Open Cut » Health and Safety
The objective of this project was to examine two methods for improving the safety of handling large mining tyres using tyre handlers. These two high risk issues identified are, security of the tyre while being manoeuvred, and the interaction between personnel and the handler while aligning the tyre for mounting.
The issues involved with handling tyres are due to the conflicting nature of providing adequate mechanism for gripping the tyres without making the grips themselves too big so as to interfere with the tyre handling process. The grips have tended to be as small as possible in an aim to provide clearance to the structures located on the side of the vehicles. Tyre locations on vehicles tend to be surrounded with mud guards, tanks or similar.
The new grab design was developed so that the tyre is supported both above and below the tyre centre line. The profile of the grab is designed so that any slippage of the tyre results in the tyre wedging itself and therefore provides more grip and so is less reliant on the clamping forces to restrain the tyre, especially in wet conditions.
The nature of handling tyres while mounting them onto vehicles results in a workshop environment where the vehicle has reduced visibility to the front, but is required to work in close proximity with personnel. This is especially the case when the tyre has to be mounted back onto its rim or wheel hub. In this case the operator has to align a small target (wheel studs) with the tyre hub from a relatively large distance. To compound the problem the area of operation is not always in the best position as his line of site can be obscured by the tyre handling apparatus.
The use of a camera system was trialled so as to provide the operator with a better visibility in this area. The use of a target system with the video monitor was also trialled so that the operator could align the centre of the tyre with the rotation axis of the grab. This would allow the operator to position the tyre to give the optimum position before rotating the tyre into alignment with the studs or hub.