Comparing On-board Vibration and Sound Measurements of Trams with Their Respective Pass-by-levels

In a first step towards mapping the sound and vibration immission produced by trams in Vienna, a trial was conducted in 2016 which saw a tram in the city´s public transport network being equipped with an on-board microphone near its unpowered bogie. The tram was previously equipped with four accelerometers on the wheel bearings of the same bogie, one accelerometer on the bogie itself and another one on the chassis. On-board data is collected with a sampling rate of 8192 Hz per accelerometer and 48 kHz for the microphone when the tram is in motion. As the instrumented car covers all of Vienna´s tram network at regular intervals, the aim of the study was to examine the correlation between the on-board records (emission) and the pass-by levels (immission) when the tram travels at different velocities. The initial setup examined the correlation along a straight section of grooved rail (gauge 1435 mm), while ongoing work aims to examine the correlation in curves and at junctions when driving over switches.