Work will start soon on a $9-billion metro line in Melbourne, Australia. The project, said to be the state of Victoria’s largest-ever trans­portation investment, follows a larger expansion of the metro serving Sydney, some 800 kilometers away.

The Victoria state government last month closed a $4.8-billion, availability-based public-private partnership on the Melbourne metro with an Australian-French consortium and covering the line’s 9 km of twin tunnels and five underground stations.

The tunnels will carry two of the city’s busiest existing lines through downtown Melbourne. It will boost peak-time network capacity by 39,000 passengers, according to government officials.

The new P3 deal between Melbourne Metro Rail Authority (MMRA) and Cross Yarra Partnership covers 25 years of maintenance after construction completion, due in 2026. It includes development of parks as well as pedestrian and retail space in public areas around the stations.

The consortium is owned by Lendlease Engineering Pty. Ltd., John Holland Group Pty. Ltd. and France’s Bouygues Construction S.A. Lendlease subsidiary Capella Capital is the team’s infrastructure developer, financial adviser and equity investor. Bouygues estimates the job will create about 5,000 construction jobs.

Of four tunnel-boring machines due to be procured early this year to drive the tunnels, the first is planned to start work next year, says a MMRA spokesman.

Having supported the winning bid, the joint-venture design team of Arcadis N.V., Arup Group Ltd. and WSP Global Inc. will handle design of the tunnels and stations for Cross Yarra Partnership.

Preparatory work on the new metro began in fall 2016 under a $261-million contract with John Holland, awarded that June. The contract includes the relocation of 100 utilities and the sinking of a 35- meter-deep access shaft, near Swanston Street, for station construction.

Victoria state also has awarded a roughly $900-million contract to Metro Tunnel Project Rail Systems Alliance to equip the line. The contract covers around 90 km of existing rail corridors and the new 9-km twin tunnels.

The alliance, including CPB Contractors and Bombardier Transportation, will design, supply, install and commission train, power control and operational control systems, as well as conventional and high-capacity signaling.