OSH alert – Cable contact (May 2015)

Key learnings from a High Potential Incident.

HPI OSH Alert #467

Date of incident: 12 May 2015

Safety Flash issued: 15 May 2015

467cableWhat happened?

While installing a temporary power supply connection at an existing WWPS switchboard, a contractor drilled a tek-screw into the switchboard from the outside. The tek-screw made contact with, and penetrated, a live low voltage cable. No injury was received.The damage was undetected until the next day when the switchboard was opened, and evidence of arcing was identified at the location of the damage.

Why did this happen?

  • The task had not been identified as high risk work (electrical) and the safe job planning undertaken was inadequate.
  • The task was inadequately supervised, due to an assumption that it was a low risk task and supervisors were focused on other works occurring on the site at the same time.
  • A permit to work was not raised for installing the temporary power supply, as required by the contractors OSH Management System for penetrations into surfaces where there are suspected services.
  • The Water Corporation District Electrical Technician (DET) advised the subcontracting electrician to prepare and prewire the temporary power supply. It was assumed that this did not include mounting the temporary power supply to the existing switchboard without the Water Corporation DET being present.
  • The qualified electrician carrying out the works did not have experience working on this type of asset and made an error of judgement in fastening the box to the side of the live electrical cabinet.

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

  • Embed the Clearance to Work (CTW) process to ensure:
    • Project Managers engage the authorised person to discuss and agree the required CTWs at project start-up.
    • Superintendents Representatives (Contract Managers) identify and track upcoming works requiring a CTW at progress meetings.
    • where possible, detail which parts of the work will require a CTW in the bid documents.

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

When individual contractors and/or their subcontractors are subject to disciplinary action resulting from an incident on a Corporation site, notes will be added to the individual’s HSE Contractor Induction record and the individual’s induction revoked as appropriate.


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

  • Simple tasks can include high risk activities which need robust safe job planning
    • Question one: What jobs are scheduled that will involve high risk tasks? What are the Safety Essentials requirements for these high risk activities?
    • Question two: Have we booked safety observations around these tasks? Is so, when will they happen?
    • Question three: Do we have any examples of where high risk tasks are overlooked or not adequately considered in the Safe Job Planning for the job?
  • Proper subcontractor management and/or supervision of employees is essential
    • Question one: How do we ensure adequate levels of supervision for any high risk work activities?
    • Question two: Do we have any subcontractors doing work in our area? If so, how are we ensuring that adequate supervision, safe job planning and clear communication between the contractor’s representative and Water Corporation of the works occurs?

Further information

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

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