HMS ''L27'' was a L-class

submarine A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...

built for the

Royal Navy The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against F ...

during

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

. 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 World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

. She served as training boat before being broken up in 1944.

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

overall Overalls, also called bib-and-brace overalls or dungarees, are a type of garment usually used as protective clothing when working. The garments are commonly referred to as a "pair of overalls" by analogy with "pair of trousers". Overalls were ...

, a

beam Beam may refer to: Streams of particles or energy *Light beam, or beam of light, a directional projection of light energy **Laser beam *Particle beam, a stream of charged or neutral particles **Charged particle beam, a spatially localized grou ...

of and a mean

draft Draft, The Draft, or Draught may refer to: Watercraft dimensions * Draft (hull), the distance from waterline to keel of a vessel * Draft (sail), degree of curvature in a sail * Air draft, distance from waterline to the highest point on a vessel ...

of .Gardiner & Gray, p. 93 They displaced on the surface and submerged. The L-class submarines had a crew of 35 officers and ratings.Akermann, p. 165 They had a diving depth of . For surface running, the boats were powered by two 12-cylinder

Vickers Vickers was a British engineering company that existed from 1828 until 1999. It was formed in Sheffield as a steel foundry by Edward Vickers and his father-in-law, and soon became famous for casting church bells. The company went public in 18 ...

diesel engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-call ...

s, each driving one

propeller shaft A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power and torque and rotation, usually used to connect ...

. When submerged each propeller was driven by a

electric motor An electric motor is an Electric machine, electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a Electromagneti ...

. They could reach on the surface and underwater. On the surface, the L class had a range of at .Harrison, Chapter 11 The boats were armed with four

torpedo tube A torpedo tube is a cylindrical device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units (also referred to as torpedo launchers) installed aboa ...

s in the bow and two tubes in broadside mounts. They carried four reload torpedoes for the 21-inch tubes for a grand total of ten torpedoes of all sizes. They were also armed with a

deck gun A deck gun is a type of naval artillery mounted on the deck of a submarine. Most submarine deck guns were open, with or without a shield; however, a few larger submarines placed these guns in a turret. The main deck gun was a dual-purpose ...

Construction and career

HMS ''L27'' was built by

at their

Barrow-in-Furness Barrow-in-Furness is a port town in Cumbria, England. Historically in Lancashire, it was incorporated as a municipal borough in 1867 and merged with Dalton-in-Furness Urban District in 1974 to form the Borough of Barrow-in-Furness. In 2023 the ...

shipyard A shipyard, also called a dockyard or boatyard, is a place where ships are built and repaired. These can be yachts, military vessels, cruise liners or other cargo or passenger ships. Dockyards are sometimes more associated with maintenance a ...

, launched on 14 June 1919. She was then towed and completed at

HM Dockyard Royal Navy Dockyards (more usually termed Royal Dockyards) were state-owned harbour facilities where ships of the Royal Navy were built, based, repaired and refitted. Until the mid-19th century the Royal Dockyards were the largest industrial c ...

Sheerness Sheerness () is a town and civil parish beside the mouth of the River Medway on the north-west corner of the Isle of Sheppey in north Kent, England. With a population of 11,938, it is the second largest town on the island after the nearby town ...

and commissioned on an unknown date. 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 Dundee (; sco, Dundee; gd, Dùn Dè or ) is Scotland's fourth-largest city and the 51st-most-populous built-up area in the United Kingdom. The mid-year population estimate for 2016 was , giving Dundee a population density of 2,478/km2 or ...

and Blyth. From 20 September 1939 to 15 January 1940, the 6th Submarine Flotilla was deployed off

Skagerrak The Skagerrak (, , ) is a strait running between the Jutland peninsula of Denmark, the southeast coast of Norway and the west coast of Sweden, connecting the North Sea and the Kattegat sea area through the Danish Straits to the Baltic Sea. The ...

Jutland Jutland ( da, Jylland ; german: Jütland ; ang, Ēota land ), known anciently as the Cimbric or Cimbrian Peninsula ( la, Cimbricus Chersonesus; da, den Kimbriske Halvø, links=no or ; german: Kimbrische Halbinsel, links=no), is a peninsula of ...

and

Horns Reef Horns Rev is a shallow sandy reef of glacial deposits in the eastern North Sea, about off the westernmost point of Denmark, Blåvands Huk.

. On 15 October 1940 ''L27'' attacked a German convoy unsuccessfully in the

English Channel The English Channel, "The Sleeve"; nrf, la Maunche, "The Sleeve" (Cotentinais) or ( Jèrriais), (Guernésiais), "The Channel"; br, Mor Breizh, "Sea of Brittany"; cy, Môr Udd, "Lord's Sea"; kw, Mor Bretannek, "British Sea"; nl, Het Kana ...

. Beginning on 22 March 1941, the Royal Navy and

Allies An alliance is a relationship among people, groups, or states that have joined together for mutual benefit or to achieve some common purpose, whether or not explicit agreement has been worked out among them. Members of an alliance are called ...

began deploying submarines off

Brest, France Brest (; ) is a port city in the Finistère department, Brittany. Located in a sheltered bay not far from the western tip of the peninsula, and the western extremity of metropolitan France, Brest is an important harbour and the second French mi ...

to prevent the German

battleship A battleship is a large armored warship with a main battery consisting of large caliber guns. It dominated naval warfare in the late 19th and early 20th centuries. The term ''battleship'' came into use in the late 1880s to describe a type of ...

s and from leaving port. ''L27'' was among the submarines assigned to the patrol. On 15 October 1941, the submarine unsuccessfully attacked a merchant vessel off

Cherbourg Cherbourg (; , , ), nrf, Chèrbourg, ) is a former commune and subprefecture located at the northern end of the Cotentin peninsula in the northwestern French department of Manche. It was merged into the commune of Cherbourg-Octeville on 28 Feb ...

. ''L27'' was converted into a training boat at

Portsmouth Portsmouth ( ) is a port and city in the ceremonial county of Hampshire in southern England. The city of Portsmouth has been a unitary authority since 1 April 1997 and is administered by Portsmouth City Council. Portsmouth is the most dens ...

before being broken up in

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

in 1944.Colledge, p.350Gardiner and Gray claim the submarine was broken up in 1946.

Notes

Citations

References

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