Vibration transmitted by excavators and wheel loaders: assessment of the seat transmissibility

The occupational exposure to whole-body vibrations represents a primary health risk for the drivers of earth-moving machinery typically used in mining, mine reclamation and construction work. The measurements taken on a considerable number of off-road vehicles showed that the vibration transmitted through the vehicle seat usually exceeds the exposure action value established by law. The article discusses the latest development in an on-going research project which was started three years ago and involves a number of mines and mining remediation sites located in Sardinia. The results of the most recent measurements taken on a number of excavators and wheel loaders have been analysed in order to assess the dynamic response of the seat-person system; for each case under investigation the transmissibility of the seat was established by comparing the vibration signals provided by two accelerometers mounted on the seat pan and at the base of the seat.