Modelling the interactions between heavy axle weight freight traffic and underbridges

Faced with a combination of ageing infrastructure, changing traffic patterns, climate change impacts and the need for modal shift to rail, freight train operators and railway infrastructure managers need improved methods and tools for the planning and management of freight train paths and infrastructure maintenance, renewals and enhancement. Since underbridges tend to be the limiting factor for the accommodation of heavy axle weight freight traffic, they require particular attention. In order to meet these needs, new methods and an integrated tool were developed to visualise the railway network and its assets, and to model the routeing of freight services and the degradation of underbridges, the interactions between traffic and the bridges, and the impacts and constraints they impose on each other. The integrated modelling tool combines data from a range of sources in an online geospatial database, making use of industry standard, open-source techniques and tools, and thus maximising reliability and deployment flexibility and the scope for further expansion of the system. The database interacts with bespoke structural degradation modelling tools to determine the impacts of traffic on bridges and vice versa. Work is continuing to extend the model’s coverage from an initial exemplar route to Britain’s full national railway network, and the possibility of expanding its coverage to include additional infrastructure asset categories is being considered.