Dartford-Thurrock Crossing Act 1988

14 (1) Without prejudice to the provisions of paragraph 15 below, the Secretary of State shall provide, or afford reasonable facilities for the Port Authority to provide, at the bridge such navigational lights, signals, radar or other apparatus for the benefit, control and direction of navigation as the Port Authority may reasonably consider necessary by reason of the construction of the bridge or the carrying out of operations for the construction or maintenance of any tidal work affecting the river.

(2) The Secretary of State shall pay to the Port Authority the costs reasonably incurred by them in connection with the provision of that apparatus or in connection with any surveillance and regulation of river traffic which becomes reasonably necessary by reason of the construction of the bridge or the carrying out of any such operations.