The turbines developed a total of 34,000 shaft horsepower (25,000 kW) and were intended to give a maximum speed of 35.5 knots (65.7 km/h; 40.9 mph).

[2] The ships carried enough fuel oil to give them a range of 5,500 nautical miles (10,200 km; 6,300 mi) at 15 knots (28 km/h; 17 mph).

For anti-aircraft (AA) defence, they had two quadruple mounts for the 0.5 inch Vickers Mark III machine gun.

[8] Impulsive attacked and sank the German submarine U-457 in the Barents Sea north-east of Murmansk in Russia on 16 September 1942.

[9] Impulsive was sold for scrap to W. H. Arnott, Young and Company, Limited on 22 January 1946 and broken up at Sunderland.