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Tips for avoiding powerline shocks

Queensland’s Electrical Safety Office has stated that during the 2016-17 year, there were 74 accidental contact incidents with overhead powerlines in Queensland in the building, construction, and demolition industries. Of those, six were serious incidents, with eight people requiring treatment from a doctor for electrical shock or injury.

All the incidents involved contact or near contact with overhead powerlines by excavators, concrete pumping booms, concreting screed poles, ceiling battens, aluminium ladders and edge protection rails. 

“There’s no great secret here - powerlines are deadly,” said Victoria Thomson, head of Queensland’s Electrical Safety Office. “Contact doesn’t even have to be made for electricity to arc and electrocute people in the vicinity.”

On top of the real potential for serious injury or death, there are other ramifications such as time lost to projects and damage to power networks that may incur liability.

Energy Queensland believes the development and construction industries often leave it until the last minute before seeking its advice on electrical safety. This means that on many construction sites, attention doesn’t turn to overhead powerlines until the builders are on site and ready to break ground.

“That usually creates an eleventh-hour rush, with attention to detail overlooked. This approach leads to limited options for controlling risks. Often tiger tails and temporary marker flags are the only strategies used – just a visible reminder of the location of power lines,” Ms Thomson said. 

While tiger tails and temporary marker flags are relatively inexpensive and can be installed quickly, they are the lowest order control measure. They also have added safety requirements which ultimately incur added costs. Generally an observer or spotter is needed to enforce exclusion zones. The principal contractor and other contractors must develop safe work method statements (SWMS) for all work carried out on or near energised electrical installations or services, and provide induction, supervision and ongoing training for workers and other people to ensure the SWMS are implemented. These additional requirements substantially add to the cost, in time and money, of not implementing higher order control measures to minimise the risks of overhead powerlines on construction projects.

The Electrical Safety Office urges those involved in the early stages of the construction supply chain, including parties who commission structures and undertake design work, to focus on electrical safety in the design period.

Safe design means the integration of hazard identification, including electrical hazards, risk assessment and control methods, early in the design process to eliminate or minimise risks to health and safety, both during construction and over the life of the structure.  Some example of engineering solutions include:

Option

Time to deliver

Indicative costs

Switching high voltage
 

Six weeks
 

$2,000 per day
 

Installation of aerial bundled conductors (ABC)
for both high and low voltage overhead mains

 

Two months
 

1 span will cost approx. $10,000
 

De-energising the overhead low voltage service line
 

Seven days
 

$450
 

Removal or re-routing of overhead mains (high
and low voltage)

 

Significant lead-in time for design solution 
 

Costed per project
 

In addition to compliance with the Electrical Safety Act 2002 and the Electrical Safety Code of Practice 2010 (Working Near Overhead and Underground Electric Lines), parties who commission, design, or construct structures have duties under the Work Health and Safety Act 2011 (WHS Act) to ensure the health and safety of workers and others. Failure to comply with these duties could end in criminal prosecution.

A person who commissions construction work has a duty to commission safe structures (s.26 WHS Act). This includes ensuring the safety of workers during construction, use, maintenance and demolition stages. To achieve this, they must consult with the designer on how risks to health and safety can be eliminated or minimised. A party who commissions construction also has specific duties to consult with other duty holders, including the designer and principal contractor (s.46 WHS Act). Consultation involves advising the principal contractor about any hazards and risks at the workplace where the construction work is to be carried out, including powerlines.

Designers of structures have a duty to ensure the design is without risks to health or safety at any time it is to be used as or at a workplace (s.22 WHS Act). They must also provide a safety report to the party who commissioned the work, specifying the hazards unique to that particular design. An example of this is location and interaction with essential services. In addition, the designer has to show how a structure was designed to be without risk to health or safety.

The Safe Design of Structures Code of Practice 2013 includes examples of design options to control risks associated with the construction phase, including that the designer should ensure that the design provides adequate clearance between structures and overhead powerlines by burying, disconnecting or re-routing cables before construction begins.

“It’s fair to say that if everyone contacts electricity entities or the ESO earlier, higher order control methods, including solutions that eliminate risk, can be employed,” Ms Thomson said.  

For more information, visit worksafe.qld.gov.au/construction.