AES was contracted by LaTrobe University to survey land south of Hasting Caves in the remote SE corner of Tasmania as a suitable site to install the TIGER Radar (SuperDARN).

The TIGER Radar had to achieve a distance of 3,000Km to the Antarctic continent. During final testing and adjustment in the Radar waveform, a range of 6,800 Km was reached.

The size of the site required was 500metres by 300metres. This size is required to install 20 HF horizontally polarised log-periodic antenna. The antenna array is 16 antenna in-line in the front and 4 parallel, 100metres behind, forming the interferometer.

To make this site acceptable would have required the removal of 30metres of rock from the top of the ridge. This site was only 2.2 Km from the Hastings Caves and may have cause some damage to the caves whilst removing the rock in large quantities.

Based at the Antarctic Division at Kingston south of Hobart, AES obtained assistance from Tasmanian Forestry and the Tasmania Energy Commission to find a site that was either flat or its ridge ran true East and West.

The ideal location was found on Bruny Island. This island is 25 minutes by ferry, South East of Kettering and south of Hobart. The site is located North of Cloudy Bay Lagoon. The negotiation for the purchase of the land was undertaken by AES on behalf of LaTrobe University.

The site was devoid of power and communications and the soil would not support any heavy vehicles due to the high water table and aqueous clay base.

In 1890, an easement had been surveyed along a property boundary for a road, however it was never built. The nearest power was 1.5Km away and communications was 1.8Km away.

AES selected and negotiated all the subcontractors and services to undertake and complete the site.

A local contractor was engaged to build a rubble road with a base, top surface and drain pipes to support concrete trucks and vehicles for the next 10 years.

This meant obtaining permission from the Kingston council to open a quarry to provide the amount of material required to build the road. AES, with LaTrobe University, assisted a local farmer to obtain this license.

A large semi-trailer concrete batching plant had to be shipped to the site, via the ferry, along with water and base materials for the mix.

A soil report informed us that there was aqueous clay mix from 800mm below the surface to the length of the longest backhoe available at the time, 7.8metres.
In summer the water table is only 600mm below the surface and the concrete base for each tower and guy was 900mm down from the surface. For accuracy in spacing the antenna apart, and to keep these in-line for the next 10 to 20 years, required a firmer base than was present. Tasmanian Forestry reported that a green Tasmanian hard wood tree trunk would last approx 100years in water.

Working with a civil engineer out of Hobart, AES developed a specification for trees with trunks, 450 to 500mm in diameter and 12 metres long to be delivery to the site. A pile driver with caterpillar tracks was delivery to Bruny Island to pile drive the trunks into the subsoil.

The piles were driven in, however at nine metres they were still moving at the same rate as three metres. We found that the clay was being forced away from the trunk and no resistance was obtained. Each pole was then left for 18 hours for the aqueous clay to reform around the trunk. This then provided the necessary resistance to meet the spec of not dropping more than 6mm with a hit of two tonnes. The trunks were cut off at 9.1metres.

There are two piles under the base of each antenna and one under each out guy wire anchor. A total of 80 piles were used on the site.

During the first pour the forestry skid carrying the skip of concrete (1.3 tonn) sank down to both axles and required winching out. The site would no longer support this vehicle and its concrete load.

AES then obtain extra timber from the Tasmanian Forestry to make a corded road from the boundary, past the proposed location of the site building to the centre of the front array. A “T” section was formed and a concrete pump was placed at this point so that concrete could be pumped 150 metres in each direction. The concrete was mixed at the boundary by the batching plant and a 5 cubic metre concrete truck then transported the mix to the pump, which distributed the mix.

The power and communications connections were negotiated by AES for supply to the boundary (meter box). From this location power and communications were run underground to the site building.

The Antarctic Division constructed the site building, to house the transmitter, receivers, computers and communications equipment. This was an insulated shipping container previously used in the Antarctic.

The Laser Sounder group at the Antarctic Division provided the staff to assemble the antenna from kit form into main sections, which were transported to the site. This team also assembled and raised the antennae on site.

The guy wires have iridescent strips of plastic, which wave in the breeze to alert bird life to the presence of wires - no bird kills have been reported to date.

Once the site was finished, mounds of soil were levelled and the area fertilised and seeded for pasture. Sheep are used to keep the pasture under control.

During the development of the site AES had to negotiate with the following parties:

• Local council/shires for permission to build the radar,
• The Tasmania Parks and Wildlife over issues with bird and wildlife migratory bird paths and bird collision codes,
• Aboriginal sacred and heritage sites.