The three are Capstone, G2K Konnect and Regionerate Rail. The submissions will take the route from Gowrie, near Toowoomba to Kagaru, near Beaudesert and include the 6.2km tunnel through the Toowoomba Range and 128km of track.

Capstone consists of CPB Contractors, Ghella, UGL, DIF, Pacific Partnerships. G2Konnect comprises Acciona, Ferrovial, Cintra, Macquarie while Regionerate Rail comprises Clough, GS Engineering and Construction, Webuild (formerly Salini Impregilo), Lend Lease Services and the Plenary Group.

Inland Rail chief executive Richard Wankmuller said it was an important milestone for the project and the winning bidder would be announced in 2022.

“The RFP process will enable ARTC to leverage the considerable global engineering expertise required to deliver innovative design solutions and efficient construction methods for this technically challenging terrain,” he said.

“The PPP will deliver the 128km from Gowrie to Kagaru and will include construction of three tunnels and numerous viaducts, bridges and crossing loops.

“The geology and topography of this section, mostly located within protected corridors, poses many challenges which have required us to undertake a lot of site investigations to obtain a better understanding of the conditions and inform the final design,” Wankmuller said.

“The PPP process will draw on the private sector’s experience and innovation to deliver the world-class engineering solution required to traverse the Great Dividing Range,” he said.

“This is the type of challenge that excites multi-national contractors, engineers and financiers. This is the type of iconic project that consortia will use to showcase their credentials when pursuing future contracts.

“The PPP section has already generated jobs associated with the geotechnical investigations, cultural heritage surveys and environmental impact assessments.

“More than $1 billion in contracts have been awarded to companies working on Inland Rail to date,” he said.