Determining the deterioration cost for railway tracks

Abstract

The cost of maintaining and renewing railway tracks affected by traffic-dependent deterioration is considerable. It is important not only to have proper maintenance regimes, but also to have knowledge of the interaction between vehicles and track in order to reduce the deterioration of both. In a joint project between Banverket (Swedish Rail Administration) and KTH (Royal Institute of Technology, Stockholm), a model for track deterioration is developed, considering track settlement, component fatigue, abrasive wear, and rolling contact fatigue of rails. The basis of the model is taken from what is considered as state-of-the-art knowledge. The model is used as a basis for a proposed new track access charging regime for Banverket, able to differ between vehicle types based on their characteristics and tendency to deteriorate the tracks. The model is implemented in an Excel® environment and applied to Swedish mainline traffic and vehicles. Using representative vehicle characteristics in determining track deterioration, it is predicted that there are large differences between different vehicles regarding their deterioration of the tracks. The model predicts axle load, unsprung mass, and wheelset steering capability as decisive for track deterioration. The model is believed to predict realistic results also for heavy-haul rail operations.