A preferred alliance partner has been selected for the final stage of South Australia’s largest infrastructure project, which is due to be completed earlier than expected.

South Australians will likely be able to enjoy the full benefits of the River Torrens to Darlington Project (T2D Project) even sooner than expected – with three Tunnel Boring Machines to be operating at the same time, instead of the expected two.

Once finished, the T2D project will allow motorists to avoid 21 existing sets of traffic lights between the River Torrens and Darlington and will complete the non-stop 78km North-South Corridor between Gawler and Old Noarlunga.

Following an exhaustive procurement process which commenced in January 2023, the consortium, comprising John Holland, Bouygues Construction, Arcadis Australia, Jacobs and Ventia, has been selected as the preferred alliance partner to deliver South Australia’s biggest-ever infrastructure project.

The successful consortium has confirmed it can deliver the T2D Project on budget, delivering significant travel, economic and community benefits for South Australians.

The consortium’s tender detailed a plan to procure three Tunnel Boring Machines (TBMs), instead of the two previously anticipated – which will mean both north and south tunnels can be constructed concurrently.

The three TBMs that will be used to excavate the T2D tunnels will be purpose-built for the local conditions they will encounter on this project.

The additional TBM gives a reasonable expectation that this state-shaping project can not only be completed by the stated 2031 deadline – but even earlier.

The successful consortium’s design delivers the key features of the December 2022 Reference Design release, while providing further traffic and community benefits.

Enhancements from the 2022 Reference Design proposed by the successful consortium include:

• A connection free from traffic lights between the motorway and James Congdon Drive, providing seamless access to and from the CBD

• Innovative tunnel portal arrangements that enable improved and lowered motorway sections with faster construction times and reduced costs

• More trees planted to help green the corridor

• Improved tunnel design and shorter cut and cover tunnel sections, which will reduce energy use and costs, and minimise surface impacts to communities next to the T2D motorway

• Innovation for the construction of tunnel cross passages, and other systems elements of the tunnels

• Improved experience for active travel users with universally accessible paths, shared-use paths and active travel corridors, with regular safe east-west connections

In the coming weeks, the construction consortium will set up the major construction site at the southern laydown area in Clovelly Park and engaging with local communities as early works continue along the corridor.

The 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.

It will also deliver unprecedented opportunities for South Australian businesses, with more than 300 local businesses already registering their interest in being involved as a sub-contractor on the T2D project through the Industry Capability Network.

The consortium has committed to a minimum of six per cent Indigenous employment on the project, as well as more than 600 jobs for apprentices and trainees, and opportunities for more than 220 long-term unemployed people.

Main construction works are proposed to start in 2025, with tunnel boring machine works for the southern tunnels planned to begin in the second half of 2026.

Federal Minister for Infrastructure, Transport, Regional Development and Local Government, Catherine King, said, “The Australian Government is pleased to be partnering with the South Australian Government to deliver the infrastructure that South Australia needs, including the major investment in the T2D.

“The project will not only revolutionise the way locals move around their region, but unlock new transport opportunities for tourists to visit the area as well.

“Our Government is working closely with the South Australian Government to deliver meaningful projects and actions, ensuring our planning and investment comes together to provide the best and safest outcomes for commuters and communities.”

South Australia Premier, Peter Malinauskas, said, South Australians have waited for a non-stop trip from North to South through Adelaide for decades.

“This is a significant milestone – one that will see thousands of South Australians employed building the biggest infrastructure project in the state’s history,” Mr Malinauskas said.

“We’ll have three Tunnel Boring Machines operating instead of two – guaranteeing this project will be delivered on time.

“In fact, once the TBMs arrive next summer, we’re hopeful the delivery deadline can be brought forward.

“Once complete, this project will see traffic move between West Hindmarsh and Darlington in just nine minutes, saving 30 to 40 minutes of travel time during peak hour.”

South Australian Minister for Infrastructure and Transport, Tom Koutsantonis, said, “We are delivering certainty for South Australians by making good on our promise to award the Alliance contract for the River Torrens to Darlington Project by the third quarter of 2024.

“The successful consortium comes with an incredible wealth of knowledge and experience, and has committed to deliver the project on budget, providing South Australians with far-reaching benefits.”

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