HMS L69

HMS L69 was a late-model L-class submarine built for the Royal Navy during the First World War. The boat was not completed before the end of the war and was sold for scrap in 1939.

History
United Kingdom
Name	HMS L69
Builder	William Beardmore and Company, Dalmuir
Laid down	7 July 1917
Launched	6 December 1918
Fate	Sold for scrapping, February 1939
General characteristics
Class and type	L-class submarine
Displacement	960 long tons (980 t) surfaced 1,150 long tons (1,170 t) submerged
Length	235 ft (71.6 m)
Beam	23 ft 6 in (7.2 m)
Draught	13 ft 2 in (4.0 m)
Installed power	2,400 bhp (1,800 kW) (diesel) 1,600 hp (1,200 kW) (electric)
Propulsion	2 × diesel engines 2 × electric motors
Speed	17 kn (31 km/h; 20 mph) surfaced 10.5 kn (19.4 km/h; 12.1 mph) submerged
Range	4,500 nmi (8,300 km; 5,200 mi) at 8 kn (15 km/h; 9.2 mph) on the surface
Test depth	150 feet (45.7 m)
Complement	44
Armament	6 × bow 21 in (533 mm) torpedo tubes 2 × 4-inch deck guns

Design and description

L52 and its successors were modified to maximise the number of 21-inch (53.3 cm) torpedoes carried in the bow. The submarine had a length of 235 feet (71.6 m) overall, a beam of 23 feet 6 inches (7.2 m) and a mean draft of 13 feet 2 inches (4.0 m).^[1] They displaced 960 long tons (980 t) on the surface and 1,150 long tons (1,170 t) submerged. The L-class submarines had a crew of 44 officers and ratings.^[2] They had a diving depth of 150 feet (45.7 m).^[3]

For surface running, the boats were powered by two 12-cylinder Vickers^[4] 1,200-brake-horsepower (895 kW) diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 600-horsepower (447 kW) electric motor. They could reach 17 knots (31 km/h; 20 mph) on the surface and 10.5 knots (19.4 km/h; 12.1 mph) underwater. On the surface, the L class had a range of 4,200 nautical miles (7,800 km; 4,800 mi) at 10 knots (19 km/h; 12 mph).^[1]

The boats were armed with six 21-inch torpedo tubes in the bow. They carried eight reload torpedoes for a grand total of a dozen torpedoes.^[5] They were also armed with two 4-inch (102 mm) deck guns.^[2]

Construction and career

HMS L69 was laid down on 7 July 1917 by William Beardmore and Company at their Dalmuir shipyard and launched on 6 December 1918. She was then towed to HM Dockyard, Rosyth for completion on 18 April 1923. The boat was sold to Arnott Young in February 1939 for scrap.

Notes

1. Gardiner & Gray, p. 94
2. Akermann, p. 165
3. Harrison, Chapter 11
4. Harrison, Chapter 25
5. Harrison, Chapter 27

References

• Akermann, Paul (2002). Encyclopaedia of British Submarines 1901–1955 (reprint of the 1989 ed.). Penzance, Cornwall: Periscope Publishing. ISBN 1-904381-05-7.
• 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.
• Gardiner, Robert & Gray, Randal, eds. (1985). Conway's All the World's Fighting Ships 1906–1921. Annapolis, Maryland: Naval Institute Press. ISBN 0-85177-245-5.
• Harrison, A. N. (January 1979). "The Development of HM Submarines From Holland No. 1 (1901) to Porpoise (1930) (BR3043)". RN Subs. Retrieved 27 September 2022.

at Dalmuir.