Photo #: NH 51157 USS D-3 (Submarine # 19), at left, and USS D-2 (Submarine # 18), center At the Philadelphia Navy Yard, Pennsylvania, 5 March 1919, with shipyard workmen on board. Note the ventilating fans on D-3's deck. A derrick barge is alongside D-2. Among the four submarines visible in the background are USS L-1 (Submarine # 40), USS L-4 (Submarine # 43) and USS L-10 (Submarine # 50). A motorcycle is parked at the far left. U.S. Naval History and Heritage Command Photograph.