HMS ''L7'' was a L-class submarine built for the Royal Navy during World War I. The boat survived the war and was sold for

scrap Scrap consists of Recycling, recyclable materials, usually metals, left over from product manufacturing and consumption, such as parts of vehicles, building supplies, and surplus materials. Unlike waste, scrap Waste valorization, has monetary ...

in 1930.

Design and description

The L-class boats were enlarged and improved versions of the preceding E class. The submarine had a length of overall, 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 of . They displaced on the surface and submerged. The L-class submarines had a crew of 35 officers and ratings.Gardiner & Gray, p. 93 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. 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 . The boats were armed with a total of six 18-inch (45 cm)

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. Four of these were in the bow and the remaining pair in broadside mounts. They carried 10 reload torpedoes, all for the bow tubes. ''L7'' was initially fitted with a

anti-aircraft gun Anti-aircraft warfare, counter-air or air defence forces is the battlespace response to aerial warfare, defined by NATO as "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It includes surface based, ...

, but this was later replaced by a deck gun.Akermann, p. 165

Construction and career

HMS ''L7'' was built by

Cammell Laird Cammell Laird is a British shipbuilding company. It was formed from the merger of Laird Brothers of Birkenhead and Johnson Cammell & Co of Sheffield at the turn of the twentieth century. The company also built railway rolling stock until 1929, ...

Birkenhead Birkenhead (; cy, Penbedw) is a town in the Metropolitan Borough of Wirral, Merseyside, England; historically, it was part of Cheshire until 1974. The town is on the Wirral Peninsula, along the south bank of the River Mersey, opposite Liver ...

. She was laid down in May 1916 and was commissioned in December 1917. She was based at Falmouth, Cornwall in 1918. She sailed with the

Submarine Depot Ship A submarine tender is a type of depot ship that supplies and supports submarines. Development Submarines are small compared to most oceangoing vessels, and generally do not have the ability to carry large amounts of food, fuel, torpedoes, and ...

Hong Kong Hong Kong ( (US) or (UK); , ), officially the Hong Kong Special Administrative Region of the People's Republic of China ( abbr. Hong Kong SAR or HKSAR), is a city and special administrative region of China on the eastern Pearl River Delt ...

in 1919 as part of the

4th Submarine Flotilla Fourth or the fourth may refer to: * the ordinal form of the number 4 * ''Fourth'' (album), by Soft Machine, 1971 * Fourth (angle), an ancient astronomical subdivision * Fourth (music), a musical interval * ''The Fourth'' (1972 film), a Sovie ...

, arriving there in January 1920. ''L7'' was sold to

Hughes Bolckow Hughes Bolckow formerly ''Messrs, Hughes, Bolckow, and Co., Limited'' was a well-known shipbreaking company based in Blyth, Northumberland. Background Intending to create an industrial park for dismantling obsolete warships in 1911, the compa ...

on 26 February 1930 for scrapping at Blyth.

Notes

References

* * * * {{DEFAULTSORT:L07 British L-class submarines Ships built on the River Mersey 1917 ships World War I submarines of the United Kingdom Royal Navy ship names