United States L-class submarine


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 were built to slightly different specifications from the other Group 1 L-boats and are sometimes considered a separate L-5 class.

Service

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.

Design

As in previous US designs, the sail was kept small for reduced drag when submerged. For extended surface runs, the sail was augmented with a temporary piping-and-canvas structure which took considerable time to deploy and dismantle. This remained standard through the N class, commissioned 1917–1918. Experience in World War I showed that this was inadequate in the North Atlantic weather, and earlier submarines serving overseas in that war had their bridge structures augmented with a "chariot" shield on the front of the bridge. Starting with the N class, built with lessons learned from overseas experience, US submarines had bridges more suited to surfaced operations in rough weather. Also, in the L class the rotating cap over the torpedo tubes was replaced by shutters that remained standard through the 1950s.
This was the first US submarine class equipped with a deck gun, in this case a 3-inch/23 caliber partially retractable design. L-9 was the first boat built with the gun; L-1 through L-8 had theirs added some time after completion. The gun was retracted vertically, with a round shield that fit in a well in the superstructure that projected into the pressure hull. Most of the barrel protruded from the deck, resembling a stanchion.

Boats in class

The 11 submarines of the L class were:
Group 1
Ship name and Hull no.BuilderLaid DownLaunchedCommissionedDecommissionedFate
Fore River Shipbuilding13 April 191420 January 191511 April 19167 April 1922Scrapped 1922
Fore River Shipbuilding19 March 191411 February 191529 September 19164 May 1923Scrapped 1933
Fore River Shipbuilding18 April 191415 March 191522 April 191611 June 1923Scrapped 1933
Fore River Shipbuilding23 March 19143 April 19154 May 191614 April 1922Scrapped 1922
Fore River Shipbuilding2 November 191427 October 19154 August 19164 May 1923Scrapped 1933
Fore River Shipbuilding17 February 191516 March 19162 August 19165 May 1922Scrapped 1922
Fore River Shipbuilding17 February 191516 May 191615 August 191628 November 1923Scrapped 1933

Group 2
Ship name and Hull no.BuilderLaid DownLaunchedCommissionedDecommissionedFate
Lake Torpedo Boat Company14 May 19141 May 191617 February 19185 December 1922Scrapped 1925
Craig Shipbuilding Company27 May 191431 August 19167 December 191725 November 1922Scrapped 1925
Craig Shipbuilding Company2 June 191428 September 19167 December 191715 November 1922Scrapped 1925
Portsmouth Navy Yard24 February 191523 April 191730 August 191715 November 1922Sunk as target 1926