4. DLRL shall not use any land or property of the Board forming part of the Dock for the passage or siting of vehicles, plant or machinery employed in the construction of the specified work other than—
(a)with the consent in writing of the engineer whose consent shall not be unreasonably withheld; and
(b)subject to compliance with such reasonable requirements as the engineer may from time to time specify—
(i)for the prevention of detriment; or
(ii)in order to avoid or reduce any inconvenience to the Board, its officers and agents and all other persons lawfully on such land or property.