A life-cycle cost analysis of railway turnouts exposed to climate uncertainties

Turnouts are the critical components of modern railway tracks where the vehicle movement is transferred between two continuing tracks, inevitably resulting in high dynamic forces on the turnout system which eventually cause the turnout failures. Consequently, the turnouts have imposed operational restrictions such as operational limits for speed, axle load and headway, and high maintenance works on the system. Numerous studies have been carried out to find a mitigation method for turnout failures. Nonetheless, most of the studies consider the physical phenomena. Hence, it is believed that it would be beneficial to investigate the problem from the economic aspect. For this purpose, a life-cycle cost analysis is done for turnouts, particularly crossing nose in this study. Life-cycle cost analysis is a total cost estimate of a system or a component from acquisition to disposal, to find a cost-effective solution. It could be a simple analysis based on an expert's judgement to evaluate the feasibility or complex analysis using statistical theories covering the uncertainties to decide the budget. In this study, the life-cycle cost analysis relies on the breakdown work structure based on the reports published by the biggest Infrastructure Manager in the United Kingdom. Additionally, the effects of extreme weathers are also concerned while calculating the life-cycle cost. The results indicate that crossing renewal and tamping activities have high costs similar to miscellaneous maintenance costs. Another interesting result is that maintenance costs could be as high as acquisition costs. Finally, crossing nose renewal and maintenance costs seem to occupy high shares in the maintenance budget.