By rosebell
While the number of TBMs previously anticipated to be used on South Australia’s River Torrens to Darlington (T2D) Project is currently up to twice, the South Australian government and the T2D Alliance have concluded a contract to purchase three initial TBMs from Herrenknecht and infrastructure. Additionally, transport minister Tom Koutsantonis confirmed plans to purchase two additional, smaller TBMs, with another likely to follow to dig the cross-passages between the main tunnels. The estimated total cost for all TBMs is almost A$180m (£93m).
Following two weeks that the main construction contract was officially signed by the T2D Alliance of John Holland, Bouygues Construction, Arcadis Australia, Jacobs and Ventia, the purchase of the three initial TBMs was done.
Before being assembled and factory assurance tested in China and then delivered to Adelaide, the TBM components are due to be manufactured in Germany and China, whereas the scheduled date for arivval of the first one is late 2025.
The TBMs used to construct the T2D tunnel will be approximately 100m in length and 15m in diameter.
By constructing the cross-passages, the additional smaller 4.1m diameter TBMs will save time on conventional construction methods.
Considering that three initial TBMs have been purchased for the major tunneling work, the northern and southern tunnels can be constructed concurrently.
The determined date for commencing the main construction works is 2025, while the second half of 2026 is the date that TBM works for the southern tunnels planned to begin and the project is slated to be completed in 2031.
As the final section of the North-South Corridor and South Australia’s largest infrastructure project, the T2D project is being jointly delivered by the Australian government and the South Australian government. Two sets of twin, three-lane tunnels will account for more than half of the 10.5km stretch of road.
