2015 large lock maintenance, Hiram M. Chittenden Locks, Seattle, Washington. At right is what would normally be considered the lower (seaward) gate of the locks; the gate at left, mitred in the opposite direction, provides the seal for pump-out. Camera here is in opening from the south penstock tunnel; the analogous north penstock tunnel can be seen near the center of the photo. To the left of that tunnel, the scaffolding constitutes a staircase to get in and out of the lock chamber.