{{Use dmy dates|date=July 2019}} {{EngvarB|date=July 2019}} {{Infobox ship |section1={{Infobox ship/image |image= L27 submarine.jpg |image_caption= HMS ''L27'' }}

|section2={{Infobox ship/career |hide_header= |country= United Kingdom |flag= {{shipboxflag|United Kingdom|naval}} |name= HMS ''L27'' |namesake= |ordered= |builder=[[Vickers Limited]], [[Barrow-in-Furness]] |laid_down= 30 January 1918 |launched= 14 June 1919 |acquired= |commissioned= 25 March 1926 |decommissioned= |in_service= |out_of_service= |struck= |reinstated= |homeport= |motto= |nickname= |honours= |fate= Broken up, 1946 |notes= }}

|section3={{Infobox ship/characteristics |hide_header= |header_caption= |class=[[British L-class submarine|L-class submarine]] |displacement=*{{convert|914|LT|t|abbr=on}} surfaced *{{convert|1089|LT|t|abbr=on}} submerged |length={{convert|238|ft|7|in|m|1|abbr=on}} |beam={{convert|23|ft|6|in|m|1|abbr=on}} |draught={{convert|13|ft|3|in|1|abbr=on}} |power=*{{convert|2400|bhp|kW|lk=in|abbr=on}} (diesel) *{{convert|1600|hp|kW|abbr=on}} (electric) |propulsion=*2 × [[diesel engine]]s *2 × [[electric motor]]s |speed=*{{convert|17|kn|abbr=on|lk=in}} surfaced *{{convert|10.5|kn|abbr=on}} submerged |range={{convert|3800|nmi|abbr=on|lk=in}} at {{convert|10|kn|abbr=on}} on the surface |test_depth={{convert|150|ft|1}} |complement=38 |armament=*4 × bow [[British 21-inch torpedo|{{convert|21|in|mm|0|abbr=on}}]] [[torpedo tube]]s *2 × beam [[British 18 inch torpedo|{{convert|18|in|mm|0|abbr=on}}]] torpedo tubes *1 × [[QF 4 inch naval gun Mk IV, XII, XXII|4-inch]] [[deck gun]] |notes= }} }} '''HMS ''L27''''' was a [[British L-class submarine|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 one of three L-class boats to serve during [[World War II]]. She served as [[training ship|training boat]] before being broken up in 1944.

==Design and description== ''L9'' and its successors were enlarged to accommodate [[British 21 inch torpedo|21-inch (53.3&nbsp;cm)]] torpedoes and more fuel. The submarine had a length of {{convert|238|ft|7|in|m|1}} [[length overall|overall]], a [[beam (nautical)|beam]] of {{convert|23|ft|6|in|m|1}} and a mean [[draft (ship)|draft]] of {{convert|13|ft|3|in|m|1}}.<ref name=gg9>Gardiner & Gray, p. 93</ref> They [[displacement (ship)|displaced]] {{convert|914|LT|t}} on the surface and {{convert|1089|LT|t}} submerged. The L-class submarines had a crew of 35 officers and [[naval rating|ratings]].<ref name=a5>Akermann, p. 165</ref> They had a diving depth of {{convert|150|ft|1}}.<ref name=h11/>

For surface running, the boats were powered by two 12-cylinder [[Vickers]]<ref>Harrison, Chapter 25</ref> {{convert|1200|bhp|lk=in|0|adj=on}} [[diesel engine]]s, each driving one [[propeller shaft]]. When submerged each propeller was driven by a {{convert|600|hp|0|adj=on}} [[electric motor]].<ref name=gg9/> 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}}.<ref name=h11>Harrison, Chapter 11</ref>

The boats were armed with four {{convert|21|in|mm|adj=on|0}} [[torpedo tube]]s in the bow and two [[British 18 inch torpedo|{{convert|18|in|mm|adj=on}} tubes]] in broadside mounts. They carried four reload torpedoes for the 21-inch tubes for a grand total of ten torpedoes of all sizes.<ref>Harrison, Chapter 27</ref> They were also armed with a {{convert|4|in|mm|adj=on|0}} [[deck gun]].<ref name=a5/>

==Construction and career== HMS ''L27'' was built by [[Vickers]] at their [[Barrow-in-Furness]] [[shipyard]], [[Ship naming and launching|launched]] on 14 June 1919. She was then towed and completed at [[HM Dockyard]], [[Sheerness]] and commissioned on 25 March 1926.

At the onset of the Second World War, ''L27'' was a member of the 6th Submarine Flotilla. From 26–29 August 1939, the flotilla deployed to its war bases at [[Dundee]] and Blyth.<ref>Rohwer, p.1</ref> From 20 September 1939 to 15 January 1940, the 6th Submarine Flotilla was deployed off [[Skagerrak]], [[Jutland]] and [[Horns Reef]].<ref>Rohwer, p.5</ref> On 15 October 1940 ''L27'' attacked a German convoy unsuccessfully in the [[English Channel]].<ref>Rohwer, p.45</ref>

Beginning on 22 March 1941, the Royal Navy and [[Allies of World War II|Allies]] began deploying submarines off [[Brest, France]] to prevent the German [[battleship]]s {{ship|German battleship|Gneisenau||2}} and {{ship|German battleship|Scharnhorst||2}} from leaving port. ''L27'' was among the submarines assigned to the patrol.<ref>Rohwer, p.65</ref> On 15 October 1941, the submarine unsuccessfully attacked a merchant vessel off [[Cherbourg]].<ref>Rohwer, p.108</ref>

''L27'' was converted into a training boat at [[Portsmouth]] before being broken up at [[Montreal]] from July 1946.

==Notes== {{reflist|group=note}}

==Citations== {{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}} * {{Colledge: Ships RN|year=2006}} * {{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}} * {{cite book |last=Rohwer |first=Jürgen |date=2005 |title=Chronology of the War at Sea 1939–1945: The Naval History of World War Two |edition=Revised & Expanded |publisher=Naval Institute Press |location=Annapolis, Maryland |isbn=1-59114-119-2}}

{{British L class submarine}}

{{DEFAULTSORT:L27}} [[Category:British L-class submarines]] [[Category:Ships built in Barrow-in-Furness]] [[Category:1919 ships]] [[Category:World War I submarines of the United Kingdom]] [[Category:Royal Navy ship names]]