"G" Class Submarine (1915)

General arrangement of the design.^[1]
Note the sheer lines indicating the bow was later raised to improve seakeeping.

Fourteen "G" Class Submarines were completed for the Royal Navy early in the war. G 15, to be built by White, was cancelled in April, 1915. The Royal Navy considered these to be "patrol" (as opposed to coastal or fleet) submarines.

Each cost about 80% of what a later "J" class boat cost to produce.^[2]

The design inaugurated the use of 21-in submarine-borne torpedoes in service.

Overview of 14 vessels
Citations for this data available on individual ship pages
Name	Builder	Laid Down	Launched	Completed	Fate
G 1	Chatham Royal Dockyard		14 Aug, 1915	Nov, 1915	Sold Feb, 1920
G 2	Chatham Royal Dockyard		23 Dec, 1915	Mar, 1916	Sold Feb, 1920
G 3	Chatham Royal Dockyard		22 Jan, 1916	Apr, 1916	Sold Nov, 1921
G 4	Chatham Royal Dockyard		23 Oct, 1915	Jan, 1916	Sold Jun, 1928
G 5	Chatham Royal Dockyard		23 Nov, 1915	Feb, 1916	Sold Oct, 1922
G 6	Armstrong, Whitworth & Company		7 Dec, 1915	May, 1916	Sold Nov, 1921
G 7	Armstrong, Whitworth & Company		4 Mar, 1916	Aug, 1916	Sunk 1 Nov, 1918
G 8	Vickers		1 May, 1916	Jul, 1916	Lost 14 Jan, 1918
G 9	Vickers		15 Jun, 1916	Sep, 1916	Sunk 16 Sep, 1917
G 10	Vickers		11 Jan, 1916	Apr, 1916	Sold Jan, 1923
G 11	Vickers		22 Feb, 1916	May, 1916	Wrecked 22 Nov, 1918
G 12	Vickers		24 Mar, 1916	Jun, 1916	Sold Feb, 1920
G 13	Vickers		18 Jul, 1916	Sep, 1916	Sold Jan, 1923
G 14	Scotts Shipbuilding and Engineering Company		17 May, 1917	Aug, 1916	Sold 11 Mar, 1921

The Grand Fleet Battle Orders specified that the top speed on the surface was 14 knots, but that a more realistic "sea-going speed" was 12 knots.^[3]

Radio

By war's end, all boats of "E" class and later were given 3 kilowatt Poulsen wireless sets, affording ranges of 200 miles submarine-to-submarine, and 300-400 miles between shore stations and submarines. Reception of shore stations of 400 miles was common, and high power shore stations could be received over 500-600 miles.^[4]