2015 large lock maintenance, Hiram M. Chittenden Locks, Seattle, Washington. Looking northwest inside the lock; to the west, its top barely visible at lower right, is the gate at the middle of the large lock, regularly used to allow a use of the lock at half size; the full lock is used only for very long ships. This is in the eastern half of the big lock: the upper gate of the lock is behind us. Crows perched at the edge of the lock, and some in the air.