North Star to Gowrie Major Survey Control works reach key milestone

Our ground survey teams have reached a key milestone, establishing the position and heights of the new rail line between North Star in New South Wales and Gowrie in Queensland, including the Macintyre River crossing.

Aerial view of the Macintyre River, New South Wales, Queensland

Our survey teams have achieved a significant milestone with works recently completed to install and observe Major Survey Control points across the Macintyre River – a vital connection between our New South Wales and Queensland projects.

Over the last six months, survey crews have been conducting high level Global Navigation Satellite System (GNSS) surveys and Two Way Differential Digital Level surveys between North Star in New South Wales and Gowrie in Queensland.

This work will provide the point of reference on which all spatial data is based. It will also ensure consistency of data across detailed design, civil works construction, track laying and ongoing maintenance processes.

From an engineering perspective and to ensure safety of the operating rail line, it’s important to get this survey work right, according to Inland Rail’s Project Manager Survey (QLD) Mark Dade.

“Our work over the last six months has been about determining the exact coordinates of the Major Survey Control to provide certainty for the position and height of the new rail alignment, particularly across the Macintyre River,” Mark said.

“There have been more than 10 surveys crews from two specialist surveying companies involved in this fieldwork to ensure we get it right.”

The crews successfully tackled several technical challenges, in particular surveying the 65-metre Macintyre River crossing. The teams used the latest digital levelling equipment to deliver survey readings to less than 1 tenth of a millimetre.

“We have a unique opportunity to deliver highly accurate GPS-based ground surveys across changing terrains within this cross-border section of Inland Rail and our teams have relished the challenge,” Mark said.

Once this survey program is completed, all the new Major Survey Control marks will be allocated a “State Survey Mark Number” and will be included in the State Survey Control network managed by the QLD Department of Resources, Mines and Energy.

Not only will these survey marks form the basis of a coordinated network for Inland Rail, they will also be made available to the broader surveying community, greatly enhancing and modernising the surveying infrastructure along the Inland Rail alignment.