52. In relation to any dispute arising under this Part of this Schedule that is referred to arbitration in accordance with article 62 (arbitration), the process referred to in article 62(2) must be varied by the arbitrator where Network Rail demonstrates to the arbitrator’s reasonable satisfaction that Network Rail is unable (acting reasonably) to comply with the process due to timing constraints that may arise for Network Rail in—
(a)obtaining clearance conditions;
(b)obtaining any engineering, regulatory or stakeholder (internal or external) consent; or
(c)assessing any matter of concern with regard to the safe operation of Network Rail’s railway,
the variation being to the extent reasonably necessary so that Network Rail is able (acting reasonably) to comply with that process.