From the magazine, HDD

Broadbanding the Top End: HDD and then some

Overseeing the project was Executive Director of Network Constructions for Telstra John Gibbs. Mr Gibbs has been involved in large scale projects, such as digitalising the Australia network, laying the optic fibre cable between Kununurra and Katherine and rolling out Telstra’s Next G network.

Mr Gibbs spoke with Trenchless Australasia about the environmental and cultural challenges of connecting Arnhem Land to the rest of the country’s fibre optic network and he highlighted the importance of horizontal directional drilling (HDD) to mitigate the projects impact. Mr Gibbs also spoke about the pride he felt in having taken part in extensive co-operation and consultation processes with the local indigenous communities.

The project was first announced in 2008 by Telstra, and was supported by the Northern Territory Government, Rio Tinto Alcan and the Northern Land Council. The project aimed to connect nine indigenous communities and the township of Nhulunbuy to the nation’s fibre optic backbone, with the cable running from the township of Jabiru in Kakadu National Park, across Northern Arnhem Land and finishing in Nhulunbuy.

Tropical weather constraints required that the project be carried out in two phases. Phase one was completed in a ten week period leading up to Christmas 2008 and involved the installation of the 800 kilometre backbone fibre. The project team then had to wait out the wet season before regrouping and returning in August 2009 to complete the installation of ancillary work to connect three offshore communities along the 800 kilometre route. The installation of 140 kilometres of additional routes and radio systems splintering off the main line was designed to join the three more remote indigenous communities to the network and was completed by October 2009.

Drilling under Arnhem Land

Of the 940 kilometres of fibre cable installed, Telstra installed approximately 12.8 kilometres using HDD.

HDD was necessary for river crossings such as the East Alligator River between Kakadu National Park and Arnhem Land and the Gouja River in Arnhem Land. Other parts of the project also required the use of HDD due to engineering and cost reasons.

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.

“If someone has never seen a directional drilling device before and you describe under road bores or under creek bores, they can’t really picture what you mean.

“But once we could demonstrate how the surface was untouched, people had a higher degree of confidence in our ability to meet their needs and leave the environment as untouched as we could,” said Mr Gibbs.

The new connection between Arnhem Land to the rest of Australia’s fibre optic network will provide the nine indigenous communities with a number of benefits; including a significantly greater capacity and speed on their internet links, enhanced reliability, and access to new education, health and policing services that were previously unavailable.

Some of the harshest conditions in Australia

Working in one of the most remote regions of the country provided the project team with their fair share of environmental challenges, as they found themselves battling amorous wildlife, harsh climates and a range of insects.

“We were installing 800 kilometres in some of the harshest conditions in Australia,” said Mr Gibbs.

Mating season required the project team to take precautions against aggressive crocodiles and buffalo. Local indigenous shooters were employed as a precaution for the HDD section on the East Alligator River where there is a well known and visible population of crocodiles. Workers often had to check under their cars before driving in case a wandering crocodile had decided to doze off underneath the vehicle.

Adding to the challenges of wildlife was a lack of commercial accommodation, leaving the project team to set up its own base camps at Telstra radio sites along the route. Food provisions and air conditioners so that workers could sleep in comfort were brought in, and all waste created at the camps was trucked out on a weekly basis.

Provisions included pallet loads of bottled water to provide workers with ten litres of water per day. With soaring temperatures and humidity hoovering over 90 per cent during the working day, it was necessary to keep workers well hydrated.

“The heat up there was horrendous. The reality of day-to-day working in that high humidity, high temperature environment was probably the biggest challenge,” said Mr Gibbs.

Reaping the rewards

Broadbanding the Top End has so far been the recipient of a number of Territory, national and international awards, including the World Communication Awards 2009 for Best Project Management. Whilst a large portion of the project was open-cut, the success of the project could not have been possible without the HDD sections to join it all up.

“It was the entire end-to-end project that got the award, but the actual boring was an integral part. We had a total of 20 bulldozers ripping or ploughing, but boring was needed to join those significant components together” said Mr Gibbs.

“It was almost like a jigsaw puzzle – you can get it 90 per cent done, but unless you’ve got those key trenchless pieces that fit in, it doesn’t work.”

However for Mr Gibbs, the real reward is the benefits to the Indigenous communities and their satisfaction with the project and the way in which the work was undertaken to best respect their areas of cultural significance. To have been told by traditional owner Joe Yunupingu that the project “was actually the best ever any white people has done on Aboriginal land” was the best form of recognition for Mr Gibbs.

“To have worked in this very difficult country with the traditional owners and to have the traditional owners acknowledge how well we did it – aside from all the engineering highlights – that gave me a great deal of personal pleasure,” said Mr Gibbs.

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