Suburban Rail Loop Tunnelling Begins on Melbourne’s Biggest Build

The launch is the start of the main tunnelling phase for SRL East, with eight tunnel boring machines ultimately expected to excavate the underground rail corridor.

The machines will work from two main launch sites. Four will operate from Burwood, tunnelling towards Glen Waverley and Box Hill, while another four will launch from Clarinda to excavate the southern section towards Glen Waverley and Cheltenham.

A third machine is due to launch from Clarinda later this year, while others machines will launch from Burwood towards Box Hill and from Heatherton towards Cheltenham in 2027.

The tunnelling program will create an underground corridor connecting six new stations at Cheltenham, Clayton, Monash, Glen Waverley, Burwood and Box Hill.

The tunnels will be an average of 26m underground and reach about 60m at their deepest point. The machines can advance by up to 90m a week depending on ground conditions.

In a Victorian first, the two Burwood machines are being launched using an “umbilical method”, allowing the front section of the machine to begin excavation while the remainder is assembled progressively behind it because of space constraints at the launch site.

The machines are being assembled in sections and lowered into the launch site, with acoustic sheds, conveyors and other infrastructure built to support tunnelling operations.

More than 3000 people are already working across the SRL East project, which has been under construction since 2022.

The tunnelling milestone comes as the Victorian Government moves to reduce the cost of SRL East. The project had been budgeted at up to $34.5 billion, but Premier Ben Carroll announced in August that the government was targeting $2 billion in savings.

The first $1 billion is being found through scope changes, including the removal of planned underground interchanges at Box Hill and Glen Waverley, a multi-level car park at Glen Waverley, a second entrance at Clayton and a pedestrian bridge at Burwood.

A further $1 billion in savings is being targeted through an independent technical review.

The cost-cutting push comes alongside funding pressure on the project. The Victorian Auditor-General reported in August that there was a $5.5 billion gap between the state’s estimated project cost and approved funding, largely because Commonwealth funding is $5.5 billion below the amount Victoria had sought.

The Federal Government has committed $6 billion to the project, including an additional $3.8 billion announced in May.

Despite the review and scope changes, the state says SRL East remains on track to open in 2035.

The project is expected to reshape development around the six station precincts, with structure plans for all six precincts finalised in July.

The government has positioned the rail loop as a catalyst for higher-density housing and new employment around stations, while providing orbital connections between Melbourne’s existing radial rail lines.

The first passengers are expected to travel on SRL East in 2035.