TBMs Dorothy and Betty power into Parramatta
Tunnelling for the Sydney Metro West project is nearly 90% complete, with the arrival of two TBMs at Parramatta’s metro station site. This marks a pivotal step forward for the city-shaping project and brings Sydney’s second CBD closer than ever to fast, frequent and reliable turn-up-and-go metro services, connecting Greater Parramatta to the Sydney CBD.
TBM Dorothy is at Parramatta after breaking through a solid rock wall to reach the site last week, while TBM Betty is already 175 m into its final stretch of tunnel to Westmead after departing Parramatta on 17 July.
The TBMs worked around the clock, five days a week for 17 months to build the 7km tunnels between Sydney Olympic Park and Parramatta.
They have excavated approximately 1.25 million tonnes of earth - and installed more than 48,000 precast concrete segments, each weighing up to 4 tonnes, to line the tunnels.
Both TBMs will complete the main line tunnels at the western end of the line by the end of the year.
Six of the nine station boxes for the Sydney Metro West project have been excavated and lined; including at The Bays, Five Dock, Burwood North, North Strathfield Sydney Olympic Park and Westmead. Work continues at Parramatta, Pyrmont and the Hunter Street station in the Sydney CBD.
Parramatta metro station will anchor a mixed-use development of four buildings spanning 24,150 square metres over the equivalent of two city blocks, providing about 100 new homes, office and retail spaces, dining and entertainment.
The new transit hub will be a short stroll to nearby Eat Street, adjacent to Light Rail services and link directly to the new Civic Link, a 450-m-long pedestrian spine connecting the metro precinct to the future Powerhouse Parramatta.
TBMs Jessie and Ruby have broken through to the Pyrmont Station cavern
The Sydney Metro West project reaches a significant milestone with the arrive of the two TBMs Jessie and Ruby in the Pyrmont station cavern, 24 m below ground.
This carefully coordinated breakthrough followed weeks of detailed planning. Inside the cavern, the construction team used a roadheader to excavate 1.2 m of rock from the tunnel face. The TBMs then advanced the final 300 mm safely navigating a known fault zone and the slurry pressure of the mixed shield machines.
Now with the breakthrough complete, both machines will have a five-week pit stop at Pyrmont as they traverse through the station and crossover caverns, 168 m and 145 m long. Once they reach the eastern end of the cavern, the TBMs will undergo maintenance ahead of starting their final stretch of tunnelling, under Darling Harbour to Hunter Street Station in the Sydney CBD.
The arrival of the TBMs on the same day, five hours apart, was a landmark event for the tunnelling team, marking the second double TBM breakthrough for the project. The first “double breakthrough” was achieved when TBMs Daphne and Beatrice broke through two minutes apart to arrive at the site of the future Five Dock Station in December 2023.
The TBMs are building the 2.3-km section of Metro West tunnels from The Bays and have just over 1km of tunnelling remaining to connect the city-shaping project to the heart of the city. The 7 m wide tunnels - sit at an average depth of 37 m - are lined with precast concrete segments produced at the Eastern Creek facility.
To arrive at Pyrmont, the 1,100-t machines have completed one of the most complex digs on the project, moving within 25 m of the Anzac Bridge, under Johnstons Bay and through the complex geographical ground of the Luna Park Fault Zone.
Pyrmont Station and the 31-storey over station development will contribute to the vibrancy of Sydney’s Pyrmont peninsula, making it easier for passengers to access the area than ever before.
For further information click here and au/11 for tunnelbuilder archive. Visit https://www.sydneymetro.info/ and https://www.ghella.com/. 31/25.
