Tunnelling in full swing

Tunnel Boring Machines (TBMs) Millie and Alice are making great progress, with Millie now having completed more than a quarter of her journey towards the eastern tunnel entrance in South Yarra and Alice not far behind. Having progressed more than 170 metres through the Anzac Station box under St Kilda Rd since being launched in April and May, both TBMs Millie and Alice have so far completed more than 311 and 211 metres of the Metro Tunnel, respectively. Crews of 10, including a TBM operator, are working around the clock on each tunnelling machine as the TBMs move underground excavating rock and soil, then progressively lining the tunnel with concrete segments. Above ground, works are continuing to complete construction of the Anzac Station roof. The station is being built “top down”, with the walls and roof built first followed by excavation underneath. This methodology minimises disruption and keeps the community moving safely around the worksite. Roadheader breakthrough under Swanston St Workers have excavated deep under Swanston St to create a space longer than a city block and as deep as a five-storey building for the Metro Tunnel Project’s new Town Hall Station. An excavating machine known as a roadheader broke through recently into the central cavern, where another two roadheaders had been excavating the station and three underground passenger walkways with entrances at Federation Square, City Square and Flinders Quarter (next to the Young & Jackson Hotel). More than 42,000 cubic metres of soil and rock was dug by the roadheaders –– with the machines now set to dig another eight metres down to the final depth of around 33 metres. The roadheaders – named Lily, Sharon and Clara – have been operating around 25 metres below one of Melbourne’s busiest streets since late 2019. The machines weigh up to 118 tonnes and are equipped with cutter heads that can cut through rock three times harder than concrete. This means that the full length of future Town Hall Station is now connected underground from Collins St to Flinders St and to Federation Square. Town Hall Station will give commuters access to Melbourne landmarks such as Federation Square and the Arts Centre and other popular tourist locations and allow passengers to switch easily from Metro Tunnel services to City Loop services at Flinders Street Station. Work continues across Metro Tunnel sites in accordance with strict safety measures – supporting jobs and supplying businesses through the coronavirus pandemic •