Mont Blanc Tunnel

• Workforce: five engineers and 350 workmen worked an estimated grand total of 4.6 million man-hours to complete the project
• Explosives: 711 tonnes (700 long tons; 784 short tons) of explosives were used to blast 555,000 m³ (19,600,000 cu ft) of rock
• Energy: 37 million kilowatt-hours and 2,700,000 litres (590,000 imp gal; 710,000 US gal) of fuel for trucks and engines
• Other facts: 771,240 bolts, 6,900 drill rods, and 300 tonnes (300 long tons; 330 short tons) of iron were used to support the vault, 5,000 m³ (180,000 cu ft) of formwork for 60,000 tonnes (59,000 long tons; 66,000 short tons) of cement (mixed with 280,000 m³ (9,900,000 cu ft) of aggregates)

Inaugural Plaque, French side

The idea of building a tunnel underneath the Mont Blanc to avoid the need for lengthy circumnavigation dates back to the nineteenth century during the heyday of the railway. However, the idea did not receive widespread attention until 1907, when Francesco Farinet, a Member of Parliament of the Aosta Valley, advocated constructing of the tunnel.[5] In 1908, a first design was presented by French engineer Arnold Monod, to much interest from Italian and French politicians.[5] However, due to political turmoil and World War I and World War II, the project did not start until 1959, when excavations on the tunnel officially began.[5] This was preceded by the signing of a national charter for the tunnel construction, ratified by the parliaments of France (1957) and Italy (1954). That same year, the STMB (Société du tunnel du Mont Blanc) was formed, which became ATMB (Autoroutes et Tunnel du Mont Blanc) in 1996.[5]

In 1962, the French and Italian drilling teams met on 4 August. The opening was successful, with an axis variation of less than 13 centimetres (5 inches).[6] Three years later the tunnel was inaugurated by the French president, Charles de Gaulle, and the Italian President, Giuseppe Saragat on 16 July 1965. Tunnel opens to traffic on 19 July.[6] Surveillance cameras were installed in 1978.[7]

The tunnel underwent extensive modernisation works in 1990, including the addition of safety features such new video surveillance cameras, 8 pressurized emergency shelters, a sprinkler system and other safety maintenance. In 1997, a fire detection system was installed along with centralized safety equipment management, and new variable message signs.[8]

On the morning of 24 March 1999, the engine of a Belgian transport truck caught fire in the tunnel (see below).[1] The event expanded into a catastrophe which cost the lives of 39 people[9] and led to a three-year tunnel closure until 9 March 2002.[10] The reopening followed an extensive overhaul of the safety features.[11]

The highway trunk from Aosta to the tunnel on the Italian side was completed in 2007.[12]

A commemorative plaque on the French side of the tunnel, remembering those who were killed in the fire.

On the morning of 24 March 1999, 39 people died when a Belgian transport truck carrying flour and margarine entered the French-side portal and caught fire in the tunnel.[9][1] After several kilometres, the driver realized something was wrong as cars coming in the opposite direction flashed their headlights at him; a glance in his mirrors showed white smoke coming out from under his cabin. This was not yet a fire emergency; there had been 16 other truck fires in the tunnel over the previous 35 years, always extinguished on the spot by the drivers. At 10:53 CET, the driver of the vehicle, Gilbert Degrave, stopped in the middle of the tunnel to attempt to fight the fire but he was suddenly forced back by flames from his cabin.[1] With Degrave unable to fight the fire, he was forced to flee.

At 10:55, the tunnel employees triggered the fire alarm and stopped any further traffic from entering. At this point there were at least 10 cars and vans and 18 trucks in the tunnel that had entered from the French side. A few vehicles from the Italian side passed the Volvo truck without stopping. Some of the cars from the French side managed to turn around in the narrow two-lane tunnel to retreat back to France, but negotiating the road in the dense smoke that had rapidly filled the tunnel quickly made this impossible. The larger trucks did not have the space to turn around, and reversing out was not an option.

Most drivers rolled up their windows and waited for rescue. The ventilation system in the tunnel drove toxic smoke back down the tunnel faster than anyone could run to safety. These fumes quickly filled the tunnel and caused vehicle engines to stall because of lack of oxygen. This included fire engines which, once affected, had to be abandoned by the firefighters. Many drivers near the blaze who attempted to leave their cars and seek refuge points were quickly overcome.

Within minutes, two fire trucks from Chamonix responded to the unfolding disaster. The fire had melted the wiring and plunged the tunnel into darkness; in the smoke and with abandoned and wrecked vehicles blocking their path, the fire engines were unable to proceed. The fire crews instead abandoned their vehicles and took refuge in two of the emergency fire cubicles (fire-door sealed small rooms set into the walls every 600 metres). As they huddled behind the fire doors, they could hear burning fuel roll down the road surface, causing tires and fuel tanks to explode. They were rescued five hours later from a third fire crew that responded and reached them via a ventilation duct; of the 15 firefighters that had been trapped, 14 were in serious condition and one (their commanding officer) died in the hospital.

Some victims escaped to the fire cubicles. The original fire doors on the cubicles were rated to survive for two hours. Some had been upgraded in the 34 years since the tunnel was built to survive for four hours. The fire burned for 53 hours and reached temperatures of 1,000 °C (1,830 °F), mainly because of the margarine load in the trailer, equivalent to a 23,000-litre (5,100 imp gal; 6,100 US gal) oil tanker, which spread to other cargo vehicles nearby that also carried combustible loads. The fire trapped around 40 vehicles in dense and poisonous smoke (containing carbon monoxide and cyanide). Due to weather conditions at the time, airflow through the tunnel was from the Italian side to the French side.[13] Authorities compounded the effect by pumping in further fresh air from the Italian side, feeding the fire and forcing poisonous black smoke through the length of the tunnel. Only vehicles below the fire on the French side of the tunnel were trapped, while cars on the Italian side of the fire were mostly unaffected. There were 27 deaths in vehicles, and 10 more died trying to escape on foot. All the deceased were ultimately reduced to bones and ash. Of the initial 50 people trapped by the fire, 12 survived.[1] It was more than five days before the tunnel cooled sufficiently to start repairs.

Aftermath

Thermographic inspection station on the Italian side

The tunnel underwent major changes in the three years it remained closed after the fire.[18] Renovations include computerised detection equipment, extra security bays, a parallel escape shaft and a fire station in the middle of the tunnel complete with double cabbed fire trucks. The safety shafts also have clean air flowing through them via vents. Any people in the security bays now have video contact with the control centre, so they can communicate with the people trapped inside and inform them about what is happening in the tunnel more clearly.

A remote site for cargo safety inspection was created on each side: Aosta in Italy and Passy-Le Fayet in France. Here all trucks are inspected well before the tunnel entrance. These remote sites are also used as staging areas, to smooth the peaks of commercial traffic.

The experience gained from the investigation into the fire was one of the principal factors that led to the creation of the French Land Transport Accident Investigation Bureau.[19]

TV documentaries were also made concerning the disaster, all distributed worldwide and focussing on either safety aspects or the circumstances that turned what should have been a serious, but controllable incident into a disaster. The first, Seconds from Disaster – Tunnel Inferno (aired 2004), was a reconstruction of the events leading up to and during the disaster and the conclusions of the investigation that followed. The second, Into the Flames – Fire Underground (aired 2006), revisited the circumstances and showed how new technology in the form of a new type of fire extinguisher could have reduced the scale of the disaster and enabled the fire service to reach and remain in the vicinity to fight the fire.

Traffic Statistics - Mont Blanc and Fréjus Road Tunnels

In 2010, the average traffic volume was 4,945 vehicles per day, or around 1.80 million vehicles per year. In 2011, there were an average of 5,113 vehicles per day (about 1.87 million vehicles per year).

Although several lines of vehicles can queue up at the toll station, only a limited number of vehicles per unit time is allowed to transit the tunnel to ensure a safety distance between them.

Within the tunnel, a minimum speed of 50 km/h and a maximum speed of 70 km/h applies, while the prescribed distance between vehicles is 150 m; trucks are allowed to enter in groups of five. These security measures were taken as a consequence of the 1999 tunnel fire.

Pedestrians can cross the tunnel by bus; bicycles can also be carried through the tunnel with a reservation.

Receipt for tunnel crossing of 28 July 1969

The tunnel crossing is subject to a toll; the toll differs from Italy to France because of their different VAT rates.

In 2013, the one-way ticket for a car was €40.90 (€41.40 on the Italian side), while the return ticket, valid for 7 days, was €51 (€51.60 on the Italian side).[21] In 2016, the one-way ticket for a car cost €43.50 (€44.20 on the Italian side).

Mont Blanc Tunnel Tolls on the Italian side from 1st January 2019 (22% VAT included)

Mont Blanc Tunnel Tolls on the French side from 1st January 2019 (20% VAT included)

[22]

• National Geographic Seconds From Disaster episodes

Wikimedia Commons has media related to Mont Blanc Tunnel.

• Official website
• "Traffic Tunnel to Pierce Mt Blanc." Popular Mechanics, April 1952, pp. 92–96. Detailed drawings of planned tunnel construction
• ATMB, Official Company Website (in English)
• ATMB, Official Company Website (in French)
• ATMB, Official Company Website (in Italian)
• Mont-Blanc Tunnel at Structurae
• Chamonix-Mont-Blanc Map
• BBC story on fire trial