The Dynamic Behaviour Of Railway Vehicles With Solid Rubber Tyres

Mathematical models have been developed and computer programs written to simulate the dynamic behaviour of typical underground railway vehicles used in coal mines. Equipment has been designed and constructed to allow the required track and wheel data to be collected for input to the models. Both linear and non-linear simulations have been carried out using these models and the results have been validated by full size vehicle tests.
Railway vehicles with solid rubber tyres running on steel rails are in common use underground in British coal mines where the additional traction offered by a rubber tyre over a steel wheel is useful. The particular problem of the tangential forces in the contact patch of a solid rubber tyre has been examined both practically and theoretically. The results have been compared with those predicted by theory for steel wheels and for pneumatic tyres and some similarities have been established. A theory for this case has been set up and confirmed by tests on a scale roller rig.
The new theory has been used together with the mathematical models to investigate fully the dynamic behaviour of the tyred locomotive. After initial validation of the techniques with tests on a full size vehicle the model has been used to analyse the design of the tyre itself. A new tyre design is suggested with a coned tread profile instead of the normal cylindrical profile. The predicted performance of this design was checked with the scale roller rig and the improved dynamic performance confirmed.
It is hoped that use of tyres of this type will increase, possibly with an internal polymer fill, to reduce hysteresis heating effects. Higher speeds as a result of the improved dynamic performance would encourage the use of solid rubber tyres on a wider range of rail vehicles.