The fourth of five tunnel boring machines (TBMs) has started tunnelling under Sydney.
TBM Mabel has been launched at Chatswood to help deliver 31km of tunnels between Marrickville and Chatswood on Sydney Metro, extending Australia’s biggest public transport project into the Sydney CBD.
The new TBM, together with TBM Wendy which launched last month, will each build 6.2km tunnels to the edge of Sydney Harbour and tunnel towards the new Sydney Metro stations being constructed at Crows Nest and North Sydney.
Mabel is one of five TBMs that will excavate 5.9M.t of rock and a fifth TBM will deliver the twin tunnels under Sydney Harbour.
TBMs Nancy and Mum Shirl, which started work late last year from Marrickville, are excavating 8.1km tunnels which will pass underneath the CBD and on to Barangaroo, and with TBM Wendy have already built more than 2.5km of tunnels between them –10% of the tunnelling.
The TBMs are about 150m long and designed for Sydney’s geology to cut through hard sandstone.
The latest TBM is named after Mabel Newill, who was a matron at Royal Prince Alfred Hospital and an Australian war nurse in World War I. Newill made a significant contribution to medicine in Sydney by introducing sanitation techniques to help stop the spread of typhoid at RPAH in the early 1900s.