100. Where any street is temporarily closed or diverted under the powers of article 14 (temporary closure of streets, cycle tracks and public rights of way) of this Order, the Statutory undertaker shall be at liberty at all times to take all necessary access across any such closed highway and/or to execute and do all such works and things in, upon or under any such highway as may be reasonably necessary or desirable to enable it to maintain any apparatus which at the time of the closure or diversion was in that highway, subject always to the undertaker’s unimpeded ability to carry out the Works.