By rosebell
In early September TBM Ruby was commissioned on a 1.1km journey from Pyrmont to the future Hunter Street Station and digging process was commenced on the final leg of tunneling for the Sydney Metro West project.
This TBM with 1,100-tonne weight is expected to break through later this year and in order to building the tunnel around 37m beneath the surface its weekly average speed during excavation through Sydney sandstone will be 90m. The scheduled date for its break through at Hunter Street Station is later this year.
The travel path of this TBM is due to be below Darling Harbour from the Australian Maritime Museum to King Street Wharf for 250m, whereas the location of these metro tunnels will be 35m under the water surface level, where there is almost 5m between the harbour floor and the top of the tunnel.
The responsibility of guiding Ruby to the finish line will be up to a team of 12 TBM operators working in 12-hour shifts. Considering that the TBMs tunnel within metres of the Australian Maritime Museum, the City East electricity cable tunnel and Wynyard Station, this complex dig will require precision.
With the aim of making the final trip to Hunter Street, building the parallel tunnel to TBM Ruby, TBM Jessie is going to be relaunched from Pyrmont in the coming weeks.
Completing the 2.3km section of tunnel between The Bays and Hunter Street, the TBMs are slated to reach their final destination by the end of the year, that includes the TBMs boring below Sydney Harbour three times at Rodd Point, Johnsons Bay and Darling Harbour and tunneling within 25m of the Anzac Bridge.
Additionally, two TBMs made a double breakthrough at Pyrmont in July, while advancing with bulk excavation and profiling in the underground station and crossover cavern at Pyrmont was done by John Holland, CPB Contractors, and Ghella joint venture. The detailed boring along the edge walls of the invert, as well as the ramps that link the TBM tunnel alignment at the western and eastern ends of the cavern will be the next stage.
The planned date for starting this work, which will involve trimming and removing hard rock in small sections, progressing at approximately 60m every seven to 10 days for up to eight weeks, was 15 September.
The early 2023 was the date of commencing tunneling for Sydney Metro West, whereas linking Westmead to the Sydney CBD, major tunneling has reached 90% completion for the 24km line.
The scheduled inauguration date by Sydney Metro West is 2032 and the new line is going to double rail capacity between Parramatta and the Sydney CBD.
