• Published: Sunday, 29 September 2024

Up to twice the number of Tunnel Boring Machines previously anticipated will be delivered to South Australia for the landmark River Torrens to Darlington (T2D) Project, giving hope the state’s biggest ever infrastructure project can be completed even quicker.

In an historic signing ceremony, the South Australian Government and the T2D Alliance have formally sealed a contract to purchase three initial TBMs from world-leading manufacturer Herrenknecht.

Infrastructure and Transport Minister Tom Koutsantonis can also today confirm plans to purchase two additional, smaller TBMs – with another likely to follow – to carry out  excavation work between the main tunnels. The total cost of all TBMs is expected to be around $180 million.

The purchase of the three initial TBMs comes just two weeks after the main construction contract was officially signed by the consortium of John Holland, Bouygues Construction, Arcadis Australia, Jacobs and Ventia – with the Government wasting no time in getting ready for the start of main construction.

Minister Koutsantonis formalised the purchase of the initial three TBMs at a signing ceremony and tour of the Herrenknecht Headquarters in Schwanau, Germany.

Herrenknecht has delivered TBMs around the world, including to the United States, England, China, Singapore, Italy and Qatar - as well as Australia for projects such as the Sydney Metro and the North East Link and West Gate Tunnel Projects in Melbourne.

The TBM components will be 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 in late 2025.

Once in Adelaide, it will take time to assemble and commission the TBMs before they can start tunnelling works.

The TBMs being used to construct the T2D tunnel will be approximately 100m in length and 15m in diameter - roughly the height of the Thebarton Theatre or Edwardstown Bunnings.

New, smaller 4.1m-diameter TBMs will also be ordered to construct the cross passages of the T2D tunnels – saving time and endeavour on conventional construction methods.

These cross passages will house equipment which support the day-to-day operations of the tunnels. They will also form part of the safety systems in the tunnels as they provide a means of emergency egress in the event of a major incident in one of the tunnels.

Achieving this significant milestone on schedule provides more confidence for local industry to prepare for potential opportunities, with the State Government committed to maximising opportunities for South Australian businesses to ensure the T2D Project leaves a skills legacy.

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

The procurement of three initial TBMs for the major tunnelling work means both northern and southern tunnels can be constructed concurrently - giving a reasonable expectation that the project can not only be completed by the stated 2031 deadline, but even earlier.

The companies in the consortium have successfully delivered major tunnelling and infrastructure projects nationally and internally, including WestConnex, Sydney Metro and Southwest Tunnels and Station Excavation and Sydney Airport Rail Link, as well as the Trunk Road T2 Project in Hong Kong and High Speed 2 Link in the United Kingdom.

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.

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.

The T2D project is being jointly delivered by the Australian Government and the South Australian Government.