8. The railway shall be constructed and operated on a nominal gauge of1.435 metres (4 feet 8½ inches) and the motive power shall be steam,diesel-electric, diesel, internal combustion, electric-battery or suchother motive power as the Secretary of State may approve:
Provided that nothing in this Order shall authorise the Company touse electrical power as motive power on the railway unless such power isobtained from storage batteries or from a source of generation entirelycontained in and carried along with the engines and carriages:
Provided also that, if electrical power is used as motive power on the railway, such electrical power shall not be used in such a manner as to cause or be likely to cause any interference with any telecommunicationsapparatus (as defined in Schedule 2 to the Telecommunications Act 1984(1)) or with telecommunication by means of such apparatus.