The Castle-class corvette was an ocean going convoy escort developed by the United Kingdom during the Second World War. It was the follow-on to the , and designed to be built in shipyards that were producing the Flowers. The Castle-class was a general improvement over the smaller Flowers which were designed for coastal rather than open ocean use.

The Castle-class corvettes started appearing in service during late 1943.

Background

In mid-1939, the Admiralty ordered 175 Flower-class corvettes for protecting shipping on the west coast of Britain as well as the Western Approaches. They were designed to be built in large numbers in small shipyards without propulsion and other components (mainly gearboxes, but also guns) then in short supply so not to compete with other warships for construction. By the time the Flowers began entering service in late-1940, due to their long range they were required to undertake missions beyond coastal waters. The Flowers were unsuited for open-ocean escort in the North Atlantic, especially in poor weather; they lacked speed, endurance, and habitability but became the mainstay of the Mid-Ocean Escort Force protecting convoys crossing the Atlantic.

The Royal Navy recognized the limitations of the Flower and began designing an open-ocean escort in November 1940, which became the . The larger Rivers were too expensive to produce at the required rate and needed larger slipways. The was developed in late-1942, which was derived from the River and designed for prefabricated construction. The Castle was developed from a proposal by Smith's Dock Company – who had designed the Flower-class – for a stretched Flower. The result was a smaller version of the Loch for shipyards that only built corvettes using mainly traditional methods.

The design was approved in May 1943 and 96 Castles were ordered from yards in the UK and Canada. A lattice mainmast was used instead of the pole version fitted to the Flowers.

Construction used mainly traditional methods with as much welding as possible. Scantling was based on the Flower, but lightened in some areas. The wireless office The first operational Type 147 and Squid were installed aboard HMS Hadleigh Castle in September 1943. They were operated from 1946 to 1958 but were heavy on fuel and had limited cargo capacity, for example they could not carry cars in the hold.

  • SS Camosun III – ex-HMCS St. Thomas, HMS Sandgate Castle
  • SS Chilcotin – ex-HMCS Hespeler, HMS Guildford Castle
  • SS Coquitlam II – ex-HMCS Leaside, HMS Walmer Castle

References

Citations

Sources

  • Twigg, Arthur M.: Union Steamships Remembered: 1920–1958 (1997) .
  • Castle-class corvette (Frigate) Association
  • Castle-class corvettes on U-Boat.net