Melbourne progresses Rail Loop early works 17 Dec 2020

Expressions of interest are invited by the Victoria State Government in Australia for a package of early enabling works to prepare for Stage 1 construction of the planned 90km long Melbourne Suburban Rail Loop that comprises the 26km underground route to the south east of the city (Fig 1). The works package will comprise road upgrades, installation of new substations and power supply lines, utility relocations and protection, ground improvements, and development of construction to prepare for construction of six underground stations and launch of TBMs for excavation of the Stage 1 twin running tunnels. After registering in a prequalification process, leading construction companies have signalled interest in delivering the enabling program of early works.

The 90km long rail loop will begin with the 26km underground Stage 1 element

Early works will also prepare for detailed site investigations that will include ecology and geotechnical studies. Initial site investigations started in the second half of 2019 to identify and confirm the broad alignment and general precincts of station locations. The rail corridor between Cheltenham and Box Hill was defined following 18 months of project development and design, site investigations and engineering assessments, and consultation with local stakeholders and communities. Almost 300 boreholes were drilled as part of geotechnical investigations, and the proposed station sites will now be subject to a concentrated ground testing program to determine the precise footprints and entrances to the underground stations.

Procurement of the project began when the State Goverrment allocated AUD $2.2 billion in its 2020/21 to buy the land required for the TBM launch sites and facilitate construction of the six new underground stations. The proposed locations of Stage 1 underground stations include the starting point of the line near Southland, adjacent to Monash and Deakin Universities, and a transport hub north of Carinish Road, Clayton, to connect regional passengers to the new rail loop service. The depot and train stabling facility for the Stage 1 line is proposed near the southern Cheltenham underground terminus station.

Stage 1 will include six new underground rail stations

The Suburban Rail Loop is an investment in the long-term rail service infrastructure of Victoria to support continued growth of its State capital city of up to a projected nine million people by 2050. Following Stage 1, connecting health, education, retail and employment precincts in the south east of the city, future stages will continue the line through the northern suburbs to connect the major railway lines from the Frankston Line to the Werribee Line via the Melbourne international airport. Additional technical investigations will develop subsequent stages of the project, which are expected to be a combination of underground and surface rail infrastructure.

Rail Projects Victoria (RPV) is the team leading the design development, station location assessments and operational requirements of the project. RPV has engaged the assistance of the Aurecon-Jacobs-Mott MacDonald Joint Venture (AJM) as technical adviser to the project and KPMG as the commercial adviser. The project will allow people to travel by train around Melbourne without having to connect in and out of the central city rail station hubs.

TBMs will excavate the 26km of twin tube alignment

Premier of Victoria Daniel Andrews is championing the project stating that “we are not wasting a minute getting this vital project started”. Minister responsible for the project Jacinta Allan said: “This is the biggest transport project in Victorian history. After saying we would get on and deliver Stage 1, we know that the best construction companies want to be a part of delivering it. The $2.2 billion investment for the initial and early works on Stage 1 will help drive our State’s recovery from the coronavirus pandemic.” Works are to start in 2022 and create up to 800 direct jobs in initial and early works. A $300 million allocation in the 2019 State budget delivered progress in the design and development of the project, enabled engineering and rolling stock assessments, and advancement of the investment case which is expected to be completed by early 2021.

The Suburban Rail Loop project adds to current major underground projects in the State of Victoria for improving and expanding transportation infrastructure in and around Melbourne including the West Gate highway project, which has deployed two mega TBMs to excavate the 6.6km three-lane tunnels, and the Melbourne Metro project that is currently using four slurry TBMs to excavate 9km of twin running tunnels linking five new underground stations.