Powercor's power pole maintenance and replacement program has been caught out by independent testing, forcing the electricity distributor to overhaul procedures.
Powercor will now double the number of wooden power poles it replaces annually in a major shake-up and the company has committed to look at better and new testing technologies.
Stunningly of the eight poles removed from The Sisters Sparrow Spur line, only one - pole No.11 - failed to meet Powercor's standard when independently assessed at pole supplier Kopper’s Grafton test facility.
Pole No.2 - the infamous see-through pole that prompted dairy farmer Jill Porter to conduct independent tests - met Powercor's current standard, based on old SECV criteria.
That's raised further questions about the base requirements.
Pole No.2 was just metres from pole No.4 which snapped at just before 9pm on St Patrick's Day last year on Jack Kenna's property, sparking The Sisters/Garvoc fire that destroyed 18 homes and farms across the district.
Highly-placed industry sources have described a Powercor two-page press release on Thursday announcing the results of south-west pole inspections as "corporate spin" and "hogwash".
Powercor chief executive officer Tim Rourke said the pole inspections in the network servicing a region from Warrnambool to Port Campbell and Hamilton in January and February revealed high standards of strength in the infrastructure.
He said of the 19,663 poles tested, only nine have been replaced as a priority (0.05% of poles) after being rated as unserviceable.
“During these inspections we found the number of poles needing to be replaced was lower than what is usually found during our normal inspection cycles,” Mr Rourke said.
“We are confident in the network to deliver safe and reliable power to the south-west community.
“Our Powercor teams based in Warrnambool and Colac do an outstanding job to continuously maintain the network and their extra effort in the past few months, to accommodate the additional testing and inspections, is much appreciated.”
Mr Rourke said Powercor undertook the additional pole inspections out of respect for the heightened sensitivity in the community regarding network safety following the St Patrick's Day bushfires last year.
All four fires in the south-west were started by Powercor infrastructure.
The CEO said of the nine poles replaced, only one was due to levels of sound wood, four had been struck by lightning and four were due to visual appearance.
He said the additional inspections came after community members raised concerns about the appearance and age of poles and, as a result, 15 poles were removed from the Sparrow and Craven Spur lines near Terang in December and January.
Two independent industry experts were engaged to assess the breaking strength of these poles at specialist pole supplier Kopper’s Grafton test facility, witnessed by representatives of Energy Safe Victoria.
Mr Rourke said that eight, including the worst looking poles, had an actual safety factor close to or better than the strength of a new pole.
“It just emphasises that it is the health of the pole which is important, not its age or what it looks like,” he said.
“These tests show our approach to inspecting, maintaining and replacing poles is reliable and safe.”
In addition to the recent inspections, Powercor’s inspection methodology has been updated with new measures for pole serviceability, increased inspection frequency and clarifications to the use of signage on poles.
“Our safety program is always evolving as technology and methods that network businesses like ours use to inspect infrastructure is improving. We continually review and investigate ways to deliver a safer network for the community and these latest changes are an example of this work,” Mr Rourke said.
Under the new measures:
- Powercor has replaced the ‘Limited Life’ category to ‘Serviceable – Added Controls’ reflecting that the poles are still strong but will be inspected more frequently
- Those rated ‘Serviceable - Added Controls’ will be inspected annually in preparation for the summer season
- Poles will be classed as unserviceable when their safety factor has dropped to 1.40. Previously, they would be replaced if their safety factor reduced to 1.25. (The higher the safety factor, the stronger the pole.) This conservative approach will add an additional 5mm - or 15 per cent - of sound wood to poles.
- Powercor is undertaking another round of testing to evaluate new technology to improve pole inspection methods.
Under the new methodology, the number of unserviceable poles expected to be replaced each year will increase from 1200 to about 2200.
These changes will be incorporated into Powercor’s Draft 2021-2022 regulatory reset proposal, with the business seeking $332 million for its overall pole and line replacement program.
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