The work is designed to ensure that the project is ‘shovel ready’, with a focus on assessing the structural integrity of the line's partially constructed sections.

“As with any new, major piece of infrastructure, we need to make sure that we get the planning right from the very beginning. What's more, the work of the consultants will be vital to securing the necessary planning and environmental approvals,” said Federal Infrastructure and Transport Minister Anthony Albanese.

“Our aim is to have all pre-construction activities wrapped up in time for the project to be considered for possible inclusion in our next multi-billion dollar road and rail construction program, due to start in mid-2014.”

The large-scale project will involve laying 35km of standard-gauge track connecting Port Kembla to the Main North-South Line via Dombarton. It will include two passing loops, new bridges over the Nepean and Cordeaux rivers, and one of Australia's longest tunnels.

“The engineering team is focusing on design and safety issues associated with operating diesel-hauled freight trains through a 4km long tunnel,” said Albanese.

Additional work includes surveying the connecting ends of the line, assessing the condition of embankments, drainage and cuttings, and potential construction sites along the corridor.