Construction of SRL East is underway, with tunnelling now started.

Suburban Rail Loop (SRL) East will slash travel times and cut congestion, while helping deliver thousands more homes within walking distance of the new stations - close to jobs, healthcare, green open spaces and universities. Trains will be taking passengers in 2035.

Tunnels are being built using specialised tunnel boring machines (TBMs). TBMs started arriving on site in late 2025 to build 26 kilometres of twin tunnels between Cheltenham and Box Hill. At their deepest point, the tunnels will be approximately 60 metres below ground, the equivalent depth of a 16-storey building.

Each TBM is more than 100 metres long, with a cutterhead more than seven metres in diameter. All TBMs will be powered by renewable electricity.

Introducing out TBM names

Tunnel boring machines (TBMs) around the world are given names to give each machine its own identity and help crews and the community follow their progress underground.

TBMs are named after women, as a sign of good luck. This dates back to the 1500s, when workers prayed to St Barbara, the patron saint of miners and tunnellers, for protection underground.

The SRL East TBMs have been named by local primary school students, honouring Victorian women who have made a big contribution to our community.

TBMs for Burwood to Box Hill

TBMs for Burwood to  Glen Waverley

TBMs for Glen Waverley to Clarinda

TBMs for Clarinda to Cheltenham

About the TBMs

Our tunnel boring machines (TBMs) are more than 7 metres in diameter and between 100 metres and 150 metres long.

TBMs are like underground factories, with a state-of-the-art navigation system. They are fully equipped with facilities for staff, including an office, kitchen and toilets. Each TBM is staffed and monitored 24 hours a day, 7 days a week with up to 25 people working in each TBM. Workers include the pilot, who drives the TBM, as well as tunnel and electrical engineers.

The rotating cutterhead grinds through rock and soil. As the TBM moves, it installs a concrete lining behind it, which then becomes the tunnel walls.

The soil passes through the TBM cutterhead, into the excavation system, where it will be carried to the surface by conveyor or slurry pipe, depending on the TBM type.

Find out more about our tunnelling works

SRL East underground stations will be as close to the surface as possible to minimise travel times for passengers. The stations will vary in depth, between 15 and 30 metres below street level.

What will you do with rocks and soil excavated from the tunnelling?

Construction of SRL East will generate around 3.5 million cubic metres of excavated rock and soil during tunnelling.

Excavated material is transported via enclosed conveyor systems into purpose-built acoustic sheds, where it is stored in enclosed bins before being removed from site. Trucks are loaded inside the acoustic shed and are washed, weighed, covered, and GPS tagged before leaving the site. All trucks are fully sealed so there is no soil dropping onto the road.

Excavated soil is tested and managed safely in line with EPA requirements and environment and planning controls arising from the comprehensive SRL East Environmental Effects Statement.

Inside the TBMs

This type of TBM is being used along the northern section of the SRL East tunnelling alignment. All SRL TBMs will be powered by 100 percent renewable energy.

What to expect during tunnelling

Will I hear or feel tunnelling under my home or business?

The SRL East tunnels will be constructed deep underground, generally between 20 and 40 metres below the surface, with the deepest sections approximately 60 metres underground.

Tunnel boring machines (TBMs) are designed to minimise noise and vibration. The vast majority of people who live above the proposed path for tunnelling will not notice tunnelling occuring underground.

We have undertaken extensive modelling and monitoring to predict and manage potential impacts from tunnelling. Noise, vibration and ground movement will be continuously monitored to ensure tunnelling remains within strict environmental requirements and safe operating limits.

The level of any ground-borne noise or vibration experienced at surface level will vary depending on local ground conditions, tunnel depth and building type.

For additional peace of mind, properties located directly above the tunnel alignment will be offered a property condition survey ahead of tunnelling works.