|Builder:||Scotts Shipbuilding and Engineering Company|
|Laid down:||1 December 1914|
|Launched:||17 May 1917|
|Commissioned:||31 August 1917|
|Fate:||Sold 11 March 1923 to Stanlee, Dover|
|Class and type:||G-class submarine|
|Length:||187 ft 1 in (57.0 m)|
|Beam:||22 ft 8 in (6.9 m)|
|Draught:||13 ft 4 in (4.1 m)|
|Range:||2,400 nmi (4,400 km; 2,800 mi) at 12.5 kn (23.2 km/h; 14.4 mph) surfaced|
The G-class submarines were designed by the Admiralty in response to a rumour that the Germans were building double-hulled submarines for overseas duties. The submarines had a length of 187 feet 1 inch (57.0 m) overall, a beam of 22 feet 8 inches (6.9 m) and a mean draft of 13 feet 4 inches (4.1 m). They displaced 703 long tons (714 t) on the surface and 837 long tons (850 t) submerged. The G-class submarines had a crew of 30 officers and other ranks. They had a partial double hull.
For surface running, the boats were powered by two 800-brake-horsepower (597 kW) Vickers two-stroke diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 420-horsepower (313 kW) electric motor. They could reach 14.25 knots (26.39 km/h; 16.40 mph) on the surface and 9 knots (17 km/h; 10 mph) underwater. On the surface, the G class had a range of 2,400 nautical miles (4,400 km; 2,800 mi) at 16 knots (30 km/h; 18 mph).
The boats were intended to be armed with one 21-inch (53.3 cm) torpedo tube in the bow and two 18-inch (45 cm) torpedo tubes on the beam. This was revised, however, while they were under construction, the 21-inch tube was moved to the stern and two additional 18-inch tubes were added in the bow. They carried two 21-inch and eight 18-inch torpedoes. The G-class submarines were also armed with a single 3-inch (7.6 cm) deck gun.
- Gardiner & Gray, p. 90
- Colledge, J. J.; Warlow, Ben (2006) . Ships of the Royal Navy: The Complete Record of all Fighting Ships of the Royal Navy (Rev. ed.). London: Chatham Publishing. ISBN 978-1-86176-281-8. OCLC 67375475.
- Gardiner, Robert & Gray, Randal, eds. (1984). Conway's All the World's Fighting Ships: 1906–1921. Annapolis, Maryland: Naval Institute Press. ISBN 0-85177-245-5.
- McCartney, Innes (2008). British Submarines of World War I. New Vanguard. 145. Oxford, UK: Osprey. ISBN 978-1-84603-334-6.