18.—(1) Subject to sub-paragraph (2), any specified work, and all protective works required by the Agency under paragraph 17, must be constructed—
(a)without unreasonable delay in accordance with the plans approved or deemed to have been approved or settled under this Part of this Schedule; and
(b)to the reasonable satisfaction of the Agency,
and an officer of the Agency is entitled to watch and inspect the construction of such works.
(2) Network Rail must give to the Agency not less than 14 days’ notice in writing of its intention to commence construction of any specified work and notice in writing of its completion not later than 7 days after the date on which it is brought into use.
(3) If any part of a specified work or any protective work required by the Agency is constructed otherwise than in accordance with the requirements of this Part of this Schedule, the Agency may by notice in writing require Network Rail at Network Rail’s own expense to comply with the requirements of this Part of this Schedule or (if Network Rail so elects and the Agency in writing consents, such consent not to be unreasonably withheld or delayed) to remove, alter or pull down the work and, where removal is required, to restore the site to its former condition to such extent and within such limits as the Agency reasonably requires.
(4) Subject to sub-paragraph (5) and paragraph 22, if within a reasonable period, being not less than 28 days from the date when a notice under sub-paragraph (3) is served upon Network Rail, it has failed to begin taking steps to comply with the requirements of the notice and subsequently to make reasonably expeditious progress towards their implementation, the Agency may execute the works specified in the notice and any expenditure incurred by it in so doing is recoverable from Network Rail.
(5) In the event of any dispute as to whether sub-paragraph (3) is properly applicable to any work in respect of which notice has been served under that sub-paragraph, or as to the reasonableness of any requirement of such a notice, the Agency must not except in emergency exercise the powers conferred by sub-paragraph (4) until the dispute has been finally determined.