The L-class boats designed by Lake Torpedo Boat (L-5 through L-8) were built to slightly different specifications from the other L boats, which were designed by Electric Boat, and are sometimes considered a separate L-5 class. The Lake boats had a length of 165feet overall, a beam of 14feet and a mean draft of 13feet. They displaced 451LT on the surface and 527LT submerged. The L-class submarines had a crew of 28 officers and enlisted men. They had a diving depth of 200feet.[1]
For surface running, the boats were powered by two 6000NaN0 diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 400hp electric motor. They could reach 14kn on the surface and underwater. On the surface, the Lake boats had a range of 5150nmi at [1] and 150nmi at 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. The L-class submarines were also armed with a single 3"/50 caliber deck gun.[2]
L-6s keel was laid down on 27 May 1914 by Craig Shipbuilding Company in Long Beach, California. L-6 was launched on 31 August 1916 sponsored by Mrs. William R. Monroe, and commissioned on 7 December 1917.
After exercises along the West Coast, L-6 departed Pacific waters on 20 April 1918, arriving Charleston, South Carolina, on 10 June. Following a brief overhaul, the submarine patrolled off Charleston until she sailed on 15 October for the eastern Atlantic. Arriving Ponta Delgada, Azores, in early November, L-6 joined Submarine Division 6 just prior to the signing of the Armistice with Germany on 11 November.
After making stops in Caribbean Sea and Central American ports, L-6 arrived San Pedro, California, on 14 February 1919, completing one of the best long-distance seagoing performances of the United States's youthful submarine force. From 1919 to 1922, she remained on the West Coast, experimenting with new torpedoes and undersea detection equipment. L-6 was placed in commission, in ordinary, on 24 March 1922; returned to full commission on 1 July; and sailed for the East Coast the same month. Upon arrival Hampton Roads, L-6 decommissioned on 25 November 1922, and was sold to M. Samuel and Sons on 21 December 1925 for scrapping.