Determining the deterioration cost for railway tracks

Abstract

The cost of maintaining and renewing railway tracks affected by traffic-dependent deterioration is considerable. It is important not only to have proper maintenance regimes, but also to have knowledge of the interaction between vehicles and track in order to reduce the deterioration of both.In a joint project between Banverket (Swedish Rail Administration) and KTH (Royal Institute of Technology, Stockholm), a model for track deterioration is developed, considering track settlement, component fatigue, abrasive wear, and rolling contact fatigue of rails. The basis of the model is taken from what is considered as state-of-the-art knowledge. The model is used as a basis for a proposed new track access charging regime for Banverket, able to differ between vehicle types based on their characteristics and tendency to deteriorate the tracks.The model is implemented in an Excel ® environment and applied to Swedish mainline traffic and vehicles. Using representative vehicle characteristics in determining track deterioration, it is predicted that there are large differences between different vehicles regarding their deterioration of the tracks. The model predicts axle load, unsprung mass, and wheelset steering capability as decisive for track deterioration. The model is believed to predict realistic results also for heavyhaul rail operations.

Bogies towards higher speed on existing tracks

“…The first two are aspects of track friendliness according to references [1,4,6]. The last two are related to the active secondary suspension.…”

“…Track friendliness depends on different properties and features of the vehicles, the most important being low axle load and unsprung mass, the ability of the wheelsets to steer radially in curves as well as low centre of gravity [4]. Operational parameters, such as speed and cant deficiency, also naturally affect track deterioration [5,6].…”

Enhancing rail infra durability through freight bogie design

“…Apart from track radii below 2000 m, vehicle curving behaviour is particularly challenged at the diverging route through a turnout. Öberg and Andersson [2] identify three deteriorating mechanisms, together determining the overall track degradation cost. In accordance with the [1] reported main track problems, the identified mechanisms are track settlement, component fatigue of the super structure and wear and rolling contact fatigue of rails.…”

A laboratory study of rail–wheel interaction monitoring using acoustic emission: Effect of rolling conditions with and without lateral rattling

“…Vertical wheel load is related to axle load, but will be dynamically amplified roughly in proportion to speed, with frequencies in the tens of hertz range. 2 Much of the work on monitoring the dynamics of wheel-rail contact has been applied noise reduction, and this work has revealed some very complex interactions between wheel and track roughness, rail and wheel stiffness, and track foundations, the overall effect being that noise is generated by rail and wheel vibrations in the frequency range from about 50 Hz to 2 kHz, although curve squeal is much less well-understood because the forcing [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] {SAGE}PIF/PIF 458497.3d (PIF) [PREPRINTER stage] function is believed to be frictional instability rather than roughness-induced vertical displacements. 3 Given this complex loading situation, traditional mean gross tonnage (MGT)-based rail life prediction methods are not reliable since dynamic loading produces non-uniform and dynamic stress distributions from traction, braking and steering forces, often giving rise to multipoint contact pressure distributions rather than the Hertzian distribution traditionally assumed.…”

“…Average kurtosis of cross-correlation function between track defects and AE above normal rolling background for all experiments with no spacer installed [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. {SAGE}PIF/PIF 458497.3d (PIF) [PREPRINTER stage]…”