2(1)The piers in the river Thames carrying the central span of the bridge shall be so placed that, on the centre line of the bridge as constructed, there shall be a distance of not less than 440 metres between the riverward faces of the piers, and any permanent fenders for the protection of any such pier shall not extend more than 20 metres riverward from the face of the pier.
(2)Each of those piers shall be so constructed as to allow for dredging of the river between the permanent fenders for the protection of the piers to a depth of 15.7 metres below ordnance datum (Newlyn).
(3)The span of the bridge between those piers shall be so constructed that, for a distance of 100 metres, there is a headway under the deck of the span of not less than 57.5 metres above ordnance datum (Newlyn).
(4)The height of the towers above those piers shall not exceed 148 metres above ordnance datum (Newlyn).