Managing Whole Body Vibration at Surface Coal Mines

The web page ergonomics.uq.edu.au/wbv provides information about the project including a link to the free WBV application and java application tool, documentation and manual.  This will be a great benefit to the industry.

This project has validated, implemented, and evaluated the use of an iOS application (WBV) installed on iPod Touch devices as an inexpensive whole body vibration measurement device.   

Operators of earth moving equipment are exposed to vibration through the seat.  Prolonged exposure to high amplitude whole body vibration causes serious long term health effects, particularly back disorders.  Management of this hazard is difficult, in part because measurement of vibration exposure requires expensive equipment and expertise, and measurements are consequently undertaken infrequently. More frequent measurements undertaken as part of a comprehensive vibration management plan will enable the identification of effective control measures to reduce vibration exposures.

Workplace management of whole‐body vibration exposure requires systematic collection of whole-body vibration data in conjunction with the numerous variables which influence vibration amplitudes.  The cost and complexity of commercially available measurement devices is an impediment to the routine collection of such data by workplaces.  An iOS application has been developed which allows an iPod Touch to be used to measure whole‐body vibration exposures.  The accuracy of the application was demonstrated by simultaneously obtaining 98 pairs of whole‐body vibration measurements from both the iPod Touch application and a commercially available whole‐body vibration measurement device during the operation of a variety of vehicles and mobile plant in operation at a surface coal mine.  Situations in which vibration levels lay within the ISO2631.1 health guidance caution zone were accurately identified, and the qualitatively features of the frequency spectra were reproduced.  The low cost and relative simplicity of the application has potential to facilitate its use as a screening tool to identify situations in which musculoskeletal disorders may arise as a consequence of exposure to whole‐body vibration.  

Considerable variability in measurement amplitudes, even within the same equipment type operated at the same site, has been noted.  However, the measurements have previously been undertaken for relatively short durations.  Fifty-nine measurements were collected from a range of earth‐moving equipment in operation at a surface coal mine.  Measurement durations ranged from 100 minutes to 460 minutes (median = 340 minutes).  The results indicate that the measurements previously observed are not an artifact of the relatively short durations and confirm that operators of surface mining equipment are relatively frequently exposed to vertical whole‐body vibration levels which lie within, or above, the Health Guidance Caution Zone defined by ISO2631.1.   

Dozers, in particular, are sometimes associated with extreme whole‐body vibration levels.  Data gathered regarding operator experience, task and geological conditions did not allow the causes of these extreme exposure to be determined.  Subsequent measurements which included simultaneous video recording of the dozer operation failed to capture the same extreme vibration levels.  It may be that the operator's knowledge that they were being video recorded influenced their behaviour.  This, in turn, suggests that systematic observation, feedback, training and supervision may be an effective strategy to reduce the prevalence of extreme dozer vibration exposures.