Mont Blanc better equipped for tunnel fires

After nine weeks of maintenance work, the Mont Blanc tunnel is fully accessible again. Among other things, the ventilation system, which plays a particularly important role in the event of a fire, has been renewed. How safe is the 60-year-old road tunnel today? Two experts explain.

It took nine weeks, but now the maintenance work on the Mont Blanc Tunnel has been completed. Three days earlier than planned, traffic will once again be able to pass through the twelve-kilometre-long artery on 15 December. More than 200 workers were involved in the technical work. According to the operating company, the project cost 20 million euros. On December 18 - the date originally set for the reopening - the annual safety exercise is to take place. More than 130 people from Italy and France will be involved.

Jochen Riepe is Chairman of the Board of the Tunnel-Portal e.V. association founded in Berlin in 2007.

In an interview with ntv.de, Jochen Riepe reveals what a security exercise like this might look like. He is the chairman of the non-profit association Tunnel-Portal e.V. based in Berlin. Riepe himself was a participant in several so-called fire tests and reports: "A kind of fog is generated in the tunnel. It's similar to a disco when the fog machine comes on. But that only gives you an approximate idea of what it means when there is a fire in the tunnel." However, he has also experienced exercises in which tubs with a petrol-diesel mixture are ignited: "Then the whole tunnel is black within a very short time and you can no longer see your hand in front of your eyes. Even signs with escape symbols don't help much," says Riepe.

According to Roland Leucker from the Studiengesellschaft für Tunnel und Verkehrsanlagen e.V. (STUVA), traffic accidents in which fire breaks out pose the greatest risk in tunnels. However, it is not the flames themselves that are particularly dangerous, but the smoke and gas development. "Because many people feel safe in their vehicle, they often stay in it, where they may suffocate," he explains in the ntv.de interview.

Don't wait for rescue in the event of a fire

Roland Leucker is an engineer and managing director of the non-profit and internationally active research organization STUVA e.V.

If a fire breaks out in a road tunnel, it is therefore important to act quickly, according to Leucker. "In the event of a fire, leave the car immediately and leave the tunnel as quickly as possible via the marked emergency exits or go to a safe area. Under no circumstances should you stay in your car and wait to be rescued."

Even after the devastating fire disaster in the Mont Blanc tunnel in 1999, the fire department "found many dead people in their cars" during rescue operations, explains Leucker. On March 24, 1999, a truck caught fire in the tunnel and 39 people lost their lives in the accident. The Mont Blanc tunnel was subsequently closed for three years.

And what to do if there is an accident in the tunnel? Leucker explains: "In the event of an accident, as on the open road, you should switch on your hazard lights and, if possible, drive out of the tunnel. Otherwise, simply pull over to the right or into a breakdown bay. Then set up the warning triangle and drive to safety. Preferably in one of the designated emergency exits or safety areas." In principle, however, tunnels are safe for drivers because, unlike open roads, they are protected from snow and crosswinds and are constantly illuminated.

"Working in tunnels is not without danger"

In order to be prepared for emergencies and to prevent another fire drama like the one in 1999, the Mont Blanc tunnel must be regularly maintained and renewed. The most recent work included replacing the tunnel's ventilation system. "The fans in the smoke extraction ducts of road tunnels can be up to three meters in diameter and weigh several tons. As parts of the ventilation systems, they are particularly important in the event of a fire," explains Leucker.

Maintenance and renovation work on tunnel systems is not without danger, says Riepe. "Such cases are very rare. But in Germany, workers have repeatedly been seriously injured or even died during such construction work in recent years." However, accidents such as the recent one in India, where 41 workers were trapped in a collapsed highway tunnel, are "extremely rare" according to Leucker and "tend to occur during the construction phase, if at all".

Lifespan of 130 years

Incidentally, road tunnels are generally designed for a service life of 100 to 130 years, reveals Leucker. And what happens when they have reached their maximum age? "Then they are usually kept in operation," explains the tunnel expert. "Ongoing maintenance and refurbishment allow them to continue operating well beyond the 130-year mark. Some railroad tunnels in Germany are already a good 180 years old and still fully functional."

Maintenance work will continue in the coming years to ensure that the Mont Blanc Tunnel can still be used by an average of 3600 cars and 1700 trucks per day, even in its old age. As the ADAC reports, it is expected to be closed again from September to December 2024. The actual renovation of the toll tunnel is scheduled to begin in 2025. However, according to the ADAC, the operating companies do not want a complete closure over several years. Instead, three to four-month closures are to be expected over the next 18 years. For now, however, the Mont Blanc Tunnel is open again - until next fall.