[1][a] The vessels are powered by four MTU 20V538 TB 91 diesel engines turning four propeller shafts creating 18,000 brake horsepower (13,000 kW) and a maximum speed of 37 knots (69 km/h; 43 mph).

The two ST802 radars work in tandem with the Marconi Sapphire fire control system alongside two Lawrence Scott optical directors.

The ships are also equipped with a Decca-Racal Cygnus jammer, two MEL Protean chaff dispensers and Cutlass intercept radar.

These all supply information to the Ferranti CAAIS automated data system.

[1] The six ships were ordered on 4 September 1977 from Vosper Thornycroft of the United Kingdom.