Open Cut » Health and Safety
Tyre, rims and wheel assemblies are safety critical items which must be maintained and operated correctly to provide a safe working environment.
Unfortunately less than adequate (LTA) awareness of ‘off the road’ (OTR) tyre and rim related hazards, and lack of application of correct and proven approaches to deal with these hazards, in both the maintenance and operations areas continue to cause tyre and rim related accidents and incidents across the industry, some of them fatal.
This review has shown that OTR tyre maintenance and service work in particular is a high risk activity as it involves working with a number of high potential energy and hazard sources. At the immediate work interface, tyre maintenance by its nature requires the tyre serviceman to use compressed air to inflate tyre assemblies, use heavy manual and hydraulic tooling such as very large vehicle jacks and various other equipment, often air over hydraulic to break apart wheel assemblies and utilise bulky tyre handlers to manipulate the very large and heavy earthmover tyres and rims, to mention a few hazards that have played part in the causation of many incidents and accidents. Inflated tyre assemblies both off and on vehicles pose another important set of hazards.
One of the key differences between passenger and highway transport industry tyre maintenance, and maintenance required for OTR tyre assemblies, apart from physical differences, is that OTR tyre and rim assemblies are in the most part ‘multi component’ assemblies. As such they consist of the tyre, a rim or wheel base and its components -flange rings, bead seat band, O-ring, and lockring, while passenger and non OTR tyre assemblies are single piece, i.e. consist of a tyre mounted to a single piece rim. Attachment of the OTR assembly to the vehicle is either achieved through wheel nuts/studs for tyre/wheel assemblies, or cleat type/wedges/ wheel nut systems for rim/ tyre assemblies. OTR rim manufacturers offer several designs all of which, as a critical attribute rely on the correct selection/ matching, fitment of all components and inflation to considerably higher inflation pressures compared to passenger tyres, to deliver the overall integrity of the assembly ‘system’.
Given the criticality of correct fitment, and the much higher inflation pressures, working with OTR rim/wheel assembly systems carries much higher risks than working with passenger and
truck tyres where risks have largely been ‘designed out’ through the ongoing evolution and improvement to large volume production passenger and trucking vehicles .
Examination of the data and actual or potential injury outcome suggests that OTR tyre and rim related work results in a disproportionately high incidence, larger than 80%, of fatal or potential fatal outcomes for the personnel involved requiring strict controls at the management and team level, and by the individual carrying out the task.
The risk of sustaining severe or fatal injuries is further amplified in that any damage to OTR tyres and rims can often not be readily identified, which if not observed/corrected, will result in a safety issue. Risks here do not only expose tyre maintenance personnel, but also operations personnel. Operation of a mining vehicle with incorrectly fitted or damaged OTR tyres and rims, and operations outside the tyres design operating envelope is extremely hazardous and will continue to cause incidents and high consequence accidents.
This review has shown that 51% of incidents and accidents occur during, or are based in ‘LTA tyre and rim related maintenance’, followed by ‘LTA awareness, competence and behaviour’ (17%), ‘LTA operations, crisis and emergency management’ (each contributing 8%), and ‘LTA design, construction and commissioning’ (7%).
Based on these statistics, a number of recommendations are offered which, if implemented, should assist in making working with tyre and rim assemblies safer.