|Laid down:||12 November 1911|
|Commissioned:||17 October 1913|
|Fate:||Sunk by mine, 26 December 1915|
|Class & type:||E-class submarine|
|Length:||178 ft (54 m)|
|Beam:||15 ft 5 in (4.70 m)|
|Armament:||4 × 18-inch (457 mm) torpedo tubes (1 bow, 2 beam, 1 stern)|
E6 had a short career in World War I. On 5 August 1914, she was towed by the light cruiser Amethyst to Terschelling along with E8 which was towed by the destroyer Ariel. E6 and E8 then made the first Heligoland Bight patrol. On 28 August 1914, E6 and E8 other boats took positions in a planned raid against the German Heligoland Bight patrol using surface ships. On 25 September 1914, E6 fouled on two mines in Heligoland Bight, but escaped. E6 was mined on 26 December 1915 in the North Sea off Harwich.
Like the first eight British E-class submarines, E6 has a displacement of 652 tonnes (719 short tons) at the surface and 795 tonnes (876 short tons) while submerged. It had a total length of 176 feet (54 m) and a beam length of 22 feet 8.5 inches (6.922 m). It contained two diesel engines each providing a power of 1,750 horsepower (1,300 kW) and two electric motors each providing 600 horsepower (450 kW) power. Its complement was thirty-one crew members.
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). E6 was capable of operating submerged for five hours when travelling at 5 knots (9.3 km/h; 5.8 mph). It was fitted with a 4 inches (100 mm) quick-firing gun and four 18 inches (460 mm) torpedo tubes. One torpedo tube was fitted at the front, one on the aft, and two in the midship section (the transverse area of the amidships); the two in the midship section were removed in post-E8 submarines.
E-Class submarines contained 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. Its claimed highest dive depth was 100 feet (30 m) although it was capable of reaching depths of below 200 feet (61 m). Some submarines contained Fessenden oscillator systems.
- Keyes, Sir Roger (1934). The Naval Memoirs of Admiral of the Fleet Sir Roger Keyes. Vol. 1: The Narrow Seas to the Dardanelles 1910-1915. London: Thornton Butterworth. p. 68.
- Innes McCartney; Tony Bryan (20 February 2013). British Submarines of World War I. Osprey Publishing. pp. 11–12. ISBN 978-1-4728-0035-0.
- "E Class". Chatham Submarines. Retrieved 20 August 2015.
- Hutchinson, Robert (2001). Jane's Submarines: War Beneath the Waves from 1776 to the Present Day. London: HarperCollins. ISBN 978-0-00-710558-8. OCLC 53783010.
- Preston, Antony. The Royal Navy Submarine Service, A Centennial History.