Castle-class corvette

Castle-class corvette
Denbigh Castle
Class overview
Operators:	Royal Navy Royal Canadian Navy Royal Norwegian Navy
General characteristics
Type:	Corvette
Displacement:	1,060 long tons (1,077 t)
Length:	252 ft (77 m)
Beam:	37 ft (11 m)
Draught:	10 ft (3.0 m)
Installed power:	2,750 hp (2.05 MW)
Propulsion:	2 × water-tube boilers 1 × 4-cylinder triple-expansion steam engine Single screw
Speed:	16.5 knots (30.6 km/h; 19.0 mph)
Range:	9,500 nmi (17,600 km) at 10 kn (19 km/h; 12 mph)
Complement:	112
Sensors and processing systems:	• Type 272 radar • Type 144Q sonar • Type 147B sonar
Armament:	• 1 × 4-inch (102-mm) Quick Firing Mk.XIX High Angle/Low Angle combined air/surface gun • 1 × Squid anti-submarine mortar • 1 × depth charge rail, 15 depth charges • 2 × 20 mm twin anti-aircraft cannon • 6 × 20 mm single anti-aircraft cannon

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.

Design

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. The Castle-class was designed to be built on small slipways for about half the overall effort of a Loch-class frigate. The Loch was a River built using the "American system" of prefabrication.

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Armament was similar except that the depth charge fitment had been replaced by one for the Squid anti-submarine mortar. HMS Hadleigh Castle received the first production Squid mounting.

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 Squid attacks 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 HMS 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

The following vessels were all originally built for the Royal Navy, but were transferred to the RCN on completion (for details of builders and construction dates see under Royal Navy below). All their pennant numbers (except Hedingham Castle, which was never completed), as well as their names, were changed when transferred.

• HMCS Arnprior (K494) (ex-HMS Rising Castle)
• HMCS Bowmanville (K493) (ex-HMS Nunney Castle)
• HMCS Copper Cliff (K495) (ex-HMS Hever Castle)
• HMCS Hespeler (K489) (ex-HMS Guildford Castle) (later SS Chilcotin)
• HMCS Humberstone (K497) (ex-HMS Norham Castle)
• HMCS Huntsville (K499) (ex-HMS Wolvesey Castle)
• HMCS Kincardine (K490) (ex-HMS Tamworth Castle)
• HMCS Leaside (K492) (ex-HMS Walmer Castle, later SS Coquitlam II)
• HMCS Orangeville (K491) (ex-HMS Hedingham Castle)
• HMCS Petrolia (K498) (ex-HMS Sherborne Castle)
• HMCS St. Thomas (K488) (ex-HMS Sandgate Castle, later SS Camosun III)
• HMCS Tillsonburg (K496) (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.

Pennant	Name	(a) Hull builder	Ordered	Laid down	Launched	Commissioned	Paid Off	Fate
K689	Allington Castle	Fleming & Ferguson	9 December 1942	22 July 1943	29 February 1944	19 June 1944	1947	Scrapped 1958
K412	Bamborough Castle	John Lewis & Co. Ltd	9 December 1942	1 July 1943	11 January 1944	30 May 1944	1950	Scrapped 22 May 1959
K690	Caistor Castle	John Lewis & Co. Ltd	9 December 1942	26 August 1943	22 May 1944	29 September 1944	1947	Scrapped March 1956
K696	Denbigh Castle	John Lewis & Co. Ltd	9 December 1942	30 September 1943	5 Augusut 1944	30 December 1944		Declared Constructive Total Loss, 13 February 1945
K413	Farnham Castle	John Crown & Sons Ltd	9 December 1942	25 June 1943	25 April 1944	31 January 1945	1947	Scrapped, 31 October 1960
K529	Hedingham Castle	John Crown & Sons Ltd	9 December 1942	2 November 1943	30 October 1944	12 May 1945	August 1945	Scrapped, April 1958
K355	Hadleigh Castle	Smiths Dock Company	9 December 1942	4 April 1943	21 June 1943	18 September 1943	August 1946	Scrapped, January 1959
K420	Kenilworth Castle	Smiths Dock Company	9 December 1942	7 May 1943	17 August 1943	22 November 1943	1948	Scrapped, 20 June 1959
K691	Lancaster Castle	Fleming & Ferguson	9 December 1942	10 September 1943	14 April 1944	15 September 1944	1947	Scrapped, 20 June 1959
K443	Maiden Castle	Fleming & Ferguson	9 December 1942	1943	8 June 1944	November 1944		Became rescue ship Empire Lifeguard before completion. Scrapped, 22 July 1955
K447	Norham Castle (originally Totnes Castle)	A. & J. Inglis	9 December 1942	30 September 1943	12 April 1944	6 September 1944		Transferred to Canada as HMCS Humberstone 1944. Sold for mercantile service 1947
K530	Oakham Castle	A. & J. Inglis	9 December 1942	30 September 1943	20 July 1944	10 December 1944	1950	Became the weather ship Weather Reporter 1957.
K450	Pembroke Castle	Ferguson Shipbuilder	9 December 1942	3 June 1943	12 February 1944	29 June 1944		Transferred to Canada as HMCS Tillsonburg in 1944. Sold for mercantile service 1947. Sold to Republic of China as Kao Tan 1952
K695	Rayleigh Castle	Ferguson Shipbuilder	9 December 1942	1943	12 June 1944	October 1944		Became rescue ship Empire Rest before completion.

The remaining eighty-one ships were all ordered for the RN under the 1943 War Programme, of which thirty were completed. Fifty-one of these ships (15 from UK shipyards and 36 from Canadian shipyards) which were cancelled late in 1943 are shown separately below.

Fourteen ordered 19 January 1943, of which 3 were cancelled:

• Alnwick Castle, built by George Brown, at Greenock; begun 12 June 1943, launched 23 May 1944 and completed 11 November 1944. Paid off 1957 and broken up December 1958.
• Barnard Castle, built by George Brown, at Greenock; begun 1943, launched 3 October 1944 and completed 1945 as convoy rescue ship Empire Shelter.
• Flint Castle, built by Henry Robb, at Leith; begun 20 April 1943, launched 1 September 1943 and completed 31 December 1943. Paid off March 1956 and broken up 10 July 1958.
• Guildford Castle, built by Henry Robb, at Leith; begun 25 May 1943, launched 13 November 1943 and completed 11 March 1944; to Canada as HMCS Hespeler, 1944. Sold for mercantile service 1946 (later SS Chilcotin)
• Hedingham Castle, built by Henry Robb, at Leith; begun 23 July 1943, launched 26 January 1944 and completed 10 May 1944; to Canada as HMCS Orangeville, 1944. Sold for mercantile service 1947; to Republic of China Navy 1951 as Te An.
• Knaresborough Castle, built by Blyth Dry Dock; begun 22 April 1943, launched 1 September 1943 and completed 5 April 1944. Paid off 1947 and broken up 16 March 1956.
• Launceston Castle, built by Blyth Dry Dock; begun 27 May 1943, launched 27 November 1943 and completed 20 June 1944. Paid off 1947 and broken up 3 August 1959.
• Sandgate Castle, built by Smiths Dock, at Middlesbrough; begun 23 June 1943, launched 28 December 1943 and completed 18 May 1944; to Canada as HMCS St. Thomas, 1944. Paid off 22 November 1945 and sold for mercantile service 1946 (later SS Camosun III).
• Tamworth Castle built by Smiths Dock, at Middlesbrough; begun 25 August 1943, launched 26 January 1944 and completed 3 July 1944; to Canada as HMCS Kincardine. Paid off 17 February 1946 and sold for mercantile service 1946.
• Walmer Castle, built by Smiths Dock, at Middlesbrough; begun 23 September 1943, launched 10 March 1944 and completed 5 September 1944; to Canada as HMCS Leaside. Paid off 16 November 1945 and sold for mercantile service 1946 (later SS Coquitlam II).
• York Castle, built by Ferguson Brothers, at Port Glasgow; begun 1944, launched 20 September 1944 and completed February 1945 as convoy rescue ship SS Empire Comfort.

Sixteen ordered 23 January 1943, of which five were cancelled:

• Hever Castle, built by Blyth Dry Dock; begun 29 June 1943, launched 24 February 1944 and completed 15 August 1944; to Canada as HMCS Copper Cliff, 1944. Sold for mercantile service 1947, then became Chinese (People's Liberation Army) 1949.
• Leeds Castle, built by William Pickergill, at Sunderland; begun 22 April 1943, launched 12 October 1943 and completed 15 February 1944. Paid off November 1956 and broken up 5 June 1958.
• Morpeth Castle, built by William Pickergill, at Sunderland; begun 23 June 1943, launched 26 November 1943 and completed 13 July 1944. Paid off 1946 and broken up 9 August 1960.
• Nunney Castle, built by William Pickergill, at Sunderland; begun 12 August 1943, launched 26 January 1944 and completed 8 October 1944; to Canada as HMCS Bowmanville, 1944. Sold for mercantile service 1946, then became Chinese (People's Liberation Army) Kuang Chou 1949.
• Oxford Castle, built by Harland and Wolff, at Belfast; begun 21 June 1943, launched 11 December 1943 and completed 10 March 1944. Paid off 1946 and broken up 6 September 1960.
• Pevensey Castle, built by Harland and Wolff, at Belfast; begun 21 June 1943, launched 11 January 1944 and completed 10 June 1944. Paid off February 1946 and became weather ship Weather Monitor in 1959.
• Rising Castle, built by Harland and Wolff, at Belfast; begun 21 June 1943, launched 8 February 1944 and completed 26 June 1944; to Canada as HMCS Arnprior, 1944. Paid off 14 March 1946 and transferred to Uruguay as Montevideo.
• Scarborough Castle, built by Fleming & Ferguson, at Paisley; begun 1944, launched 8 September 1944 and completed January 1945 as convoy rescue ship Empire Peacemaker)
• Sherborne Castle, built by Harland and Wolff, at Belfast; begun 21 June 1943, launched 24 February 1944 and completed 14 July 1944; to Canada as HMCS Petrolia, 1944. Paid off 8 March 1946 and sold for mercantile service 1946.
• Tintagel Castle, built by Ailsa, at Troon; begun 29 April 1943, launched 13 December 1943 and completed 7 April 1944. Paid off August 1956 and broken up June 1958.
• Wolvesey Castle, built by Ailsa, at Troon; begun 1 June 1943, launched 24 February 1944 and completed 15 June 1944; to Canada as HMCS Huntsville, 1944. Paid off 15 February 1946 and sold for mercantile service 1947.

Five ordered 2 February 1943:

Pennant	Name	(a) Hull builder	Ordered	Laid down	Launched	Commissioned	Paid Off	Fate
K386	Amberley Castle	S P Austin & Son Ltd	2 February 1943	31 May 1943	25 November 1943	24 November 1944	1947	Became the weather ship Weather Adviser in 1960
K387	Berkeley Castle	Barclay Curle	2 February 1943	23 April 1943	19 August 1943	18 November 1944	1946	Scrapped 24 February 1956
K379	Carisbrooke Castle	Caledon Shipbuilding & Engineering Company	2 February 1943	12 March 1943	31 July 1943	17 November 1943	1947	Scrapped 14 June 1958
K388	Dumbarton Castle	Caledon Shipbuilding & Engineering Company	2 February 1943	6 May 1943	28 September 1943	25 February 1944	1947	Scrapped March 1961
K416	Hurst Castle	Caledon Shipbuilding & Engineering Company	2 February 1943	6 August 1943	23 February 1944	9 June 1944		Sunk by U-482 on 1 September 1944

Three ordered 6 February 1943:

Pennant	Name	(a) Hull builder	Ordered	Laid down	Launched	Commissioned	Paid Off	Fate
K362	Portchester Castle	Swan Hunter	6 February 1943	17 March 1943	21 June 1943	8 November 1943	1947	Scrapped 14 May 1958
K372	Rushen Castle	Swan Hunter	6 February 1943	8 April 1943	16 July 1943	24 February 1944	1946	Became the weather ship Weather Surveyor in 1960
K374	Shrewsbury Castle	Swan Hunter	6 February 1943	5 May 1943	16 August 1943	24 April 1944		Transferred to Norway on completion and renamed HNoMS Tunsberg Castle. Sunk by mine 12 December 1944

Two ordered 3 March 1943, three ordered 4 May 1943 and two ordered 10 July 1943 were all cancelled, as were all thirty-six ordered from Canadian shipyards on 15 March 1943.

Royal Norwegian Navy

• HNoMS Tunsberg Castle – (ex-Shrewsbury Castle, lost on 12 December 1944).

Cancelled

15 ships ordered for the Royal Navy from UK shipyards as part of the 1943 Programme were all cancelled on 31 October 1943:

• Caldecot Castle – ordered 19 January 1943 from John Brown & Company, Clydebank.
• Dover Castle – ordered 19 January 1943 from A. & J. Inglis, Glasgow.
• Dudley Castle – ordered 19 January 1943 from A. & J. Inglis, Glasgow.
• Bere Castle – ordered 23 January 1943 from John Brown & Company, Clydebank.
• Calshot Castle – ordered 23 January 1943 from John Brown & Company, Clydebank.
• Monmouth Castle (originally to have been Peel Castle) – ordered 23 January 1943 from John Lewis & Sons, Aberdeen.
• Rhuddlan Castle – ordered 23 January 1943 from John Crown & Sons, Sunderland.
• Thornbury Castle – ordered 23 January 1943 from Ferguson Brothers, Port Glasgow.
• Appleby Castle – ordered 3 March 1943 from Austin, at Sunderland.
• Tonbridge Castle – ordered 3 March 1943 from Austin, at Sunderland.
• Norwich Castle – ordered 4 May 1943 from John Brown & Company, Clydebank.
• Oswestry Castle – ordered 4 May 1943 from John Crown & Sons, Sunderland.
• Pendennis Castle – ordered 4 May 1943 from John Crown & Sons, Sunderland.
• Alton Castle – ordered 10 July 1943 from Fleming & Ferguson, Paisley.
• Warkworth Castle – ordered 10 July 1943 from Fleming & Ferguson, Paisley.

36 ships were ordered on 15 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 Bridgnorth 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

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

Post-war 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

• Friedman, Norman: British Destroyers and Frigates: the Second World War and After (2006) Chatham Publishing. ISBN 1-86176-137-6.
• Twigg, Arthur M: Union Steamships Remembered: 1920–1958 (1997) ISBN 1-55056-516-8.
• Brown DK Nelson to Vanguard

External links

• Castle-class corvette (Frigate) Association
• Castle-class corvettes on U-Boat.net