A mega tunnel boring machine has broken through a rock wall at North Sydney and entered the biggest underground cavern built so far on the Sydney Metro project.
Mega borer Wendy broke through at the new Victoria Cross Station 25 metres below ground.
TBM Wendy has tunnelled 4.5 kilometres from Chatswood in eight months and only has another 1.7 kilometres to reach the edge of Sydney Harbour at Blues Point.
TBM Wendy is one of five boring machines busy excavating 15.5 kilometre twin railway tunnels to help deliver more metro rail services as quickly as possible.
The huge cavern at Victoria Cross is 40 per cent bigger than both the cavern being built at Barangaroo and the cavern built 25 metres under Castle Hill on the new North West Metro.
TBM Wendy will spend about three weeks undergoing maintenance before being re-launched to complete the last 1.7 kilometre section of the 6.2 kilometre tunnel between Chatswood and the edge of Sydney Harbour.
The 150-metre-long TBM Wendy is named after Wendy Schreiber, a volunteer at Bear Cottage.