Onboard Load Sensor for Use in Freight Railcar Applications

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Approximately 40% of intercity freight transportation occurs by rail, making it the most widely used method of transporting large commodities. This trend is expected to persist over the next thirty years as our highway systems are strained and experiencing increased congestion and costly delays. Currently, the load of freight railcars is typically measured by weighbridges or retrofitted tracks at isolated locations. This practice is not efficient and limited by the fact that the load of the railcar cannot be monitored continuously, not to mention the inherent inaccuracies of such systems. Hence, there is great merit for an onboard load sensor that can accurately and effectively track the load of a railcar, minimizing overloading issues that can result in costly fines and damages to the rail infrastructure. The proposed onboard load sensor equipped with temperature sensing capability can also be used in bearing condition monitoring, as it will be able to identify unbalanced loading of the railcar. This paper provides proof of concept validation for an onboard railcar load sensor and presents analysis on the accuracy of two proposed correlations: one second-order model, and one multivariate model that incorporates the bearing operating temperature as read by the onboard sensor. The proposed load sensor can be readily implemented in freight railcars with minimal adjustments to the current bearing-adapter assembly. Laboratory testing is used to extrapolate different hypothetical operation scenarios that serve to demonstrate the use of this sensor in field service. The incorporation of the temperature sensors to the proposed onboard load sensing system provides added condition monitoring capability and allows for a much-improved load measurement with an accuracy of within 2% of the actual value.


© Saxe-Coburg Publications, 2017

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International Journal of Railway Technology