The effects of tamping on railway track geometry degradation

The UK rail industry remains a safe, reliable and competitive alternative to other forms of transport. Maintaining such an ageing, increasingly utilized, railway network with limited financial resources is a major challenge. By utilizing data on the UK network track geometry collected over six years, along with available records of maintenance performed during this period, the effects of tamping on track geometry degradation have been analysed. This paper presents a Weibull approach to analyse the distributions of times for the track geometry to degrade to specified states following maintenance. Track quality is given by the standard deviation of the averaged vertical position of the rails taken over a 35m wavelength. The quality of the track geometry is also investigated after tamping has been performed. The results of this study show that traffic speed and the maintenance history of any line have an effect on geometry deterioration. Furthermore, support is provided to the argument that tamping damages track ballast.