The first TBM is being assembled for Melbourne’s North East link twin road tunnels.

Components of the first of two Herrenknecht TBMs are being lowered into the 200m-long launch box in Watsonia by a 550-tonne gantry crane. The TBMs have a diameter of more than 15m and are among the largest in the southern hemisphere. Each is 90m long and weighs 4000 tonnes.

They will start digging the 6.5km tunnels in the middle of this year. They will work their way south from Watsonia toward Bulleen, installing around 44,000 concrete segments.

Work has also started on the underground box structures where the TBMs will end their journeys.

North East Link will be completed in 2028. It is Victoria’s largest road project, and the biggest investment in Melbourne’s north-east. As well as the tunnels, it includes the Hurstbridge Line Duplication, Fitzsimons Lane Upgrade and removing 21 level crossings.

Spark consortium, comprising Webuild, GS Engineering and Construction, CPB Contractors, China Construction Oceania, Ventia, Capella Capital, John Laing Investments, DIF and Pacific Partnerships, was awarded the contract to build, operate and maintain the tunnels and key interchanges.