18. In determining the terms and conditions mentioned in paragraph 17 in respect of alternative apparatus to be constructed across or along the authorised works the arbitrator shall—
(a)give effect to all reasonable requirements of the Company for ensuring the safety of the authorised works and for securing any subsequent alterations or adaptations of the alternative apparatus which may be required to prevent interference with any such works; and
(b)so far as it may be reasonable and practicable to do so in the circumstances of the case, give effect to any terms and conditions applicable to the apparatus (if any) constructed across or along the authorised works for which the alternative apparatus is to be substituted and to any other reasonable requirements of the specified undertaker.