Concrete pole line supports electrification of rail spur

High-capacity electric trains will be able to operate along Queensland’s 108km Bauhinia rail spur, from Rangal south to the Rolleston mine, before the end of this year, thanks to a new concrete pole transmission line.

The Aurizon project, using Rocla Duraspun concrete poles and manufactured at Rocla’s Rockhampton-based facility, is a 132kV transmission powerline. The substation features a total of 49 poles ranging from 20.0M 80kN to 34.5 80kN.

Gavin Roberts, Laing O’Rourke site engineer for the contractors responsible for construction of the line, said the vast majority of transmission poles were specially designed for extra height and strength due to the site being a flood risk zone.

“This meant the poles needed to be installed in three separate sections, and required the pole bases to be perfectly level and orientated to prevent any pole lean or twist. This was a challenge given the bored holes were 6m deep, meaning the pole base only stands 1m out of the ground,” he said, acknowledging Rocla provided a zero point on the pole bases, which allowed the surveyors to mark out either side of the pole to line up the orientation points.

“With all the poles pre-drilled it’s pretty essential to get the orientation right so that when we run the wire the cross arms are spot on.”