Type 12M ('Leander' class) Frigate
The frigate building programme of the early 1950s had resulted in some 35 vessels of various classes ('Whitby', 'Blackwood', 'Salisbury', 'Leopard' and 'Rothesay') which gave a good sized fleet of modern escort vessels, but resulted in standardisation problems. These included the cost of building, designing and maintaining several classes of vessels, and the problems of ensuring such specialist vessels were available for deployment. The new class was to be known as the Type 12M and its armament was a balanced one, with twin 4.5 inch guns combined with the new Type 903 radar, a quadruple Seacat launcher (although the first seven vessels had twin 40mm guns initially), two single 20mm guns (fitted in the 1960s), Corvus chaff launchers, Limbo anti-submarine mortar and Wasp helicopter. A variety of sonars were fitted (Types 177 or 184, 170B, 162 and 199) as was the Type 965, 993 and 975 or 978 radars. The resultant ships formed the backbone of the Royal Navy frigate fleet in the 1970s and early 1980s. The ships were built in three distinct batches. The first batch of ten ships were built to the original design. The second batch of six had a revised engine room layout. The third batch of ten had their beam increased to 43 feet, which increased stability and internal volume. The strength of the design was obvious with four vessels being built for export in UK yards (for the Royal New Zealand and Chilean navies) and eleven built to the design in India, the Netherlands and Australia. At their mid-life refits, the Batch I ships (except Penelope and Cleopatra) were converted to carry the Ikara anti-submarine system (which replaced the 4.5 inch gun turret), as installed on HMS Bristol (Type 82 destroyer). The Limbo mortar and Wasp helicopter were retained, thus giving the ships a strong anti-submarine slant and was a departure from the original intention of a general purpose design. The converted vessels had two quadruple Seacat launchers and two single 40mm guns mounted. The Batch II ships (along with the Cleopatra and Penelope from Batch I) were modified with four Exocet missiles replacing the twin 4.5 inch gun turret, the Limbo anti-submarine mortar was removed and the flight deck and hanger enlarged to take the Lynx helicopter, three quadruple Seacat launchers installed (with two single 40mm guns) for anti-aircraft defence and the Ships Torpedo Weapon System-1 mounted. Five of the Batch III vessels (Andromeda, Charybdis, Hermione, Jupiter and Scylla) were converted to carry the GWS25 missile system which involved stripping all the armament and radars off the ships and replacing them with the sextuple Seawolf launcher and Type 910 radar, converting the hangar and flight deck to take the Lynx helicopter, a Type 975 navigation radar, two 20mm guns, and the new Type 2016 sonar. Andromeda, Minerva, Argonaut and Penelope took part in the Falklands conflict of 1982, where the Argonaut was damaged by two bombs, which failed to explode. The 'Leanders' were gradually retired from service in the late 1980s and early 1990s.
Names: Leander, Ajax, Dido, Penelope, Aurora, Euryalus, Galatea, Arethusa, Naiad, Cleopatra (Batch I); Minerva, Phoebe, Sirius, Juno, Argonaut, Danae (Batch II); Hermione, Andromeda, Jupiter, Bacchante, Charybdis, Scylla, Achilles, Diomede, Apollo, Ariadne (Batch III).
How to cite this article:
Antill, P. (6 February 2001), Type 12M ('Leander' class) Frigate, http://www.historyofwar.org/articles/weapons_type12m.html