Sydney’s new metro railway will run through two purpose designed and built tunnels.
A number of factors determine the tunnel route and alignment. These include:
- the location, depth and structure of the stations
- vertical track grade
- rock conditions
- track curvature, to allow train speeds of up to 100 kilometres an hour
- the physical constraints of the route, including crossing under Sydney Harbour.
Stage 1: Sydney Metro Northwest
Tunnelling finished in January 2016 on Australia’s longest railway tunnels – twin 15 kilometre tunnels from Bella Vista to Epping as part of Stage 1 of Sydney Metro.
Stage 2: Sydney Metro City & Southwest
Tunnelling will start in 2018 on the twin tunnels for Stage 2, from Chatswood to Sydenham, including under Sydney Harbour and through the central business district (CBD).