EastLink Tunnels

Ventilation and Building Services

EastLink is the largest road infrastructure project ever built in Australia. The sheer size of the project presented a range of engineering, logistical and program complexities never seen before.

Featuring two 1.6km tunnels, 17 major interchanges and 88 bridges, EastLink demanded outstanding design, engineering excellence and innovative construction methods, all driven by expert scheduling and project management.

EastLink was completed five months ahead of an already breakthrough contractual date, with limited disruption to surrounding communities and stakeholders.

A.G. Coombs were responsible for the installation and commissioning of the tunnel ventilation systems for EastLink’s Mullum Mullum and Melba tunnels. The ventilation systems included specialised Fantech tunnel ventilation fans as well as horizontal jet fans located at high level throughout the 1.6km vehicle tunnels.

To control air movement within the tunnels in the event of an emergency, the systems incorporated high temperature tunnel ventilation smoke control dampers fitted with specialised position monitoring, reporting back to an incident control centre.

To minimise air discharge, noise levels within the environmentally sensitive Mullum Mullum Valley as well as within the tunnels, noise attenuators and extensive sound absorption paneling was installed throughout the tunnel ventilation system.

Given the critical life safety function provided by the ventilation systems, rigorous testing and commissioning of the installation, including verification of system capacities and system resilience were completed prior to placing the system into service.

HV power reticulation to the ventilation systems and other critical tunnel infrastructure are air conditioned with systems designed to provide a high level of reliability and availability.

Since completion, the systems have maintained the air quality within the tunnels within safe limits and provided fire mode exhaust whenever called upon.

In addition to the tunnel ventilation systems A.G. Coombs provided air conditioning and mechanical systems to the Eastlink Operations Centre located adjacent to the Ringwood exit. Advanced 3D modelling was also used to coordinate and set out the multiple in ground services that entered and exited the centre including specialist cabling for all transport management systems, road signals, controls, camera feeds and alarms.