament Division using the QF 105 mm L13 of the Abbot self-propelled gun as a starting point with electrical primer. The turret was built from glass-reinforced plastic (GRP). The idea was a quick fire (first round) ability from shutdown state, to face missiles, over a high rate of fire. This enabled a lighter, single barrel mounting and one-piece ammunition.

The mount combined electrical and hydraulic components but it was three deck levels deep below the weather deck for the magazine, gun control room and power room. The gunhouse was relatively small and in recent years, it was reshaped in a stealthy way. Semi-automatic there is a manual 2-men backup. Normal use was from the gunbay below, to load the feed ring and pass ammunition from the ammunition room below. It was capable of 25 rounds per minute. The Vosper Iranian frigate Zaal was the first to feature it in 1971, followed by the destroyer Bristol. However it proved less reliable than the older 4.5-inch Mark V/Mark 6 and heavily criticized in the Falklands War.
Mod 1 was developed in 1998 in two tranches. It was nicknamed the “Kryten gun” from the series Red Dwarf. Upgrades were performed between 2005 and 2012.

Specs 4.5 in Mark 8

Barrel 244.75 inches (6.217 m) bore (55 calibres). Shell 113×700mmR 46 pounds (21 kg) HE.
Rate of fire: 25 rpm auto, max range 27.5 km (17.1 mi) with late extended rounds. Initially 10 nautical miles.

20 mm Oerlikon guns

Single mounts, manual, located behind the bridge and upgraded with two more mounts close to the hangar shortly after the Falklands.

GWS-24 Sea Cat

The Seacat was a short-range surface-to-air missile designed by Short and in service in 1962, so County class ships in construction could be completed by two systems installed on the broadside, each with four missiles. They were light enough to be reloaded by hand. Contrary to the Sea slug they enjoyed a considerable export success.

Specs

Missile length : 1480 mm (58,29 inch), Wing span : 650 mm (25,6 inch), Body diameter 191 mm (7,62 inch)
Missile weight : 62,71 kg (138,25 Lb). Continuous rod warhead : 13,83 kg (30,65 Lb)
Operational oil pressure on steering cylinders during flight : between 79 and 103 Bar (1150 to 1500 lbf/ in2)
Operational range : 500 to 5000 mtrs. Speed : Mach 0,8 (272,24 mtrs/sec).
Guidance system : CLOS (Command Line Of Sight) and radio link

Sensors

Type 992Q

Low-level search Radar in service from 1952. High power, operating in S band for rapid target indication, medium range air and surface warning radar. cheese antenna used, streamlined for high rotation. The band is covered by three interchangeable liquid cooled magnetrons. The modenrized 992Q used solid-state with a parametric amplifier, 6.4 m long with a linear slotted array enclosed in a cylindrical plastic radome. Beamwidth 1.2 degrees. FRQ up to 3060 MHz at 2 MW PP. PRF 833 Hz. Range 30 NM (55 km).

Type 978

Navigation Radar. The ATZ antenna is a 6 feet wide double-cheese, upper for transmission, lower for reception. Rotation speed depends on the feed, on 50 or 60 Hz voltage. Frequency: 9,410 MHz
(X band). PRF 1000 or 2000 Hz. Pulsewidth 1 µs or 0.2 µs. Range 40 NM (74 km) at resolution 46 m, accuracy 2%. Rotating at 20-24 min.

Type 912

Fire control Radar, Italian system called originally RTN-10X Orion. Work in I-band, two operating channels: pulse mode for target search and continuous wave mode for target illumination radar. range 40 km.

Type 184M/162M

Sonar suite. The 184 is a hull mounted, passive radar of the Type 82 Bristol class, Type 21 Amazon and Argentinian Hercules class (Type 42) DDs. The Type 162 Cockwhafer is a side-looking and bottom-scanning shipboard sonar, named after its beetle with fan-like antennae that aid in sensing. It classifies objects at mid-depth and on the sea floor, the three transducers working together to provide a profile of the area surrounding the ship.

Air Group

wasp helicopter
The Wasp was a lightweight piston-powered model just developed and usable as scout mostly (first flight 1962) developed from the Saro P.531 to fit on small ships such as frigates and destroyers.
It was limited to 104 knots (120 mph, 193 km/h) and a range of 263 nmi (303 mi, 487 km) but could carry a large payload of armaments and carry four personal. In ASW role the Wasp could carry two Mk.44 or a single Mk.46 acoustic torpedo or two Mk.11 depth charges, or even a WE.177 600lb tactical nuclear depth bomb. In an antiship role, it could also carry four SS.11 or two larger AS.12 missiles. The ARA Santa Fe was sunk by those missiles in 1982.

⚙ specifications (original)
Displacement	2,750 tons standard 3,250 tons FL
Dimensions	360 ft wl/384 ft oa x 41.8 ft x 19 ft (110/117 x 12.7 x 5.8 m)
Propulsion	2 shaft COGOG, Tyne CRT 8,500 shp, Olympus boost turbines 50,000 shp
Speed	32 knots (59 km/h; 37 mph), see notes
Range	4,000 nmi (7,400 km; 4,600 mi) at 17 knots
Armament	4.5 in Vickers Mark 8 gun, 2×20 mm Oerlikon, 1×4 GWS-24 Sea Cat
Protection	2×8 Knebworth Corvus countermeasure launchers
Sensors	Radar Type 992Q SR, Type 978 NavR, Radar Type 912 FC, Sonar Type 184M/162M.
Air Group	Westland Wap, Helideck and Hangar
Crew	13 officers, 164 ratings

Modifications

Curing the top-weight issues

The MoD discovered the calculation errors concerning the vertical centre of gravity about 6 months after the launch. There was a probably great deal of shouting and tese flews became apparent as the first ships entered service. The Type 21s not only rolled considerably, but they were criticized to be under-armed in relation to their size and cost. A programme was thus started both to increase firepower and correct stability. MM38 Exocet and extra ASW torpedoes were installed, quickly carried out to all ships except Amazon, Antelope and Ambuscade. Amazon and Ambuscade were fitted with Exocet in 1984/85. The lack of stability destroyed however all margins intended to replace Seacat by the Seawolf as well as fitting the new Type 2016 bow sonar. This precluded major modernization. Measures were taken to increase ballast, massively strenghtening the hull (120 tonnes), and modify the bilge keel but there was not much else left. Five modernisation proposals for the Type 21s were considered but rejected in 1979, postponed until 1988 and later killed by the end of the cold war. It was quite limited.

MM-38 Exocet SSM

The well-known sea-skimming missile was adopted well before thge Falkland war by the RN. It started be installed in the mid-1970s already. The Type 12I and Type 21 frigates were no exeption. MM-38 Exocet SSM were installed forward of the bridge screen aft of the forecastle. This forced the displacement of the Corvus countermeasure launchers amidships. They were placed in four canisters pointing inwards up in two pairs. This 1st gen. missile, designed aznd produced until 1999 by Aérospatiale. It had a solid propellant engine for 40 km (25 mi; 22 nmi) in range. Sea-skimming at max Mach 0.93 or 1,148 km/h (713 mph; 620 kn) it had an inertial guidance, and active radar homing for the final phase. The later mods had GPS guidance. This missile weight 780 kg (1,720 lb), for 6 m (19 ft 8 in) long and 34.8 cm (1 ft 1.7 in) in diameter, 1.35 m (4 ft 5 in) in wingspan, and carried a 165 kg (364 lb) warhead designed to explode inside the target and cause an intense fire. The British developed their own variant of the MM 38 in 1984, deployed 1985-97 at Gibraltar, the “Excalibur”.

324 mm Mark 46 ASWTT

Two 12.75 in (324 mm) 3-tube STWS-1 anti-submarine torpedo launchers were installed abaft the hangar on deck to provide additional ASW protection. They fired the Mark 46 US pattern torpedo.
The western world backbone against Soviet subs was the Mark 46 acoustic torpedo. It weighted 508 lb (230 kg) for a length of 8 ft 6 in (2.59 m), a diameter of 12.75 in (323.8 mm) and carried a warhead of PBXN-103 high explosive bulk charge weighting 96.8 lb (43.9 kg). It Two-speed, reciprocating external combustion ran on Otto fuel II for a max range of 12,000 yd (11,000 m), top speed of 40 kn (74 km/h; 46 mph) and max depth of 1,200 ft (370 m), using active or passive/active acoustic homing. It could be deployed by the Westland Wasp helicopter as well. They could fire also the Mark 44. HMS Amazon was not fitted.

Westland Lynx

The small Wasp was replaced by the vastly superior Westland Lynx when available post-Falklands. The Lynx was fastern carried its own sensors and better weapons.

After the Falklands War, two more 20 mm Oerlikon guns were mounted on some ships either side of the hangar. The first were salvaged from the wreck of Antelope by divers, fitted to Avenger, and ‘Antelope’s Avenger’ was painted on the gunshield. The type 978 radar was removed on all ships by the type 1006 radar. In 1988-90 on all ships, the type 992Q radar and type 184M sonar were exchanged respectively by the type 992R radar and type 184P sonar. Arrow and Avenger were the only ones fitted with two type 670 ECM suites.

⚙ specifications (as modified 1980s)
Displacement	2,860 tons (standard), 3,360 tons (full load)
Armament	+ 4x MM38 Exocet SSM, 2x 20mm Oerlikon, 2×3 STWS-1 TTs
Protection	+ type 182 Torpedo Decoy, type 670 ECM*
Sensors	Type 1006 radar, type 992R radar, type 184P sonar
Air Group	Westland Lynx

*Only Arrow and Avenger.

Criticism in Service

Criticism was already present when entering service, the ships being seen as underarmed and unstable, but their performance of the type in the Falklands conflict even increased dissatisfaction with the type. In the rough south atlantic weather their hulls developed decks cracks due to lack of strength and fatigue resulting from the junction of steel and aluminium. Severe weather conditions showcased these strenght issues, and steel reinforcing plates were eventually fitted down the sides and on No. 1 Deck. Albeit built under a tight budget and design specification they had not been designed to face the Argentines in this war. The only positive was their accurate gunfire support for the Royal Marines and British Army at San Carlos. Two ships were lost however, having gunnery stoppages at the worst time possible. Once hit, they burned fast and heavily due to heavy use of aluminium, escaping all control.

They were also criticized as overcrowded, 177 crewmen at 384 feet (117 m), versus 185 on 436 feet (133 m) on the next Type 23 frigate. This was especially acute when facing a manpower shortage.
The standard of accommodation for officers was better than average however, perhaps due to specifics of the export market. Senior ratings notably enjoyed separate cabins. Ratings accommodation were improved, with four-man sleeping berths close to the communal mess deck. Higher automation for the Mk 8 gun and well studied electronic fit made them simpler, less work-intensive than the Leanders or Type 42. However as warships, they lacked the long range Type 965 radar, and the lack of margin to accept the Type 2031 towed array, and Limbo mortar, that sealed their fate. They were to be all sold.

In service, except for HMS Amazon that operated in the Persian Gulf, all took part in the 1982 Falklands War in the 4th Frigate Squadron. They performed extensive shore-bombardment missions, provided ASW and AA escort for the task force but on 10 May, HMS Alacrity and Arrow were looking for minefields in a way that made them “expendable”. Alacrity sank an Argentine naval supply vessel in the Sound but when exiting the Sound at daybreak they were targeted by the submarine San Luis, firing two torpedoes. One hit Arrow’s submarine towed decoy when deployed as intended and the other bounced off her hull, failing to arm. But Ardent was hit by bombs from Skyhawks on 21 May, consumed by fire. Antelope was hit by bombs on 23 May, one detonating, another later after being considered a dud by bomb disposal team on 24 May. She caught fire, this set off her magazines, breaking her back. In both cases, they could have shot down the Skyhawks with their main gun, but the latter suffered malfunctions, and the jets arrived too low to be picked up by radar. The 20 mm Oerlikon proved useless and the Corvus proved of no use. But the aluminium certainly not contributed to their survival.

Gallery

HMS Ambuscade in Bermuda

Tippu Sultan, ex Avenger

Avenger at Corpus Christi

Avenger at Tampa Bay

F169 model as of 1971

Model at the Malta Maritime Museum

Embuscade off Norway for NATO exercise Teamwork 92

HMS Arrow in port

HMS Amazon at Pearl Harbor 1986

Lynx HAS2 on F-169 in Pearl Harbor 1986

HMS Active

HMS Active in Amsterdam

HMS Antelope underway

Frigates in Devonport, inc. a Type 21.

HMS Amazon (F169)

In RIMPAC 1986
Amazon was ordered from Vosper Thornycroft, the first of three, at Woolston, on 26 March 1969, laid down on 6 November 1969, launched on 26 April 1971, in service by 19 July 1974 for £16.8M. In June 1977 she was part of the Fleet Review, at Spithead, HM the Queen’s Silver Jubilee. In July she qualified her Lynx helicopter. In November she suffered a serious engine room fire due to fuel leak when near Singapore. Aluminium ladders melted on the doors, prevented to respond. From 1978 her Wasp helicopter was replaced by a Lynx. In December 1980 she struck a coral pinnacle off Belize. She did not took part in the Falklands War, remaining in the Persian Gulf. She however carried out a patrol in the South Atlantic by August–November 1982. Due to cracking in her hull she was refitted, extra hull plates welded down each side and modifications made to reduce hull noise. Four Exocet launchers were fitted last in class to be so fitted. No logs for her service afterwards.

Babur
She was decommissioned and was sold to Pakistan on 30 September 1993, renamed PNS Babur, but without Exocet and Sea Cat. Instead, Babur and other ships transferred received two quadruple Harpoon missile launchers and the Signaal DA08 air search radar as well as the US SRBOC chaff launchers and two 30 mm guns added. She was decommissioned in December 2014, after 22 years of service.

HMS Antelope (F170)

HMS Antelope at San Carlos Water on 23 May 1982. Note damaged mast (mostly hidden by smoke) and bomb entry hole on hull below funnel.
Antelope was ordered from Vosper on 11 May 1970, laid down on 23 March 1971, launched on 16 March 1972 and commissioned on 30 June 1975 for a cost of £14.4M. In 1977, she took part in the Silver Jubilee of Elizabeth II as part of the 7th Frigate Squadron. She took part in the Falklands War, arriving on 21 May 1982 and two days later, while on air defence picket at the entrance to San Carlos she was attacked by four Argentine A-4B Skyhawks of Grupo 5. The first two from astern, the other forward. Seacat missiles were fired. One broke the attack of the flight leader as it dexploded under his port wing. Captain Pablo Carballo, managed return to Rio Gallegos. The second managed to drop a 1,000-pound bomb on the frigate’s starboard side, killing Steward Mark R. Stephens. It was a dud. Damaged by small arms fire, the Skyhawk retired. The second pair arrived minutes later from starboard. Luciano Guadagnini was hit by 20 mm fire and collided with Antelope’s main mast but had released the bombs, one penetrated the hull amidships, but was a dud. Antelope fired a Seacat on a fifth attacker. Captain Carballo saw the missile missed, and this was enough to break his attack.

After initial damage control Antelope sailed to the more sheltered waters for bomb disposal technicians from the Royal Engineers to attempt to defuse the two duds. One was inaccessible in the wreckage. The other had been damaged and in a dangerous condition. Three attempts failed. A fourth with a small explosive charge detonated the bomb, killing Staff Sergeant James Prescott and badly wounding Warrant Officer John Phillips. The blast torn open the ship from waterline to funnel, starting major fires in both engine rooms, spreading. The Starboard fire main failed and she lost all electrical power. Commander Nick Tobin, gave the order to abandon ship and was the last to leave. Just 5 minutes after, the missile magazines detonated, and explosions continued throughout the night. Still afloat the next day, she sank in shallow waters, her keel broken, superstructure melted. She became one of the icons of the Falklands War on TV. Corporal Alan White received a commendation later from Admiral Sir John Fieldhouse, fo rescuing 41 from Antelope on his Mark 2 LCVP Foxtrot 7 from HMS Fearless. It is now exposed at the Royal Marines Museum in Portsmouth. Anrelope’s wreck was surveyed in January 2002 by a team from HMS Montrose. It is a prohibited area under the Falkland Islands Protection of Wrecks Act.

HMS Active (F171)

HMS Active at Tampa Bay, Florida 1994.
Active was the last ship ordered from Vosper Thornycroft on 11 May 1970, she was laid down on 21 July 1971, launched on 23 November 1972 and commissioned on 2 June 1977 of £24.1M. She was part of fleet exercises, patrols, showing the flag missions before the Falklands war. Sailing from HMNB Devonport on 10 May 1982 (Bristol Group) she arrived on 21 May, part of the main fleet, operating east of the Falklands daily, escorting supply convoys to San Carlos and in shore bombardment by night. On 13/14 June, she shelled Argentine positions, playing a decisive role at the Battle of Mount Tumbledown. Same at Bluff Cove, Fitzroy, Berkeley Sound, Mount Tumbledown, and Port Stanley actions for which she recived commentations. Postwar she received two more 20mm Oerlikon saved from the wreck of her sister Ardent. In the mid-1980s hull cracking led to modifications her of steel plating and to reduce hull noise.

As Hurricane Gilbert struck Jamaica, Grand Cayman in September 1988, she departed with RFA Oakleaf and arrived on 13 September for emergency relief, remaining for seven days. She was decommissioned and sold to Pakistan on 23 September 1994 as Shah Jahan. She receioved the same mods (new radar and Harpoon, plus a 20mm Phalanx CIWS). Shah Jahan was sunk as target on 12 January 2021 in a live-firing exercise.

HMS Ambuscade (F172)

Ambuscade was the led ship ordered from Yarrow Shipbuilders, Scotstoun (YSL) on 11 November 1971. She was laid down on 1 September 1971, launched on 18 January 1973 and commissioned on 5 September 1975 for a cost of £16.5M. Ambuscade took part in the Falklands War as an Electronic Warfare picket ship for the Task Force. By night she took part in several bombardments of Argentine positions. On 25 May she was targeted by two Exocet from Super Étendard aircraft. Ambuscade detected them from 30 miles and the missile from 22 miles, visually, eventually, firing chaff decoys in an attempt to confuse their seekers but both missiles locked on to SS Atlantic Conveyor and hit her port quarter, setting her on fire. She later sank under tow on 28 May. On the night of 13/14 June Ambuscade landed some 228 4.5-inch shells for 2nd. Para assaulting Wireless Ridge.

On 27 April 1983, Ambuscade was in tactical manoeuvres with USN ships in the Indian Ocean when colliding with the missile cruiser cruiser USS Dale. Her bow was partly torn away. Ambuscade was thus laid up in Bombay for six weeks wfor repairs. She then sailed to Jacksonville, Florida for more. Ambuscade also collided back home with the trawler Ester Colleen in heavy fog off Torbay, 26 October 1983. From November 1983 to February 1984, she was a West Indies Guardship. On 8 June 1984, she assisted the schooner Stena of Sitoo in the North Sea. In late 1984, cracking in her hull, she was taken led to the same refitting as her sisters. She also received four Exocet launchers then. She was decommissioned in 1993 and sold to Pakistan as PNS Tariq. By December 2021, she was to be decommissioned, returned for preservation as a museum ship, a plan backed by the RN in February 2023, to be preserved in Glasgow. But as of 2026, nothing came out of it.

HMS Arrow (F173)

HMS Arrow underway in 1982
Arrow was the second ship ordered from YSL on 11 November 1971, laid down on 28 September 1972, launched on 5 February 1974 and commissioned on 29 July 1976 for £20.2M. She was completed with Exocet launchers. She took part in the 1982 Falklands War, first British ship to see action when shelling Argentine positions around Port Stanley on 1 May. She was also the first hit by an Argentine aircraft, cannon hits to her funnel uptake and superstructure, with one casualty from shell splinters. On 4 May she assisted the Type 42 destroyer HMS Sheffield on fire after an Exocet missile hit. She rescued 225 of the 261 survivors, from which Commander Paul Bootherstone was later awarded the DSC. On 6 May she shelled Argentine positions at Fox Bay, West Falkland. On 10–11 May, she was in the northern end of Falkland Sound while HMS Alacrity transited to assess if the channel was mined. Alacrity left before dawn, Arrow was waiting to accompany her back to the Task Force when the submarine ARA San Luis (Capt. Fernando Azcueta) attacked. He fired two SST-4 torpedoes from 5000 yards. She missed.

On 28 May, Arrow provided naval gunfire support for the Second Battalion, Parachute Regiment at Goose Green, notably lighting up Argentine defenders with 22 star shells, and landing 135 rounds for 90-minute. She was sent then to “Bomb Alley” (San Carlos anchorage) longer than any other RN ship for temporary repairs after hull cracks. While udnerway to Fitzroy on 5/6 June, Arrow detected a surface target close to shore. She fired three star shells (last fire in this war) and spotted a British Landing Craft Mechanised (LCM). She escorted her to Berkeley Sound. In early June 1982 she provided gunfire support for the last battles before the Argentine surrender. She was welcomes back at Devonport on 7 July 1982. The Argentines claimed to bag the frigate postwar, with her silhouette paintained on a Dagger C-412 alongside HMS Brilliant.

Like her sisters, Arrow suffered from hull and deck cracking and in the war, already received steel plates and girders and she was taken over for refitting. In early 1985 she became a Guardship in the West Indies. In July 1991, while back from the South Atlantic she joined a US Coast Guard patrol boat, resulting in the seizure of 1,500lbs of smuggled cocaine. Her service went on until 1994, when decommissioned and stricken on 1 March that year. She was transferred to Pakistan and renamed PNS Khaibar. She was still in active service in the 2020s.

HMS Alacrity (F174)

Alacrity was ordered on 11 November 1971, laid down on 5 March 1973, launched on 18 September 1974 and completed, commissioned on 2 July 1977 for £23.8M. In 1977, she took part in the Fleet Review at Spithead for the Queen’s Silver Jubilee. In 1980, she took part ina Far-East deployment and visuted Shanghai. She was even the first British warship to enter the Yangtse since 1949. She was sent to the Falklands, departing Devonport on 5 April 1982 under Commander Christopher Craig. On 1 May 1982 she was attacked by Skyhawks and lightly damaged by a near miss. The same day her Lynx helicopter on patrol spotted and machine-gunned the well named Argentinian coastguard “Islas Malvinas” and armed coastal transport ARA Forrest near Kidney island. Both were damaged. The Lynx however was fired upon by Forrest. On the night of 10–11 May 1982, Alacrity was sent to detect if the Argentines had mined the north entrance of Falkland Sound. While close to the Swan Islands, she spotted and sank the 3000-ton Argentine supply ship ARA Isla de los Estados by gunnery (a first since a long time). Apparently she landed rounds that detonated a cargo of jet fuel and ammunition. She rescued only two survivors.

Alacrity left the channel before dawn, with Arrow waiting to accompany her back when they were attacked by ARA San Luis, launching two SST-4 torpedoes but missing. On 25 May, Alacrity her had bow while rescuing survivors from SS Atlantic Conveyor. Postwar, her hull racking led to a refit. In 1989 she was in a West Indies guard ship, sent for humanitarian relief on Montserrat after Hurricane Hugo. Her Lynx helicopter was particularly helpful. She was decommissioned, transferred to Pakistan on 1 March 1994, renamed Badr and refitted like her sisters in Pakistani service.
On 11-21 May 2008, Badr took part in “Inspired Union”, a multi-national North Arabian exercise with her sister Shah Jahan, and US DDs Curts and Ross. She was decommissioned in April 2013.

HMS Ardent (F184)

Ardent was ordered on 11 November 1971, but only laid down on 26 February 1974, launched on 9 May 1975 and commissioned on 14 October 1977 for £26.3M. On 19 April 1982 she left HMNB Devonport for the Falkland Islands and en route, escorted the second task force to Ascension Island, on 3 May and sailing again on 7 May. On the 9th she crossed the troopship Canberra and made a gun salute. On 21 May 1982, while in Falkland Sound for Operation Sutton shelling the airstrip at Goose Green, she was attacked by at least three waves of skyhawks causing her loss. The British account reported she was hit by two bombs at 16:00 straddling her but duds. The main attack commenced at 17:40 while she was ordered to proceed west of North West Island with HMS Yarmouth to split air attacks from the south.

Skyhawks or IAI Daggers crossed Falklands Sound from the west, turned to their left and attacked from the north east. They landed Cannon fire and three bombs on her port side, under 20 mm AA cannon fire. The Sea Cat failed to track them, and they skillfully outmanoeuvred the 4.5″ gun. Two bombs exploded in the hangar, destroying the Lynx helicopter, blowing the Sea Cat into the air, before it landed and wrecked the flight deck. The third bomb went through the aft auxiliary machinery room but was a dud. The aft switchboard failed and she lost almost all power, notably for the main gun. The hangar burst into flames, and number casualties were heavy. However at this point she was still parlty operational, had her engines and steering working. She was ordered to head north, to Port San Carlos. At 18:00, five Skyhawks approached, dropped free-fall bombs, some with retarding setup.

Some exploded on her port quarter aft and the others were duds. She had minor flooding in her forward auxiliary machine room. Cdr. John Murray Sephton her Lynx helicopter Flight Commander, organised a platoon of small arms for defence, but could not prevent the final attack around 15:00. Sephton’s Sterling submachine gun damaged a A-4 Skyhawk but the latter landed bombs struck onto the flight deck, killing Sephton and three of his fire team. Her was posthumouslmy awared the DSC. The ship lost all communications and steering, as well as causing many more casualties, notably the damage-control team in the hangar.

She ended in the shallow waters of Grantham Sound but her fires were now out of control and she was listing heavily. Commander Alan West gave the order to abandon ship. HMS Yarmouth came alongside in assistance to rescue survivors, later retransferred to Canberra. 22 men had been killed. Ardent burned throughout the night and sank at 6:30 the next day. Seaman John Dillon by saving an injured sailor from the debris was also awarded a George Medal. Commander Alan West was the last to leave, also awarded the DSC. He became First Sea Lord in 2002–2006. Divers later salvaged what they could, notably her 20 mm guns. She is now in a prohibited area under the Falkland Islands Protection of Wrecks Act.

HMS Avenger (F185)

HMS Avnger as part of the Bristol Group in 1982
Avenger was ordered on 11 November 1971, laid down on 30 October 1974, launched on 20 November 1975 and commissioned on 15 April 1978 for £27.7M. In 1981 under Captain Hugo White, she became leader of the 4th Frigate Squadron. She was sent late in the Falklands War, departing on 10 May, arriving on 25 May, albeit this was the fastest transit achieved, in 14 days at an average of 28 knots. This earned her the nickname “Boy Racer”. On 30 May 1982 she survived an Exocet attack aimed at HMS Invincible (R05). Her divers armed her with the 20 mm Oerlikon recovered from HMS Antelope. On 11 June she provided naval gunfire support off Port Stanley, but one shot landed in a house, killing three Falkland Islander, only British civilian casualties of the war. She developed in operation a serious hull crack that progressively worsened in heavy weather. Back home she was taken up for refitting.

On 4 May 1983, HMS Avenger and HMS Ambuscade were part of the ‘Armilla’ patrol in the Persian Gulf during. She lost Captain Peter Woodhead, returning from a visit ashore in the ship’s Lynx which suffered a tail rotor control failure and disappeared off Muscat. HMS Avenger approached the crash site, the crew observed clothed bodies. Captain Woodhead and the three other crew members survived the incident. Avenger remained leader of the 4th Frigate Squadron until 1986. She was decommissioned and sold to Pakistan on 23 September 1994, refitted, renamed Tippu Sultan, joining the 25th Destroyer Squadron and ended her career on 27 April 2020 as a target.