WestConnex Stage 3A M4-M8 Link Tunnels

From construction to operation, our innovative NoiseCheck™ tool and technical expertise set new benchmarks in project delivery.

Acciona Samsung Bouygues Joint Venture | Sydney, NSW

Project overview
The WestConnex Stage 3A project, also known as the M4-M8 Link Tunnels, is a critical component of Sydney’s WestConnex motorway network. This project involves the construction of twin 7.5-kilometre tunnels connecting the M4 Motorway at Haberfield to the M8 Motorway at the St Peters Interchange. The tunnels are designed to alleviate congestion by providing a western bypass of the central business district, thereby improving traffic flow and reducing travel times for commuters. The project commenced in June 2018 and was completed in early 2023, marking a significant milestone in enhancing Sydney’s transport infrastructure.
Our involvement

EMM played a critical role in managing noise and vibration impacts throughout the construction and operation of the WestConnex Stage 3A tunnels. During construction, our team delivered comprehensive solutions, including the design of acoustic sheds, noise treatment for tunnelling ventilation systems, noise and vibration assessments for surface and tunnelling activities and noise monitoring.

For the operational phase, EMM was engaged to conduct road traffic noise modelling and designed noise mitigation measures for mechanical and electrical systems.

A key feature of EMM’s involvement was the provision of NoiseCheck™ which was the first web-based construction noise and vibration prediction tool to be used in NSW..

Our value

EMM’s seamless support across both construction and operational phases over five years was a key driver of project success. Our ability to stay agile and scale resources during peak demand ensured the project remained on track, delivering critical outcomes without disruption.

We worked collaboratively with other key stakeholders including the Transport for NSW the project’s Acoustics Advisor which helped streamline the peer review of technical documents and overarching approval processes.

Our deep understanding of engineering noise and vibration controls led to the successful design and commissioning of the operational tunnel ventilation and supporting mechanical and electrical systems which met all project technical criteria.

The provision of NoiseCheck on the project was a differentiator as it allowed ASBJV to streamline out of hours noise assessments and increase collaboration between the environment and broader project team when planning out of hours activities with the view of minimising noise impacts and noise mitigation and management requirements, reducing project cost.

Noisecheck

"NoiseCheck™ is a gamechanger for any Construction Environmental Manager. With conditions of approval and EPA regulations, the ability to do out of hours work is particularly difficult, but it’s made easier with a tool like NoiseCheck."
Grant Sainsbery WestConnex Environment and Sustainability Manager