tunnelling works australia
Sydney’s NorthConnex project tunnelling work has been wrapped up. Credit: Engineers Australia.

Tunnelling work of Australia’s longest road tunnel, as part of the A$3bn ($2.12bn) NorthConnex project in Sydney, has now been wrapped up.

The twin 9km tunnel will connect Sydney’s M1 Pacific Motorway at Wahroonga to the Hills M2 Motorway at the existing Pennant Hills Road interchange.

The tunnel currently has two lanes with an option to add three additional lanes for future expansion and can accommodate vehicles up to 5.3m high.

The tunnel will help motorists to drive between Newcastle and Melbourne without stopping at traffic signals.

The tunnelling commenced in mid-2016 with the first road header entering the ground at West Pennant Hills.

“The tunnel will help motorists to drive between Newcastle and Melbourne without stopping at traffic signals.”

NSW Minister for Transport and Infrastructure Andrew Constance said: “Fast forward two years, 14 breakthroughs, 2.4 million cubic metres of spoil, and the twin 9km tunnels are ready to be paved.”

During the entire tunnelling project, nearly 2,550,000m3 of spoil has been excavated and approximately 300,000m3 of shotcrete and concrete has been used to its development.

The NorthConnex project will help to cut down traffic volume by diverting up to 5,000 trucks per day from Pennant Hills Road, save up to 15 minutes travel time to motorists, and allow travellers to bypass up to 21 traffic lights. The project will also enable the integration of the regional transport network by connecting the orbital network with the M1.

NorthConnex project is expected to complete by the end of next year.