Two Admiralty three-drum water tube boilers fed steam to a vertical triple expansion engine rated at 2,750 indicated horsepower (2,050 kW) which drove a single propeller shaft.

[4] 200 tons of oil were carried, giving a range of 4,000 nautical miles (7,400 km; 4,600 mi) at 12 knots (22 km/h; 14 mph).

She was laid down at Hall, Russell & Company's Aberdeen shipyard on 21 January 1940, was launched on 4 September 1940 and completed on 28 February 1941.

That night, the convoy was attacked by the German submarine U-94 200 miles (320 km) south west of Reykjavík, Iceland.

Meanwhile, U-94 was driven off by a sustained depth charge attack by the destroyers Bulldog and Amazon and the sloop Rochester.

[11] Attacks on OB 318 continued, with three merchant ships sunk on 8 May, at the cost of U-110 which was captured by British warships, sinking under tow.

While four Italian submarines were deployed against the convoy, none managed to find it, and HG 71 reached Liverpool unharmed on 1 September.

Two merchant ships were sunk by the German submarine U-124 on the night of 20/21 September, while the rescue ship Walmer Castle was badly damaged by a German Focke-Wulf Fw 200 Condor long-range bomber on 21 September and was scuttled by Marigold and the sloop Deptford.

The operation was a dummy convoy (with empty merchant ships) intended to attract attention of German and Italian air power away from the land battle.

[27][28] On 13 November 1942 she rescued 81 survivors from the British merchant SS Maron which had been torpedoed and sunk by U-81 off Oran, Algeria.