Type 21 frigate

The Type 21 frigate or "Amazon" class frigate was a Royal Navy general-purpose escort designed in the late 1960s, built in the 1970s and that served throughout the 1980s into the 1990s.

History

The class was designed to fulfil a requirement for a relatively cheap yet modern general purpose escort vessel to fill a projected gap in the number of escort hulls in the fleet. Many older vessels were rapidly approaching the end of their useful lives yet their replacements, the Type 42 destroyer and Type 22 frigate, would not be ready until the mid-to-late 1970s. The Admiralty design board were busy with the latter, therefore the Type 21 project was given to private shipyards Vosper Thornycroft and Yarrow. The unmistakably yacht-like and rakish lines were indicative of their commercial design. Their handsome looks combined with their impressive handling and acceleration lent itself to the class nickname of "Porsches". The design was partially funded by the Royal Australian Navy who had originally intended to buy five vessels, but in the event did not purchase any. The first of the eight built, HMS "Amazon", entered service in May 1974.

Design

These ships were the Royal Navy's first privately designed modern frigates. They were also the first design to enter service which used solely gas-turbine propulsion, as opposed to the steam turbines or diesel engines of their predecessors. The design made use of large amounts of aluminium alloy in the superstructure to lower the amount of topweight but worries later surfaced about its 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. Later warships reverted to using steel again.

As originally built, the Type 21 design made use of a lot of "off the shelf" technology, such as the old Sea Cat missile (combined with the Italian-built Alenia Orion-10X fire-control system - as the GWS-24 system), the Wasp anti-submarine helicopter, and marinized Rolls-Royce aircraft engines. Yet it also featured modern electronics such as the CAAIS (Computer Assisted Action Information System) system 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.

In terms of automation, systems integration and habitability they were well in advance of many of their older Royal Navy contemporaries, such as the Type 81 frigate and Rothesay class frigate, the latter of whose basic design could be traced back to 1945.

Modifications

When they entered service, the Type 21s were immediately criticized for being woefully under-armed. A program was put in hand to increase their fire power by fitting 4 French-built MM38 Exocet anti-ship missiles. These were sited in front of the bridge screen aft of the forecastle, displacing the "Corvus" countermeasure launchers to amidships. This improvement was carried out to all ships of the class. An interesting point to note was the fact that the Exocet 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. This differed to the later type 22 frigates where deployment of the missiles was to the same side of the vessel as the missile pairs were fitted. When it became available, the Westland Wasp, a single-role torpedo-carrying helicopter, was replaced by the vastly more capable multi-mission Westland Lynx. Ship-launched anti-submarine torpedoes were also fitted as and when ships came in for refit, in the form of two STWS-1 triple-tube launchers capable of firing United States USN/NATO-standard Mark 44 or Mark 46 torpedoes. After the Falklands War two more 20mm Oerlikon guns were mounted each side of the hangar to provide extra close-in armament on some ships of the class.

Analysis

Criticism was levelled at the performance of the type in the Falklands conflict. The ships developed cracks in their decks due to the differing expansion properties of steel and aluminium. This was a vulnerability particularly demonstrated under the severe weather conditions they encountered in the South Atlantic. Steel reinforcing plates were eventually fitted down the sides of the ships. Built to an exacting budget and design specification (and although carrying obsolete anti-aircraft weaponry), they distinguished themselves in a theatre for which they were not designed.

The class was also criticised for being overcrowded; however, at 384 ft (117 m) they had 177 crewmen compared to 436 ft (133 m) and just 185 crewmen for the modern Type 23 frigate. This was important at a time when the Royal Navy was facing a manpower shortage. The standard of accommodation for the officers was better than the RN average and the senior ratings enjoyed separate cabins – unlike the petty officers 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. The accommodation arrangements (designed by a woman)Fact|date=August 2007 were far better than those of the Type 42 destroyer. With little capability to modernise (owing to its small size) and already being close to its topweight limit, the Type 21's days were numbered. Nevertheless, these ships were regarded favorably with their crews and proved to be useful assets in a navy severely depleted in the number of modern escort hulls.

Active service

All of the class except "Amazon", as the 4th Frigate Squadron, took part in the Falklands War of 1982. They were heavily involved, performing extensive shore-bombardment missions and providing anti-submarine and anti-aircraft duties for the task force. Two vessels were lost, "Ardent" was hit by bombs dropped by Argentine aircraft on May 21 and was consumed by fire. HMS "Antelope" was hit by bombs on May 23, one of which was set off by the bomb disposal team attempting to defuse it on May 24, causing the ship to break her back and sink. It is highly unlikely that any ship of this size would be able to survive a direct hit from aerial bombs, and that they stayed afloat as long as they did to allow the evacuation of their crews is testament to the design.

Disposal

All six of the surviving Type 21 frigates were sold to Pakistan in 1993–1994. The class was renamed by the Pakistani Navy as the "Tariq" class, after the first vessel that was acquired, the PNS "Tariq", formerly the "HMS Ambuscade (F172)". All six ships remain in service, as of 2007. They have had their Sea Cat launcher removed, as well as their Exocet missiles. Three of the ships had their Exocet missiles replaced by the more capable US-made Harpoon missile. In 2005, it was reported that a Chinese made LY-60 / FD-60 / PL10 (Hunting Eagle - Navy version) anti-air missile launcher was installed aboard the other three frigates by PakistanFact|date=August 2007.

hips

References

*"Royal Navy Frigates 1945-1983" Leo Marriot, Ian Allan, 1983 ISBN 0-7110-1322-5
*"Warships of the Royal Navy; New Edition" Capt. John E. Moore, Jane's Publishing, 1981 ISBN 0-7106-0105-0
*"World's Worst Warships", Anthony Preston 2002, Conway's Maritime Press