The ships were part of the Royal Navy's 1927 Build Programme as replacements for the Flower-class sloop.

Bridgewater was moved to the Cape in 1935, while Sandwich remained in China until the outbreak of the Second World War in 1939.

Both ships were active in the Battle of the Atlantic, Bridgewater being based at Freetown carrying out patrols and escorting convoys until November 1943, when she moved to cover the Western Approaches.

Sandwich was also used in home waters, being based out of Plymouth, Liverpool, and Freetown between 1940 and 1944, though by 1945 her condition had deteriorated so much that she was kept at Bizerta.

Bridgewater was retained for slightly longer, being used for static bomb trials during 1946 and 1947, until being sold and broken up in May 1947.