Measurement of wheel/rail contact forces, such as wheel loads and lateral forces are very important for railway safety, but it is difficult to measure them. Conventionally strain gauges attached on wheels have been used in the measurement, and slip rings or telemeters, which are difficult to handle, have been also used for the transmitter of the data. In this paper we propose a new method for measurement of contact forces between wheel and rail. The new method does not use strain gauges on wheels and complicated transmitters, but uses simple non-contact gap sensors for measuring lateral force. According to the results of full-size truck stand tests and train running tests, we have verified that the new method has sufficient accuracy of measuring compared with conventional methods.
