Sydney Metro’s third of five Herrenknecht TBMs has now started tunnelling, marking the next stage in delivering the new 31km of metro twin 6m i.d. tunnels below the centre of Sydney and deep under Sydney Harbour.
TBM Wendy has started digging the 6.2km of tunnel from Chatswood to the edge of Sydney Harbour at Blues Point.
Premier Gladys Berejiklian said it is another major metro milestone.
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“Yesterday we saw a metro train complete its first full journey on the entire length of the Metro Northwest railway line, and now we’re starting work on another key stage of the project,” Ms Berejiklian said.
“Wendy joins TBMs Nancy and Mum Shirl, the mega borers which launched last year and are now tunnelling from Marrickville towards the CBD.
“With two more machines due to start work this year, the borers will build 31km of Sydney Metro tunnels between Marrickville and Chatswood, including the first rail tunnels under Sydney Harbour.
So far, TBMs Nancy and Mum Shirl have excavated 1.3km of tunnel and 114,000 tonnes of crushed rock from Marrickville on the 8.1km journey to Barangaroo.
The five purpose-built TBMs, four double-shield, hard-rock TBMs to bore through Sydney’s hard sandstone, and a mixed-shield slurry TBM, specially designed to excavate in the under-harbour ground conditions.
Wendy and another TBM will tunnel towards the new Sydney Metro stations being constructed at Crows Nest and North Sydney before being retrieved at a temporary construction site at Blues Point.
A fifth machine has been specially designed to deliver the twin tunnels under Sydney Harbour.
The Sydney Metro tunnelling contractor is John Holland CPB Ghella wjoch was awarded the $2.81bn contract in June 2017.
Metro rail is being extended into the Sydney CBD and beyond to Bankstown – in 2024, Sydney will have 31 metro stations and a 66km metro railway.