ABSTRACT
This chapter describes the conventional and state-of-the-art machines and methods used in track maintenance. It focuses on track geotechnology and maintenance of tracks in cold regions, and describes various techniques, which can minimise the construction and maintenance challenges in permafrost regions. Ballast tamping is a traditional method and is frequently used all over the world to correct the track geometry. Tamping consists of lifting the track and laterally squeezing the ballast beneath the sleeper to fill the void spaces generated by the lifting operation. ‘Stoneblowing’ is a new mechanised method of reinstating railway track to its desired line and level. Freezing of some soils can cause the ground surface to heave by as much as several tens of centimetres. There are three preconditions that are necessary for frost heave to occur, frost-susceptible soil, freezing temperature, and availability of water. Before laying the tracks, frost protection works are mandatory in permafrost regions (northern hemisphere in arctic regions).
