HMS ''E21'' was a British E class submarine built by

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 ...

Barrow-in-Furness Barrow-in-Furness is a port town and civil parish (as just "Barrow") in the Westmorland and Furness district of Cumbria, England. Historic counties of England, Historically in the county of Lancashire, it was incorporated as a municipal borou ...

. She was launched on 24 July 1915 and commissioned on 1 October 1915. ''E21'' was sold on 14 December 1921.

Design

Like all post-''E8''

British E-class submarine The British E-class submarines started out as improved versions of the British D-class submarine. The E class served with the Royal Navy throughout World War I as the backbone of the submarine fleet. The last surviving E class submarines we ...

s, ''E21'' had a displacement of at the surface and while submerged. She had a total length of and a beam of . She was powered by two Vickers eight-cylinder two-stroke diesel engines and two electric motors.Akerman, P. (1989). ''Encyclopaedia of British submarines 1901–1955''. p.150. Maritime Books. The submarine had a maximum surface speed of and a submerged speed of . British E-class submarines had fuel capacities of of diesel and ranges of when travelling at . ''E21'' was capable of operating submerged for five hours when travelling at . ''E21'' was armed with a 12-pounder QF gun mounted forward of the conning tower. She had five 18 inch (450 mm)

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, two in the bow, one either side amidships, and one in the stern; a total of 10 torpedoes were carried. E-Class submarines had wireless systems with power ratings; in some submarines, these were later upgraded to systems by removing a midship torpedo tube. Their maximum design depth was although in service some reached depths of below . Some submarines contained

Fessenden oscillator A Fessenden oscillator is an electro-acoustic transducer invented by Reginald Fessenden, with development starting in 1912 at the Submarine Signal Company of Boston. It was the first successful acoustical echo ranging device. Similar in operat ...

systems.

Crew

Her

complement Complement may refer to: The arts * Complement (music), an interval that, when added to another, spans an octave ** Aggregate complementation, the separation of pitch-class collections into complementary sets * Complementary color, in the visu ...

was three officers and 28 men.

References

Bibliography

* {{DEFAULTSORT:E21 British E-class submarines of the Royal Navy Ships built in Barrow-in-Furness 1915 ships World War I submarines of the United Kingdom Royal Navy ship names