Mineral Mines & Quarries Inspectorate | Alert | No.385 V 1 | 09 February 2021
Rockfall injures jumbo operator
What happened?
Recently a jumbo operator suffered a serious injury (broken rib) when he was struck by a rock that fell from the back (roof) of unsupported ground of an incline. The rock was deflected by partially installed steel mesh back into and beneath supported ground where he was inspecting a hydraulic leak on one of the booms of the jumbo.
Figure 1 shows a schematic diagram of the layout of the scene of the incident, showing the approximate trajectory of the rock.
How did it happen?
The jumbo operator was installing the first sheet of mesh in the back of the incline when he noticed a hydraulic leak on the right-hand boom requiring inspection to repair the leak.
The operator retracted both booms so they were positioned just inside and beneath the last row of fully installed splitsets and mesh. A rock dislodged from the back, slid down over the partially secured sheet of mesh, struck the raised left-hand boom and deflected to the ground, striking the operator on the back of his shoulder.
Key issues
- The positioning of heavy mobile equipment being prepared for maintenance activity in relation to nearby unsupported ground.
- Insufficient separation between the edge of fully supported ground and support being installed on the incline to allow for trajectory of potential rockfall into supported ground that is assumed safe.
Recommendations
Prior to servicing, inspecting or maintaining plant underground, the plant must be withdrawn to a safe location under supported ground. The distance of withdrawal from unsupported ground should be defined in the plant's operating procedure.
Workers carrying out ground support activities in front of the operator's cabin should be trained how to 'read the ground' and always be vigilant for rockfall hazards from any nearby unsupported ground.
Investigations are ongoing and further information may be published as it becomes available. The information in this publication is what is known at the time of writing.
We issue Safety Notices to draw attention to the occurrence of a serious incident, raise awareness of risks, and prompt assessment of your existing controls.
References and further information
Mining and Quarrying Safety and Health Regulation 2017, Chapter 2 - Ways of achieving an acceptable level of risk, s44 Ground Control [in particular s44(2)(b) and (c) and s44(3)(c) and (d)].
Guidance Note QGN13 - Safe Work near Drawpoints in Underground Metalliferous Mines*
*Special case, see schematic below (Figure 1)
Contact: Trevor Brown, Deputy Chief Inspector of Mineral Mines and Quarries , +61 7 4447 9253 QldMinesInspectorate@rshq.qld.gov.au
Issued by Resources Safety & Health Queensland
Placement: Place this announcement on noticeboards and ensure all relevant people in your organisation receive a copy, understand the content, findings and recommendations as applicable to their operation. SSEs should validate that recommendations have been implemented.
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