Metal shard projectile from excavator track sprocket

Mines safety alert no. Newsflash | 12 June 2020 | Version 1

What happened?

Following an undercarriage track change on an excavator, a metal shard (refer Figure 1) was ejected from the track sprocket. The metal shard travelled 35 meters breaking a side window and entering the cabin of a parked service truck (refer Figure 2).

In this incident, the metal shard ejected in line with the track frame, however, metal shards may be ejected at any angle from the tracks. Whilst no injuries were reported on this occasion, coal mine workers have suffered serious injuries from flying metal shards in cases reported to the Mines Inspectorate. The track sprocket was a refurbished sprocket and not an original OEM sprocket.

How did it happen?


Key issues


Site Senior Executives should;

  • Ensure that OEMs or service providers provide all replacement components that are fit for purpose. This includes confirmation and documentation of component refurbishment processes, quality control checks and engineering certification of components including tracks sprockets and idlers.
  • Review risk assessments for track maintenance and consider enforcing a 360-degree exclusion zone around excavators when track maintenance is in progress. In particular, consider the radius of the exclusion zone.
  • Ensure that suitable ballistic protective equipment is available to spotters required by maintenance procedures.
  • Consult with the OEMs or service providers to ensure that the correct track maintenance procedures are available.
Investigations are ongoing and further information may be published as it becomes available. The information contained in this publication is based on knowledge and understanding at the time of writing.

References and further information

Authorised by Peter Newman - Chief Inspector of Coal Mines
Contact: , +61 7 3199 8001

Issued by Resources Safety & Health Queensland

Safety: This information is a guide only and is issued to promote safety through experience. It is not to be taken as a statement of law and must not be construed to waive or modify any legal obligation.; General: This information is a guide only. It is not to be taken as a statement of law and must not be construed to waive or modify any legal obligation.; Placement: Place this announcement on noticeboards and ensure all relevant people in your organisation receive a copy.

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