Eastern tunnel entrance construction overview
Construction is underway on the eastern tunnel entrance located within the South Yarra Siding Reserve.
A decline structure (descending tracks) will allow trains to enter the new Metro Tunnel near William Street and pass underneath the Sandringham and Frankston lines.
The decline structure and tunnel entrance are being built via a 'cut and cover' method, which involves excavating from the top down, with the surface then reinstated over the top of the tunnels.
Rail corridor widening
To construct the eastern tunnel entrance, the rail corridor between William and Chapel streets has been widened and reconfigured to allow two additional tracks to be constructed. These new tracks will then enter the new Metro Tunnel.
Tunnel boring machines
A tunnel boring machine (TBM) retrieval box is being constructed in the rail reserve between Osborne Street and the existing Sandringham line. TBMs will be used to create the tunnels linking the eastern tunnel entrance to Anzac Station and the rest of the network.
Two tunnel boring machines have been launched separately from the Anzac Station site, travelling a distance of 1.7 kilometres towards the Metro Tunnel’s eastern entrance at South Yarra. TBM Millie was launched in April 2020 with Alice following in May. The TBMs will line the twin tunnels with concrete segments to form the tunnel walls as they dig towards South Yarra.
These tunnels will pass under Osborne Street, Davis Avenue, Powell Street, Myrtle Street and Macfarlan Street and travel west under Toorak Road and St Kilda Road to connect with the new Anzac Station.
Closure of South Yarra Siding Reserve
South Yarra Siding Reserve closed in 2018 and will be used to support construction activities for up to four years.