2015 large lock maintenance, Hiram M. Chittenden Locks, Seattle, Washington. At left is what would normally be considered the lower (seaward) gate of the locks; there is a further gate at right (just a bit of it visible at right here, but see Chittenden Locks during large lock maintenance 002.jpg or Chittenden Locks during large lock maintenance 003.jpg) mitred in the opposite direction, which provides the seal for pump-out.