Rails play a significant role in transport of goods and passengers. In Australia railway transport industry contributes 1.6% of GDP with goods and services worth $AUD 8 billion each year which includes $ AUD 0.5 billion per year in exports (Australasian Railway Authority Inc, 2002).Rail track maintenance plays an important role in reliability and safety. The Office for Research and Experiments (ORE) of the Union International des Chemins de Fer (UIC) has noted that maintenance costs vary directly (60-65 per cent) with change in train speed and axle load. It was also found that the increase in these costs with increased speed and axle load was greater when the quality of the track was lower(ORR, 1999). Failures during operation are costly to rail players due to loss of service, property and loss of lives. Maintenance and servicing keep rail tracks in operating, reliable and safe condition. Therefore, technical and economical analysis is needed by rail players to reduce maintenance cost and improve reliability and safety of rail networks.Over the past few years, there have been major advances in terms of increased speed, axle loads, longer trains, along with increased traffic density in corridors. This has led to increased risks in rail operation due to rolling contact fatigue (RCF) and rail wear. The infrastructure providers have less incentive to maintain a given infrastructure standard if its access charges are rigid and rolling stock standard is not achieved. It has been estimated that between 40 to 50 per cent of wagon maintenance costs and 25 per cent of locomotive maintenance costs are related to wheelmaintenance (Railway Gazette International, 2003). The economic analysis of Malmbanan indicates that about 50% of the total cost for maintenance and renewal were related to traffic on rails and 50% not related to traffic, such as signaling, electricity and snow-clearance. The results from the analysis have made it possiblefor the mining company LKAB to start up the 30 Tonnes traffic with new wagons and locomotives on the Malmbanan line in year 2001 (Åhrén et al 2003). The rail infrastructure providers have challenges to maintain infrastructure due to government control on access charges and limited control on rail operations. The aim of the research is to:· Develop a maintenance cost model for optimal rail grinding for various operating conditions; and· Develop integrated rail grinding and lubrication strategies for optimalmaintenance decisions.In this research real life data has been collected, new models have been developedand analysed for managerial decisions. Simulation approach is used to look into theimpact on various costs such as rail grinding, operating risk, down time, inspection,replacement, and lubrication. The results of the models for costs and the effect of rail grinding and lubrication strategies are provided in this thesis.In this research rail track degradation, rail failures and various factors that influencerail degradation are analysed. An integrated approach for modelling rail track degradation, rail wear, rail grinding and lubrication is developed. Simulation model and cost models for rail grinding are developed and analysed. It has been found through this research that rail grinding at 12 MGT interval is economic decision for enhancing rail life. It was also found that lubrication is most effective compared tostop/start and no lubrication strategies in steep curves.Rail grinding strategies developed in this research have been considered by Swedish National Rail for analysing the effectiveness of their existing policies on grinding intervals. Optimal grinding and lubrication decisions have huge potential for savings in maintenance costs, improving reliability and safety and enhancing rail life.
