30 August 2021
In a world first, Ausgrid has used a drone to untangle 800 metres of twisted powerlines in a remote, inaccessible part of the electricity network in Sydney’s North.
The twisted wires were caused by strong winds and discovered during a routine tower inspection in a large valley between Davidson and St Ives.
Ausgrid Executive General Manager of Network Delivery Services Kelly Wood said Ausgrid approached drone technology company Infravision to see if they could find a solution to untangle the wires safely.
Infravision were known to Ausgrid as a market leader in the use of drone technologies to support the delivery of works on transmission lines.
“While the tangled wires weren’t immediately affecting power supply, the friction between the two wires would have eventually severed them, potentially cutting power to 70,000 customers,” Ms Wood said.
“Replacing broken lines in such an inaccessible area would be a major job, so we were hopeful Infravision could come up with a solution to untangle the wires.”
Infravision Director of Operations Paul Crawford said the team rose to the challenge and worked out a method to utilise a heavy-lift drone with a specially designed hook and release mechanism to lift and untangle the wires.
“Our engineering team designed several 3D printed ‘hook’ attachment prototypes, and after extensive testing a final version was decided on for this project,” Mr Crawford said.
“The hook, tether and release mechanism had to be able to withstand extreme loads, be non- conductive and designed in a manner to minimise the risk of any further entanglement and prevent any further damage to the cable during the operation.”
“It was also designed to allow the wire to easily slide into the hook, making it easier for the drone pilot to engage and reposition the wire.
“Safety is our number one priority. As we were working with High Voltage Lines we designed an automatic release mechanism to detach the hook in an emergency, allowing it to roll off the wire and prevent it being caught on the line.”
The use of drone technology meant Ausgrid personnel and the community were exposed to significantly less risk as there were no individuals working at height and no low-flying helicopters used.
“After an initial test flight to view the wires, the drone with the hook was deployed and performed several lifts, untangling the wire in 40–60 metre sections at a time until the lines were completely untangled,” Ms Wood said.
“I believe the success of this joint operation will be a gamechanger for Ausgrid and other companies which are moving towards an increased use of drone technology to improve the safety and efficiency of business operations in the future.”