Two Rocks bushfire
Issue Date: - Friday, 20 February 2009
A major fire at Two Rocks last month, which burned a large portion of pine plantation, was caused by clashing high voltage Western Power lines.
This is the principal conclusion of a report into the 16 January fire, released today by EnergySafety, Western Australia’s electricity and gas regulator.
“Burn marks and melting show clearly on two conductors immediately over the fire’s point of origin,” Ken Bowron, Director of Energy Safety, said today.
“When electricity wires clash they cause a high-temperature arc which instantly melts the metal at the point of contact,” Mr Bowron said.
“Globules of metal, still very hot, fall to the ground. If they come in contact with dry combustible material, a fire often results, especially in hot, dry, windy weather.”
The report states that Western Power recorded a fault on the power line at 9.41am, which coincides with the time of origin of the fire.
The temperature at the time was over 33 degrees, with very low relative humidity at 15 per cent. The hot easterly wind speed was 29-50 kmh, with strong gusts.
“These are precisely the conditions likely to generate a fire when overhead conductors clash,” Mr Bowron said.
The EnergySafety report reveals that a conductor anchor bolt on the pole next to the fire origin point had pulled through the pole. This reduced significantly the tension of the conductor concerned. It sagged closer to its immediate neighbouring conductor, making a clash much more likely.
EnergySafety will work with Western Power to investigate the maintenance and inspection history of the power line involved to determine whether improvements are necessary.
The full report may be seen on http://www.commerce.wa.gov.au/EnergySafety/
Contact: Nicola Easton 9422 5208