8.—(1) Subject to the following provisions of this paragraph, Network Rail shall repay to an undertaker the reasonable expenses incurred by that undertaker in, or in connection with, the inspection, removal, alteration or protection of any apparatus or the construction of any new apparatus which may be required in consequence of the execution of any such works as are referred to in paragraph 5(2).
(2) There shall be deducted from any sum payable under sub-paragraph (1) the value of any apparatus removed under the provisions of this Schedule, that value being calculated after removal.
(3) If in accordance with the provisions of this Schedule—
(a)apparatus of better type, of greater capacity or of greater dimensions is placed in substitution for existing apparatus of worse type, of smaller capacity or of smaller dimensions; or
(b)apparatus (whether existing apparatus or apparatus substituted for existing apparatus) is placed at a depth greater than the depth at which the existing apparatus was,
and the placing of apparatus of that type or capacity or those dimensions or the placing of apparatus at that depth, as the case may be, is not agreed by Network Rail or, in default of agreement, is not determined by arbitration to be necessary, then, if such placing involves cost in the construction of works under this Schedule exceeding that which would have been involved if the apparatus placed had been of the existing type, capacity or dimensions, or at the existing depth, as the case may be, the amount which apart from this paragraph would be payable to the undertaker in question by virtue of sub-paragraph (1) shall be reduced by the amount of that excess.
(4) For the purposes of sub-paragraph (3)—
(a)an extension of apparatus to a length greater than the length of existing apparatus shall not be treated as placing of apparatus of greater dimensions than those of the existing apparatus; and
(b)where the provision of a joint in a cable is agreed, or is determined to be necessary, the consequential provision of a jointing chamber or of a manhole shall be treated as if it also had been agreed or had been so determined.
(5) An amount which apart from this sub-paragraph would be payable to an undertaker in respect of works by virtue of sub-paragraph (1) shall, if the works include the placing of apparatus provided in substitution for apparatus placed more than 7 years and 6 months earlier so as to confer on the undertaker any financial benefit by deferment of the time for renewal of the apparatus in the normal course, be reduced by the amount which represents that benefit.