Limits of deviation
8. In carrying out the authorised development Network Rail may—
(a)deviate laterally from the lines or situations of the authorised development shown on the works plans to the extent of the limits of deviation shown on those plans; and
(b)deviate vertically from the levels of the authorised development shown on the sections—
(i)to any extent not exceeding 2 metres upwards; or
(ii)to any extent downwards as may be found to be necessary or convenient.