Where, immediately before the commencement of this Act, an authorisation granted before 1st October 1982 under Part III of the M1Petroleum and Submarine Pipe-lines Act 1975 is in force in relation to any pipeline, that pipeline shall not be regarded for the purposes of section 18(6) to (8) or 19(1) as comprising any such associated apparatus as is mentioned in section 26(1)(b).