Construction work on Melbourne’s Metro Tunnel Project has reached a new milestone as the third roadheader has broken through at the site of the future Town Hall Station.
Workers have excavated a space longer than a city block and as deep as a five storey building for the Town Hall Station using the massive excavating machinery. Two roadheaders have also been used to excavated the station and three underground passenger walkways with entrances at Federation Square, City Square and Flinders Quarter.
More than 42,000 cubic metres of soil and rock has been dug by the roadheaders – enough to fill 17 Olympic swimming pools – with the machines set to dig another eight metres down to the final depth of around 33 metres.
After being launched from City Square in 2019 the first roadheader tunnelled directly under Swanston Street and began to excavate the main station cavern. The second was launched at Federation Square to build the underground passenger connection across Flinders Street. Finally the third roadheader has been working to excavate the passenger connection between Flinders Quarter across Swanston Street to the station site.
Each roadheader has been operating around 25 metres below the CBD. Weighing 188 tonnes the machines are equipped with cutter heads that are capable of smashing through rock three times harder than concrete.
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Town Hall Station is expected to provide access to the city’s landmarks such as Federation Square, Southbank, the Arts Centre, St Pauls Cathedral and other tourist locations. It will also give commuters simple access to City Loop services at Flinders Street.
Despite COVID-19 safety restrictions the Metro Tunnel construction has been making significant progress. Four tunnel boring machines are all at work underneath the city with more than three kilometres of tunnelling completed since September 2019.
Once the roadheaders have completed excavation of the tunnels through the CBD stations tunnel boring machines will carve out the twin tunnels between the Town Hall and State Library Stations.
Transport Infrastructure Minister Jacinta Allan said this is a huge milestone for this important project, bringing Melbourne another step closer to a turn up and go rail system, while keeping our construction workers safely on the job.
“We’ve made such amazing progress, we now have deep underground a new station entrance at Federation Square, the length of the future station platform and come out at the new entrance at City Square,” Allan said.