Fréjus Highway Tunnel
Mont Cenis Pass has played a crucial role connecting France and Italy ever since the Middle Ages, when it was one of the key crossroads of the Via Francigena.
In 1871 a railway tunnel that took 14 years to excavate was added to the ancient connection between Susa Valley and Savoy. A century later, the railway connection turned out to be wholly inadequate to satisfy the new demands of the automobile culture and the European Common Market.
In the early 1970s, Italian and French authorities first began working on a project for a highway link that could overcome car and truck transportation by way of shuttle-trains; in 1975 a contract for the project was awarded to the Consorzio Traforo Frejus, sponsored by Cogefar of Milan.
The tunnel was built a short distance from the railway connection, and it is almost 13 km long: an uncommon length that required particular attention and the creation of three ventilation ducts. While the first railway tunnel witnessed the first application of compressed air perforations, the new project was the first case of an electrohydraulic perforation being used for a tunnel so long was able to improve both the execution times and the construction site’s environmental conditions.
As part of the project a self-propelled cart was designed, capable of easily allowing for the drilling and the charging of the blast holes, as well as for the complete implementation of the bolting.
The last diaphragm was knocked down on April 5, 1979. The tunnel did not just represent one of the most important engineering works at the time, but also earned itself another important record: throughout the duration of the construction site not a single fatality accident occurred.
In its first twenty years of service, over 20 million vehicles have driven through the highway tunnel.