13.—(1) The Agency must, so far as is reasonably practicable, exercise the powers conferred by article 21 (protective works) so as not to obstruct or render less convenient the access to any apparatus.
(2) The Agency must not, in the exercise of the powers conferred by section 11(3) of the 1965 Act (powers of entry), as applied by this Order, or by article 23 (power to survey and investigate land, etc.), make any trial holes which interfere with any apparatus without the consent of the specified undertaker (which must not be unreasonably delayed or withheld).