You might use them to zip under the city, cross the harbour or pass through a mountain.
Tunnels are a major part of Australia’s road and rail infrastructure. With lengths of up to nine kilometres, they require precise planning, engineering and ongoing maintenance. These efforts keep users safe and avoid the types of disasters we only want to see in movies. Remember Sylvester Stallone’s character in Daylight?
Tunnel safety specialist services
Our Infrastructure Technologies teams provide specialist services to the owners and managers of this type of national infrastructure. We work with a wide range of companies including those that paint lines on roads to those that install and manage ventilation.
Safety measures are especially important in a tunnel. Particularly those which prevent accidents or activate in the event of fire. Every single element of installed safety systems must undergo meticulous testing. They must work as designed and continue to operate over time. They should be ready to perform to their exact specification in the event of an emergency.
The tests we undertake on products and systems installed in tunnels cover:
- structural fire performance
- smoke management and ventilation
- fire detection and alarm transmission
- speaker systems
- road markings
Joe Abraham, Alex Webb, Neythra Weerakkody and Nathan White at work underground.
It’s getting hot in here
Fire is one of the biggest threats to the safety of tunnel occupants. But next time you drive through one you should have confidence. We know that in the unlikely event of a fire, every safety element has been thoroughly considered.
High temperatures affect each material in different ways. But in a tunnel, it’s vital that the structure of its linings (the walls and ceilings that define the tunnel) are not adversely affected by fire. We expose concrete tunnel segments to temperatures of up to 1350°C using a gas-fired furnace. This represents the intensity of an environment of burning hydrocarbons, typical vehicle fuels.
We maintain this extreme environment for many hours. Our team checks the structural performance of the segments during this time. We’re committed to ensuring the tunnel can maintain its integrity during a car fire – or worse a tanker fire.
Our team conducting hot smoke tests in a tunnel.
Adequate ventilation is crucial to ensure safety while a tunnel is in operation.
In the event of an underground fire, it is very important that ventilation systems can clear large volumes of smoke while tunnel users evacuate.
We test tunnel ventilation systems using large-scale hot smoke generators. These produce and direct heated smoke and mimic the buoyancy and flow characteristics of real fires.
Our researchers ditch their white lab coats and pop on their hi-vis protective clothing, helmets and breathing apparatus for these tests. Admittedly, they look more like firefighters than engineers and scientists. But it’s essential to keep our staff safe while they’re doing work which keeps us safe.
Triple zero heroes
Fires require a rapid response. In the event of an emergency, the fire brigade and tunnel management systems are automatically notified of incidents. A series of advanced smoke and heat detection sensors and control systems sends these alerts.
These systems go largely un-noticed by the travelling public. But they quietly monitor the tunnel year in; year out. The system is always ready to raise an alarm and alert the fire services within seconds of detecting a fire.
CSIRO operates Australia’s only laboratory which tests and assesses these advanced fire detection systems. Our team tests many types of detectors and interconnected control systems to ensure that they respond to fires and reliably transfer emergency information to the fire services.
Warning, warning, warning
In case of an emergency, tunnels include a network of occupant warning systems using emergency sounders and loudspeakers. They alert tunnel users with safety warning messages to assist with safe evacuation.
We subject loudspeakers and sounders to an extensive acoustic and durability test program. Our scientists test them in our anechoic chamber to confirm their audio performance. We also ensure they can produce messages with good speech intelligibility when required. Our tests also expose loudspeakers to temperature extremes, high levels of humidity, corrosion, shock and vibration. We do this to ensure emergency messages will be clearly heard throughout the equipment’s lifetime.
Users are warned to evacuate tunnels by the sounding of emergency alarms. Our team evaluates the design of escape pathways by mathematically modelling expected travel direction and evacuation times.
Watching paint dry
While most tunnel users may not give it a second thought, road markings are a critical safety component of the transport system. We test the coatings and reflective materials of road markings for both their performance and durability over time.
CSIRO operates accreditation schemes for organisations that apply the road markings. We individually audit each accredited company. Our team checks their processes and systems to ensure they apply the tested coatings correctly every time.
But there’s a lot more to a white line than one may imagine. Our paint and coating accreditation programs write and manage hundreds of technical specifications. They cover everything from durability and light reflectance to how long the coatings take to dry.
We don’t intend for the above discussion of emergencies and disasters to cause concern.
Although accidents may happen from time to time, Australia’s road and rail tunnels have comprehensive safety systems. These systems allow all of us to enjoy the benefits of a quick trip from A to B without any worries.
Hundreds of Australian companies and thousands of talented experts deliver our nation’s safe tunnel infrastructure. We’re proud to support them with the scientific services they need to do this important job.
Find out how road markings save lives.