Coal Inspectorate | Alert | No.407 V 1 | 06 May 2022

Near miss - blasthole drill rig trammed onto the highwall protection berm

What happened?

A near miss occurred when a coal mine worker was operating a DK90 rotary blasthole drill rig during nightshift. When relocating to the next hole position, the trainee operator trammed the rig onto the highwall edge protection berm. By the time the operator has stopped tramming, the nose of the tracks had reached the top of the berm and the operator's cab was likely suspended past the edge of the highwall.

Key issues

• The rig was directly perpendicular on its approach to the highwall berm without considering the edge of the berm.
• The shape and material of the highwall berm allowed the tracks to readily climb through it.

Recommendations

• Review the adequacy of high wall demarcation on high wall benches.
• Drillers should inspect their work area (drill pattern) to identify high-risk areas and safe paths of travel between holes; acknowledging drill cab, mast and highwall positions.
• Drilling operations near high/low/end walls should be conducted during daylight hours as far as reasonably practicable, with appropriate rigour within risk assessment and planning activities for the management of this hazard.
• Drills should never be positioned parallel to a highwall edge.
• Potential geological/geotechnical hazards that may be present in the highwall should be identified and assessed prior to commencing drilling activities.
• Training and competence arrangements that allow trainee drillers to not work under close personal supervision should be reviewed with reference to restricting and managing high risk drilling work until competency is obtained.
• Supervision and management of trainee drillers should consider high-risk areas on the drill pattern through:
• specific task planning inclusive of the drill travel on patterns
• restricting their work activities
• implementing additional controls to manage the risk of drilling work outside of daylight hours.