The Impact of Running Gear Design and Its Position Within the Car Body on Comfort and Suitability as a Night Train—Part 2

The renaissance of night trains and the growing interest in high-speed night services raise the question of which vehicle concepts offer the acoustic conditions required for restful sleep on board. This study therefore examines the interior noise of passenger trains with a view to their suitability for night-train operation, focusing on the influence of the running gear concept and of the measurement position within the car body. In-service measurements were carried out on regional, long-distance and high-speed trains equipped with conventional bogies, Jacobs bogies and single-wheel running gear, including single- and double-deck configurations. A-weighted equivalent continuous sound pressure levels were recorded above the front bogie, in the centre of the carriage and above the rear bogie, following the principles of ISO 3381 as far as ongoing commercial operation permits. Sound levels rise with increasing speed at roughly 0.5 dB per 10km/h in regional and long-distance service, with a markedly flatter increase above 250km/h. The centre of the carriage tends to be the quietest position, whereas the area above the rear bogie is generally the loudest. No systematic acoustic advantage of Jacobs bogies over conventional bogies could be demonstrated from the available measurements. As all data were recorded in regular commercial service, the levels reported here should be understood as comparative real-operation values rather than as standardised certification measurements.