Paul Mittermayr
Bureau of Applied Mechanics & Mathematics

The close link between vehicle and track in railway traffic requires careful tuning of wheel and rail in order to ensure safe and efficient operation. This also means that both components have to be monitored permanently during operation. Considering the high cost involved in infrastructure installation and maintenance, the monitoring of wheel and rail profiles – and thus the rail-wheel contact – is an essential tool for controlling and directing the available resources, which are usually getting ever tighter.

Specifically, a crucial parameter in railway traffic is the track gauge, which characterizes the space available for unconstrained running. The corresponding measure for the wheel set is the wheel gauge. A correct combination of both quantities – also accounting for fabrication tolerances and the ongoing wear – is required for the safe running of a vehicle.

This track data has been collected automatically in urban rail networks since more than a decade ago. Here, we are specifically looking at data collected in the Wiener Linien network in Vienna: as a new application of this extensive data base, it has now been used for an in-depth analysis of the relevant track and wear parameters.

This post-processing involves a number of more or less complex aspects, like the exact synchronization of measured quantities under the influence of measurement errors or data gaps, maintenance-induced modifications (e.g., replacement, grinding, or milling), etc. An extensive statistical analysis provides insights into the previous wear trends, and – even more important – delivers a much more reliable prognosis of the remaining service life than has been possible before. This in turn is now being used for a much better resource planning, yielding significant efficiency gains.