South Australia’s $15.4 billion River Torrens to Darlington (T2D) Project has reached new milestones as it progresses through construction.
Workers at the State’s largest sheds at Waterloo Corner are celebrating a new manufacturing milestone, with 1,000 precast tunnel-lining segments completed and ready to be installed.
More than 55,000 concrete segments are being manufactured at the Waterloo Corner facility, which will line both the Northern and Southern Tunnels. This project is supporting about 60 local jobs at peak production.
Around 160 segments that weigh about 12 tonnes each will be manufactured at the 285-metre-long shed every single day during the peak production period.
An on-site concrete batch plant is supporting operations at the facility by supplying the 280,000 cubic metres of concrete needed for the segments – equivalent to 112 Olympic-sized swimming pools.
“Every segment manufactured at Waterloo Corner is another piece of the puzzle helping to create a non-stop South Road.
“The project is ramping up across a number of sites like the precast facility at Waterloo Corner, as we prepare for tunnelling to get underway in the second half of the year.
“Beyond the concrete and construction, this project is helping build a skilled local workforce that will leave a lasting skills legacy for South Australia,” SA Minister for Infrastructure and Transport Joe Szakacs said.
Once the segments are completed, they will be transported to the Tunnel Boring Machine (TBM) launch sites where they will be placed on high-tech battery-electric Multi-Service Vehicles (MSVs) to deliver them to the TBMs to build the tunnel walls.
Inside the TBMs, a specialised segment erector will progressively install the precast pieces into rings to form the tunnel walls – each ring is made up of 10 concrete segments.
In an Australian first, a new nationally recognised Certificate III in Manufacturing Mineral Products (Precast) has been introduces to support the T2D Project’s growing precast workforce. This will help create new training opportunities for South Australians entering the industry.
More than 60 workers have already enrolled in the traineeship and are helping lay the foundations for a skilled local workforce now and into the future.
The first concrete tunnel-lining segment is anticipated to be installed in the second half of 2026.
“The North-South Corridor is one of Adelaide’s most important transport corridors, and this project will provide road users with improved access to key travel gateways and better support the community.
“This milestone marks another step forward on this important project as tunnelling starts to become a reality,” Federal Member for Spence Matt Burnell said.
Marking yet another milestone on the T2D Project, the third and final TBM cutterhead has already been carefully craned into place at the Central North Precinct in Hilton.
The cutterhead was safely lowered into the 20-metre-deep launch box by a 500-tonne gantry crane and now sits at the front of the TBM. The cutterhead will rotate to excavate rock and soil – also known as spoil – from the tunnel face using cutting teeth and discs.
With the cutterhead now in place, the remaining components of the TBM will be assembled before final testing and commissioning. Tunnelling will begin in the second half of this year as well.
The third TBM will build the Northern Tunnels by launching from Hilton and excavating about 2.2 kilometres towards the project’s Northern Precinct near Brickworks Marketplace in Torrensville, where it will be turned around to make its way back to Hilton.
“With the final cutterhead craned into place, this milestone marks another step forward on this game-changing infrastructure project.
“These tunnels will take thousands of cars off local roads, making it faster and safer for people travelling through our community,” Federal Member for Adelaide Steve Georganas said.
The TBM cutterheads each weigh more than 300 tonnes, and all three have now been lifted into place for the massive diggers.
The T2D Project is making Australian history as the first road project operating three large-scale TBMs at the same time. By using three TBMs concurrently, it will allow both the Northern and Southern Tunnels to be constructed simultaneously and enabling the entire T2D Project to be delivered by 2031, if not before.
The TBMs will operate 24 hours a day, seven days a week and progressing about 8-10 metres per day. Around 20 specialised workers will be inside the TBMs at any one time to assist with tunnelling activities.
Each TBM is up to 100 metres long and 15 metres in diameter, roughly the height of the Thebarton Theatre or the goal post at Adelaide Oval.
“The $15.4 billion T2D Project is not only the largest infrastructure project in South Australian history, but also the first road project in Australia to operate three large-scale TBMs concurrently.
“This historic first highlights the scale of what we are delivering.
“For motorists driving past these sites every day, this milestone is another visible sign that we are moving closer to a non-stop South Road,” Minister Szakacs said.
The River Torrens to Darlington Project is jointly funded by the Australian and South Australian Governments, each contributing $7.7 billion.
The T2D Project is delivering the final 10.5-kilometre section of the North-South Corridor. This massive road project will also complete the 78-kilometre non-stop, traffic light-free motorway between Gawler and Old Noarlunga.
Upon completion, drivers will be able to bypass 21 sets of traffic lights between the River Torrens and Darlington while travelling through two separate tunnels that are connected by an open motorway.
The overall T2D Project is made up of:
“This is an important project for South Australia and will make a real difference to getting Australians home quicker and safer.
“With over 100,000 vehicles travelling across the corridor each day, the project will improve travel efficiency and facilitate job growth across the region.
“The project is another example of the State and Federal Labor Governments working in partnership to deliver the infrastructure Adelaide needs,” Federal Infrastructure, Transport, Regional Development and Local Government Minister Catherine King said.
Source: Minister for Infrastructure, Transport, Regional Development and Local Government (1, 2); Government of South Australia – News (1, 2); T2D Torrens to Darlington