 The "Blackwood"-class ships had the same sonar suite as the larger s where the Limbo mortars were controlled by three sonars, the Type 174 search set, Type 162 target-classification set and the Type 170 'pencil beam' targeting set to determine the bearing and depth of the target.The ship was named after Captain Sir Edward Pellew, later Viscount Exmouth.In 1965 "Pellew" was part of the 2nd Frigate Squadron based at Portland.