Royal Navy lost 8 vessels in that conflict. What I could gather about Amazon Class frigates was that equipped with 4.5 inch (112.5 mm) gun, these were very good for the shore bombardment, however their anti-ship warfare capability was limited. Aluminium reduced the weight but caught fire when hit by the Exocet missiles. The remaining 6 were later sold to Pakistan and after modification, have served well with PN with 5 still in active service.
Even though these ships were originally commission in 1974; as long as the hull is solid, a naval vessel can be modernized. Understand Turkish corvettes will cost around $250 to $ 300-million each. A complete refurbishment at Karachi shipyard with modern weapons, radar and command & control systems etc (say $50 to 60-million per unit), PN can possibly have 5 capable littoral warships for the price of one Ada class corvette.
However the “Hull” is still good enough to last another 20 years?
Actually 7 hulls. However, an LCU isn't really a ship (its a craft carried by an LPD). Of the remaining 6 hulls, 1 was an unarmed civilian ship (Atlantic Conveyor) and 1 a barely armed Landing Ship. So, in effect, 4 warships lost.
Type 21 was intended as a relatively cheap, yet modern, general purpose escort vessel. It was also envisaged as an out-of-area RN gunboat that would retain UK presence in South America and Australasia, as well as the Caribbean and the Gulf; essentially replacing the diesel Types Type 41, Type 61 and COSAG Type 81 with smaller crewed vessels. 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.
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 Sea Cat surface-to-air missile aft. The Italian Selenia Orion-10X lightweight fire control radar was adopted to control both the gun and the Sea Cat 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. 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 and
Rothesay-class frigate.
When they entered service, the Type 21s were criticized for being under-armed in relation to their size and cost. A program 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 countermeasure launchers to amidships. This improvement was quickly carried out to all ships of the class except
Antelope and
Ambuscade. The Westland Wasp, a single-role torpedo-carrying helicopter, was replaced by the vastly more capable multi-mission Westland Lynx when it became available. As and when ships came in for refit, ship-launched anti-submarine torpedoes were also fitted, 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, one each side of the hangar, to provide extra close-in armament on some ships of the class.
By the late 1970s it was clear the commercially designed Type 21 had 'insufficient margin' , of weight and space allowed in in-house Royal Navy warship designs, for major modernization of the type being applied to other classes e.g. Leander. Five modernization proposals for the Type 21s were considered by the Royal Navy and rejected by 1979 when it was 'reluctantly' decided not to modernize the class
