The War Emergency Programme destroyers were destroyers built for the British Royal Navy during World War I and World War II.

World War I emergency programmes

The 323 destroyers ordered during the First World War belonged to several different classes and were the subject of 14 separate War Programmes between 1914 and 1918. 40 of these were cancelled at the end of the war. The total excludes destroyers building in UK for other navies which were purchased for the Royal Navy following the outbreak of war.

World War II emergency programme

The 112 destroyers built during the Second World War were based on the hull and machinery of the earlier J-, K- and N-class destroyers of the 1930s. Each of the fourteen flotillas produced consisted of eight destroyers. Due to supply problems and the persistent failure by the Royal Navy to develop a suitable dual-purpose weapon for destroyers, they were fitted with whatever armament was available. Advances in radar and weaponry were incorporated as they came available. As a result, they were a relatively heterogeneous class incorporating many wartime advances, but ultimately based on a hull that was too small and with an armament too light to be true first-rate vessels equivalent of their contemporaries. As such they are often described as "utility" destroyers. It was not until the Battle-class destroyer of 1944 that the Royal Navy returned to building larger destroyers. Many vessels were transferred to friendly navies. The 15th Emergency Flotilla, which would have had ships with names starting with Ce, was cancelled in favour of building the Weapon-class destroyers. The two ships being built, Centaur and Celt, became Tomahawk and Sword.

Design changes