USS H-7 underway, circa 1922
History
United States
Name	H-7
Ordered	by the Imperial Russian Navy, 1915
Builder	Puget Sound Navy Yard, Bremerton, Washington
Laid down	15 May 1918
Launched	17 October 1918
Acquired	20 May 1918
Commissioned	24 October 1918
Decommissioned	23 October 1922
Reclassified	SS-150, 17 July 1920
Stricken	26 February 1931
Fate	Sold for scrapping, 28 November 1933
General characteristics
Class and type	H-class 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) 340 hp (250 kW) (electric motors)
Propulsion	2 × New London Ship & Engine Co. diesel engines 2 × Electro Dynamic Co. electric motors
Speed	14 kn (26 km/h; 16 mph) surfaced 10.5 knots (19.4 km/h; 12.1 mph) submerged
Range	2,300 nmi (4,300 km; 2,600 mi) at 11 knots (20 km/h; 13 mph) on the surface 100 nmi (190 km; 120 mi) at 5 knots (9.3 km/h; 5.8 mph) submerged
Test depth	200 ft (61 m)
Complement	25
Armament	4 × 18-inch (450 mm) torpedo tubes

USS H-7 (SS-150) was a H-class submarine originally built for the Imperial Russian Navy. Six of these were not delivered pending the outcome of the Russian Revolution of 1917 before being purchased by the United States Navy on 20 May 1918.

The H-class submarines had a length of 150 feet 4 inches (45.8 m) overall, a beam of 15 feet 10 inches (4.8 m) and a mean draft of 12 feet 5 inches (3.8 m). They displaced 358 long tons (364 t) on the surface and 467 long tons (474 t) submerged. The boats had a crew of 2 officers and 23 enlisted men. They had a diving depth of 200 feet (61.0 m).^[1]

For surface running, they were powered by two New London Ship & Engine Co. 475-brake-horsepower (354 kW) diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 170-horsepower (127 kW) Electro Dynamic Co. electric motor. They could reach 14 knots (26 km/h; 16 mph) on the surface and 10.5 knots (19.4 km/h; 12.1 mph) underwater.^[1] On the surface, the boats had a range of 2,300 nautical miles (4,300 km; 2,600 mi) at 11 knots (20 km/h; 13 mph) and 100 nmi (190 km; 120 mi) at 5 knots (9.3 km/h; 5.8 mph) submerged.^[2]

The boats were armed with four 18-inch (450 mm) torpedo tubes in the bow. They carried four reloads, for a total of eight torpedoes.^[2]

H-7 was launched on 17 October 1918 and commissioned on 24 October. The submarine, attached to Submarine Division 6 (SubDiv 6) and later to SubDiv 7, operated out of San Pedro, California, on various battle and training exercises with the other ships of her division. She also patrolled out of San Pedro with interruptions for overhaul at Mare Island. H-7 reached Norfolk on 14 September 1922, having sailed from San Pedro on 25 July, and decommissioned there on 23 October. Her name was struck from the Naval Vessel Register on 26 February 1931. She was sold for scrapping on 28 November 1933.

• Friedman, Norman (1995). U.S. Submarines Through 1945: An Illustrated Design History. Annapolis, Maryland: Naval Institute Press. ISBN 1-55750-263-3.
• Gardiner, Robert & Gray, Randal, eds. (1985). Conway's All the World's Fighting Ships 1906–1921. Annapolis, Maryland: Naval Institute Press. ISBN 0-85177-245-5.
•  This article incorporates text from the public domain Dictionary of American Naval Fighting Ships. The entry can be found here.

• PigBoats.COM H-class page
• Photo gallery of USS H-7 at NavSource Naval History