The five TBMs are part of the AU$2.81bn (£1.6bn) tunnelling contract awarded to the John Holland CPB Ghella joint venture, which chose Herrenknecht to design, build and deliver the machines.
Minister for transport and infrastructure Andrew Constance has confirmed tunnelling will start before the end of the year. “The arrival of these giant machines is a key milestone in the Sydney Metro project,” he said. “The sheer size of each tunnel boring machine is hard to comprehend – at around 150 metres long it’s the equivalent length of two Airbus A380 jets nose to tail. They’re also extremely powerful and have been specially designed for Sydney’s geology to cut through hard sandstone.”
This is the first time in Australian history that five TBMs have worked on a transport infrastructure project. They will deliver new 15.5km twin metro railway tunnels from Chatswood to Sydenham, including under Sydney Harbour. Two will dig 6.2km from Chatswood to the edge of Sydney Harbour. Two will travel 8.1km from Marrickville to Barangaroo. The fifth TBM has been specially designed to deliver twin 1km-long tunnels under Sydney Harbour. Each machine is expected to tunnel an average 120 metres a week.
Each TBM is arriving at the Marrickville launch site in eight shipping containers accompanied by 23 other separate pieces so big they don’t fit into a container. These pieces include a 100t cutter head and a 128t section of the round steel tunnelling chamber, each delivered on truck trailers with 68 wheels.
The first 1,100t TBM will now be assembled and tested ready for launching later this year. It will tunnel to the new Waterloo Station, then continue under the Sydney central business district via new metro station sites at Central, Pitt Street, Martin Place and on to Barangaroo Station.