Why measure the track?

Track measurements are required not only due to mandatory legal stipulations, but above all as a basis for decision-making for cost-efficient maintenance.

For a serious consideration of the cost-efficiency of maintenance measures and as a basis for the selection of the best maintenance method, the application of a track recording car with analyzing measuring systems is imperative. Not only is the momentary quality of the track parameters being measured of interest but also their development over time. This allows forecasts to be made with regard to when the next track maintenance work should be performed and further detailed analyses.

Measuring as a basis for a maintenance strategy

To reduce maintenance costs of the track, the goal is to extend the track service life to achieve greater cost-efficiency. The correction of spot faults is costly. Far greater economic benefit is obtained by ensuring a high initial quality of the track geometry and a maintenance strategy which defines the ideal maintenance intervals. The Plasser & Theurer track recording cars provide full information about the state of the track.

Three guidelines serve as cornerstones of the legal stipulations for track recording

Guidelines for track measurement have been introduced for the European railways which are regarded as exemplary world wide.

TSI “Technical specifications for interoperability”
The European Union strives to achieve European harmonization of technical regulations in the railway sector in order to ensure interoperable, border-crossing railway traffic. The trains should be able to use the different railway networks in the EU without barriers. This will be done gradually, firstly for the high-speed railway traffic. In the section concerning track geometry quality (track gauge, alignment, longitudinal profile, equivalent conicity, etc.) of the EU directive “Infrastructure for High Speed Traffic” (2003), quality standards are defined in the form of speed limits. Each country defines those routes which fit this directive.
Maintenance plan
To create a national legal basis, national thresholds have to be defined. Infrastructure managers (from the ministries or from the railways) draw up a national maintenance plan which is based on speed-related limits. This maintenance plan contains over 30 criteria and defines which threshold values should be observed for individual defects.
EN 13848 as an international regulation
Like the TSI, this standard defines threshold values (TSI – low threshold values, European Standard – high threshold values). Part 1 of the European Standard EN 13848 defines the parameters, Part 2 the measuring systems and track recording vehicles and Part 5 the geometric quality levels, which are laid down as follows:
Immediate Action Limit (IAL)
Intervention Limit (IL)
Alert Limit (AL)