Open Cut » Health and Safety
Rim disassembly is extremely hazardous and has been the cause of several tyre fatalities. To better control this fatal hazard a mechanical interference feature, often called the Surelock3 bead seat band, was patented in 1986. This design prevents the inflation and consequential dangerous disassembly of earthmover rim and tyre assemblies should a correctly matching lock ring be incorrectly seated or fitted. Surelock style bead seat bands do provide considerable and undeniable safety advantages. The actual level of adoption remains low however, in the order of 15 to 20%, despite only marginal extra purchase costs. Their unquestionable value in preventing dangerous and fatal rim disassembly should be communicated through focussed industry-wide education, update of existing Standards, training materials and mandate by individual mining companies.
This report details discussions from a 2-day workshop held in May 2018.
As identified in a FMECA4 carried out by the workshop participants, they should not be considered a cure-all to prevent all instances of dangerous rim disassembly. Instead, Surelock style bead seat bands should be considered only part of the solution as there are other failure modes that can cause rim or wheel disassembly. Importantly their effectiveness in preventing dangerous disassembly critically depends on the selection and right fitment of correct and dimensionally matching components, particularly the lock ring into a clean lock ring groove. Other industry accepted programs such as non - destructive testing of rim components, as an indicator of rim fatigue, must continue.
In addition to a wider adoption of Surelock bead seat bands, considerable complimentary and systematic safety improvements will only be achieved by creating, implementing and maintaining an improved universal (global) marking and labelling standard. This Standard will need to ensure all earthmover rim and wheel components are marked unambiguously and allow tyre service personnel to more easily, without error, select matching rim and wheel componentry thereby maximizing the design integrity of the assembly. This initiative must be supported by OEM verified selection/matching and component reusability criteria, processes and tools that allow the tyre fitter to check all components and facilitate the verification of rim assembly integrity and safety, during assembly and prior and during initial inflation.