The wedge failure caused some material to fall onto the main ramp.
Luckily much of that was caught by the berms and had broken up during the fall.
Nonetheless, about 2t of rock landed on the main pit ramp with some hitting the grader.
At the time of the incident the pit was closed due to heavy rain and the grader operator was working to get the mine reopened.
The grader operator was not injured.
The NSW Resources Regulator said mine operators should review the frequency of assessments of high wall stability and confirm appropriate triggers were included to increase assessments after rainfall.
Mine operators should also ensure water egress is minimised to highwall crests to reduce the potential of a failure occurring.
