Predictions of external noise generated by rail vehicles for the layout of noise abatement measures for transit systems

For predicting sound emissions of rail vehicles, transit systems and industrial facilities noise calculation programs are already in use for many years. Relying on standardised models the sound pressure levels of the impacting noise can be obtained in relation to the distance of the sound source. These calculation programs for instance are employed for noise map calculations as a part of noise protection schemes within urban planning projects.

For predicting the external noise generated by rail vehicles PROSE recently uses the new “CadnaA” program by Datakustik. This program does not only allow the virtual arrangement of different sound sources along the vehicle’s shape, but also maps the ambience conditions of the noise tests considering the effects of sound reflection and absorption.

The noise emission data for each of the sound sources either are provided by the vehicle manufacturer or are generated by PROSE based on their long lasting experience in this area and also on the use of the well-known “sonRAIL” tool. Thus noise emission values for rail vehicles can be calculated according to EN ISO 3095 in relation to the requested mode of pass-by and standstill operation.

Apart from the reference track sites according to TSI Noise also any other kind of environment can be investigated , e.g. inner city surroundings in the case of LRV or Tram systems, operation on bridges, on elevated track, along sound barriers, or in the vicinity of marshalling yards.

In addition PROSE can process complete noise maps employing the “CadnaA” program. These maps comply with the EU environmental noise directive 2002/49/EG or with the corresponding national regulations for rail infrastructure.