Detection of Brake Type and Tread Surface Quality of Passing Trains Based on Rail-Sleeper-Force Measurements

Summary

Tread surface quality and tread defects of the wheels of passing trains are the predominant influences on the noise radiated from wheels and rails. It is well known that the wheels of vehicles with cast iron tread brakes are much noisier than wheels with other brake types.

In many cases the train operator does not know which kind of brakes the vehicles of a train are equipped with. However, when analyzing trackside noise measurements it would be very helpful to have information on noise level relevant data like wheel tread state and brake type. But it is usually not possible to gather such data of arbitrary passing trains.

Recent imb-dynamik measurements with the rail-sleeper-force measurement system MONI from INNOtec Systems GmbH, Germany, have shown that this information can be gathered even for passing trains at arbitrary speed.

When evaluating simultaneous measurements of noise and rail-sleeper-force a very good correlation between tread state, rail-sleeper-force and radiated noise could be found. In addition the brake type – cast iron and K-block – could be identified by evaluating the roughness of the wheel tread. German railways DB confirmed the brake type identifications performed during the measurements so far.

Now the relationship between tread state and radiated noise can be determined even for individual wheels. It is possible to detect precisely how much noise is caused by a particular wheel tread quality or a particular tread defect.

Rail-sleeper-force measurements can be used to predict wheel-rail noise levels and to design countermeasures.