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  • Route availability

  • Train crossing viaductRoute availability (RA) defines the axle weight which can be conveyed over any given route. It is mainly determined by the strength of underline bridges.

    The route availability number for a vehicle is principally determined from its gross weight divided by the number of axles, however axle spacing may also be a factor.

    Examples of route availability capabilities are:

    • RA 3 = up to 16.5 tonnes per axle
    • RA 5 = up to 19.0 tonnes per axle
    • RA 8 = up to 22.8 tonnes per axle
    • RA 10 = up to 25.4 tonnes per axle (the current maximum for freight on the network)

    More technical details on how to determine the route availability number for a vehicle are given in the industry standard GE/RT8006 Interface between Rail Vehicle Weights and Underline Bridges, which is available from the Rail Safety and Standards Board website.

    A train is automatically permitted to travel over a route if the highest vehicle route availability number is equal to or less than the route route availability number.

    Trains exceeding a route's route availability

    Trains are often permitted to operate with a higher route availability than that published for the route subject to certain conditions being met, such as special speed restrictions. This is to allow train operators to carry more commercially advantageous payloads.

    We document each instance with a special authority form. For any new such operation it will be necessary to email our Access Coordinator to establish the relevant requirements.

    Early consultation is recommended when considering options for new vehicles or operations that exceed the verified route availability.

    Route availability tables

    Details of route availability across the network are published in Table D of the Sectional Appendix, except in Scotland where they are contained in a separate publication called Route Availability Table – Scotland.

    To find out how to access these details, see our page on the National Electronic Sectional Appendix (NESA). There is a link from NESA to the Route Availability Table - Scotland.

    Route availability and total tonnage capability

    These two capabilities should not be confused with each other. You can find more information in the section on total tonnage capability.