Castle class corvette

The Castle-class corvettes were an updated version of the much more numerous Flower-class corvettes of the Royal Navy, and started appearing during late 1943. They were equipped with radar as well as asdic.

The Admiralty had decided to cease Flower class construction in favour of the larger River-class frigates as the Flower class had originally been intended for coastal escort work and were not entirely satisfactory for Atlantic convoy service. In particular, they were slow, poorly armed, and rolled badly in rough seas which quickly exhausted their crews. However, many shipyards were not large enough to build frigates and so the Castle class was designed to be built on small slipways.

Appearance was much like the later "long forecastle" variant of the Flowers and they were a little larger (around 1,200 tons — about 200 tons more than the Flowers, and 40 ft (12 m) longer).

The most obvious difference was the lattice mainmast instead of the pole one fitted to the Flowers. There was also a more "square cut" look to the stern although it was still essentially a cruiser spoon type, this difference was only visible from abaft the beam.

Armament was similar except that the depth charge fitment had been replaced by one for the Squid anti-submarine mortar.

Propulsion machinery was identical to the Flowers, and experienced officers felt that they were seriously under powered, having a tendency to turn into the wind despite everything the helmsman could do. The fact that attacks with Squid required a fairly low speed compared to depth charge attacks only made matters worse.

Most had been scrapped by the end of the 1950s, but a few survived a little longer as weather ships. However, the last was the Uruguayan "Montevideo", originally "Rising Castle" and scrapped in 1975.

Most were operated by the Royal Navy, but twelve were assigned to the Royal Canadian Navy and one to the Royal Norwegian Navy. Three Castles were sunk through enemy action, and Castles participated in the sinking of seven U-boats.

Ships

Royal Canadian Navy
*"Arnprior" (ex-HMS "Rising Castle") [http://www.readyayeready.com/cgi-bin/query/display.pl?index=1017 link]
*"Bowmanville" (ex-HMS "Nunney Castle")
*"Copper Cliff" (ex-HMS "Hever Castle")
*"Hespeler" (ex-HMS "Guildford Castle") (later SS Chilcotin)
*"Humberstone" (ex-HMS "Norham Castle")
*"Huntsville" (ex-HMS "Woolvesey Castle")
*"Kincardine" (ex-HMS "Tamworth Castle")
*"Leaside" (ex-HMS "Walmer Castle") (later SS Coquitlam II)
*"Orangeville" (ex-HMS "Hedingham Castle")
*"Petrolia" (ex-HMS "Sherborne Castle")
*"St. Thomas" (ex-HMS "Sandgate Castle") (later SS Camosun III)
*"Tillsonburg" (ex-HMS "Pembroke Castle")

Royal Navy

The initial Castle was the "Allington Castle", re-ordered on 9 December 1942 (from the previous order placed for a Modified Flower Class corvette named "Amaryllis"); another 13 vessels were ordered on 19 December, also under the 1942 War Programme.
*"Allington Castle"
*"Bamborough Castle"
*"Caistor Castle"
*"Denbigh Castle" (lost on 13 February 1945)
*"Farnham Castle"
*"Gorey Castle" (K529) - renamed "Hedingham Castle" (ii) in 1945.
*"Hadleigh Castle"
*"Kenilworth Castle"
*"Lancaster Castle"
*"Maiden Castle" (converted to convoy rescue ship "Empire Lifeguard")
*"Norham Castle" (to Canada as HMCS "Humberstone")
*"Oakham Castle"
*"Pembroke Castle" (to Canada as HMCS "Tillsonburg")
*"Rayleigh Castle" (converted to convoy rescue ship "Empire Rest")The remaining ships were all ordered under the 1943 War Programme.
*"Alnwick Castle"
*"Amberley Castle"
*"Barnard Castle" (converted to convoy rescue ship "Empire Shelter")
*"Berkeley Castle"
*"Carisbrooke Castle"
*"Dumbarton Castle"
*"Flint Castle"
*"Guildford Castle" (to Canada as HMCS "Hespeler") (later SS Chilcotin)
*"Hedingham Castle" (K491) (to Canada as HMCS "Orangeville")
*"Hever Castle" (to Canada as HMCS "Copper Cliff")
*"Hunney Castle" (to Canada as HMCS "Bowmanville")
*"Hurst Castle" (lost on 1 September 1944)
*"Knaresborough Castle"
*"Launceston Castle"
*"Leeds Castle"
*"Morpeth Castle"
*"Oxford Castle"
*"Pevensey Castle"
*"Portchester Castle"
*"Rising Castle" (to Canada as HMCS "Arnprior")
*"Rushen Castle"
*"Sandgate Castle" (to Canada as HMCS "St. Thomas") (later SS Camosun III)
*"Scarborough Castle" (converted to convoy rescue ship "Empire Peacemaker")
*"Sherborne Castle" (to Canada as HMCS "Petrolia")
*"Shrewsbury Castle" (to Norway as HNoMS "Tunsberg Castle")
*"Tamworth Castle" (to Canada as HMCS "Kincardine")
*"Tintagel Castle"
*"Walmer Castle" (to Canada as HMCS "Leaside") (later SS Coquitlam II)
*"Woolvesey Castle" (to Canada as HMCS "Huntsville")
*"York Castle" (converted to convoy rescue ship "Empire Comfort" before completion)

Royal Norwegian Navy
*HNoMS "Tunsberg Castle" (ex-HMS "Shrewsbury Castle", lost on 12 December 1944)

Cancelled

15 ships ordered for the Royal Navy from UK shipyards were cancelled:
*"Alton Castle" - from Fleming & Ferguson, Paisley.
*"Warksworth Castle" - from Fleming & Ferguson, Paisley.
*"Tonbridge Castle" - from Austin.
*"Appleby Castle" - from Austin.
*"Bere Castle" - from John Brown & Company, Clydebank.
*"Caldecot Castle" - from John Brown & Company, Clydebank.
*"Norwich Castle" - from John Brown & Company, Clydebank.
*"Calshot Castle" - from A. & J. Inglis, Glasgow.
*"Dover Castle" - from A. & J. Inglis, Glasgow.
*"Dudley Castle" - from A. & J. Inglis, Glasgow.
*"Monmouth Castle" - from John Lewis & Sons, Aberdeen.
*"Oswestry Castle" - from John Crown & Sons, Sunderland.
*"Pendennis Castle" - from John Crown & Sons, Sunderland.
*"Rhuddlan Castle" - from John Crown & Sons, Sunderland.
*"Thornbury Castle" - from Ferguson Brothers, Port Glasgow.

36 ships were ordered in March 1943 for the Royal Navy from Canadian shipyards for completion between May 1944 and June 1945, but were all cancelled in December 1943:
*"Aydon Castle"
*"Barnwell Castle"
*"Beeston Castle"
*"Bodiam Castle"
*"Bolton Castle"
*"Bowes Castle"
*"Bramber Castle"
*"Bridgenorth Castle"
*"Brough Castle"
*"Canterbury Castle"
*"Carew Castle"
*"Chepstow Castle"
*"Chester Castle"
*"Christchurch Castle"
*"Clare Castle"
*"Clavering Castle"
*"Clitheroe Castle"
*"Clun Castle"
*"Colchester Castle"
*"Corfe Castle"
*"Cornet Castle"
*"Cowes Castle"
*"Cowling Castle"
*"Criccieth Castle"
*"Cromer Castle"
*"Devizes Castle"
*"Dunster Castle"
*"Egremont Castle"
*"Fotheringay Castle"
*"Helmsley Castle"
*"Malling Castle"
*"Malmesbury Castle"
*"Raby Castle"
*"Trematon Castle"
*"Tutbury Castle"
*"Wigmore Castle"

Castles sunk or destroyed in action

*HMS "Hurst Castle" was sunk by "U-483" northwest of Ireland on 1 September 1944.
*HNoMS "Tunsberg Castle" was sunk by a mine near Båtsfjord, Norway on 12 December 1944.
*HMS "Denbigh Castle" was hit by a torpedo from "U-992" in the Barents Sea on 13 February 1945. She was towed by "Bluebell" to the Kola Inlet but later capsized.

U-boats sunk by Castles

*"U-744" was sunk by HMS "Icarus", HMCS "St. Catharines", HMCS "Fennel", HMCS "Chilliwack", HMCS "Chaudiere", HMCS "Gatineau" and HMS "Kenilworth Castle" on 6 March 1944
*"U-484" was sunk in the north-west of Ireland by HMS "Porchester Castle" and HMS "Helmsdale" on 9 September 1944
*"U-1200" was sunk south of Ireland by HMS "Pevensey Castle", HMS "Lancaster Castle", HMS "Porchester Castle" and HMS "Kenilworth Castle" on 11 November 1944
*"U-387" was sunk in the Barents Sea by HMS "Bamborough Castle" on 9 December 1944
*"U-877" was sunk north-west of the Azores by HMCS "St. Thomas" on 27 December 1944
*"U-425" was sunk in the Barents Sea by HMS "Lark" and HMS "Alnwick Castle" on 17 February 1945
*"U-878" was sunk in the Bay of Biscay by HMS "Vanquisher" and HMS "Tintagel Castle" on 10 April 1945

Film Appearance

The final third of the film "The Cruel Sea" is set on the Castle-class corvette "Saltash Castle" (portrayed by HMS "Portchester Castle" (pennant F362, same as in the film).

Postwar Conversions

Three were converted to passenger/cargo ships for the Union Steamship Company of British Columbia, and were known as the "White Boats" (see Twigg). 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

Twigg, Arthur M: "Union Steamships Remembered: 1920-1958" (1997) ISBN 1-55056-516-8

External links

* [http://www.castlecorvette.co.uk/ Castle Class Corvette (Frigate) Association]
* [http://www.uboat.net/allies/warships/class.html?ID=4 Castle CDlass Corvettes on U-Boat.net]