Punctuality and Railway Maintenance

The iron ore railway in northern Scandinavia is a single track line that stretches from the Gulf of Bothnia to the Norwegian Sea. Mixed traffic on a single-track railway makes the traffic sensitive and prone to disturbances. To improve punctuality and efficiency in the traffic flow, the link between disturbances and their impacts on train delays needs to be analysed and understood more precisely than today. This paper investigates the underlying causes of train delays for the iron ore transport section of the Swedish railway. The analysis presented in the paper is based on data pertinent to train delays, which are retrieved, classified and analysed in close cooperation with operation and maintenance personnel from both infrastructure and train operating companies. The focal point of our analysis is on discovering the sequence of events and the linkages therein, if any, leading to train delays. These event descriptions are subsequently compared to the records of concerned reporting systems of the Swedish railway administration. As an end result of the analysis and comparison with kept data, we are able to perceive a wider view of the causes for delays. This is expected to provide us with a more relevant and reliable feedback, which should prove useful for prioritization of maintenance work.