Sydney CBD Cable Tunnel 132kV Feeders Project
| Client: | Energy-Australia |
| Location: | Sydney CBD Tunnel, NSW |
| Start: | Nov 2002 |
| Finish: | July 2004 |
| Purpose: | Installation of 132kV Cables within Energy-Australia CBD Cable Tunnel including Design and Installation of Cable Support System in Shafts, Substation Interfaces and Substations. |
| Description: | Garde Services was contracted by Energy-Australia to install 15 kilometres of high voltage cable deep beneath the city of Sydney. The project was part of the power company's huge investment in the upgrade of its electricity network to cope with the future demand for electricity in Sydney's central business district and the surrounding suburbs. As part of the upgrade, a substation had been built in Campbell Street, Surry Hills complete with a tunnel linking the new substation with others in Ann Street, Surry Hills, Campbell Street in Sydney's CBD and a new substation constructed by TransGrid in Ultimo Road, Haymarket. The task for Garde Services was to install electricity cables through the tunnel to link up with the four substations and it was one of the most complex cable laying tasks ever undertaken in Australia. Prior to the installation Garde conducted a detailed planning, design and construction analysis in order to develop a strategy that would achieve the complex task. The company also commissioned the manufacture of a purpose built cable laying machine to assist with the laying process. The innovative machine is in effect, a Tunnel Cable Installation System and it resembles a small train which can pull more than a kilometre of cable into place at a time on numerous small trolleys. Application of the system requires a team of specialist operators using sophisticated radio communications to coordinate what is, an extremely precise cable laying process. The installation was a highly difficult logistical exercise because the cable weighed 23 kg/metre with a diameter of 120mm. Each length of cable had to be installed continuously without joints; therefore the cable had to be delicately handled as it was carefully installed in a snaking pattern onto brackets along the tunnel wall. The cable also had to be pulled up vertical shafts to reach different levels within each substation building and this aspect of the installation required a particular and sensitive strategy to ensure that the integrity of the installation process was maintained. |
