A day in the life of a jointed track

ΔG = αLΔT°. Free expansion For a free thermal expansion jointed track the rails expand and contract freely and the track components do not provide any resistance to oppose this rail length variation. The joint gap varies linearly relative to the rail temperature. The figure below presents the joint gap variation for a jointed track formed…

Significance of jointed track parameter variation

Joint resistance The normal rail joints are designed to allow the rail length variation due to temperature. To do this the joints have a well-defined maximum gap and a set of installation parameters to provide an optimum behaviour at temperature variation and a good maintenance regime. Any modern rail joint has a standard bolt tightening torque…

Jointed track breathing

Rail breathing Normally on the railway track the rail is fixed through a set of superstructure elements (fastenings, sleepers, ballast) that opposes the rail tendency to expand or contract due to temperature variations. This fixation is achieved through friction forces and once the rail axial forces are above these friction forces, the rail will start…