The project involved 121 bores. Ground conditions on the route included 3.6 kilometres through rock, 4.6 kilometres through shale, and 4.6 kilometres in ground conditions other than rock. The longest crossing was 319 metres through mostly rock and running underneath one of the rivers.
Mr Gibbs identified three key reasons why HDD was used for sections of this project: water crossings, good engineering and cultural sensitivity.
According to Mr Gibbs, the technology of directional drilling was integral to the success of the project; with some sections of the project of cultural significance left completely untouched on the surface.
Respecting the land
Installing the cable mains in areas of cultural significance proved to be one of the greatest challenges for this project. Developing and nurturing trusting relationships with the local communities and native land owners over a long period of time was of utmost importance to the project and ensured successful co-operation between all parties.
“One of the challenges was to ensure that we completely satisfied the requirements of the indigenous communities. Where they advised us an area was of cultural significance, we respected that and adhered to their requests,” said Mr Gibbs.
A lengthy two-year consultation period preceded the project as Telstra needed to obtain all the appropriate approvals from native land owners. HDD was used to respect areas of cultural significance to leave the surface of the land completely undisturbed.
Mr Gibbs said that an important part of the consultation process involved employing local guides and monitors to accompany the project team on the site, enabling the project team to demonstrate the HDD process and the ways in which it would leave the surface of the land untouched.