Sydney Park to Haymarket 330 kV Cable Circuits


Sydney, New South Wales, Australia

After previously working together to deliver TransGrid’s Cable 42 project, Diona formed a joint venture with J-Power Systems (JPS) to deliver this project, which involved installation of two separate cable routes traversing almost 20km through the Sydney metropolitan area.

This was Diona’s largest electrical infrastructure project to date and was the first time in Australia that XLPE insulation was used in cable of this voltage.

The project encompassed design, manufacture, supply, and install 330 kV XLPE (cross-linked polyethylene) underground cable, and associated accessories, sub-systems and civil works for:

  • A single circuit between the tunnel portal at Sydney Park, and Haymarket Substation
  • Twin circuits between Holroyd and Rookwood Road Substations

Complexity delivered

The project required a large volume of high-risk work including deep excavations (up to 8m), tunnels and confined spaces, working at heights, live rail work, traffic, heavy equipment and high voltage electricity.

Detailed planning ensured that target deadlines were met and that over 200,000 man-hours were worked with no lost-time injuries.


Collaborating for best outcomes

The decision to work as a consortium was seen as a way to utilise each party’s expertise and provide TransGrid a proven team that they could have confidence in to deliver this complex project.

Diona was responsible for route design, design and construction of civil structures, cable laying. Additionally, Diona was the principal contractor for work, health, and safety (WHS) purposes and had overall WHS and environmental responsibility on all site works, including cable jointing by JPS.


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Charlie Haire


+61 2 8867 8000

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