The turbine drove the same shaft as her piston engine by double-reduction gearing and a Föttinger fluid coupling.

[4] On 27 May 1940 Clan Macalister was in Southampton when the Admiralty requisitioned her to assist the evacuation of UK and Allied forces from Dunkirk.

[6] On the morning of 29 May Clan Macalister anchored about 1+1⁄2 nautical miles (2.8 km) off Dunkirk and with her derricks unloaded her landing craft.

[6] At 1545 hrs three bombs dropped by German aircraft hit the ship, and a fire broke out in her number 5 hold.

The destroyer HMS Malcolm rescued her troops and wounded members of Clan Macalister's crew, and tried to fight the fire.

The minesweeper HMS Pangbourne rescued the remainder of Clan Macalister's crew,[4] including her Master, RW Mackie.