Researchers from research organisation SINTEF created a sound beacon evacuation system for tunnel fires as part of Project EvacSound, using auditory guidance as an aid to evacuate smoke filled tunnels.
The project is being conducted under contract for the Norwegian public Roads Administration and transport systems developer Trafsys.
Gunnar Jenssen, SINTEF, has worked on tunnel safety issues. Jenssen said: “When a fire breaks out, queues will form, vehicles will collide with each other and drive into the tunnel walls. Some will be abandoned in the middle of the road”,
“This makes it difficult for the fire and rescue services to provide any assistance. Fire and rescue response times may be up to 30 minutes in the most remote Norwegian tunnels. During the fire in the Gudvanga tunnel in 2013, 67 people found themselves trapped by the smoke. More than 60 percent of these were foreign tourists from a number of different countries.”
Both audial and visual guidance systems have been tested for drivers and passengers who may have visual or hearing impairments.
Jenssen: “If we want to help everyone involved in such a situation, it‘s important to have a language-neutral auditory guidance system. There is no time to play the same emergency announcement in 15 or 20 languages. Time is precious when you’re trying to escape from a tunnel fire.”
Experiments were carried out in a cavern under the Ladehammeren hill in Trondheim, Norway, with thirty people from a variety of ages wearing tight fitting glasses to simulate vision impairment from smoke.
The sound came from loudspeakers at 20-metre intervals along the length of the tunnel, being used to test two different directional auditory beacons.
Noises made by tunnel fans were also simulated during the experiment with two different noise levels, simulating the sounds of fans cutting out to reduce oxygen supply to a fire and a simulation of the fans on full speed to force smoke out of the tunnel.
The test subjects were asked to find their way out of the tunnel without direct instruction, using the sound from the beacons to escape. Two out of three people in the experiment managed to find their way out with the help of the audio beacons despite a lack of prompting or explanation for the audio beacons’ purpose.