WorkCover warns of dangers of powerlines when pumping concrete

WorkCover NSW recently issued a safety alert to warn of the dangers of powerlines when pumping concrete, following an incident where the operator of a concrete-placing boom received a serious electric shock when the boom came into contact with 22 kV overhead powerlines that crossed over the construction site. The work was being carried out in almost dark conditions in a fogbound area, where the overhead powerlines were unsighted.

The OHS Regulation 2001 requires employers to ensure that workers, plant, tools and materials used in the work don’t come into close proximity with overhead powerlines — except if the work is done in accordance with a written risk assessment and a safe system of work and the requirements of the relevant electricity operator.

To safely work near overhead powerlines, the following risk control measures should be considered:

• Overhead powerlines, including service lines to buildings, are clearly identified and the height and voltage of powerlines established
• Consult the electricity network operator regarding the proposed work and comply with conditions imposed by it
• Eliminate the risk by arranging for the electricity operator to isolate or re-route the electricity supply for duration of work
• If risk can’t be eliminated, separate electrical hazard from concrete-placing boom and workers by maintaining the following approach distances:

–up to 132 kV — 3 m

–between 132 and 330 kV — 6 m

–above 330 kV — 8 m.

When applying these distances, take into account the ‘sag and swing’ of the powerlines, movement of the boom when pumping, strength of the wind and possible operator error or equipment malfunction, ensuring:

• Trained safety observer is used whenever a concrete-placing boom is in motion and is likely to come closer than approach distances
• Effective communication system is in place for workers performing work
• Process is in place to monitor compliance with adopted risk control measures and safe work practices.