Now that tunnelling is complete, tunnel boring machines (TBMs) Zelda and Gillian have been officially dismantled and removed from site – here’s a look back on their journey:
Now that tunnelling is complete, tunnel boring machines (TBMs) Zelda and Gillian have been officially dismantled and removed from site – here’s a look back on their journey:
The TBMs began their 5.3 kilometre tunnelling venture in late-2024, breaking through approximately 2 years later with Zelda completing her journey first in May 2026 followed by Gillian in July 2026.
They removed 5 million tonnes of rock and dirt and installed more than 43,000 pre-cast tunnel segments.
Our TBMs were named after local legends Zelda D’Aprano AO (1938-2018), a prominent women’s rights activist in Victoria advocating for equal pay, and Dr. Gillian Opie, a neonatal paediatrician who founded Australia’s first breast milk bank more than 10 years ago.
After completing their journeys, they were dismantled with parts being recycled or sent back to the manufacturer for other use.
For TBM Zelda, the cutterhead weighing more than 380 tonnes was lifted out of site and then dismantled.
The cutterhead centre was cut into smaller pieces and transported to a mill to be recycled.
At the mill, the pieces were cut down even further, to go into furnace to be melted down, reshaped into steel reinforcement and reused on different Melbourne projects.
Now what’s next for the tunnels?
The remaining 1.2km of the overall 6.5km tunnels have been built via road headers and top-down construction, allowing for 4 lanes to be constructed in each direction between Manningham and Bulleen.
Now that both TBMs have been successfully removed from the tunnel area, fit out works are underway, including:
- building the road (3 lanes each way) inside the tunnels using approximately 700,000 tonnes of reinforced concrete
- installation of approximately 3,300 kilometres of cabling
- completion of 51 emergency access passages between the tunnels
- completing tunnel entry and exit ramps at Manningham and Yallambie.
Once completed in 2028, the North East Link tunnels will connect the M80 Ring Road and the upgraded Eastern Freeway, fixing the missing link in Melbourne’s freeway network.
