South Australia’s $15.4 billion River Torrens to Darlington Project has reached another construction milestone, with workers at Waterloo Corner completing 1,000 precast tunnel-lining segments as the worksite continues to feed the state’s largest infrastructure project.
More than 55,000 concrete segments are being manufactured at the Waterloo Corner facility, and the pieces will line both the Northern and Southern Tunnels. At peak production, the site is expected to support about 60 local jobs while turning out around 160 segments a day, each weighing about 12 tonnes.
The scale of the operation is hard to miss. The Waterloo Corner shed stretches 285 metres, and an on-site concrete batch plant is supplying 280,000 cubic metres of concrete — enough to fill the equivalent of 112 Olympic-sized swimming pools — for the segment line. Once completed, the precast pieces will be moved to the Tunnel Boring Machine launch sites, where high-tech battery-electric Multi-Service Vehicles will carry them to the TBMs.
Inside the machines, a specialised segment erector will install the pieces into rings that make up the tunnel walls. Each ring uses 10 concrete segments, linking the manufacturing line at Waterloo Corner directly to the underground drive that will eventually carry traffic through the corridor.
Infrastructure and Transport Minister Joe Szakacs said each segment made at Waterloo Corner is one more piece of the puzzle toward a non-stop South Road. He said the project is ramping up across several sites, including the precast facility, as tunnelling prepares to begin in the second half of this year. He also said the work is helping create a skilled local workforce that should leave a lasting skills legacy for South Australia.
The workforce push is now being backed by training as a new nationally recognised Certificate III in Manufacturing Mineral Products is being introduced for the project’s precast sector. More than 60 workers have already enrolled in the traineeship, adding another layer to a project that is as much about people as it is about concrete and steel.
At the Central North Precinct in Hilton, the third and final TBM cutterhead has now been craned into place. The cutterhead was lowered into the 20-metre-deep launch box by a 500-tonne gantry crane and will rotate to excavate rock and soil from the tunnel face using cutting teeth and discs. The remaining components of the TBM will be assembled before final testing and commissioning.
Matt Burnell said the North-South Corridor is one of Adelaide’s most important transport corridors and said the project will give road users improved access to key travel gateways while better supporting the community. He called the latest step another sign that tunnelling is becoming a reality. The first concrete tunnel-lining segment is expected in the second half of 2026, but the broader timetable is already moving, with tunnelling due to begin in the second half of this year.
