The engines produced a total of 1,750 shaft horsepower (1,300 kW) and gave a maximum speed of 16.5 knots (30.6 km/h; 19.0 mph).

Gleaner carried a maximum of 252 long tons (256 t) of fuel oil that gave her a range of 6,000 nautical miles (11,000 km; 6,900 mi) at 10 knots (19 km/h; 12 mph).

[4] Gleaner was completed by William Gray & Company, Hartlepool, as a survey vessel, but she was converted into a minesweeper when the war began.

On 12 February 1940, Gleaner sank German U-boat U-33 (55°25′N 05°07′W / 55.417°N 5.117°W / 55.417; -5.117) using depth charges and deck gun.

The British seized some materials from the U-boat, including Enigma machine rotors VI and VII, whose wirings were unknown at the time.