Lehigh Canal
Weighlock @ Lock 2
Lehigh Valley Railroad grade is uphill to left, Lock 2 is to right.
Weighlock is only wide enough for one boat, but twice as long with a step down in the floor.
Boats apparently entered the upper part from above, the lock drained for weighing, then the lock was refilled and they moved to the lower section where they were lowered to the basin below in background.