In July 2015, a grader was working in good conditions, near the entrance of an active waste dump, grading into oncoming traffic. As a haul truck drove up the pit ramp and turned off onto the dump’s haul road, the truck’s driver failed to see the operating grader.
In an effort to avoid a collision, the grader operator moved out of the anticipated path of the oncoming haul truck and stopped. However, the haul truck continued along the haul road, colliding with the left side of the grader.
The haul truck driver did not see the grader until after the collision. Fortunately, no one was injured.
Direct causes
The driver of the haul truck did not see the grader.
Contributory causes
- The gradient of the pit ramp, the sharp corner at the dump entrance, the windrow height and a blind spot created by the cab’s pillar and doorframe limited the haul truck driver’s visibility.
- There was no communication between personnel:
- the grader operator did not use the two-way radio to inform haul truck drivers of the grading activity at the entrance to the dump’s haul road
- the proposed grading work was not discussed at the pre-start meeting.
- The grader was operating opposite to traffic flow, near the dump entrance, without physical controls in place (e.g. warning signs, temporary hazard controls).
- Workers and supervisors failed to recognise and manage the risks associated with mobile plant interaction (e.g. no risk assessment).
- Due to noise in the cab (i.e. radio and two-way radio), the haul truck driver did not hear the vehicle proximity alarm, which sounded for 9 seconds before the collision.
- The condition of the dump area was such that it required constant grading, increasing the interaction with haul trucks.