The River Torrens to Darlington Project (T2D) has reached a new stage in its delivery of a non-stop South Road, with the establishment of a second purpose-built construction precinct.
The Central North Construction Precinct at Richmond – located between Sir Donald Bradman Drive and Keswick Creek – is where the T2D Project’s third Tunnel Boring Machine (TBM) will be constructed and launched to build the twin 2.2km tunnels.
Once complete, the Northern Tunnels will run between James Congdon Drive and the existing open motorway south of Grange Road.
Construction has commenced at the Central North site on the diaphragm walls, which will form a deep, reinforced concrete pit called a ‘launch box’.
The diaphragm walls will be up to 38m deep and are constructed one panel at a time to form the launch box trench where the third TBM will be assembled and then begin excavating the tunnels.
A bentonite plant has recently been built at Central North to produce and recycle bentonite slurry – a wet clay that is pumped into the trenches being excavated for the diaphragm walls to ensure ground stability.
Nine 14m tall silos have been installed in the bentonite plant, which are capable of holding 90 cubic metres of bentonite slurry each.
A water treatment plant is being built to treat and reuse water during the tunnelling process, as well as a 100-cubic-metre buffer pond to hold spare water produced by construction activities.
It’s estimated more than 500 workers will be employed to work at the Central North site during peak construction.
Work is already underway to enable the first two TBMs to be launched from the Southern Precinct at Clovelly Park to construct the 4.5km Southern Tunnels, which will run between the open motorway at Darlington to just south of Anzac Highway in Glandore.
The entire T2D Project will support approximately 5,500 jobs per year during main construction, with 90 per cent of labour hours to be undertaken by South Australians, creating a skills legacy for South Australia.
The TBM components are being manufactured in Germany and China, before being assembled and factory assurance tested in China and then delivered to Adelaide. The first of three TBMs is expected to arrive late this year.
Excavation by the TBMs of the Southern Tunnels is planned to begin in the second half of 2026.
The $15.4 billion project to create a non-stop South Road is being jointly funded by the Federal and South Australian governments.
Deputy Premier of South Australia, Susan Close, said that the establishment of the Central North Construction Precinct is a significant milestone in creating a non-stop South Road that will ease congestion, improve safety and create more connected communities.
“Every step forward on the River Torrens to Darlington Project brings South Australians closer to a more modern transport network that strengthen our state and serve our community for generations to come,” Close said.
