Tunnelling under the Sydney Harbour is now complete, with 87,400 tonnes of sandstone, clay and sediment excavated by tunnel boring machine (TBM) Kathleen.
It is the first metro rail tunnel ever to be built under the Sydney Harbour and is a major milestone for the Sydney Metro project.
Premier Gladys Berejiklian and Transport Minister Andrew Constance visited the deepest point of the tunnel, 40 metres below the harbour floor to meet workers who built it.
“This is an engineering feat of historic proportions for our great city which will forever change how we get around Sydney,” Berejiklian said.
“Today we have made history walking deep beneath Sydney Harbour for the first time, inside one of two metro railway tunnels to be built as part of this mega project.”
- TBM Kathleen begins digging under Sydney Harbour
- Sydney Metro to launch TBM under Sydney Harbour
- TBM Wendy breaks through at North Sydney
TBM Kathleen has been digging railway tunnels under harbour since June, having been launched from the site of the new Barangaroo Station. It took almost four months to tunnel almost one kilometre to the northern side of the harbour at Blues Point.
It has new been disassembled and its 90-tonne cutter head and front sections have been barged back across Sydney Harbour where it will then be reassembled in order to start digging the second tunnel.
TBM Kathleen is named after Kathleen Butler, who played a vital role in the construction of the Sydney Harbour Bridge, as the technical advisor to engineer John Bradfield.
TBM Wendy has also reached the harbour’s edge at Blues Point, making it the first of the five bring machines to officially finish tunnelling on the Sydney Metro City and Southwest project.
Metro trains are expected to start running through the tunnels in 2024, extending the North West Metro into the city and beyond to Bankstown.
Sydney Metro will have the capacity of a train every two minutes in each direction. It will be able to move more people across the harbour in peak hour than the Harbour Bridge and Harbour Tunnel combined.