The Mont Blanc Tunnel: An unparal-
leled engineering masterpiece

In 2015 it celebrated its 50th anniversary, and the 60 million vehicles that passed through it

In 1887, Horace-Bénédict de Saussure, who is considered to be the founder of alpinism, after reaching the top of the Mont Blanc, at 4,808 metres of height, exclaimed «The day will come when under the Mont Blanc a road for vehicles will be built, and then these two valleys, the Chamonix and Aosta one, will finally be united». The French naturalist was right: Today, the Mont Blanc Tunnel connects Italy to France. To be more precise, it connects Courmayeur, in the Aosta valley, to Chamonix, in the French department of Haute-Savoie.

The Mont Blanc Tunnel measures 11.6 kilometres. Of these, 7.6 are located on French soil, while the remaining 3.9 in Italy. Where the tunnel passes the frontier, above it, there are 2,480 metres of granitic covering, until it reaches 3,842 metres at the Aiguille du Midi, the highest spire of the Aiguille du Midi, in the southern part of the Mont Blanc. For years, this was Europe's longest tunnel. Today, there are many longer tunnels, but the fact that one is passing under Europe's tallest mountain, makes the Mont Blanc an unbeatable engineering work.

In July 2015, the Mont Blanc Tunnel celebrated its 50th anniversary: It’s impressive to know that, in only half a century, 60 million vehicles passed through it. Today, thanks to this record-breaking structure, people can travel from Italy to France in approximately 10 minutes. Before, for millennia, the massif was just an impregnable barrier. Building it certainly was not an easy task. The energy, material and workforce costs of the Mont Blanc Tunnel were also huge: i.e. more than 1,500 tonnes of explosive were used, 200 cubic metres of concrete and 235,000 screw bolts.

Before works began

The idea of building the Mont Blanc tunnel goes back many years before it came into being. In fact, in 1814, the inhabitants of the Aosta Duchy asked their sovereigns, the Savoia, to build a tunnel to connect the two sides of the Alps. Their request was not acknowledged. During the forthcoming decades, many had thought about creating a tunnel through the Mont Blanc. In fact, many, more or less, fantastic projects, designed by XIX century engineers, and promoted by ambitious and visionary politicians, were also later suggested. Still, for the rest of the XIX century, and up to almost half a of the XX century, it all just remained an idea. In 1934, a revolutionary study of Arnold Monod, showed a 12-kilometre-long double-barreled Mont Blanc tunnel. The idea was partly successful, but not carried through due to the deteriorating French-Italian political relations. An not until after the Second World War.

An engineer, then decided to put theory into practice. Through his personal initiative, in 1946, Count, Dino Lora Totina, from the Italian region of Piedmont, decided to excavate the Italian side of the massif. He encountered many difficulties, including the mandatory halting of all works, imposed by Italian authorities the following year. Only 250 metres had actually been excavated when works were stopped. Despite this, the courageous endeavor of Totino made politicians more willing to talk about the Mount Blanc Tunnel.

The Mont Blanc tunnel: A brief overlook on how it was built

In 1949, an Italian-French Investigative Commission for the Tunnel’s construction was established. An agreement was established in the 1953 convention. The Italian and French parliaments respectively signed the agreement, in 1954 and 1957. Following this, two companies, one on each border, were specifically established to build the tunnel: The SITMB (Società Italiana per Azioni per il Traforo del Monte Bianco) company was founded in Aosta, Italy, while the French had their STMB (“Société du Tunnel du Mont Blanc”). The Mont Blanc tunnel was not solely a fantasy anymore. In 1959, when all triangulations were carried out, works finally began. In January, excavations began on the Italian side, while a few months later, in June, the French also started to work. The two companies agreed to each excavate 5,800 metres of the tunnel, meeting half-way.

Works were carried out with a huge machinery named "Jumbo", which weighed over 10 tonnes and was made of 16 drills positioned on 4 storeys. It was possible to create 4-metre-wide holes filled with explosives. An estimated one million cubic metres of rock were extracted from the mountain thanks to this method. The task was not easy, nor was it safe. In fact, 23 workmen died building the Mont Blanc Tunnel: 14 on the Italian side, and 7 on the French one. Two alpine guides also went missing during the triangulations.

STIMB recalled that the French mostly found good quality rocks, while the Italians, on the contrary, had to immediately (after the first 368 metres) deal with frequent, significant jets of water, which caused works to be suspended for a month. The two sides were competing, with the French stating that they would have finished their part well before the Italians. This is why the Italian Works Director, Giulio Cesare Meschini, in an interview with the Italian newspaper La Repubblica said «We asked our workers to work without ever stopping, in four daily shifts of six hours each, but paid as if they were eight. There was also a special premium given for every additional 50 cm excavated every day. We invented shift turnovers with machinery on, so the French were easily beaten».

The Italians managed to complete their side of their tunnel on August 3, 1962, with the French following, 11 days later. The French kindly offered four champagne bottles to their Italian colleagues, therefore ending all competition between the two parties. The Mont Blanc Tunnel was inaugurated 3 years later, with a ceremony attended by the Italian President, Giuseppe Saragat, and the French President, Charles De Gaulle.

The accident in 2002

The history of the Mont Blanc Tunnel is not just a hall of successes. Besides the 23 workmen who died during the actual construction phase, we also need to remember its darkest historical moment, which occurred on March 24, 1999, when a heavy lorry caught fire inside the tunnel (after it entered with its engine already slightly on fire). 39 people died that day. The tunnel remained closed until 2002, after being fully secured, with works amounting to €380 million.