Alert no. 481 | 13 July 2026 | Version 1

Dead-man control defeated on QDS bolter

What happened?

• During a pre-start inspection of a QDS bolter, an operator identified a plastic zip-tie restraining a dead-man lever in the 'on' position.
• Safety critical hold-to-run controls must not be restrained, bypassed or defeated, and their correct operation must be verified before the plant is used.
• The machine was stood down and moved to a safe location for investigation. The investigation is ongoing.

How did it happen?

During a pre-start inspection at an underground coal mine, an operator identified a plastic zip-tie restraining the dead-man lever of a QDS bolter in the 'on' position.

The zip-tie bypassed the intended two-handed operating safety measure and could allow hydraulic functions without continuous engagement of the dead-man control. This risks accidental activation and could expose people near the machine to crush, entanglement and struck-by hazards, with the potential for serious injury or death.

The machine was immediately stood down, the district ERZ controller was notified, and the bolter was moved to a safe location for further examination. No injury was reported. The event was notified to RSHQ as a high potential incident.

The investigation is ongoing and, at the time of publication, has not established who installed the zip-tie or when it was installed.

Figure 1 - QDS bolter control station showing the zip-tie restraining the dead-man lever.

Figure 2 - QDS bolter involved in the incident.

Recommendations

• Machinery should only be operated as intended and in line with established site procedures.
• Do not alter a safety-critical control, except through the mine’s formal plant-modification and change-management process. This should include risk assessment, competent engineering or designer input, authorisation, documentation and functional testing before the plant is returned to service.
• Site senior executives (SSEs) should ensure QDS bolters and similar hydraulically operated plant are inspected for any device or arrangement that restrains, bypasses or defeats a dead-man, hold-to-run, or other control.
• Ensure pre-start inspections include a functional test that checks if safety-critical controls are working and respond as expected, including stopping or preventing further actuation of the relevant hazardous function.
• A visual inspection alone may not identify a defeated or ineffective controls.
• Confirm that releasing the dead-man or hold-to-run control causes the machine to respond as designed, including stopping or preventing further actuation of the relevant hazardous function.
• Restrained, bypassed, damaged or non-functioning safety-critical controls should be treated as serious defects. Stand the plant down and apply the mine’s defect-management, isolation and tagging procedures. Preserve the condition of the plant and notify the relevant supervisor or ERZ controller so the circumstances can be investigated.
• Supervisors should periodically verify the quality of pre-start inspections and reinforce that safety controls must not be defeated for operational convenience.
• Inspect similar plant and review recent pre-start, defect and maintenance records for evidence of repeated defects, unauthorised alterations or ineffective functional checks.

References and further information

• Coal Mining Safety and Health Act 1999 - sections 29–31, 39, 39A, 41 and 42
• Coal Mining Safety and Health Regulation 2017 -  sections 68, 71, 73, 78 and 80
• Recognised Standard 23: Fluid Power Safety in Coal Mines — sections 8.7, 11.3, 11.4, 12.1 and 13
• Mines Safety Bulletin 189: Bypassed methane detector on explosion-protected diesel engines