United States N-class submarine

The United States N-class submarines were a class of seven coastal defense submarines built for the United States Navy during World War I.

USS N-7 (SS-59)
Class overview
Name: N class
Operators:  United States Navy
Preceded by: AA-1 class
Succeeded by: O class
Built: 19151917
In commission: 19171926
Completed: 7
Scrapped: 7
General characteristics
Type: Submarine
  • N-1 to N-3:
  • 348 long tons (354 t) surfaced
  • 414 long tons (421 t) submerged
  • N-4 to N-7:
  • 340 long tons (345 t) surfaced
  • 415 long tons (422 t) submerged
  • N-1 to N-3: 147 ft 3 in (44.88 m)
  • N-4 to N-7: 155 ft (47 m)
  • N-1 to N-3: 15 ft 9 in (4.80 m)
  • N-4 to N-7: 14 ft 6 in (4.42 m)
  • N-1 to N-3: 12 ft 6 in (3.81 m)
  • N-4 to N-7: 12 ft 4 in (3.76 m)
  • 13 knots (24 km/h; 15 mph) surfaced
  • 11 knots (20 km/h; 13 mph) submerged
Test depth: 200 ft (61 m)
  • N-1 to N-3: 25 officers and men
  • N-4 to N-7: 29 officers and men
Armament: 4 × 18 inch (450 mm) torpedo tubes, 8 torpedoes


The boats were constructed by two companies to slightly different specifications; N-1, N-2, and N-3 were designed by the Electric Boat Company of Groton, Connecticut and built by the Seattle Construction and Drydock Company of Seattle, Washington, and N-4, N-5, N-6, and N-7 were designed and built by the Lake Torpedo Boat Company of Bridgeport, Connecticut. The N-boats built by Lake are sometimes considered a separate class.

The Electric Boat submarines had a length of 147 feet 3 inches (44.9 m) overall, a beam of 15 feet 9 inches (4.8 m) and a mean draft of 12 feet 6 inches (3.8 m). They displaced 347 long tons (353 t) on the surface and 414 long tons (421 t) submerged. The N-class submarines had a crew of 2 officers and 23 enlisted men. They had a diving depth of 200 feet (61.0 m).[1]

The Lake submarines had a length of 155 feet (47.2 m) overall, a beam of 14 feet 6 inches (4.4 m) and a mean draft of 12 feet 4 inches (3.8 m). They displaced 331 long tons (336 t) on the surface and 385 long tons (391 t) submerged. The N-class submarines had a crew of 3 officers and 26 enlisted men. They also had a diving depth of 200 feet (61.0 m).[1]

For surface running, the Electric Boat submarines were powered by two 240-brake-horsepower (179 kW) diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 280-horsepower (209 kW) electric motor. The Lake boats had 300-brake-horsepower (224 kW) diesels and 150-horsepower (112 kW) motors. Regardless of designer, the N-class submarines could reach 13 knots (24 km/h; 15 mph) on the surface and 11 knots (20 km/h; 13 mph) underwater.[1] On the surface, the boats had a range of 3,500 nautical miles (6,500 km; 4,000 mi) at 11 knots (20 km/h; 13 mph) and 30 nmi (56 km; 35 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. They were the last submarines to be designed without a deck gun until 1946.[2]

This class was the first US Navy submarine class completed with metal bridge shields. These had been omitted from previous classes to increase underwater speed. These classes used piping-and-canvas temporary bridges for extended surface runs; these were found to be inadequate on North Atlantic patrols in World War I. All forward-deployed submarines were back-fitted with metal "chariot" bridge shields during the war. The coastal patrol nature of the small N-class submarines was emphasized by their lack of a deck gun.

Ships in class

The seven submarines of the N-class were:

Ship name and Hull no. Builder Laid Down Launched Commissioned Decommissioned Fate
USS N-1 (SS-53) Seattle Construction and Drydock Company 26 July 1915 30 December 1916 26 September 1917 30 April 1926 Scrapped 1931
USS N-2 (SS-54) Seattle Construction and Drydock Company 29 July 1915 16 January 1917 26 September 1917 30 April 1926 Scrapped 1931
USS N-3 (SS-55) Seattle Construction and Drydock Company 31 July 1915 21 February 1917 26 September 1917 30 April 1926 Scrapped 1931
USS N-4 (SS-56) Lake Torpedo Boat Company 24 March 1915 27 November 1916 15 June 1918 22 April 1922 Scrapped 1922
USS N-5 (SS-57) Lake Torpedo Boat Company 10 April 1915 22 March 1917 13 June 1918 19 April 1922 Scrapped 1922
USS N-6 (SS-58) Lake Torpedo Boat Company 15 April 1915 21 April 1917 9 July 1918 16 February 1922 Scrapped 1922
USS N-7 (SS-59) Lake Torpedo Boat Company 20 April 1915 19 May 1917 15 June 1918 7 February 1922 Scrapped 1922


Commissioned after the American entry into World War I, they were assigned to the 1st Naval District, primarily operating from Naval Submarine Base New London with some boats operating out of New York City at times, all patrolling the New England coast.

By 1922 the Seattle boats were assigned to the Submarine School, New London, while the Lake boats (sometimes called the N-4 class) were all scrapped in that year, their engines having been removed in 1921 to re-equip some of the L class. The Seattle boats were decommissioned in 1926 and scrapped in 1931 to comply with the limits of the London Naval Treaty.


  1. Friedman, p. 307
  2. Gardiner & Gray, p. 129


  • 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.
  • Silverstone, Paul H., U.S. Warships of World War I (Ian Allan, 1970), ISBN 0-71100-095-6.
  • Navsource.org early diesel submarines page
  • Pigboats.com N-boats page
  • This article incorporates text from the public domain Dictionary of American Naval Fighting Ships.
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