Tunnelling teams working on the Coffs Harbour bypass have hit another major milestone after ‘breaking through’ on what will be the second largest of three tunnels being built for the project.

The breakthrough at Shephards Lane means people can pass from one side of the 320m tunnel to the other and follows a breakthrough at the 410m Gatelys Road tunnel in November last year.

Transport for NSW North Region Director, Anna Zycki, said breaking through was a significant achievement but there was still plenty of work to do before the tunnels could take traffic.

“The top of the tunnel tube, called the heading, will be excavated and then the project team will go through again to excavate the base of the tunnel tube, known as the bench,” Ms Zycki said.

“All the electrical equipment needs to be installed, the inside of the tunnel waterproof sealed, the road and cycleways constructed, and system testing carried out.

“Waterproof sealing stops water getting onto the road, which improves safety. It also increases the tunnel lifespan.

“This work will continue over the next 18-20 months, but this milestone is worth celebrating.”

Ms Zycki said work was also progressing well on Gatelys Road tunnel, which is already being sprayed with a waterproof lining, and excavation would start next month on the 160m Roberts Hill tunnel.

“That work will be carried out 24/7 and we’re anticipating we’ll have breakthrough there by mid-year,” she said.

"We expect all three tunnels will be waterproofed by Christmas this year and then we’ll spray them with concrete, install the paving and finally carry out the electrical fit out.”

source/text: NSW Gov. /video:youtube