NOISE: Baden Württemberg-based software specialist SoundPLAN has developed a noise mapping tool intended to help railways better understand and mitigate lineside noise emissions.
This takes information on the types of rail and rolling stock on a given route, as well as operating parameters including train frequency, size and speed. It then produces graphical representations of noise emissions using colours to depict different impacts.
The results cover two main outputs: an emissions value and a propagation calculation. The software features a library into which operating data can be added; noise emission levels are calculated for the hourly equivalent sound level and can also be assessed for maximum noise level. Sound power or sound pressure levels can be also calculated at a given reference distance from the rail and at different points along the line, accounting for changes in traffic or rail type.
The noise propagation calculation can be performed for single receivers or by producing different types of maps including grid, façade, triangulated, or horizontal. Results can be incorporated into documentation, spreadsheets and in the sound map graphics. Noise levels can be modelled at a range of locations and from multiple sources; for new line construction or major rebuilding work, these assessments can be performed at the design stage.
According to the supplier, the software has greater functionality than conventional measuring techniques, which usually only allow noise to be recorded as it occurs at a specific geographic point. The SoundPLAN maps are able to identify individual sources of that noise and the direction it is travelling.