United States H-class submarine

	USS H-1, ex-Seawolf, off the Mare Island Navy Yard, California, 30 January 1914
Class overview
Name	H class
Builders	Electric Boat (design); Union Iron Works, San Francisco, California (H-1 & H-2); The Moran Company, Seattle, Washington (H-3); British Pacific Construction and Engineering Company, Vancouver, British Columbia / Puget Sound Navy Yard, Bremerton, Washington (H-4 to H-9);
Operators	United States Navy
Preceded by	G class
Succeeded by	K class
Built	1911–1918
In commission	1913–1922
Completed	9
Lost	1
Retired	8
General characteristics
Type	Submarine
Displacement	358 long tons (364 t) surfaced; 467 long tons (474 t) submerged;
Length	150 ft 4 in (45.82 m)
Beam	15 ft 10 in (4.83 m)
Draft	12 ft 5 in (3.78 m)
Installed power	950 hp (710 kW) (diesel engines); 600 hp (450 kW) (electric motors);
Propulsion	2 × NELSECO diesel engines; 2 × Electro Dynamic electric motors; 2 × 60-cell batteries; 2 × Propellers;
Speed	14 kn (26 km/h; 16 mph) surfaced; 10.5 kn (19.4 km/h; 12.1 mph) submerged;
Range	2,300 nmi (4,300 km; 2,600 mi) at 11 kn (20 km/h; 13 mph) surfaced; 100 nmi (190 km; 120 mi) at 5 kn (9.3 km/h; 5.8 mph) submerged;
Test depth	200 ft (61 m)
Capacity	11,800 US gal (45,000 L; 9,800 imp gal) fuel
Complement	2 officers; 23 enlisted;
Armament	4 × 18 inch (450 mm) bow torpedo tubes (8 torpedoes)

The United States H-class submarines were Electric Boat design EB26A and EB26R design coastal patrol submarines used by the United States Navy.

The first three submarines of the class were laid down in March–April 1911, as Seawolf, Nautilus, and Garfish, and were renamed H-1, H-2, and H-3, while still under construction on 17 November 1911, as part of a forcewide submarine redesignation. They were commissioned in December 1913/January 1914.

In 1915, the Imperial Russian Navy had ordered 18 H-class submarines built to a modified EB602 design. Ordered from the Electric Boat Company, they were to be built in Canada, at a temporary shipyard near Barnet, Vancouver, British Columbia, to avoid US neutrality concerns, which had derailed the delivery of ten similar submarines to the British. The shipyard was owned by the British Pacific Construction and Engineering Company. Twelve were delivered, and served as the American Holland-class submarines, but the shipment of the final six was held up, pending the outcome of the Russian Revolution of 1917, and the boats were stored in knockdown condition at their construction yard. All six were purchased by the US Navy on 20 May 1918, and assembled at Puget Sound Navy Yard, before being commissioned as H-4 to H-9, in late 1918.

H-1 ran aground and was wrecked off the coast of Mexico, on 12 March 1920, while the remaining eight submarines were decommissioned in late 1922, and laid up in the Reserve Fleet. Finally stricken from the Navy List in 1930, they were sold for scrap in 1931 and 1933.