Coal Inspectorate | Alert | No.460 V 1 | 07 October 2025

Bulldozer enters coal valve void

Summary

• While pushing out coal on a stockpile at a mine site, a bulldozer entered an open coal valve void.
• Luckily, the worker involved was not injured.
• A video of the incident as well as learnings are outlined below.

Issue Explained

• A high potential incident (HPI) occurred recently when a bulldozer was pushing out coal on a stockpile.
• The bulldozer operator drove over the coal valve and, when reversing, the void opened, and the bulldozer entered it in an uncontrolled manner.
• Appropriate controls for operating mobile equipment like bulldozers on stockpiles were the subject of a directive issued to mine operators by RSHQ in February 2023.
  • The directive (summarised in learnings below) followed a series of similar incidents where mobile equipment operated by workers sunk into voids that had developed in stockpiles.

Learnings

• Footage obtained by the mine in its investigation of the incident highlights the significance of the risk relating to this activity.
• Sites should review the directive issued directly to coal mines on 6 February 2023 and ensure their current system for managing risk associated with stockpile operations complies with the requirements in the directive and can ensure workers are not exposed to an unacceptable level of risk.
• In summary, remote controlled equipment offers the highest level of protection, eliminating the need for workers to be on the stockpile at all. Where coal mine workers are required to operate equipment on the stockpile, measures should be in place to ensure:
  • Equipment is fit for purpose and, as a minimum, is fitted with an oxygen self-rescuer to be used in the event of engulfment of the equipment for the duration of the recovery, and a fully enclosed cab that can withstand engulfment, protecting the operator within the equipment in all orientations.
  • Systems allow operators to have continuing awareness of their location – for example by fitting equipment with GPS and associated monitoring. Areas of high risk, such as in the influence of the conveyor feed valves, should be clearly identified as an exclusion zone on the monitoring equipment with visual and audible alarms, where the machine enters the zone.
  • The mine communication system always remains effective during stockpile operations.
  • The mine’s safety and health management system requires stockpile operations to cease in the event of the GPS and monitoring system on the equipment becoming ineffective.
  • Operators of equipment are trained and competent in all aspects of the mine’s safety and health management system as it relates to stockpile activities.
  • The mine has a system that manages movement of mobile equipment and personnel on coal stockpiles.
    • This should include site hazard management plans including controls, fit-for-purpose equipment and trained workers - see MDG 28, the Safety requirements for coal stockpiles and reclaim tunnels, for more detail.
  • Mines rescue capacity and capability is always maintained at the mine when these activities are being undertaken.

References and further information

• Reference the Coal Mining Safety and Health Act 1999, including:
  • Section 17 - Meaning of high potential incident – A "high potential incident" at a coal mine is an event, or a series of events, that causes or has the potential to cause a significant adverse effect on the safety or health of a person.
  • Part 2 The control and management of risk and other basic concepts under Division 1 Control and management of risk:
  • Section 29 - What is an acceptable level of risk
  • Section 30 - How is an acceptable level of risk achieved
  • Section 31 - What happens if the level of risk is unacceptable
  • MDG 28 - Safety requirements for coal stockpiles and reclaim tunnels.