Panoramic view inside the large lock, Hiram M. Chittenden Locks, Seattle, Washington, during maintenance. View is looking west toward the inner lower gate (past which the outer lower gate, angled in the opposite direction, is closed to seal the locks for pump-out and maintenance). In foreground, two large pieces of plastic that will be installed as seals on the underside of the the gates. Artifact in the panorama: a partial double image of another photographer, at right.