On 7 March 1960, the Civil Lord of the Admiralty C. Ian Orr-Ewing stated that the "Type 12 "Whitby"-class anti-submarine frigates are proving particularly successful ... and we have decided to exploit their good qualities in an improved and more versatile ship. This improved Type 12 will be known as the "Leander" class. The hull and steam turbine machinery will be substantially the same as for the "Whitby"s. The main new features planned are a long-range air warning radar, the Seacat anti-aircraft guided missile, improved anti-submarine detection equipment and a light-weight helicopter armed with homing torpedoes. We shall also introduce air conditioning and better living conditions." The 1963 edition of "Jane's Fighting Ships" described it as a "mainly anti-submarine but flexible and all-purpose type".