HMS E20 in harbour
|Laid down:||25 November 1914|
|Commissioned:||30 August 1915|
|Fate:||Sunk 6 November 1915|
|Class and type:||E class submarine|
|Length:||181 ft (55 m)|
|Beam:||15 ft (4.6 m)|
|Complement:||3 officers, 28 men|
HMS E20 was a British E-class submarine built by Vickers, Barrow-in-Furness. She was laid down on 25 November 1914 and was commissioned on 30 August 1915. She was sunk, torpedoed by UB-14, on 6 November 1915.
Like all post-E8 British E-class submarines, E20 had a displacement of 662 tonnes (730 short tons) at the surface and 807 tonnes (890 short tons) while submerged. She had a total length of 180 feet (55 m) and a beam length of 22 feet 8.5 inches (6.922 m). She was powered by two 800 horsepower (600 kW) Vickers eight-cylinder two-stroke diesel engines and two 420 horsepower (310 kW) electric motors. The submarine had a maximum surface speed of 16 knots (30 km/h; 18 mph) and a submerged speed of 10 knots (19 km/h; 12 mph). British E-class submarines had fuel capacities of 50 tonnes (55 short tons) of diesel and ranges of 3,255 miles (5,238 km; 2,829 nmi) when travelling at 10 knots (19 km/h; 12 mph). E20 was capable of operating submerged for five hours when travelling at 5 knots (9.3 km/h; 5.8 mph).
E20 was fitted, possibly uniquely within her class, with a 6-inch Howitzer deck gun, forward of the conning tower. She had five 18 inch (450 mm) torpedo tubes, 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 1 kilowatt (1.3 hp) power ratings; in some submarines, these were later upgraded to 3 kilowatts (4.0 hp) systems by removing a midship torpedo tube. Their maximum design depth was 100 feet (30 m) although in service some reached depths of below 200 feet (61 m). Some submarines contained Fessenden oscillator systems.
On 30 November 1915, Turkish forces captured the French submarine Turquoise before the submarine or any of the confidential papers on board could be destroyed. When Turquoise was caught, her commander had not signaled her predicament to anyone, so a scheduled rendezvous with E20 — as far as anyone other than the crew of Turquoise or the Germans and Turks knew – was still on. The Imperial German Navy submarine UB-14, which was at Constantinople, was sent to keep the rendezvous, reportedly going so far as to radio messages in the latest British code. Upon arriving at the designated location, UB-14 surfaced and fired a torpedo at E20 from a distance of 500 metres (550 yd). Only when E20's crew saw the torpedo did they realize something was amiss, but it was too late to avoid the weapon. The torpedo hit E20's conning tower and sank the submarine with the loss of 21 men. UB-14 rescued nine men, including E20's captain who, reportedly, had been brushing his teeth at the time of the attack.
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