8U.K.The fact that any act or thing may have been done in accordance with plans approved by the principal engineer of the Harbour Board, or in accordance with a requirement made by him, or under his supervision, shall not (if it was not attributable to the act, neglect or default of the Harbour Board, or of any person in their employ, or of their contractors or agents) excuse the Concessionaires from any liability under this Part of this Schedule.