These submarines were built to two distinctly different designs at four separate shipyards. The
Electric Boat Company (EB) of
New York City, later
Groton, Connecticut, went the route they followed with previous designs and simply scaled up their standard
single hull, spindle shaped, twin
propeller, axial
rudder design to meet the requirements of the Navy. They were contracted for
L-1 through
L-4 and
L-9 through
L-11, and these would be built at EB's sub-contractor, the
Fore River Shipbuilding Company, in
Quincy, Massachusetts. For the first time EB did away with the rotating bow cap for the
torpedo tube muzzle doors. It was replaced by individual faired-in shutter doors that would later become a standard design feature.
Simon Lake's
Lake Torpedo Boat Company returned to the fold and submitted a very different design that would become
L-5 through
L-8. These boats were similar in size and capability to the EB design, but they had a ventrally mounted rudder and propeller shafts, a watertight superstructure to aid in surface buoyancy, and different engines and motors. They also had three sets of amidships mounted
diving planes, as opposed to EB's standard bow and stern planes. The only one of the four that would actually be built at Lake's
Bridgeport, Connecticut, yard was
L-5. The Navy wanted some of the boats built at a
West Coast shipyard, so Lake sub-contracted with the
Craig Shipbuilding Company, of
Long Beach, California, to build
L-6 and
L-7. Desirous of creating their own in-house submarine construction capability, the Navy's
Bureau of Construction and Repair obtained a license from Lake to build the
L-8 at the government owned
Portsmouth Navy Yard, in
Kittery, Maine.
L-8 would be the first of many submarines built at government Navy Yards. The Electric Boat submarines, referred to as the
L-1-class, had a length of
overall, a
beam of , and a mean
draft of . They
displaced , on the surface, and , submerged. All L-class boats had a crew of 2 officers and 26 enlisted men. They all had a diving depth of . The Lake submarines, referred to as the
L-5-class, had a length of overall, a beam of , and a mean draft of . They displaced , on the surface, and , submerged. For surface running, the Electric Boat submarines were powered by two
NELSECO diesel engines, each driving one
propeller shaft. When submerged each propeller was driven by an
Electro Dynamic electric motor. The Lake boats had two
Busch-Sulzer diesels, and two
Diehl electric motors. Regardless of designer, the L-class submarines could reach on the surface, and underwater. On the surface, the boats had a range of at , and at submerged. 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 EB boats were also armed with a
/23 caliber retractable
deck gun forward of the
conning tower. The gun was retracted vertically, with a round shield that fit over the top of a well in the superstructure that projected into the pressure hull. Most of the barrel protruded from the deck, resembling a stanchion. The round shield doubled as a blast deflector for the gun crew, and as the watertight top of the well. This gun was roundly disliked by the submarine crews because it lacked range, hitting power, and had the tendency to retract back into the well when fired, presenting a great hazard to the gun crew. As in previous US designs, the conning tower and
fairwater was kept small for reduced drag when submerged. For extended surface runs, the fairwater was augmented with a temporary piping-and-canvas structure which took considerable time to deploy and dismantle. Experience in
World War I showed that this was inadequate in the North Atlantic weather, and these boats, along with other submarines serving overseas in that war,
E-class and
K-class, had their
bridge structures replaced with a permanent steel "chariot" shield on the front of the bridge. Chariot style bridges became standard on later U.S. submarines. ==Service==