The Leanders were regarded as very excellent frigates, developed form the type 12 frigates they implemented a wide range of capabilites over the older whitby and rothesay classes: mainly in terms of Radar, armaments, improvements in seakeeping (per example the addition of active stabalizers) and Sonar. With a total of 42 Type 12 ships build by several nations and some beeing still in service today they were an icon of the cold war because of their large number and realiable and ridgid nature.
The Type 12I orginated from the quite succesful Type 12 Whitby and Type 12M Rothesay classes of frigates. In 1960 it was decided to design a new class of frigate that would use the same hull and machinery of the Type 12 but would incorperate multiple design changes and optimizations to make them from convoy escord anti-submarine focused frigates (12 and 12M)into multi-pourpose frigates in the spirit of the Type 81 class. The first ones were originally delivered with a dual 40mm bofors mount which then was replaced by Seacat missle launchers when those became available. During their service life they recived multiple upgrades which can be categorized into 3 Batches:
Batch 1: replacement of the 4.5 inch turret with an Ikara anti Submarine missle and the addition of another seacat launcher plus torpedos
Batch 2: addition of 4x Exocets and an additional Seacat+ torpedoes
Batch 3: Exocets plus Seawolf missles + torpedoes
Some also got a Towed array refit and improved boilers.
They were in use with the Royal Navy, India, Ecuador, Netherlands, Chile and Austrialia. They served from the early 60s until the 80s with the Royal Navy. Of a total of 42 ships build to the Type 12 or modified designes 26 were Leander classes which made them the most numerous. They got extra fame with the TV show the Warship made by the BBC and 2 of these ships are still in service with the exuadorian navy in form of the codell class, which underlines their reliabilty.
Length: 113.4m (372ft)
Beam: 12.5m (41ft)
Draught: 4.5m (15ft)-5.5m (18ft)
Propulsion: 2 2 Babcock & Wilcox oil-fired boilers, geared steam turbines, 2 shafts, 30k hp
Speed: 27knots (50 kph)
Crew number: 260
Radars: Type 965 air waring radar (D-Band), Type 992 Q, Type 903, Type 974/978
Sonar: Type 162, 184, 199
1 twin mounting 4.5-inch mk 6 guns
2x20mm MRS mk 3 guns mounted to either side of the superstructure
1x quadruple GWS.22 Seacat launcher
1x Limbo ASW mortar
Seacat and why it could be introduced into the game without disturbing the balance:
Currently we have 3 guided missle ships in game: Douglas, Bravy and Saetta. All of those missles have ranges from 10-16km while Seacat iis listed at around 5-7km range and mach 0.9 which would make it the worst range wise and second worst speed wise. It has SACLOS like the other missles and it also can be used against ships. So all in all it would not bring anything new to the table and certainly nothing game breaking or overpowered. BR wise I would put her at 4.7-5.0 for the start.
Video for ppl more intressted into the Ship class:
Old Forum Suggestion made by Shrike142 which included the other Batches:
Sea Cat - Naval Missiles of the United Kingdom/Britain - NavWeaps
Leander class Type 12I Frigate - Royal Navy Seacat Seawolf Exocet
Leander class frigate | Against All Odds Wiki | Fandom
Sea Cat anti-aircraft missile system | Missilery.info
Leander-class frigate - Wikipedia
Warship Wednesday: HMS Scylla - Chatham Historic Dockyard Trust
Leander-class frigate (Type 12I frigates) — Shipshub