The first of two Robbins 7.2m diameter hard rock TBMs was transported by road to the site of the 28km long Parramatta Rail Link project in Sydney, Australia, last month. It should start boring in September, with the second machine starting a month later.
The machines have been built, assembled and tested at the Forgacs Shipyard, Tomago, in the Hunter region of New South Wales, involving the input of more than 100 companies.
The US$457M first stage of the Rail Link Project will be constructed by Thiess/Hochtief JV, and will involve the construction of a 12.5km long twin-bore tunnel between Epping station and Chatswood in four drives.
The shaft (close to the centre of the alignment) and 143m long roadheader-excavated TBM launch chambers were completed in June 2003. Ground conditions were described as good; consisting of moderately jointed sandstone with minimal water inflows.
The TBMs will first bore parallel 6.4km long tunnels to Epping station, before being brought back to the shaft to bore 6.2km in the opposite direction to Chatswood. Three new underground stations at Macquarie University, Macquarie Park and Delhi Road are also being excavated.
Good quility sandstone and shale make up the geology for the majority of the alignment, which is expected to provide excellent conditions for tunnelling This section of the rail link should be completed by mid-2008.
See photos: The two 7.2m diameter Robbins hard rock TBMs, designed for the Parramatta rail link in Sydney, Australia, were constructed at the Forgacs Shipyard in Tomago, New South Wales. This project is reported to have been a boost for the region, creating 70 direct jobs and injecting about US$10M into the local economy. Each TBM and its backup is 210m long, and weighs 1,060t. Overall, 1Mbcm will be excavated (equivalent to 150,000 truck/bogey loads), and 220,000m3 of concrete will be used in the construction of the tunnels
