United States L-class submarine

USS L-1 (SS-40) lead ship of her class during running trials.
Class overview
Name:	L class
Builders:	Electric Boat (Gp 1 design), Fore River Shipbuilding Company, Quincy, Massachusetts (L-1 to L-4, L-9 to L-11) Lake Torpedo Boat Company, Bridgeport, Connecticut (Gp 2 design) (L-5) California Shipbuilding Co., Long Beach, California (L-6 & L-7) Portsmouth Navy Yard, Kittery, Maine (L-8)
Operators:	United States Navy
Preceded by:	K class
Succeeded by:	USS M-1
Built:	1914–1917
In commission:	1916–1923
Completed:	11
Retired:	11
Preserved:	0
General characteristics
Type:	Submarine
Displacement:	Group 1: 450 long tons (457 t) surfaced 548 long tons (557 t) submerged Group 2: 456 long tons (463 t) surfaced 524 long tons (532 t) submerged
Length:	Group 1: 167 ft 5 in (51.03 m) Group 2: 165 ft (50 m)
Beam:	Group 1: 17 ft 5 in (5.31 m) Group 2: 14 ft 9 in (4.50 m)
Draft:	Group 1: 13 ft 7 in (4.14 m) Group 2: 13 ft 3 in (4.04 m)
Installed power:	Group 1: 1,300 hp (970 kW) (diesel engines), 800 hp (600 kW) (electric motors) Group 2: 1,200 hp (890 kW) (diesel engines), 800 hp (600 kW) (electric motors)
Propulsion:	Diesel-electric Group 1: 2 × NELSECO Diesel engines, 2 × Electro Dynamic electric motors, 2 × 60-cell batteries, 2 × shafts Group 2: 2 × Busch-Sulzer Diesel engines, 2 × Diehl electric motors, 2 × 60-cell batteries, 2 × shafts
Speed:	14 knots (26 km/h; 16 mph) surfaced 10.5 knots (19.4 km/h; 12.1 mph) submerged
Range:	4,500 nmi (8,300 km) at 7 kn (13 km/h; 8.1 mph) (surfaced) 150 nmi (280 km) at 5 kn (9.3 km/h; 5.8 mph) (submerged)
Test depth:	200 ft (61 m)
Complement:	28 officers and men
Armament:	4 × 18 inch (457 mm) torpedo tubes, 8 torpedoes 1 × 3"/23 caliber retractable deck gun

The United States L-class submarines were a class of 11 submarines built 1914–1917, and were the United States Navy's first attempt at designing and building ocean-going submarines. At the time there was a significant gap in long-range submarine design compared with other major navies. The Group 2 L-boats designed by Lake Torpedo Boat Company (L-5 through L-8) were built to slightly different specifications from the other Group 1 L-boats (which were designed by Electric Boat) and are sometimes considered a separate L-5 class.

After service in the Atlantic Flotilla by the Group 1 boats, most required extensive refits at Philadelphia after the USA's entry into the First World War, which reflected the US Navy's then-limited experience in submarine ocean operations. In December 1917, the seven boats were sent to Bantry Bay as Submarine Division 5 for convoy escort and anti-U-boat patrols. The four new Group 2 L-boats later deployed to the Azores in November 1918 as Division 6 to reinforce four K-class submarines sent there in October 1917. While forward deployed, US L-class submarines displayed "AL" pennant numbers to avoid confusion with British L-class submarines.

US submarines did not sink any U-boats in World War I. The class was generally under-powered, but they enjoyed good endurance for patrols in the North Atlantic and in British waters. After the war, the L class were involved in trials of new torpedoes and hydrophone equipment on both the east and west coasts before decommissioning in 1922 and 1923. At least L-3, L-9, and L-11 were re-engined with Busch-Sulzer diesels removed from Lake-built N-boats in 1921. Three Group 1 boats were scrapped in 1922, the four Group 2 Lake boats were scrapped in 1925, and the remainder were scrapped in 1933 under the London Naval Treaty limiting naval armament.