History
United Kingdom
Name	HMS Lassoo
Builder	William Beardmore & Company, Dalmuir
Launched	24 August 1915
Fate	Sunk 13 August 1916
General characteristics
Class and type	Laforey-class destroyer
Displacement	965–1,010 long tons (980–1,026 t)
Length	268 ft 10 in (81.94 m) o/a
Beam	27 ft 8 in (8.43 m)
Draught	10 ft 6 in (3.20 m)
Installed power	24,500 shp (18,300 kW) 4 × Yarrow boilers
Propulsion	2 Shafts; 2 steam turbines
Speed	29 knots (54 km/h; 33 mph)
Range	1,720 nmi (3,190 km; 1,980 mi) at 15 knots (28 km/h; 17 mph)
Complement	74
Armament	3 × QF 4-inch (102 mm) Mark IV guns 2 × QF 1.5-pounder (37 mm) or QF 2-pounder (40 mm) "pom-pom" anti-aircraft guns 2 × twin 21-inch (533 mm) torpedo tubes

HMS Lassoo was a Laforey-class destroyer built for the Royal Navy during the 1910s.

The Laforey class were improved and faster versions of the preceding Acasta class.^[1] They displaced 965–1,010 long tons (980–1,026 t). The ships had an overall length of 268 feet 10 inches (81.9 m), a beam of 27 feet 8 inches (8.4 m) and a draught of 10 feet 6 inches (3.2 m). Lassoo was powered by two Parsons direct-drive steam turbines, each driving one propeller shaft, using steam provided by four Yarrow boilers.^[2] The turbines developed a total of 24,500 shaft horsepower (18,300 kW) and gave a maximum speed of 29 knots (54 km/h; 33 mph). The ships carried a maximum of 280 long tons (280 t) of fuel oil that gave them a range of 1,750 nautical miles (3,240 km; 2,010 mi) at 15 knots (28 km/h; 17 mph). The ships' complement was 74 officers and ratings.^[3]

The ships were armed with three single QF 4-inch (102 mm) Mark IV guns and two QF 1.5-pounder (37 mm) anti-aircraft guns. These latter guns were later replaced by a pair of QF 2-pounder (40 mm) "pom-pom" anti-aircraft guns. The ships were also fitted with two above-water twin mounts for 21-inch (533 mm) torpedoes.^[3]

She was built during the First World War as part of an emergency program of naval construction, to an Admiralty design by William Beardmore & Company, Dalmuir. She was originally to have been named Magic but she was renamed Lassoo on 15 February 1915 before being launched on 24 August 1915. She was sunk by the German U-boat SM UB-10 on 13 August 1916 off the Maas lightship in the North Sea.

• 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.
• Dittmar, F.J. & Colledge, J.J. (1972). British Warships 1914–1919. Shepperton, UK: Ian Allan. ISBN 0-7110-0380-7.
• Friedman, Norman (2009). British Destroyers: From Earliest Days to the Second World War. Barnsley, UK: Seaforth Publishing. ISBN 978-1-84832-049-9.
• Gardiner, Robert & Gray, Randal (1985). Conway's All The World's Fighting Ships 1906–1921. London: Conway Maritime Press. ISBN 0-85177-245-5.