Track innovations by Austrian railways

As with any railway company, Austrian Railways infrastructure is under constant pressure to provide optimum availability of their tracks at minimum cost. Key to achieving this objective is ongoing research in track technologies, analyses of economic and technical dependencies and implementation of innovative track maintenance and track components. This paper describes OEBBrs innovative methods: Austrian Railways infrastructure strategies are based on life cycle cost analysis, for which a model was developed jointly by the Technical University of Graz and OEBB. In order to monitor track condition, a comprehensive data base has been implemented, which allows prognosis of track and track component degradation, based on long-term observation. The track condition analysis is based on the lNATASr system which uses the lgliding standard deviationr for track geometry condition and integrates ground penetration radar measurement into the track report. Another newly developed important information tool is the geotechnical database, the so-called lextended structurer where each 200-metre section of the whole main-line network is classified according to the condition of ballast, substructure, drainage and adjacent structures. This allows optimal planning of the sequence of rehabilitation projects. The exact investigation into the cause of track failures has led to the improvement of track components, such as rails, fastenings and rail pads. This increases the working-life of components and reduces the occurrence of track defects. A helpful tool developed is the measurement and analysis of rail inclination which can indicate pad or fastener failure. Furthermore, the right elasticity of the whole track system is of major importance for a cost-effective track strategy. OEBB, therefore, now installs concrete sleepers with under sleeper pads and pays utmost attention to the condition of ballast and formation. Formation rehabilitation always includes the application of a gravel-sand layer above a geo-synthetic layer. Another new strategy is lintegrated maintenancer where tamping and rail grinding is carried out in one common track occupation; the results are longer lasting track quality and reduced development of rail defects. For track work, Austrian Railways apply high capacity machines which are contracted on a long-term basis (three- to five-year contracts). Machine systems used are: - Track geometry maintenance machine groups with four sleeper tampers, stabilisers and ballast distribution systems - Continuous action turnout tamping machines with integrated ballast distribution - Ballast cleaning machines - Formation rehabilitation systems combined with drainage maintenance systems - Combined track relaying and ballast cleaning systems - Transport and laying systems for preassembled lplug inr turnouts