Carlingford’s cables are disappearing underground

A cable drum is set up for laying cable in ducts
A cable drum is set up for laying cable in ducts

Sydney developers are establishing Carlingford as the benchmark for future urban village developments – bustling, high-density communities free from overhead cables.

Taihan Electric Australia (Taihan), is working on a long-term, major project in the Sydney suburb of Carlingford. The suburb, which is 22km north-west of the Sydney CBD, is experiencing rapid urbanisation, subdivision and population growth – and the boom is projected to continue into the next decade.

But property values aren’t the only thing increasing in Carlingford. In 2013, developers began eyeing-off land for residential, commercial and recreational projects, and they wanted large, overhead cables out of the picture. As a result, Taihan began moving cables underground last year.

When the project is completed, project manager Gary Sharp said the Hills Shire will be given the freedom to transform into a modern, interconnected and stylish community.

“Removal of the 132,000V overhead cables should be completed late this year when the 132kV underground system, about 1.1km long, will replace it,” Gary said.

“There will be 12 underground cables in total. Six cables were installed in July, and the remaining six will be pulled in about one month’s time.

“This second lot of cables has to navigate local obstacles that can’t be relocated, such as bridges, heritage-listed properties and essential infrastructure. With this in mind, we’ll have to use horizontal directional drilling for the ducting. The initial six cables used the open trench method.

Suitable ducts are being buried along the cable path. These can be quickly backfilled and covered over to minimise interruption to road users and the wider community. The cables will be pulled through these ducts with a winch. At 1.1km, this project will boast the longest single pull in Australia.

The Taihan extra high voltage (EHV) cable consists of a copper core, a special cross-linked polyethylene (XLPE) insulator and a metal outer earth conductor, and is covered in high-density polyethylene (HDPE) protection. Manufactured in Korea, Gary said the cable is larger than most people expect.

“The average diameter of a 132kV cable is 13cm – it’s big!” he said.

The underground system should be completed in September, at which point it will be handed over to the electricity network provider for testing. After connecting the system to its network, the provider will program the removal of the overhead cables and towers, which is expected to wrap-up at the end of 2016.