Road closures as massive North-South Corridor drilling machine rolls into town
Roads will be closed and traffic lights pulled out as a giant tunnel boring machine weighing more than 175 tonnes arrives to start drilling under Adelaide soil for the North-South roadway. See the video.
The first tunnel boring machine (TBM) components have arrived by ship at Port Adelaide wharves to support workers in extensive underground drilling work on the $15.4 billion North-South Corridor, billed as South Australia’s largest infrastructure project.
Wednesday’s shipment included a TBM cutterhead delivered in five pieces, which, once assembled, would be roughly 15 metres in diameter.
The largest and heaviest centre section weighed about 175 tonnes and measured nine metres in diameter.
Federal Infrastructure, Transport and Regional Development Minister Catherine King said it was a significant step forward in the non-stop South Road project.
“(This project) will create thousands of jobs, boost productivity and better connect communities in southwest Adelaide,” she said.
There will be progressive road closures on Saturday night so the components can be transported from Port Adelaide to the River Torrens and then onto the Darlington Project Southern Precinct in Clovelly Park.
Sections of South Road will be gradually closed to traffic over short periods from 10pm on Saturday to transfer the nine-metre-wide mason cutterhead, which is so large that it will require traffic lights to be removed.
The parts will then be reassembled and commissioned ahead of tunnelling works, which are scheduled to start in the second half of 2026.
In total, three large-scale TBMs, each measuring more than 100 metres long, will be used to construct the twin 4.5km Southern Tunnels and twin 2.2km Northern Tunnels as part of the North-South Corridor.
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Two TBMs will launch from the project’s Southern Precinct in Clovelly Park, while the third is set to launch from the Central North Precinct at Richmond.
“Once complete, the non-stop South Road project will allow motorists to bypass 21 sets of traffic lights between the River Torrens and Darlington, improving travel times for South Australian motorists by up to 40 minutes in peak hour traffic,” said federal Boothby member, Louise Miller-Frost.
“This is part of a coordinated strategy to manage traffic in the southern suburbs, along with the recently opened Majors Road on-off ramps, and the tram overpasses, making commuting safer and more direct and returning local roads to locals.”
The major route, jointly funded by the state and federal governments, covers a distance of 78 kilometres between Gawler and Old Noarlunga.
It was initially meant to cost $9.9 billion under the former Marshall-Liberal government, but when the design was revised in 2022, that number increased to $15.4 billion.
According to the State and Federal Governments, the T2D is expected to support around 5,500 jobs per year during construction, with 90 per cent of labour hours undertaken by South Australians.
Construction for the T2D has begun, with an expected completion date of 2031.
Correction: This article has been updated to clarify that not the whole of South Road will be closed at once.
