HMS L21
{{Short description|British submarine}}
{{Use dmy dates|date=December 2016}}
{{Use British English|date=December 2016}}
| {{Infobox ship begin}}
{{Infobox ship image |Ship image= |Ship caption= }} {{Infobox ship career |Hide header= |Ship country= United Kingdom |Ship flag= {{shipboxflag|United Kingdom|naval}} |Ship name= HMS L21 |Ship namesake= |Ship ordered=December 1916Gardiner and Gray 1985, p. 93. |Ship builder=Vickers Limited, Barrow-in-Furness |Ship laid down= 15 September 1917 |Ship launched=11 October 1919 |Ship acquired= |Ship commissioned= |Ship decommissioned= |Ship in service= |Ship out of service= |Ship struck= |Ship reinstated= |Ship homeport= |Ship motto= |Ship nickname= |Ship honours= |Ship fate= Sold for scrapping, February 1939 |Ship notes= }} {{Infobox ship characteristics |Hide header= |Header caption= |Ship class=L-class submarine |Ship displacement=*{{convert|914|LT|t|abbr=on}} surfaced
|Ship length={{convert|238|ft|7|in|m|1|abbr=on}} |Ship beam={{convert|23|ft|6|in|m|1|abbr=on}} |Ship draught={{convert|13|ft|3|in|1|abbr=on}} |Ship power=*{{convert|2400|bhp|kW|lk=in|abbr=on}} (diesel)
|Ship propulsion=*2 × diesel engines
|Ship speed=*{{convert|17|kn|abbr=on|lk=in}} surfaced
|Ship range={{convert|3800|nmi|abbr=on|lk=in}} at {{convert|10|kn|abbr=on}} on the surface |Ship test depth={{convert|150|ft|1}} |Ship complement=38 |Ship armament=*4 × bow British 21-inch torpedo torpedo tubes
|Ship notes= }} |
HMS L21 was a L-class submarine built for the Royal Navy during World War I. The boat was not completed before the end of the war and was sold for scrap in 1939.
Design and description
L9 and its successors were enlarged to accommodate 21-inch (53.3 cm) torpedoes and more fuel. The submarine had a length of {{convert|238|ft|7|in|m|1}} overall, a beam of {{convert|23|ft|6|in|m|1}} and a mean draft of {{convert|13|ft|3|in|m|1}}.Gardiner & Gray, p. 93 They displaced {{convert|914|LT|t}} on the surface and {{convert|1089|LT|t}} submerged. The L-class submarines had a crew of 38 officers and ratings.Akermann, p. 165 They had a diving depth of {{convert|150|ft|1}}.
For surface running, the boats were powered by two 12-cylinder VickersHarrison, Chapter 25 {{convert|1200|bhp|lk=in|0|adj=on}} diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a {{convert|600|hp|0|adj=on}} electric motor. They could reach {{convert|17|kn|lk=in}} on the surface and {{convert|10.5|kn}} underwater. On the surface, the L class had a range of {{convert|3800|nmi|lk=in}} at {{convert|10|kn}}.Harrison, Chapter 11
The boats were armed with four 21-inch torpedo tubes in the bow and two 18-inch (45 cm) in broadside mounts. They carried four reload torpedoes for the 21-inch tubes for a grand total of ten torpedoes of all sizes.Harrison, Chapter 27 They were also armed with a {{convert|4|in|mm|adj=on|0}} deck gun.
Construction and career
HMS L21 was laid down on 15 September 1917 by Vickers at their Barrow-in-Furness shipyard, launched on 11 October 1918, and completed on 5 October 1920. L21 was sold in February 1939 and ran aground on the Isle of Arran, Bute whilst under tow to the breakers on 22 February 1939. She was refloated two days later on 24 February.{{Cite newspaper The Times |title=News in Brief |date=25 February 1939 |page=9 |issue=48239 |column=G }}
Notes
{{reflist|30em}}
References
- {{cite book|last=Akermann|first=Paul|title=Encyclopaedia of British Submarines 1901–1955|edition=reprint of the 1989|year=2002|publisher=Periscope Publishing|location=Penzance, Cornwall|isbn=1-904381-05-7}}
- {{Cite Colledge2006}}
- {{cite book |editor1-last=Gardiner|editor1-first=Robert|editor2-last=Gray|editor2-first=Randal|title=Conway's All the World's Fighting Ships 1906–1921|year=1985|location=Annapolis, Maryland|publisher=Naval Institute Press|isbn=0-85177-245-5|name-list-style=amp}}
- {{cite web|url=http://rnsubs.co.uk/dits-bits/br-3043.html|title=The Development of HM Submarines From Holland No. 1 (1901) to Porpoise (1930) (BR3043)|last=Harrison|first=A. N.|date=January 1979|publisher=RN Subs|access-date=27 September 2022}}
{{British L class submarine}}
{{February 1939 shipwrecks}}
{{DEFAULTSORT:L21}}
Category:British L-class submarines
Category:Ships built in Barrow-in-Furness
Category:World War I submarines of the United Kingdom