By the mid-1970s, it was apparent that the then twenty-year-old Mont Blanc Tunnel just wasn't built to accommodate the increasing numbers of vehicles driving between France and Italy, a new route was needed to ease congestion, and so came about the Fréjus Road tunnel.
Built parallel to the now redundant Fréjus Rail tunnel, it successfully levelled traffic numbers and took the strain off the Mont Blanc tunnel.
Following the 1999 Mont Blanc fire, the tunnel, like many other road tunnels across France and its neighbouring countries, implemented new and up-to-date safety measures.
Mont Blanc Tunnel
Length: 11.61 km
Road: RN205/Traforo T1/European Route E25
Construction started: 1959
Links: Chamonix, France with Courmayeur, Italy
Formerly the holder of the 'Longest Road Tunnel in the World' title from 1959 - 1978, the Mont Blanc tunnel was one of the great engineering and architectural feats of the twentieth century.
After the French and Italian governments reached an agreement on the tunnel in 1949, a workforce of over 350 began boring in 1959 and 700 tonnes of explosives and six years later, the tunnel opened to the public.
In 1999 the tunnel suffered a major fire after a truck carrying flour, and margarine caught fire 2km into the tunnel. The resulting thick black smoke leading to low oxygen levels and lack of safety procedures at the time led to 37 people being killed. It led to a major safety overhaul of tunnels across Europe.
Length: 50.45 km
Route: HS1/LGV Nord high-speed line
Construction started: 1988
Links: Coquelles, France with Folkestone, UK
Although no longer the world's longest rail tunnel (overtaken by the Gotthard Base Tunnel in Switzerland in 2016), it does still hold the titles of 'Longest Underwater Section of a Tunnel' and 'Longest International Tunnel' and is seen as the biggest engineering feat of the twentieth century
The idea of a cross-channel tunnel wasn't new. The concept was put forward as early as 1802, but the project wasn't realised until 1988, when tunnelling began on the French side. The famous handshake between the French and the British happened in 1990 when the two boring operations finally met in the middle 75m below the seabed.
The tunnel was formally opened by then-President Mitterrand and Queen Elizabeth II, and rail operations began soon after. Since its opening, more than 10 billion passengers have travelled through the tunnel between France and the UK.
Mont d'Ambin Base Tunnel
Route: Turin-Lyon high-speed line
Construction started: 2019
Estimated completion date: 2025
Links: Saint-Jean-de-Maurienne, France to Susa Valley, Italy
The Mont d'Ambin Base Tunnel is located in the Western Alps and is currently under construction. When completed, it will connect Saint-Jean-de-Maurienne in France with the Susa Valley in Italy. With a length of 57.5 km, it will be the longest rail tunnel in the world and an important link in the European rail network. Construction of the tunnel began in 2019 and is scheduled to be completed in 2025, though the whole line won't be operative until 2032.
Also known as the Mont Cenis Base Tunnel, the tunnel will provide a vital transportation link between France and Italy, reducing travel time between the two countries significantly. It will also serve as an important freight corridor, carrying goods between Northern Europe and the Mediterranean. The tunnel is part of the larger Turin-Lyon high-speed rail project, which aims to improve transportation connections between the two countries, and, ultimately, to connect Northern Europe with the Mediterranean. However, the project has been controversial due to concerns over environmental impact and cost, and has faced opposition from local communities and environmental groups.
Waterway: Canal de Marseille au Rhône
Construction started: 1906
The Rove Tunnel was a major work of civil engineering upon completion in the late 1920s. When it was built, along with the construction of the Canal du Marseille au Rhône in the early twentieth century, it was the longest tunnel of its kind in France, but its success was short-lived. After a catastrophic collapse in 1963, the tunnel was closed. The canal then became a redundant route and closed shortly after, although it does still remain today.
Waterway: Canal du Midi
Hailed as Europe's first navigable canal tunnel, the Malpas tunnel was bored by hand in 1679 and took less than a month to complete under the direction of chief engineer Pierre-Paul Riquet. Just 12 years prior in 1667, construction of the Canal du Midi had begun and the tunnel provided a suitable passage through the hill of Hérault.
The site was also home to another tunnel (below the Malpas tunnel) dug in the middle ages to drain the nearby Étang de Montady, a former freshwater wetland and later on, in the nineteenth century yet another tunnel constructed (above the Malpas tunnel).
The Large Hadron Collider
The Large Hadron Collider (LHC) at CERN is a circular tunnel with a circumference of 27 kilometres (about 17 miles). The tunnel is located on the Franco-Swiss border near Geneva, Switzerland. Whilst it's not for cars, boats or trains, we felt it was such an impressive piece of underground engineering we had to include it!
The Large Hadron Collider (LHC) at CERN was built underground for several reasons:
Safety: The LHC is designed to create very high-energy particle collisions, and such collisions can be dangerous if not properly contained. By placing the LHC underground, any potential radiation or other hazardous particles released during a collision would be contained within the tunnel and not pose a threat to people or the environment.
Stability: The underground location provides a stable environment for the LHC to operate. The tunnel is shielded from cosmic rays and other environmental factors that could interfere with particle collisions. Additionally, the ground provides a solid foundation that helps to minimize vibrations and other disturbances that could affect the accuracy of the experiments.
Space: The LHC is a large machine, and building it above ground would have required a massive amount of space. By placing it underground, CERN was able to minimize the amount of land required for the project.
Cost: Finally, building the LHC underground was more cost-effective than building it above ground. Excavating a tunnel is generally less expensive than building a structure above ground, and the tunnel itself provides a natural containment structure, reducing the need for additional safety measures.
Editor - Alan Rogers Guides
Rob is the General Manager at Alan Rogers Travel Group, he is responsible for the ongoing development of the Alan Rogers website and publication of the Alan Rogers Guides.
He has been involved in the leisure industry since completing a BTEC in Travel & Tourism in 1993. Previous roles have included the promotion of tourism in Yorkshire and running a motorcycle touring company in the Australian Outback.