OSH alert – Mini excavator tip (Feb 2015)

Key learnings from a High Potential Incident.

HPI OSH Alert #463

Date of incident: 6 January 2015

Safety Flash issued: 16 September 2015

dozertipWhat happened?

While excavating a road crossing trench, a mini excavator tracked back onto a previously excavated trench. This resulted in the excavator partially straddling the previously excavated trench.

As the excavator moved forward to re-position, the right hand track passed over the end of the road crossing trench causing the wall to collapse and the excavator to
tip over. An exclusion zone was in place and the operator remained in the excavator until it was safe to exit.

Why did this happen?

The operator rolled the excavator’s right track over the edge of the Road Crossing Trench. This action combined with unstable soil conditions and a very steep road gradient, resulted in the mini excavator rolling onto its side.

What will the business area involved in the incident do to stop this from happening again?

  • The District will create and trial (3 months) a generic JSEA for excavations with the civil team and report the effectiveness to the Region’s Lead Team.

What will our organisation do to stop this from happening again?

  • OSH Branch will develop and distribute a Notification of Change, which incorporates changes to the Excavation Standard S216, role of spotter and training.
  • OSH Branch will review and update Excavation Awareness Training accordingly to address identified deficiencies and contextualise to Water Corporation needs.
  • RCSG will develop a checklist specifically for safety observations on mechanical excavations.
  • RCSG will notify all regions of the specific JSEA requirements for tasks involving the use of mechanical excavations.


What key learnings can you discuss with your team to stop this from happening again?

  • Materials, plant and equipment to be kept a safe distance from the edge of excavations
    • What does our team consider the safe distance to be for materials, plant and equipment situated near the edge of an excavation?
    • Are there any factors that would affect the distance above? E.g. soil conditions, static versus dynamic loads.
    • What will our team do to ensure that materials, plant and equipment are kept a safe distance from the edge of an excavation?
  •  Inspection of excavation faces and soil type will determine stabilisation measures required
    • What process does our team use to plan or inspect excavations?
    • What type of excavations would our team batter, shore or bench?
    • Are there any other factors we need to consider when determining excavation stabilisation measures?
  • The risk of excavation incidents involving mobile plant can be reduced by:
    • Using a seat belt at all times during operation
    • Ensuring mini excavators with adjustable tracks always have track width fully extended during operation
    • Ensuring that an excavator is never operated or traversed across a slope
    • Not straddling or tracking over the edge of a trench or excavation
    • Lowering the dozer blade during excavation (if so equipped)
    • What excavations do we have planned in our area in the near future?
    • Do our mini excavators have adjustable track width and when are the only times that our mini excavator tracks can be retracted?
    • What safety measures does our team take when excavating with mobile plant?

Further information

If you would like further information about anything included in this HPI OSH Alert, please contact Charis Neumann, Snr OSH Analyst Incidents, (08) 6330 6629.

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