Modelling complex series combinations of draft gear springs

A new approach to wagon connection modelling is proposed that allows each stiffness-damper component of each coupler system to be modelled separately instead of being combined into a single inter-wagon connection. Two passenger draft gear types were modelled and evaluated and compared to single inter-wagon connection modelling. The effect of a very different draft gear characteristic at the locomotive was also introduced by adding a friction type draft gear and a larger free slack. The results show significant differences in the acceleration response from the different modelling approaches for the train with single pack draft gears. The results for the balanced type draft gear were almost unchanged.