In 1940 & 1941 the battle of the Atlantic seemed to be being won by the U-boats. Merchants ships were being sunk quicker than they could be replaced and Britain was in danger of being starved of precious resources and food.

Existing escorts were, on the whole, not ideal. Plans were drawn up for a new frigate construction programme; the  resulting Loch Class was to prove to be amongst the best A/S frigates produced by Great Britain during the war.