SNCF Réseau and Rail Logistics Europe, an entity grouping its rail freight units, have deployed the DACE system (Detectors for Axle Load Anomalies). This checks the load on trains as they pass through sensors and detects and identifies wheel defects.
The system works on all types of trains but is particularly useful on freight trains, which are more likely to have problems with overloading, unbalanced loads, or wheel defects.
In France, about 13 % of total rail traffic is freight. As an infrastructure manager, SNCF Réseau needs to monitor the condition of the trains. A train that is not in good condition can not only damage the tracks on which it runs but, in the most serious cases, also cause an accident. For safety reasons, it is also necessary to monitor the loading of trains, for example, to check that the vehicles are not unbalanced.
To detect non-compliant trains, SNCF Réseau has installed a measuring station consisting of six sensors fixed under the rail base along a seven-meter-long track. The sensors, made up of fibre optics, detect rail deformations as the train runs and thus determine the conformity of the train based on the load and condition of each wheel.
The data transmitted when the train passes allows the relevant railway company, whose rolling stock is equipped with RFID (Radio Frequency Identification) tags, to react to possible defects. A train found to be seriously defective will be stopped on the siding for safety reasons in order not to risk further damage to the network or rolling stock and to prevent incidents that could weaken railway safety.
"The aim is not to upset the rail companies but to achieve a win-win situation. If the trains are in good condition, it's a win-win situation for carriers and infrastructure managers," explained Stéphanie Günther, train monitoring project manager at SNCF Réseau.
The main goal is to work with the carriers to avoid potential train outages through early warnings from DACE and predictive maintenance. In this way, SNCF Réseau wants to warn its freight customers well in advance of the occurrence of certain minor defects on the vehicle so that they can be correct in advance and thus contribute to preserving the integrity of the network.