4.3 Technical assumptions for route infrastructure assessment
The Isle of Wight railway network was built to a restrictive structure
gauge and subsequent works do not comply necessarily with the current standards.
The specification includes a 55 mph line speed. In considering the reopening of
routes on the Island it has been assumed that new works will have to comply with
current Railtrack and HSE standards although derogations would be sought for
existing structures. The Technical Report details the level of specification
assumed as an input to costing for permanent way, structures, stations, level
crossings, and signalling.