The other four ships planned for the C class were never ordered as an economy measure and disarmament gesture by the Labour government of Ramsay MacDonald.

They were transferred to the Royal Canadian Navy (RCN) in 1937–1939 and spent most of their time during World War II on convoy escort duties in the Atlantic Ocean.

These ships were based on the preceding B class, but were enlarged to increase their endurance and to allow for the inclusion of a QF 3-inch 20 cwt anti-aircraft gun.

The destroyers carried a maximum of 473 long tons (481 t) of fuel oil that gave them a range of 5,500 nautical miles (10,200 km; 6,300 mi) at 15 knots (28 km/h; 17 mph).

[1] Kempenfelt, leader of the C class, displaced 15 long tons (15 t) more than her destroyers and carried an extra 30 personnel who formed the staff of the Captain (D), commanding officer of the flotilla.

The C-class ships carried two 40-millimetre (1.6 in) QF 2-pounder Mk II AA guns mounted on the aft end of their forecastle deck.

The 3-inch AA gun was removed in 1936–37, and the 2-pounders were relocated between the funnels on platforms The ships were fitted with two above-water quadruple mount for 21-inch (533 mm) torpedoes.

[7] When purchased by Canada in 1937–38, the four C-class destroyers were refitted to meet Canadian specifications,[8] including the installation of Type 124 ASDIC.

Four to six QF 20 mm Oerlikon cannons were added to the surviving ships, usually replacing the 2-pounder or .50-calibre machine gun mounts between the funnels.

Kempenfelt was bought in 1939, but the Royal Navy did not turn her over until enough auxiliary anti-submarine ships had been commissioned to replace her after World War II had started.

All four 'C'-class ships were stationed at Esquimalt in British Columbia when the war began, but only Fraser and St. Laurent were immediately recalled to begin convoy escort duties on the Atlantic Coast, the other two following in November.

Assiniboine was sent to the Caribbean for local escort duties in December where she assisted in the capture of the blockade runner MV Hannover in March 1940.

Fraser was sunk on 25 June 1940 in a collision with the anti-aircraft cruiser HMS Calcutta in the Gironde estuary while the other two were assigned to the Western Approaches Command for escort duties.

Ottawa assisted the British destroyer Harvester in sinking the Italian submarine Comandante Faà di Bruno on 7 November 1940.

Restigouche never sank a submarine, but she and St. Laurent were transferred to the UK to protect the shipping mustering for Operation Overlord in May 1944 and Assiniboine followed in July.

They saw some action against German patrol boats in the Bay of Biscay, but Restigouche and St. Laurent were in poor shape by this time and were sent back to Canada for lengthy refits in late 1944.

While attempting to sail through the English Channel in daylight, contrary to orders, Delight was sunk by German aircraft on 29 July.

After a brief refit in July–August, Diana was transferred to the RCN to replace HMCS Fraser which had been sunk in a collision by a Royal Navy cruiser.

Recommissioned on 6 September and renamed HMCS Margaree, the ship was assigned to convoy escort duties in the North Atlantic.

[28] The remaining four ships of the flotilla were briefly assigned to Freetown, West Africa in early 1940 to escort convoys passing through the area and to search for German commerce raiders.

Duncan joined Force H at Gibraltar in October and participated in the inconclusive Battle of Cape Spartivento together with Diamond and Defender in November.

After Defender participated in the invasion of Vichy French-controlled Syria and Lebanon in June, she joined Decoy in escorting convoys to Tobruk and was badly damaged when returning from one of these missions.

The ship was attacked by a single German Junkers Ju 88 bomber on 11 July and had to be scuttled by her consort, the Australian destroyer Vendetta.

Duncan rejoined Force H that same month and she escorted several major convoys to Malta before returning to the UK in October for a lengthy refit.

The Japanese never spotted Force B, and the ship remained with the fleet until ordered home in September to convert to an escort destroyer.

[29] After a lengthy refit in Canada from October 1944 to February 1945, Kootenay returned to the UK and was assigned to the Western Approaches Command until the end of the war.