Evaluation of Transmissibility Factors of Pneumatic Dumper Seats Used in Indian Mines- A Pilot Study

Abstract

Whole-body Vibration (WBV) is a well- known occupational health hazard in mining industry. Dumper operators are subjected to WBV generated from road-tyre interaction and transmitted through the base of the seat. Dynamic characteristics of vehicle seat are vital contributing factor in determining the quality of a seat in use. The objective of this pilot study was to evaluate the transmissibility factor of pneumatic dumper seats used in an Indian mine. Total fifteen (15) dumpers of two different makes with pneumatic seats were selected for the study purpose. The tri-axial seat-pad accelerometers (SVANTEK make SV 38A) collected data in all three orthogonal axes of translational or rectilinear vibration. The mono-axial or single axis accelerometer (SVANTEK make SV 80 with mounting magnet SA 32) was simultaneously positioned rigidly on the floor to record signals in vertical direction. The data so obtained were then calculated using a vibration risk calculator in MS-EXCEL to quickly predict the health impacts using the measured vibration magnitude along with period of exposure per day. The results obtained clearly indicated that the drivers of all the fifteen (15) dumpers are at moderate risk of adverse health effects. It was clear from the SEAT factor calculated using rms and VDV values that the present seats installed in all the dumpers are not efficient and failed to attenuate the vibrations from the floor to seat and ultimately to the body of the dumper operator. It was observed that further in-depth evaluation of engineering and designing part of the seats used in these types of dumpers is desirable. The future scope of such evaluations must take into consideration the actual working condition to be able to realistically attenuate the vibrations so as to provide comfort and relief to the dump operators in mines.