New sensor for lateral & vertical wheel-rail forces measurements

Damage accumulated in rails can lead to railway disasters. The authors propose a new sensor which is able to measure at the same time the vertical and the lateral forces applied by the wheels on the rails. The sensor is based on very well-known and absolutely reliable strain gauge techniques with simple electronics and processing procedures. The transducer is very simply mounted on the rail and any maintenance, due for example to cables torn during unwise track tamping, is possible with simple operations and does not require specifically trained personnel. When complemented with a system capable to detect the lateral position of the wheel tread relatively to the railhead, the use of such a sensor is absolutely necessary to develop rail life prediction models to prevent failures and to increase rail performance. The results coming from some applications of the sensor are shown, including considerations on the applications to damage accumulation, vehicle dynamics and general condition monitoring (axle counting, speed measurement, train identification) problems. The sensor is self-checking, opening possible applications in the signalling field.