In the UK there are over 25,000 masonry arch bridge spans carrying railway traffic, with similarly large numbers in many other European countries. These structures were designed for lower vehicle loads than are currently being applied. The XiSPAN project is designed to extend the scope of a proven ballast strengthening technique (polyurethane/ballast composite) to encompass masonry arch bridges, allowing better distribution of the loads from trains. This joint project between the University of Sheffield, Herriot-Watt and Balfour Beatty Rail Technologies Limited will trial the system and provide the measurements and test results such that designers can apply the system in practice, reducing costs, reducing railway access times to undertake repairs and in some cases increasing load capacity of the route. The University of Sheffield is providing technical and modelling support as part of the project.