One of five custom built mega tunnel boring machines has arrived on-site in Sydney to extend the city’s metro railway, with the number of tunnel boring machines (TBMs) set to break the record for the most used on an Australian transport infrastructure project.
The five TBMs are part of the $2.81 billion tunnelling contract awarded in June 2017 to the John Holland CPB Ghella joint venture, which contracted world-leading manufacturer Herrenknecht to design, build and deliver the TBMs.
Each TBM is about 150m long – or longer than two Airbus A380 superjumbos – and specially designed for Sydney’s geology to cut through hard sandstone.
The TBM is arriving at the Marrickville launch site in eight shipping containers and 23 other separate pieces so big they don’t fit into a container – including a 100 tonne cutter head and a 128 tonne section of the round steel tunnelling chamber, each delivered on truck trailers with 68 wheels.
The 1100 tonne TBM will be assembled and tested before it is launched in late 2018. It will tunnel to the new Waterloo Station, then continue under the Sydney CBD via new metro station sites at Central, Pitt Street, Martin Place and on to Barangaroo Station.
Tunnelling will start before the end of 2018 and will deliver new 15.5km twin metro railway tunnels from Chatswood to Sydenham, including under Sydney Harbour.
Two TBMs 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.
They are expected to tunnel about 120m a week on average.