Underground » Health and Safety
The primary aim of this project was to develop a Free Steered Vehicle Vibration Assessment Procedure relevant to assessing and managing the susceptibility of Coal Mining Industry workers to back injury.
For many Coal Mining operators, back injury accounts for more OH&S claims than any other single factor. One factor which has been identified as a leading cause is the exposure of a worker to vehicle vibration.
The Australian Standard for evaluating human exposure to vibration, AS 2670.1 (1990), and its British counterpart, BS 6481 (1987), contain guidelines for evaluating continuous vibration exposure but do not give explicit rules for assessing the influence of high amplitude or shock loads and hence the acceptability or otherwise of the vibrations to which an individual may be exposed.
In other words, the Industry lacks a consistent evaluation procedure to judge individual vehicles with respect to their WBV characteristics.
Following suggestions made by interested parties within the Industry, including members of the N.S.W. Department of Mineral Resources Committee for Operator Compartment Design for Free-Steered Vehicles and using our own testing experiences with underground vehicles, VIPAC proposed to develop an FSV Assessment Procedure which would be used to assess a vehicle's vibration and related comfort characteristics via a Vibration Standardised Test Index (VSTI) which relates road roughness to vehicle vibration.
The objectives of the project were thus to develop and formalise the proposed FSV Assessment Procedure and associated "VSTI":
- Develop and show that the proposed "VSTI" correlates well with vibration characteristics measured in actual underground conditions via measured AS 2670.1 FDP limits and BS 6481 VDV levels.
- Measure road roughness and its variability and relate road roughness to the proposed VSTI and hence to vehicle speed for particular vehicles.
- Develop an above-ground Standardised Test to determine a "model" VSTI, using simulated artificial obstacles on a model test track.
- Establish a Specification for the test and assessment procedure, i.e. test track and obstacle(s) definition etc.
At initial meetings held between Vipac, the Industry Monitor and AMIRA's representative, the project objectives were altered with primary emphasis placed upon the measurement of road profile at certain minimum specified speeds. In particular, it was made a condition of the project that we should develop a system capable of measuring road roughness and Whole Body Vibration concurrently at vehicle speeds up to 25-40 kph. It was also made on condition that none of the other originally proposed project tasks would be allowed to proceed until we produced a system that could measure road profile at specified speeds and within a specified accuracy.
The above requirements implied that a dynamic road profiler suitable for use underground needed to be obtained.
An extensive literature search on road profile measurement related work was carried out. It was found that no existing road profiling devices were suitable for use underground. This left Vipac with the demanding task of developing a system from the ground up within the budget and time frame initially allocated to the project.
Due to technical issues associated with the difficulty of measuring road profile on rough unpaved roads, the development phase of a dynamic road profiler spanned a period of about seven months.
At that point, it became evident that we were not going to be able to achieve the project objectives within the original schedule.
Vipac then presented ACARP, via the Industry Monitor and AMIRA, with a range of options for future direction of the project, clearly highlighting the issues and risks involved in bringing the project to a successful end.
At this point, the Project's Industry Monitor recommended the project be abandoned. ACARP opted therefore to terminate the project at this point.
The purpose of this Report is to document all work and activities carried out for this project to date.
The decision taken on recommendation by the Project's Industry Monitor to abandon the project was ... "on the basis that the required scope of work did not appear to be achievable within the time and budgetary framework of the project and that part completion of the scope of work will be of no reasonable benefit".
Conclusions & Recommendations
Vipac is still of the opinion that there is a pressing industry need for a consistent evaluation procedure to judge individual vehicles with respect to their WBV characteristics, both from the Mine Operators point of view and equally from the Vehicle Manufacturers' point of view.
Vipac believes that the original objectives of the project would have fulfilled this aim. Consequently, they are currently pursuing these goals with interested parties and hope that, within a reasonable period of time, they will be able to develop an evaluation procedure suitable for industry needs and, at a practical level, one which can be used by manufacturers with readily available instrumentation and analysis tools.