47. If any alterations or additions, either permanent or temporary, to railway property are reasonably necessary during the construction of the specified works, or during a period of 12 months after the completion of the specified works, in consequence of the construction of the specified works, such alterations and additions may be carried out by LUL and if LUL gives to the Council reasonable notice of its intention to carry out such alterations and additions, the Council must pay to LUL the reasonable cost of such alterations and additions including, in respect of any permanent alterations and additions, a capitalised sum representing any increase in the costs which may be expected to be reasonably incurred by LUL in maintaining, working and, when necessary, renewing any such alterations or additions.