A major infrastructure client recently engaged Control Hire to deliver a compliant ventilation solution for works inside an existing tunnel during creek remediation activities. The project involved the construction of a bridged roadway over the creek, followed by excavation and deepening of the creek bed beneath.

With multiple diesel-powered assets operating inside the tunnel, our client needed to achieve compliant airflow rates based on 75% utilisation of installed equipment. This required careful consideration of diesel particulate matter and fume dilution in line with Australian WHS requirements for confined spaces and tunnelling environments.

Space within the tunnel was limited. Pumps, trucks and mobile plant needed to operate continuously, leaving minimal available footprint for ventilation infrastructure. Any solution had to maintain access, avoid interference with operations, and still deliver the required air movement.

The Solution

Control Hire worked closely with the client through multiple design meetings to develop a practical ventilation strategy that could be installed within the constraints of the structure.

A certified temporary ventilation design was completed to calculate the required airflow and confirm compliance with diesel dilution and air quality standards. This aligns with Control Hire’s in-house engineering capability, where certified ventilation plans are developed to ensure safe and compliant project delivery.

Given the limited space, footprint became a key driver of the design. Rather than placing equipment at ground level, the system was engineered to utilise the crown of the tunnel.

Precast concrete planks forming the tunnel roof included gaps between sections. Control Hire used these gaps to install a suspended fan system. Threaded rods were fixed through the planks into fabricated steel frames positioned above the tunnel crown.

Each fan assembly was mounted to bespoke frames and supported by vibration isolation hangers. This approach:

• Removed equipment from the working zone
• Maintained clear access for plant and personnel
• Reduced vibration transfer into the structure
• Delivered consistent airflow across the tunnel length

The final design provided effective ventilation without compromising site operations or safety.

Equipment and Gear

• 2 x 1250mm Axial Fans with inlet and outlet silencers
• 2 x Variable Speed Drives (VSDs) with external control panels for remote operation
• 2 x Fabricated steel mounting frames
• 8 x Vibration isolation hangers per fan setup

This configuration allowed airflow to be adjusted as site conditions changed, while keeping noise and vibration levels controlled.

Get Your Ventilation Solution:

Need a compliant ventilation solution for your tunnel or infrastructure project?

Submit the form below and speak with our team about a certified ventilation design tailored to your site conditions.