It is known that masonry arch bridges carry a lot of rail traffic in the UK; almost all of which have been in service for many years. However, they increasingly need to be maintained and hence their performance requires enhancement to ensure increased longevity. Arch structures were designed for lower vehicle loads than they are currently subjected to. Hence this work is focused on finding a new technique of extending the scope of a proven ballast strengthening technique (XiTRACK) to allow a better distribution of the loads from the trains. In this work a static 3D finite element analysis of a masonry arch railway bridge has been conducted to study the stabilizing effects on the bridge using polyurethane polymer. A moving load across the masonry arch was also analysed to detect critical loads of maximum stress applied to the arch. The results of the finite element analysis were calibrated and verified with actual data recorded on site from the Whiley Hill bridge located at Darlington. The work presented in this paper is based on a linear elastic analysis. Further simulations using non-linear plasticity analysis are currently being performed in combination with actual site measurement data to achieve more accurate results.