Infrastructure tools to support an effective radiation oncology learning health system

History
United Kingdom
Name	HMS Usurper
Builder	Vickers-Armstrongs, High Walker
Laid down	18 September 1941
Launched	24 September 1942
Commissioned	2 February 1943
Fate	Sunk 3 October 1943
General characteristics
Class and type	U-class submarine
Displacement	Surfaced – 540 tons standard, 630 tons full load Submerged – 730 tons
Length	58.22 m (191 feet)
Beam	4.90 m (16 ft 1 in)
Draught	4.62 m (15 ft 2 in)
Propulsion	2 shaft diesel-electric 2 Paxman Ricardo diesel generators + electric motors 615 / 825 hp
Speed	11.25 knots max surfaced 10 knots max submerged
Complement	27–31
Armament	4 bow internal 21 inch (533 mm) torpedo tubes – 8–10 torpedoes 1 3-inch (76 mm) gun

HMS Usurper (P56) was a Royal Navy U-class submarine built by Vickers-Armstrongs at High Walker. So far, she has been the only ship of the Royal Navy to bear the name Usurper.

Usurper had a short-lived career with the Royal Navy. During her work-up patrol off the Norwegian coast, she made a torpedo attack on the German submarine U-467. The target was not hit. On being assigned to operate in the Mediterranean, she sank the French ship Château Yquem.

Usurper had left Algiers on 24 September 1943 to patrol off La Spezia. On 3 October 1943 she was ordered to move to the Gulf of Genoa, after which there was no further contact. She was overdue at Algiers on 12 October 1943. The German anti-submarine vessel UJ-2208/Alfred reported attacking a submarine in the Gulf of Genoa on 3 October 1943 and it is believed that this may have been Usurper. During the war, Usurper was adopted by the town of Stroud as part of Warship Week. The plaque from this adoption is held by the National Museum of the Royal Navy in Portsmouth.^[1]

• "HMS Usurper (P 56)". uboat.net.
• "Ursula to Utmost". British submarines of World War II. Archived from the original on 11 July 2007.
• "Submarine losses 1904 to present day". RN Submarine Museum, Gosport. Archived from the original on 8 August 2007. Retrieved 15 July 2007.
• Colledge, J. J.; Warlow, Ben (2006) [1969]. Ships of the Royal Navy: The Complete Record of all Fighting Ships of the Royal Navy (Rev. ed.). London: Chatham Publishing. ISBN 978-1-86176-281-8.
• Hutchinson, Robert (2001). Jane's Submarines: War Beneath the Waves from 1776 to the Present Day. London: HarperCollins. ISBN 978-0-00-710558-8. OCLC 53783010.