AUTHORITIES are urging mine operators to review their mine safety management plans following several incidents including one that involved a fatality.
The incidents related to the failure of braking and steering systems on mobile equipment. Incidents involved mobile equipment in both above-ground and below ground applications.
According to the NSW Department of Primary Industries , in all circumstances the mobile equipment was descending a grade and then due to the failure of a safety critical system, control was lost. The backup emergency and secondary braking and steering systems were unable to prevent the mobile equipment from collision. While the majority of incidents involved off road and on road trucks, incidents also involved underground personnel carriers, load haul dump vehicles and mobile cranes. On four occasions the initiating event for the incident was a failure of the engine or transmission retarder (retard brake). On three occasions there was a mechanical or electrical component failure which initiated the event. On one occasion it appears the initiating event was the truck running out of diesel fuel.
In some incidents the truck’s service and emergency/secondary brake performance was not capable of pulling up the truck on the decline upon failure of the retarder brake. Other common factors were seat belts in conjunction with fit for purpose operator protection, prevented serious injury when worn. The investigations found that on all occasions the failure of safety critical systems from poor maintenance practices were contributing factors.
The investigation also found that on most occasions there was inadequate or no daily prestart safety checks being carried out which should have identified the defect and placed the mobile equipment out of service.
Maintenance was not being carried out by competent people familiar with the safety critical systems, and safety critical systems were not being periodically checked and tested for functionality. Also, maintenance was not being carried out in accordance with the equipment manufacturer’s recommendations, and documentation on daily safety checks, maintenance activities and defect rectification was inadequate. Manufacturer’s documentation was also inadequate to confirm the integrity of all safety critical systems.
On all mobile equipment the DPI recommended that designers, manufacturers and suppliers should review designs and documentation.