Safety alert issued over live powerline incidents

SafeWork SA recently issued a safety alert following incidents in which machinery has hit live powerlines or scaffolds being built within safe clearance distances.

SafeWork SA has received ten notifications so far this year after scaffolds or plant encroached safe clearance distances to underground or overhead utilities.

While no serious injuries were sustained in any of the incidents, they all had the potential to cause serious injury or death.

The notifiable dangerous incidents included:

  • A crane hit a high voltage powerline on 21 June.
  • A 95-tonne all-terrain crane made contact with an overhead powerline while lifting rainwater tanks on 22 January.
  • An excavator bringing down powerlines on 21 March and 3 June.
  • An excavator conducting earthworks striking overhead powerlines on 11 April.
  • An underground high-voltage wire exploded after being struck by an excavator on 12 April.
  • An excavator damaging a low voltage powerline after striking it on 12 April.
  • A concrete placing boom brought down powerlines at a residential construction site on 24 April.

There were also several incidents where scaffolds or plant were stationed dangerously close to powerlines. These incidents included:

  •  An electrical service line ran through a scaffold that was only about 1m from a powerline.
  • A scaffold was erected 3 metres from an overhead powerline, resulting in the immediate suspension of the scaffolder’s high-risk work licence.
  • A truck crane parked directly under a powerline at a residential construction site.

SafeWork SA has also been notified by South Australian Power Networks (SAPN) on three occasions this year that demolition has commenced without the disconnection and abolishment of the electricity supply.

Safe approach limits differ for people, machinery and structures, according to the alert, which said these distances vary between one and six metres depending on the voltage of the powerline.

Before carrying out work, a worksite inspection should be conducted to identify potential hazards including the presence of energised powerlines or associated electrical equipment that may pose a risk.

The most effective way to eliminate any risk of electric shock is by turning off the power. Options for de-energising or re-routing the electricity supply must be considered before commencing work.

De-energising or re-routing discussions should begin with SAPN as quickly as possible as it can take some time to arrange. This includes complying with any SAPN requirements under relevant electrical safety legislation.

“If eliminating the risk is not reasonably practicable, you must consider using substitution, isolation or engineering controls, or a combination of these control measures, to minimise the risk,” said the alert, which noted that this may include:

  • Substituting or replacing a hazard or hazardous work practice with a safer one, for example using non-conductive tools designed to reduce the possibility of direct contact with powerlines.
  • Separating the hazard or hazardous work practice from people by erecting non-conductive physical barriers to prevent plant or equipment, a person or anything held by or attached to a person, from entering an unsafe distance.

The alert also said to make hazards more visible by:

  •  Using warning signs to indicate the location of overhead powerlines and defined work areas.
  • Arranging for SAPN to identify exposed energised low voltage conductors (up to and including 1000 volts) and fitting them with approved visual indicators like sheeting or sleeves such as tiger tails.