Open Cut » Health and Safety
For many Coal Mining operators, back injury now accounts for more OH&S claims than any other single factor. While back injury can arise from many factors, a well-documented leading cause is the exposure of workers to vibration, e.g. the vibrations experienced by operators of heavy mining surface vehicles and underground transport (and other) vehicles. Both long-term exposure to continuous vibrations and high-amplitude shock vibrations can contribute to serious back injury.
Present practice ...
Australian Standard AS 2670.1 (1990), and its British counterpart, BS 6841 (1987), contain guidelines for evaluating workers exposure to WBV.
The methodology is reasonably complex and requires a Vibration Specialist to measure vibration levels on the vehicle in the field during normal work cycles and analyse the data in accordance with the standards. This process is time-consuming and relatively costly, especially for mines with a large fleet of vehicles.
Thus when exposure to high vibration is reported, it is not unusual for mine operators to conduct a one-off test and limit the testing to just the worst vehicles, usually one or two.
In reality however, ride quality is influenced by several factors which are prone to change with time (terrain condition, condition of vehicle suspension, condition of seat suspension, weather conditions - in wet conditions dirt roads tend to develop bigger and more pot holes, etc.).
Therefore the whole fleet of vehicles would need to be tested relatively frequently for an acceptable ride quality to be maintained.
The Solution ...
The primary aim of ACARP Project C6008 was to develop a prototype Whole Body Vibration (WBV) Dosimeter capable of measuring, computing and logging, while in the field and without expert assistance, the exposure to vehicle vibration of workers in the Coal Mining Industry in accordance with Australian and British Standards.
Prior to the development of the proposed instrument, a review of currently available and relevant equipment was carried out. The findings of this review were documented in an earlier report (VIPAC report No. 24733-001R.doc, July 1997) and confirmed that none of the existing devices was suitable for the application or amenable to be re-configured simply.
After nearly 12 months of R&D effort, a prototype instrument has been designed, built and successfully tested and without compromising any of the original objectives set out at the beginning of the project.
In addition to the fulfillment of the primary aim of this project outlined above, the prototype possess a range of unique features which include the following ...
- it is extremely compact. The computing unit is enclosed in an enclosure 140x140x140 mm and can be mounted on a vehicle dashboard. This feature is highly useful as cabin space in mining vehicles is very restricted in general.
- it can accept power from a vehicle battery allowing uninterrupted operation during shifts. This feature also relieves the operator from the task of checking and replacing or recharging the instrument's battery.
- it is fully software programmable. Hence, any changes or additions to current standards can be implemented very quickly and at low cost.
- it allows a serial interface to an external PC for data management by an OH&S Unit.
Finally, the developed WBV Dosimeter has applications beyond the Coal Mining Industry, including the Transport Industry in general (road and rail), the Construction Industry, the Army, etc.