Detailed Energy Safe investigation into Anakie transmission tower collapse concludes

Following a detailed investigation, Energy Safe Victoria (Energy Safe) has found that there is no case to prosecute AusNet Transmission under the Electricity Safety Act 1998 for the collapse of 6 transmission towers in Anakie, north of Geelong, during an extreme storm event in February 2024.

We investigated the incident to determine if AusNet had breached any of its obligations under the Electricity Safety Act 1998. Our investigation included:

• initial and subsequent attendances at the incident site
• issuing directions requiring AusNet to preserve the site including tower foundations
• issuing notices to AusNet and the Bureau of Meteorology requiring the production of documents and information
• seizure of evidence via warrant following Court application including tower bolts and structural members
• testing of portions of the towers by an independent engineering firm
• obtaining expert witness reports from:
  • an expert in weather and climate science regarding the weather around the time of the Incident
  • engineering firm HRL, who were engaged to give an expert opinion on whether the condition of the towers contributed to their collapse
• considering external factors such as air pollutants present in the vicinity of the collapsed towers
• analysis of AusNet’s safety management scheme including its inspection and maintenance procedures.

Our investigation found that AusNet acted in accordance with its electricity safety management scheme, and that the transmission towers were properly maintained, inspected regularly, and free from evidence of corrosion or structural faults before the failure.

The collapses occurred during an extreme storm event, and the location and form of damage on the structural sections were consistent with a sudden overload failure of the bolted tower structure. Chemical analysis and metallurgic examination did not identify any concerns.

This incident has added to the growing state of knowledge about the likelihood and potential impacts of weather events in Victoria, with transmission tower collapses occurring twice in Victoria since 2020.

We expect AusNet to ensure that it is proactively assessing its controls for the risk of transmission tower collapse due to weather events across its Victorian network.

Background

On 13 February 2024, Victoria experienced an extreme storm event, with peak wind gusts reaching up to 175 km/h. This severe storm caused widespread damage to buildings, infrastructure, and the environment across Victoria. The intensity of the storm resulted in power outages affecting over one million residential and business customers.

In Anakie, north of Geelong, six transmission towers collapsed bringing down a major 500 kilovolt transmission line. As a result, Loy Yang A power station generation units were disconnected, necessitating load shedding as directed by the Australian Energy Market Operator (AEMO) to stabilise the network.

AusNet Services (Transmission) Pty Ltd owns, operates and maintains Victoria’s high-voltage electricity transmission system. It consists of around 6,620km of transmission lines across 13,399 transmission towers.

Media enquiries

Jonathan Granger: 0400 948 934 or media@energysafe.vic.gov.au

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