SA North-South Corridor T2D Project marks new major milestone

Monica Gameng   |   July 9, 2021
Torrens to Darlington tunnel (cr: Government of South Australia)

Construction on the tunnels for the Torrens to Darlington Project – the final section that will complete the North-South Corridor – in South Australia is a step closer to commencing as the location for the tunnel boring machines (TBMs) launch site is revealed. 

A purpose-built site is going to be established near Tonsley Boulevard in Clovelly Park and this southern laydown area is where the two TBMs are going to be assembled and launched to dig 4 kilometres-worth of tunnels. 

This project site will also provide facilities to support the operation of the TBMs – including workshops, storage facilities, tunnel access paths and transport routes. 

“The Morrison Government has invested billions in the North-South Corridor – the most significant infrastructure project ever undertaken in the state – as part of its record $110 billion infrastructure investment pipeline, which is helping to drive the nation’s world-leading economic recovery. 

“Significant work has already been done to progress this project, including hundreds of geotechnical investigations and the design for relocation of important utility services such as water, gas and telecommunications,” Federal Minister for Communications, Urban Infrastructure, Cities and the Arts Paul Fletcher MP said. 

With this new announcement, the last and most complex section of the North-South Corridor will soon commence construction, supporting thousands of South Australian jobs. 

In addition, the project team has started engaging with affected property owners in the southern laydown area and negotiations to acquire property have commenced as well. 

“When we announced this project, we made a commitment to let the community know as soon as possible, when activities would begin in particular locations and which properties were likely to be impacted. 

“When we know, you’ll know and as soon as we get certainty on elements of the Reference Design, we’ll be engaging with impacted land owners directly, before information is shared with the broader public. 

“By announcing that we’ve started property acquisition in the southern laydown area, we’re ensuring everyone who has a stake in this project and in the local community is aware of the progress that’s been made and how the next steps will play out,” SA Minister for Infrastructure and Transport Corey Wingard MP said. 

Negotiations with affected property owners will be conducted privately, with due process and respect. 

The preferred solution for the Torrens to Darlington section of the North-South Corridor will save hundreds of homes and businesses from acquisition as this project will only require about 390 properties to be acquired – which is 480 properties fewer that an open-motorway option. 

Development of the reference design for the Torrens to Darlington Project is currently underway and it is expected to be finalised in the second half of this year. 


The Torrens to Darlington Project will have a hybrid+ design that combines the use of tunnels, lowered and ground-level motorways along with overpasses and underpasses at key intersections. 

60 per cent of the Torrens to Darlington Project is going to be underground tunnels, which will be delivered in two stages: 

  • Stage One: Southern Tunnel – Linking Anzac Highway to Darlington 
  • Stage Two: Airport Link and Northern Tunnel – Linking River Torrens to Anzac Highway 

“The hybrid+ design means around 60 per cent of the project will be tunnels. 

“We’re proud to be delivering a project of this scale and complexity, and proud of the difference it will make for thousands of South Australian each day,” Minister Wingard said. 

The 10.5-kilometre Torrens to Darlington section will complete the 78-kilometre non-stop motorway that runs from Gawler to Old Noarlunga and will allow motorists to bypass about 21 sets of traffic lights between the River Torrens and Darlington. 

This project is jointly funded by the Australian and South Australian Governments, and approximately $5.4 billion has been invested to deliver the section between Darlington and Anzac Highway. Major construction on this section is anticipated to commence in 2023 and completed in 2028. 

This multi-billion-dollar project is estimated to create up to 4,000 jobs.

Source: Premier of South Australia – Media ReleasesMinister for Communications, Urban Infrastructure, Cities and the Arts; T2D Torrens to Darlington (1, 2); Government of South Australia – Building What Matters 

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Monica Gameng
As Felix's Marketing Assistant since 2015, Monica is responsible for researching and sharing new and progressing projects within the construction and mining sectors in Australia. It's no surprise that Monica has her finger on the pulse of Australian major projects given she has produced more than 1,000 posts. She truly is an industry expert.
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