Coal Inspectorate | Bulletin | No.220 V 1 | 03 May 2024

Continuous miner cutter head stop-pin ejects and hits a nearby coal mine worker

What happened?

In the last 12 months there have been three high potential incidents at underground coal mines in Queensland involving the ejection of a cutter head stop pin from a continuous miner.

• In the first instance the coal mine worker (CMW) was struck directly in the chest.
• In the second instance the CMW was struck on the left elbow.
• In the third instance the head stop pin was ejected and hit the rib.

In the incidents involving personal injury the CMWs were transported to hospital. Medical examination indicated severe bruising but no long-term injury.

These incidents are concerning because while there were no long-term injuries, there was the potential for a fatality.

How did it happen?

The three specific incident reports indicate a variety of factors were at play. In each case the continuous miner was stopped for maintenance. The cutter head of the miner needed to rest on the head stops before maintenance could be carried out. It was found that the safety pin had not been inserted all the way and the weight of the cutter head was acting on the tapered area of the pin. This resulted in the ejection of the pin.

Key issues

• In some instances, both left and right-side head stop pins were not fitted before lowering the head, only one pin was fitted on one side.
• The head stop-pins were not pushed fully into the correct position.
• In one case the head stop-pin was bent and would not go all the way through.
• In one case the locking pin safety tabs were missing.
• Excessive hydraulic force used to power the boom down onto the clevis pins resulted in bending of the head stop pins.

Recommendations

Develop and implement a procedure in consultation with the Original Equipment Manufacturer (OEM) for installing and using the boom stop pins:

• Consider requirement from OEM technical service manuals.
  • Ensure procedures require both head stop pins be fitted.
  • Ensure risk management tools are used and exclusion zones have been considered.
  • Include recommendation and specific detail regarding the use, or non-use, of retaining plates.
  • Consider using longer pins with OEM consultation.
  • Ensure both pins are pushed all the way through when used.
  • Slowly lower the cutter boom onto the stops, do not shear down heavily.
• Review existing OEM face equipment safety notices to ensure that any recommendations are included in safety & health management system and maintenance system.
• Ensure suitable boom safety stop clevis inspections are included in plant inspections.

References and further information

JoyGlobal Safety Notice Bulletin No. GSN0095. Released 19 December 2014.