USS M-1

	USS M-1 underway during acceptance trials, off Provincetown, Massachusetts, 26 June 1916
Class overview
Name	M class
Builders	Electric Boat Company (design); Fore River Shipbuilding, Quincy, Massachusetts;
Operators	United States Navy
Preceded by	L class
Succeeded by	AA-1 class
Built	1914–1918
In commission	1918–1922
Planned	1
Completed	1
Scrapped	1
History
United States
Name	M-1
Builder	Electric Boat Company (design); Fore River Shipbuilding, Quincy, Massachusetts;
Cost	$618,899.30 (hull and machinery)
Laid down	2 July 1914
Launched	14 September 1915
Sponsored by	Miss Sara Dean Roberts
Commissioned	16 February 1918
Decommissioned	15 March 1922
Stricken	16 March 1922
Identification	Hull symbol: SS-47 (17 July 1920); Call sign: NYY; ;
Fate	Sold for scrap, 25 September 1922
General characteristics
Type	Submarine
Displacement	488 long tons (496 t) surfaced; 676 long tons (687 t) submerged;
Length	197 ft (60 m)
Beam	19 ft (5.8 m)
Draft	11 ft (3.4 m)
Installed power	840 bhp (630 kW) diesel; 340 hp (250 kW) electric;
Propulsion	NELSECO diesel engines; 2 × Electro Dynamic Company 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	2,750 nmi (5,090 km; 3,160 mi) at 11 kn (20 km/h; 13 mph) surfaced
Test depth	150 ft (46 m)
Capacity	28,422 US gal (107,590 L; 23,666 imp gal) fuel
Complement	2 officers; 26 enlisted;
Armament	4 × 18 inch (450 mm) bow torpedo tubes (8 torpedoes); 1 × 3 in (76 mm)/23 caliber deck gun;

USS M-1 (SS-47), also known as "Submarine No. 46", was a unique submarine of the United States Navy. Although built as a fully operational boat, M-1 was built with a radically different double-hulled design. This was in marked contrast to Simon Lake's and Electric Boat's single-hulled concepts. Ultimately shown to be unsuccessful, no other submarines of this class were ever built, although future advances in construction, and metallurgy science, made the double hull design a standard for the USN.