History
United Kingdom
Name	Tiara
Builder	Portsmouth Dockyard
Laid down	8 April 1943
Launched	18 April 1944
Identification	Pennant number P351
Fate	Scrapped June 1947
General characteristics
Class and type	T-class submarine
Displacement	1,290 tons surfaced 1,560 tons submerged
Length	276 ft 6 in (84.28 m)
Beam	25 ft 6 in (7.77 m)
Draught	12 ft 9 in (3.89 m) forward 14 ft 7 in (4.45 m) aft
Propulsion	Two shafts Twin diesel engines 2,500 hp (1,900 kW) each Twin electric motors 1,450 hp (1,080 kW) each
Speed	15.5 kn (28.7 km/h; 17.8 mph) surfaced 9 kn (17 km/h; 10 mph) submerged
Range	4,500 nmi (8,300 km; 5,200 mi) at 11 kn (20 km/h; 13 mph) surfaced
Test depth	300 ft (91 m) max
Complement	61
Armament	6 internal forward-facing 21 inch (533 mm) torpedo tubes 2 external forward-facing torpedo tubes 2 external amidships rear-facing torpedo tubes 1 external rear-facing torpedo tubes 6 reload torpedoes QF 4 inch (100 mm) deck gun 3 anti-aircraft machine guns

HMS Tiara (P351) was a Royal Navy Group Three T-class submarine laid down at Portsmouth Dockyard on 8 April 1943 and launched on 18 April 1944. However the war ended before she was completed and she arrived at Dover Industries for scrapping in June 1947 . Her sister vessel Thor was launched on the same day at Portsmouth dockyard and not completed either. She would have been the only ship of the Royal Navy to bear the name Tiara.^[1]

• 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.