Rail steel grades in track
1 August 2013 • Author(s): Peter Veit, Head of the Institute for Railway Engineering and Transport Economy, Graz University of Technology, Austria
Since 2002, track strategies at the Austrian Federal Railways (ÖBB) have been based on life-cycle cost calculations1. These basic strategies have been adopted due to new technologies – for example the use of under sleeper pads, changing price levels, and the phenomena of rail contact fatigue2 (RCF).
The basic data for defining life-cycle cost based strategies are so-called standard elements. These standard elements are track sections with a set of defined parameters (traffic load, alignment, type of super-structure, dewatering system, sub-layers, sub-soil quality). For all relevant standard elements, working cycles have been worked out defining the demand of maintenance for the entire life-cycle and the economic service life. These cycles exist for different types of super-structure taking into account rail profile, rail steel grade, and the type of sleepers as there are concrete sleepers with under sleeper pads, conventional concrete sleepers and wooden ones (see Figure 1).
These standard elements are cross-checked with real track sections facing these parameters and with the information provided by a data warehouse showing the deterioration function of track over time based on time periods of 12 years.