Tunnelling

1 March 2022

The West Gate Tunnel Project is building twin tunnels between the Maribyrnong River and the West Gate Freeway, providing a vital alternative to the West Gate Bridge.

The project will ensure quicker and safer journeys and remove over 9,000 trucks from streets in the inner west.

The tunnels are being built using two tunnel boring machines (TBMs) so the community and businesses can continue above ground while work happens below.

We are building:

twin tunnels under Yarraville between the West Gate Freeway and the Maribyrnong River
Freeway Management System to support good traffic flow and safety
new landscaped open space in Altona North and Footscray
entry and exit portals where the tunnels connect with surface roads
walking and cycling paths on Hyde Street, Harris Street, Maribyrnong Street and bridges over Whitehall Street, Williamstown Road, Stony
tunnel safety features for smooth operation of the tunnel including automatic detection for over-height trucks, fire systems and emergency access and exits
ventilation structures at each tunnel exit to circulate air from inside the tunnels.

Two state of the art tunnel boring machines (TBMs) will build the twin tunnels. These machines use the latest tunnelling technology and are custom designed and built to suit ground conditions in Melbourne’s west.

The TBMs start their journey at the northern portal near Whitehall Street in Yarraville and move south west towards the southern portals in the West Gate Freeway. Work will start on the 4km outbound tunnel first, closely followed by the 2.8km inbound tunnel. The longer tunnel will take around 18 months to bore.

While the TBM bores through the earth, it also installs the concrete lining – forming walls, roof and base of the tunnel. Behind the TBM, crews work to build the roads.

Tunnel portals

The portals will form the entries and exits to the tunnels. The southern portal, which is where citybound cars and trucks will enter the tunnel is just west of Williamstown Road. The southern portal where cars and trucks will exit the tunnel heading west, is near Millers Road. The 2 northern portals where vehicles will enter and exit are just south of Footscray Road on the west side of the Maribyrnong River.

Vibration and ground movement

Thousands of tunnels are constructed and operate safely in cities around the world, including the CityLink and EastLink tunnels in Melbourne. Tunnel boring machines are very good at reducing vibration so people living and working above the tunnel may not notice construction happening underground.

We will:

inspect the properties above the tunnel before and after construction
monitor ground movement and vibration levels at all times
meet strict targets set to manage vibration and minimise disruption.

Noise from above and below ground

Strict controls are in place to make sure construction noise is well managed and complies with EPA Victoria guidelines.

We will:

use noise enclosures to reduce noise from major activities at construction compounds, as well as an acoustic shed at where the soil from tunnelling will be loaded onto trucks
plan noisy works at times when they cause the least inconvenience where possible and provide advanced notice if any disruptive work is expected to take place
monitor noise levels and take action to reduce noise.

The West Gate Tunnel construction will see 1.5 million cubic metres of tunnel soil excavated from the tunnel.

The purpose-built shed near the project’s northern portal site in Yarraville has been designed to receive the soil excavated by the TBMs. Soil excavated by the TBMs will travel via the covered conveyor and be deposited straight into soil holding bins. Trucks will be loaded inside a purpose-built enclosed shed to reduce noise and contain soil, then before they leave site they are washed, weighed, covered, and GPS tagged.

All trucks will be fully covered and sealed so there is no soil dropping onto the road.

The shed is 90m wide and 180m long, and houses two 9000m3 capacity soil bins. This shed is designed to contain noise and dust associated with the soil handling process and will hold approximately two to three days of soil when both TBMs are operating.

All soil is tested and managed safely in line with EPA requirements and environment and planning controls arising from the project’s comprehensive Environmental Effects Statement.

The West Gate Tunnel Project uses approved truck routes to safely transport the soil to a purpose built disposal site in Bulla and to transport construction equipment and precast concrete segments that line the tunnel to and from our worksites.

The trucks carrying soil from the tunnel construction will use Whitehall Street, Moreland Road, Footscray Road, CityLink, Tullamarine Freeway and Sunbury Road.

This route uses freeways and arterial roads, minimises travel through residential areas and is the most direct route. By using the shortest route to travel to the disposal site, it minimises the amount of trucks required on the roads.

Given there are other major transport infrastructure projects underway in Melbourne and in case of an unforeseen incident along the preferred haulage routes, we need to ensure there are alternative routes available to transport the soil. If this happens, we will temporarily implement the use of an alternative route for the soil haulage trucks.

A detailed traffic assessment and road safety audit has been carried to ensure the most suitable routes are used and traffic impacts managed.

The precast segments from Benalla will be transported to the Northern portal site on Whitehall Street or to a holding yard in Laverton via approved truck routes.

Keeping you informed

We will keep people informed and work together to make things easier during construction.

You can expect to see regular information from us about construction activities happening in your area, including:

newsletters to keep you up to date
work notifications in your letterbox
information on the website
news and updates on social media.

Our West Gate Tunnel Project Information Centre is also open Monday – Friday from 10am–5pm and Saturday 10am–4pm for project information and enquiries.

The Information Centre is located at the corner of Somerville Road and Whitehall Street, Yarraville.

We also have a team that is dedicated to working with the community. They are available 24 hours a day, 7 days a week to answer any questions or concerns via 1800 105 105.

Download fact sheet

Tunnelling - general information fact sheet, March 2022 (PDF 898.4 KB)