Orion boosts power supply to Lyttelton

25 March 2019

Lyttelton is set to welcome the long awaited boost to its power supply when Orion puts a new 11kV electricity cable through the Lyttelton Road Tunnel in April.

The 2.2km cable will run in tandem with the existing two 11kV cables that run over the Port Hills. Together they will provide a more resilient and reliable service to the Lyttelton, Corsair Bay and Cass Bay community.

Orion says the Tunnel will remain open, and the power will stay on throughout the work which will be done overnight, and take four weeks.

The project is the culmination of three years of work by Orion to address reliability and resilience issues with the power supply to Lyttelton.

Steve Macdonald, Orion’s General Manager Infrastructure, said, “The work we’ve done over the past three years has really helped improve the reliability of the electricity service to this community, and this is the big hitter that will make all the difference.

“The lines over the hill are vulnerable to weather, vegetation and pests. With the cable we have alternatives to keep the power on.

“A cable through the tunnel provides the belt and braces service this community needs. The Port is an essential lifeline for Canterbury and increasing the resilience of the power supporting it is important for the wider region.”

To allow for future growth, the new cable, actually three separate single core cables, has a power rating of 10 Megawatts, 3 Megawatts greater than the current average demand.

“It’s the longest 11kV cable pull in Orion’s history, and gravity will help us as we’ll be pulling it downhill from Heathcote,” said Macdonald.

For more information, see Work Notice: New cable through the Lyttelton Road Tunnel

Cable facts

  • Three separate cables: 3 x single core, continuous cable, with no joints
  • A power rating of 10 Megawatts, 3 Megawatts greater than current average demand which means it is future-proofing the supply – allowing capacity for growth
  • Each cable 2.2 kilometers long, weighing 11T each
  • The cable pull through the tunnel is around 2 kilometers, with extra to take them to the connection points at either end
  • This is the longest 11kV cable pull in Orion’s history
  • Each cable drum is 3.15m diameter x 2m wide, made of steel