A railway administration may use such rolling stock as it may consider necessary for the construction, operation and working of a railway:
     Provided that before using any rolling stock of a design or type different from that already running on any section of the railway, the previous sanction of the Central Government shall be obtained for such use:
     Provided further that before giving any such sanction, the Central Government shall obtain a report from the Commissioner that he has made a careful inspection of the rolling stock and, in his opinion, such rolling stock can be used.