The C and D class was a group of 14 destroyers built for the Royal Navy in the early 1930s. As in previous years, it was originally intended to order a complete flotilla comprising eight destroyers—plus a flotilla leader as the ninth unit—in each year. However, only four ships—plus a leader—were ordered under the 1929–1930 Programme as the C class. 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. A complete flotilla—the 'D' class—was ordered under the 1930–1931 Programme.

The five ships of the C class were assigned to Home Fleet upon their completion, although they reinforced the Mediterranean Fleet during the Italian invasion of Abyssinia of 1935–1936 and enforced the Non-Intervention Agreement during the Spanish Civil War of 1936–1939. 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. Fraser (formerly Crescent) was sunk when she was accidentally rammed by the British cruiser HMS Calcutta in 1940. Ottawa (formerly Crusader) was sunk by a German submarine in 1942, though she had sunk an Italian submarine in 1940. The other ships of the class sank three German submarines during the war. They were all worn out by the end of the war and were scrapped in 1946–1947.

The D-class destroyers were initially assigned to the Mediterranean Fleet upon commissioning, but were transferred to the China Station in 1935. Like the C class, most were temporarily deployed in the Red Sea when the Italians invaded Abyssinia, but returned to the China Station when that was over. They were still there when the war began, but reinforced the Mediterranean Fleet shortly afterwards. Five ships were transferred to Home Fleet in December 1939, but Duchess was sunk en route when she was accidentally rammed by the battleship HMS Barham, and Duncan was badly damaged when she collided with a merchant ship, requiring lengthy repairs. Daring was sunk by a German submarine in February 1940. The other two participated in the Norwegian Campaign of April–June, but Delight was sunk by German aircraft in July and Diana was transferred to the RCN as a replacement for the Crescent after she was sunk by the cruiser Calcutta. However, she too was rammed and sunk several months later by a freighter that she was escorting.

The four ships that remained with the Mediterranean Fleet sank three Italian submarines in 1940 while escorting Malta convoys and larger warships of the fleet. Several participated in the Battles of Calabria and Cape Spartivento that year. Duncan joined Force H at Gibraltar in October and escorted that group. Dainty was sunk by German bombers in February 1941 and Diamond in April while evacuating Allied personnel from Greece. Defender had to be scuttled in July when she was crippled by a German bomber when returning from escorting a convoy to Tobruk. Duncan and Decoy remained on escort duties for the rest of the year before being transferred to the Eastern Fleet in early 1942. They returned to the UK late in the year to begin conversions to escort destroyers. Decoy was transferred to the RCN in early 1943, but both became convoy escorts in the Atlantic. They sank two German submarines before being assigned to the UK to protect Allied shipping during Operation Overlord. They sank three more submarines before the end of the war and were paid off in 1945. Duncan was scrapped in 1945 and Decoy during 1946.

Design and description 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. This class introduced a director-control tower for British destroyers. The 'C' class were unique in having a split bridge, with the compass platform and wheelhouse separated from the chartroom and director tower. This unusual layout was not repeated. As per Admiralty policy in alternating Two-Speed Destroyer Sweep (TSDS) minesweeping gear and ASDIC (sonar) capability between destroyer flotillas, the C class lacked ASDIC and were designed to carry only six depth charges. The D class were repeats of the C's, except that the TSDS was replaced by storage for up to 30 depth charges and ASDIC.Friedman, pp. 205–215, 298–299

The C- and D-class destroyers displaced at standard load and at deep load. The ships had an overall length of , a beam of and a draught of . They were powered by Parsons geared steam turbines, driving two shafts, which developed a total of and gave a maximum speed of .Whitley, pp. 26, 102 Steam for the turbines was provided by three Admiralty 3-drum water-tube boilers that operated at a pressure of and a temperature of . The destroyers carried a maximum of of fuel oil that gave them a range of at . Their complement was 145 officers and ratings.Lenton, p. 154

, leader of the C class, displaced more than her destroyers and carried an extra 30 personnel who formed the staff of the Captain (D), commanding officer of the flotilla.Whitley, p. 27 Unique among the C and D-class ships, she had three Yarrow water-tube boilers that operated at a pressure of . , leader of the 'D' class, displaced more than her destroyers and also carried an extra 30 personnel.Whitley, p. 101

All of the ships of the class mounted four 45-calibre 4.7-inch Mk IX guns in single mounts, designated 'A', 'B', 'X', and 'Y' from front to rear. For anti-aircraft (AA) defence, they had a single QF 3-inch 20 cwt"cwt" is the abbreviation for hundredweight, 30 cwt referring to the weight of the gun. AA gun between her funnels. The C-class ships carried two QF 2-pounder Mk II AA guns mounted on the aft end of their forecastle deck. The D-class destroyers had been intended to carry the new QF 0.5-inch (12.7 mm) Mk III machine gun in quadruple mountings on the bridge wings, but these were not initially available, so the old 2-pounder guns were retained in Daring, Diana, Diamond and Defender. 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 torpedoes.Lenton, pp. 154–55

The main guns were controlled by an Admiralty Fire Control Clock Mk I that used data derived from the director and the rangefinder. They had no capability for anti-aircraft fire and the anti-aircraft guns were aimed solely by eye.Hodges and Friedman, pp. 12, 17

When purchased by Canada in 1937–38, the four C-class destroyers were refitted to meet Canadian specifications,Douglas, p. 52 including the installation of Type 124 ASDIC.Brown, p. 164 It is not clear how much Kempenfelt had been modified when she was turned over in October 1939, other than steam heating had yet been fitted.Douglas, p. 65

Wartime modifications Beginning in May 1940, the after bank of torpedo tubes was removed and replaced with a QF 12-pounder Mk V anti-aircraft gun, the after mast and funnel being cut down to improve the gun's field of fire. 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. One pair of these was added to the bridge wings and the other pair was mounted on the searchlight platform. Early in the war, depth charge stowage increased to 33 in the C class, while the D class carried 38.Friedman, pp. 236–37 'Y' gun on the quarterdeck was removed on many ships to allow for additional depth charge stowage as was the 12-pounder. On at least one ship, this latter gun replaced 'X' gun. Most ships had either 'A' or 'B' gun replaced by a Hedgehog anti-submarine spigot mortar, although Duncan retained both and received a split Hedgehog that was mounted on either side of 'A' gun. Some ships that received the Hedgehog in 'B' position also mounted two old QF 6-pounder Hotchkiss guns for use against U-boats at very close range.Lenton, pp. 154–56

Most ships had their director-control tower and rangefinder above the bridge removed in exchange for a Type 271 target-indication radar. A Type 286 short-range surface search radar, adapted from the Royal Air Force's ASV radar, was also added. The early models, however, could only scan directly forward and had to be aimed by turning the entire ship. Some ships also received a Huff-Duff radio direction finder on a short mainmast.

Ships + C class construction dataNameBuilderLaid downLaunchedEnglish, p. 45CompletedFate J. Samuel White, Cowes18 October 193029 October 193130 May 1932To Canada as 1939, wrecked on Prince Edward Island, 10 November 1945; scrapped 1952 HM Dockyard, Portsmouth12 September 193030 September 19312 June 1932To Canada as 1938, scrapped 1946English, p. 47 2 May 1932To Canada as 1938, torpedoed by the , 13 September 1942English, p. 49 Vickers Armstrongs, Barrow1 December 193029 September 193115 April 1932To Canada as 1937; scrapped 1947English, p. 50 1 April 1934To Canada as 1937, sunk in collision with , 25 June 1940English, p. 48

+D class construction dataNameBuilderEnglish, p. 51Laid downLaunchedCompletedFate HM Dockyard, Portsmouth25 September 19317 July 193231 March 1933Scrapped, 1945English, p. 53 Fairfield, Govan20 April 19313 May 193222 December 1932Bombed and sunk, 24 February 1941English, p. 54 Thornycroft, Woolston18 June 19317 April 193225 November 1932Sunk by the , 18 February 194025 June 19317 June 193217 January 1933To Canada as 1943; sold for scrap, 1946English, p. 56Vickers Armstrongs, Barrow22 June 19317 April 193231 October 1932Bombed and sunk, 11 July 1941English, p. 57Fairfield, Govan22 April 19312 June 193231 January 1933Bombed and sunk, 29 July 1940English, p. 58Vickers Armstrongs, Barrow29 September 19318 April 19323 November 1932Bombed and sunk, 27 April 1941English, p. 59Palmers, Jarrow12 June 193116 June 193221 December 1932To Canada as 1940, sunk in collision with , 22 October 1940English, p. 6019 July 193227 January 1933Sunk in collision with , 12 December 1939

Service

All five of the C class were assigned to the 2nd Destroyer Flotilla of the Home Fleet upon commissioning during 1932. Following the Italian invasion of Abyssinia, the entire flotilla was sent to the Red Sea in August 1935 to monitor Italian warship movements until April 1936. Refitted upon their return, they were deployed to Spanish waters during the Spanish Civil War in 1936–37 to intercept shipping carrying contraband goods to Spain and to protect British-flagged ships. Crescent and Cygnet were sold to the Royal Canadian Navy in 1937 and Comet and Crusader in 1938. 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 in March 1940. Fraser, St. Laurent, and Restigouche were transferred to the UK in late May and helped to evacuate refugees from France. Fraser was sunk on 25 June 1940 in a collision with the anti-aircraft cruiser in the Gironde estuary while the other two were assigned to the Western Approaches Command for escort duties.English, pp. 45–50