A system for monitoring and managing wagon dynamic stability in long trains

A system, envisaged as a cabin instrument, to provide real time and future predictions of train dynamics and vehicle dynamics and derailment risks is proposed. Using synchronised simulation of longitudinal train dynamics to give coupler forces and accelerations, the system will provide predictive information of wheel unloading that is derived from the effects of coupler forces on curves and from wagon pitching and lifting motions derived from coupler impacts. The risks of vehicle derailment for a predetermined future time period in response to driver control and track inputs can also be determined. The assessment of derailment risk is based on the estimation of wheel unloading caused by the train’s longitudinal and lateral force components, impact forces, centrifugal forces, vehicle speed, and track geometry including irregularities. With this information made available as a cabin instrument, risk in ‘difficult to operate scenarios” can be assessed in real time and operational safety improved. The paper presents simulation examples and a discussion of the proposed device.