Investigation of the Vibroacoustic Climate Inside the Buses MAN SG242 Used in Public Transport Systems

Abstract

A driver of a municipal transport bus is more liable to vibration-acoustic stimuli connected with the movement of the vehicle than a passenger. In literature on the subject noise and vibration exposures are categorised into passive (whereby passengers are exposed) and active (driver’s or machine operator’s exposure). Despite new technological solutions and attempts to improve the working conditions during the operation of vehicles, city bus drivers are still exposed to negative impacts of noise and vibrations, causing stress, increased fatigue and lead to numerous diseases. It is required, therefore, that the working conditions for drivers should be monitored on a regular basis. In order that they work safely, their working conditions should be as comfortable as possible, in terms of physical and psychical conditions and free from any nuisance. Therefore it seems merited to investigate the acoustic climate (i.e. acoustic phenomena caused by the sources of noise of vibrations in the function of time and space) and the working conditions during the operation of MAN SG242 vehicles, widely used in public transport systems. The following conclusions can be formulated (based on the conducted tests): the highest eective weighted values of vibration acceleration aw;eq (0:823 m/s 2 ) (exceedance of the legitimate value) were noted in the passengers’ compartment in the middles of the vehicle, the lowest- in the driver’s cabin (0.411 m/s 2 ). In the driver’s cabin, the peak noise level LCpeak = 138:7 dB was exceeded; as the 1/3 octave analyses show, in the driver’s cabin dominates low-frequency noise with the frequency from 10 to 25 Hz and the acoustic pressure level of about 90 dB (G). The research has been conducted within the framework of the author’s research no 10.10.130.140 and the statuary ones no 11.11.130.119.