The former destroyer and the frigate were used for testing prototypes in 1978–81. It was planned to install them on "Rothesay" conversions, but this was not possible due to industrial strikes. Scheduling then made it easier to fit them onboard four of the Batch II "Leander"s. "Compensation for the additional 70 tons of top weight included lowering the Exocet launchers. This interesting quartet was to have been followed by five Batch III "Leander"s, but the latter fell foul of the Nott cancellations. A fifth "Leander", the Ikara-carrying HMS "Arethusa", was fitted with a towed array in 1985, the year the towed-array trials ship "Lowestoft" was withdrawn from service."