HMS Launceston Castle (K397) was a of the United Kingdom's Royal Navy, named after Launceston Castle in Cornwall. The ship was constructed during the Second World War and saw service primarily as a convoy escort.
Design
The s were an improved and enlarged derivative of the earlier s, which was intended to be built by shipyards that could not build the larger and more capable frigates. The greater length of the Castles gave made them better seaboats than the Flowers, which were not originally designed for ocean escort work. Large numbers (96 in total) were ordered in late 1942 and early 1943 from shipyards in the United Kingdom and Canada, but Allied successes in the Battle of the Atlantic meant that the requirement for escorts was reduced, and many ships (including all the Canadian ones) were cancelled.
The Castles were long overall, at the waterline and between perpendiculars. Beam was and draught was aft at full load. Displacement was about standard and full load. Two Admiralty Three-drum water tube boilers fed steam to a vertical triple expansion engine rated at which drove a single propeller shaft. This gave a speed of .
The ships had a main gun armament of a single QF 4-inch Mk XIX dual-purpose gun, backed up by two twin and two single Oerlikon 20 mm cannon.
The small size and slow speed of the Castles meant that they were considered obsolete post-war, and they underwent limited modifications, with armament changes limited to replacing the twin 20mm mounts with single 40 mm Bofors mounts. Launceston Castle had been modified to this standard by 1953.
Service history
Launceston Castle was ordered on 19 January 1943, one of 14 Castle-class corvettes ordered that day (of which three were cancelled and two completed as rescue ships). The ship was laid down at Blyth Shipbuilding's Blyth, Northumberland shipyard as Yard number 295 on 27 May 1943, with the ship's machinery being built by White's Marine Engineering Company at Hebburn. Launceston Castle was launched on 27 November 1943 and completed on 20 June 1944, and was allocated the Pennant number K397.
In the Second World War she carried out convoy escort duties and anti-submarine patrols in the Western Approaches, the English Channel and the North Sea. After commissioning, Launceston Castle joined Escort Group B4. In August 1944, Escort Group B4 was redesignated as the 30th Escort Group commanded by Denys Rayner, who carried his flag on board . On 11 November 1944, Launceston Castle, along with sister ships of the 30th Escort Group, Pevensey Castle, and , carried out a series of attacks against a sonar target with Squid and depth charges off the south of Ireland, bringing up oil and a large air bubble, and were credited with sinking the submarine, which was later identified as the . In 1999, however, the wreck of U-1200 was found south-east of Start Point, Devon, with the cause of the submarine's loss uncertain. The 30th Escort Group is now believed to have attacked a non-submarine target. On 15 November and 26–29 December, 30 Escort Group, including Launceston Castle made more attacks against suspected submarine targets.
Launceston Castle continued to serve with the 30th Escort Group for the rest of the war in Europe, but in July–October 1945, was employed on air-sea rescue duties operating out of Freetown, In 1947, the ship went into reserve at Devonport. In 1948, the Castle-class were redesignated from 'Corvettes' to 'Frigates (2nd Rate)', and so Launceston Castles pennant number changed from K397 to F397. The frigate was refitted at Bristol in 1949.
In October 1951, after a refit at Falmouth, Cornwall, In 1953 she took part in the Fleet Review to celebrate the Coronation of Queen Elizabeth II. After two Avro Shackleton maritime patrol aircraft of the RAF went missing on 11 January off Fastnet Rock in the Atlantic Ocean, Launceston Castle took part in search operations for the missing aircraft, while on 24 January that year she took part in search operations after a Fleet Air Arm Fairey Firefly ditched off Lands End. In November 1956, Launceston Castle returned to reserve at Devonport.
In 1959, Launceston Castle was sold for scrap, arriving at J. A. White's yard at St Davids on Forth for breaking up on 3 August 1959.