PM emissions from railways – Results of tests on a wheel-rail test bench

The sources of non-exhaust emissions from railways have been identified in the past. However, the quantification of the emission from railways is subject to a large degree of uncertainties, as published emission factors vary by orders of magnitude. The presented study aims a detailed quantification of the wheel-rail contact. For this reason, a series of tests at a wheel-rail test bench was conducted. The emission monitoring covered particle mass, particle size distribution and filter sampling in order to enable a chemical analysis of the particle composition. According to the test results the cumulative PM10 emissions of the wheel-rail contact (entire train) range from 0.33 to 5.57 g/km. The average proportions of PM2.5 and PM1 in the PM10 emissions were 87.5% and 68.46% respectively. While in straight-line driving and in wide curves the number of axles is the most dominant parameter, in tight curves, the bogie length becomes more relevant.