A measurement system for quick rail inspection and effective track maintenance strategy

Safety and environment impact of urban railway play a primary role in the management of Public Transportation Companies. One of the critical problem is track maintenance activity, requiring a reliable knowledge of the rail status (such as, for urban transport system, corrugation and localised damage) so that a proper intervention can be performed only when necessary. The public transportation company of Milan (ATM S.p.A.) has started a cooperation with Politecnico di Milano to develop new techniques for track condition inspection, through accelerometer measurements performed on standard operating bogies. This avoids the use of special cars that can operate only when traffic is stopped and permits the collection of a large amount of data improving reliability through measurement repetitions. A feasibility study of a foolproof diagnostic tool is developed in this paper. In particular, it shows the best measurement points, how the sub-structure on which the train is travelling, and the travelling conditions influence the recorded vibration levels. Signal processing techniques, at this stage, are still off-line. Anyway the system has already been designed in order to work under “real time” conditions (a prototype is already existing), also reducing the huge amount of collected data to keep only the essential ones. The attentions have been focused here on the measurement problem, postponing the theoretical aspects to a future paper.