© 2014 EUROSIS-ETI. We apply real time physics techniques from video game development to the simulation of rail vehicles for rapid analysis of the stability of the wheel rail interface. We introduce a fast simulation algorithm for the wheel rail interface, using a spline-based approach to approximate the gravitational stiffness force. We compare our simulation to results achieved from solving the Nadal equation for a range of rail vehicle speeds. We extend the technique to multiple railway bogies, and use the simulation to gather data on flange collisions. As we use a physics library and techniques designed for real time gaining, our results are achieved considerably more quickly than rail industry standard simulations, allowing for multiple scenarios to be modelled and analysed.