8.—(1) Subject to the following provisions of this paragraph, the undertaker shall repay to a protected undertaker the reasonable expenses incurred by that protected undertaker in, or in connection with, the inspection, removal, alteration or protection of any apparatus or the construction of any new apparatus (including costs or compensation payable in connection with the acquisition of land for that purpose) 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 Part of this Schedule, that value being calculated after removal.
(3) If in accordance with the provisions of this Part 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 of those dimensions or the placing of apparatus at that depth, as the case may be, is not agreed by the undertaker or, in default of agreement, is not determined by arbitration in accordance with article 42 (arbitration) to be necessary, then, if such placing involves cost in the construction of works under this Part of 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 sub-paragraph would be payable to the protected undertaker in question by virtue of sub-paragraph (1) shall be reduced by the amount of that excess.
(4) An amount which apart from this sub-paragraph would be payable to a protected 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 protected undertaker any financial benefit by deferment of the time for renewal of the apparatus in the ordinary course, be reduced by the amount which represents that benefit.