Coal Inspectorate | Bulletin | No.222 V 1 | 27 August 2024

Uncontrolled fall of plant – Animation video

What happened?

RSHQ has noticed a pattern at Queensland coal mines where plant has fallen from support stands in an uncontrolled manner. Three reported high potential incidents are described below and in each incident no coal mine workers (CMWs) were injured. However, there was potential for serious injury or a fatality.

Incident 1

On 16 January 2024, a CAT D11T dozer was being set up on stands in the workshop using the machine hydraulic implements and jacking. While machine jacking using the blade, the dolly positioned under the right-hand rear-pivot shaft housing has dislodged causing the machine to roll backwards and off the rear stands, dropping approximately 500mm. Two CMWs who were in the process of installing support stands were in the line of fire when the dozer moved. No injuries were sustained and both CMWs walked free of the area immediately following the uncontrolled event.

Incident 2

On 19 Dec 2023, a tyre handler pushed a Hitachi EH5000 RDT off its supporting stand whilst performing a vertical mount tyre fitment on position 2. The RDT fell approximately 600mm. Two CMWs engaged in the task, one operating the tyre handler and the second on the ground approximately 6m away, out of the firing line. The incident investigation identified issues with the jacking processes used amongst other issues.

Incident 3 (animation below)

On the 6 June 2023 CMWs were using a crane to fit a handrail on a dozer in the workshop. The dozer was sitting on four stands as both track frames and one final drive had been removed from the machine. The crane operator has used the remote control upside down, inadvertently raising the crane, which has lifted the dozer off the stands on one side causing it to slide off the stands onto the workshop floor.

Based on the mine and RSHQ’s investigations, events leading up to the incident have been recreated and are available in the following video animation:

Key issues

The three specific incident investigation reports indicate a variety of factors were at play. The most common causal factors included:

Planning

• Inadequate planning and preparation for the tasks.
• Failing to refer to original equipment manufacturer (OEM) procedures.
• Correct tooling not identified in the planning or risk management process.
• Informal shift handover processes and poor communication relating to planned and unplanned tasks.

Risk assessment

• No appropriate risk-based procedures available or reviewed prior to the work commencing.
• Risk assessments completed were inadequate. OEM procedures and manuals were not consulted.
• Risk assessment review and approval processes inadequate when higher risks identified; including, inspection of task and stop points prior to sign off.
• Work group, leading hand or supervisor did not identify line of fire, live work, and suspended load hazards.

Jacks, stands and dollys

• Jacking procedures inadequate. OEM procedures not considered.
• No appropriate type of stands were in place.
• Wear to stand and load cap spigot mating faces was not identified during the hydraulic jack and stand pre-use inspection.
• Misalignment of rear stand not identified prior to the front of the machine being raised.

Supervision

• Supervision was not effective and present for assessing high risk tasks.
• Reliance on assumed previous experience and knowledge for task.
• Inadequate verification of competencies of trade certified workers.

Training

• Limited understanding by CMWs of jacks, stands, and associated components such as dollies and saddles.
• CMW was not fully conversant with the use of the overhead crane pendent remote due to infrequent use.

Recommendations

All site senior executives should conduct a review of the site SHMS processes and procedures regarding the following:

Work planning and risk management

• Ensure risk assessed work planning processes are in place and implemented.
• Ensure OEM manuals, bulletins and procedures are available and used by CMWs when planning and undertaking tasks.
• Involve OEMs in developing site-specific procedures for maintenance tasks.
• Ensure risk management tools are used and exclusion zones have been considered.

Fit-for-purpose jacks, stands, saddles and dollies

• Provide appropriate and fit for purpose tools for all maintenance tasks.
• Review the introduction to site and pre-use inspection checklists for tooling, including defining component wear limits and cleanliness standards
• Consider use of secondary stands.

Training and ongoing assessments

• Ensure processes are in place to verify competency of CMWs when appointed to undertake works and that ongoing verification of competency processes are in place.
• Refresh CMWs in the use of risk management procedures and site SHMS expectations.

Communication

• Share the animated video of the incident with all CMWs involved in jacking and lifting activities.
• Procedure including requirements for pre-use inspections for jacks and stands to be communicated to maintenance personnel.

All coal mine workers should:

• follow site risk assessment processes.
• watch and learn from the animated incident video.