This was a British naval undertaking, together with ‘Winner’ and within ‘Shred’, by elements of Admiral Sir Henry Moore’s Home Fleet (21/23 February 1945).
Under the command of Vice Admiral Sir Frederick Dalrymple-Hamilton, the Home Fleet’s second in command, the forces involved were the escort carriers Premier and Puncher, light anti-aircraft cruiser Dido, destroyers Cavalier, Myngs and Scorpion of the 23rd Destroyer Flotilla, and minesweepers Courier, Golden Fleece, Hare, Jewel, Serene, Wave, RML-551 and RML-545 of the 10th Minesweeping Flotilla.
At this time Germany was still making extensive use of Norwegian coastal waters for the movement of iron ore convoys from Narvik, but these waters were inaccessible to British warships because of the presence of German minefields. The alternative was to force German shipping into the hands of motor torpedo boat flotillas lurking outside the Leads by the laying of British minefields, a task difficult because of the depth of the water. However, during March one such operation was carried out to produce off Stadlandet a minefield which sank a large ship on 22 March.
In February, however, the objective of ‘Groundsheet’ (i) was the aerial laying of mines in the shallow waters of the Salhusstrommen and the provision of fighter cover for the 10th Minesweeping Flotilla’s endeavours in ‘Shred’. In the course of the air operation, one Dornier Do 24 flying boat was destroyed at its moorings and buildings on shore were shot up for the loss of two Fairey Barracuda attack aircraft.