The new Lyon-Turin railway line: Eliminating the alpine bottleneck

The project and how we got there

For the new Lyon-Turin railway line, 2021 marks a turning point, with the award of the contracts for the entire cross-border base tunnel. This is an important milestone for the project, and it comes after the completion of a complex approval process in Italy and France (concluded in 2017) and, even before that, the termination of the fundamental feasibility and study phases.

Today, TELT – the French-Italian public promoter of the project – is working on the realisation of a project that has a European vocation and the ambition to be part of the Green Deal, for at least two reasons: the contribution that the railway offers to decarbonisation, and the lower energy consumption that the base tunnel requires for transport, compared to the existing mountain line. Not to mention the significant reduction in time and costs for freight and passenger transport across the Alps.

The cross-border section of the Lyon-Turin line is the central link in the Mediterranean Corridor (on the European east-west axis), one of the nine axes of the TEN-T transport network. The new infrastructure provides a link south of the Alps between Western and Central Europe; it aims to promote economic exchanges and strengthen the competitiveness of the Mediterranean European countries and is based on a freight/passenger rail network, which also passes near to major sea and river ports, large cities and airports.

The cross-border section connects the international stations of Saint-Jean-de-Maurienne (in Savoie, France) and Susa (in Piedmont, Italy), where the new railway connects to the existing line. It is 65km long, with 89 per cent of it passing through tunnels and most of the above-ground facilities located in already built-up areas. The key element is the Mont Cenis base tunnel (double tube with single track) through which the trains will travel. With its 57.5km of length (45km in France and 12.5km in Italy), it is the longest railway tunnel in the world.

One hundred and fifty years after the inauguration of the Fréjus railway tunnel (at an altitude of 1,300m), through which the current historic line passes, the construction of the new line is a solution that meets current transport standards and makes rail transport more competitive.

The route of the cross-border section on which we are currently working is the result of participatory planning on both sides of the Alps. As required by national legislation, an enquête publique was carried out in France: an independent commission collected comments and needs from the territory through public assemblies and meetings with all the stakeholders. The process ended in 2006 with a favourable opinion on the project, followed in 2007 by the declaration of public utility by the French Prime Minister. In Italy, the first plan for the project would have had a strong impact on the territory and local administrators opposed it for several years. As a result, despite there being no available analogous process to the French one, in 2006 the Italian government established the Osservatorio per la Torino-Lione. This body has managed the participatory planning, listening to, and integrating the needs of, the territory that had led to the protests against the initial project. After 205 work sessions, more than 300 hearings with technicians and experts, and 10 different alternatives for a route, a final project was drawn up, and then approved in 2015. This project is completely different to the original one envisaged for the Italian territory. For Italy, it has been a unique process and an interesting experiment. Innovative in the ways and forms in which it was carried out, it has become the basis for a new law (passed subsequently) regarding the approval process for major works.

The result of the participatory process on the Italian territory marked not only a radical modification of the route, but also had the effect of changing the opposition, which today no longer sees all the administrators of the Susa Valley serried in the front line against the project.

Current progress

Today, 13 new companies that won the tenders for the base tunnel on the French territory are about to set up on the construction sites. They join more than 150 companies and professionals already working on the sites on the various aspects of the project, from engineering, excavation and environmental monitoring, to supplies.

The awarding of the contracts for 80 per cent of the tunnel, representing 100 per cent of the route on French territory, marks a major step forward which, together with the awarding of the remaining 20 per cent (the lot on Italian territory), will be the definitive turning point towards completion within the timeframe established with the European Union, which may also take into account the impact of the pandemic.

Looking at the work in closer detail, a total of 30km of tunnels have been excavated to date, constituting more than 18 per cent of the 162km planned for the project, a complex machine consisting of two parallel tunnels, four access adits and 204 safety bypasses. In order to carry out the final work, 113km of exploratory surveys and core drilling had to be carried out in Italy and France. The study phase included the excavation of the access adits necessary to open the construction sites in the mountains: in France, at Villarodin-Bourget/Modane (4,000m, completed in 2007), La Praz (2,480m, completed in 2009) and Saint-Martin-la-Porte (1,800m completed in 2016 and 2,400m completed in 2010); in Italy, at Chiomonte (Susa Valley, 7,020m).

On the base tunnel, work is advancing and the 10km of the south tube through which trains will travel have been completed: 9km have been excavated using the Federica tunnel boring machine, while work is proceeding with traditional methods at Saint-Martin-la-Porte. In parallel with the advance of the base tunnel, work is being carried out above ground on French and Italian territory.

On the cross-border section, the work just assigned will start from the access points already completed: the four access adits provide access points for work vehicles and, at full capacity, there will be 15 excavation fronts and seven tunnel boring machines advancing simultaneously to complete the tunnel through which the trains will travel.

There are eight operational construction sites. In addition to the excavation of the base tunnel, which continues at Saint-Martin-La-Porte using the traditional method, work is under way at Saint-Jean-de-Maurienne (France), where the international station will be built. Work on the artificial tunnel at the entrance to the base tunnel, on the French side, is almost complete, and consolidation of the embankments along the River Arc is under way at Saint-Julien-Montdenis and Villargondran (France). In Italy, work continues on the expansion of the construction site which will become the base tunnel site. The tender has been awarded and work is starting on the construction of the motorway junction that will bring vehicles directly to the site from the motorway, without impacting the local road system. Subsequently, the infrastructure will remain available for local traffic. The necessary preliminary operations have begun on the areas where the recycling site for spoil from the base tunnel construction site on the Italian side will be located. It is here that the plant producing segments for the lining of the tunnel will be located. The construction site has begun for the relocation of the Susa freight and car terminal, whose area will be occupied by the technical facilities of the Lyon-Turin international station.

This project is one of the largest currently under way in Europe and one of its most important effects concerns employment: the acceleration of the work has already brought the first visible benefits, not only in terms of the involvement of a considerable number of companies, but also in terms of the workforce employed. Currently, 1,000 people are working on the infrastructure, including construction sites and services and engineering. The work in peak periods will require 4,000 directly employed workers and it is estimated that 125,000 full-time workers will be needed for the years the construction site will be operational, 73 per cent of whom will be in sectors other than construction (agriculture, industry, trade, transport, tourism, services for businesses and people).

Next steps and future prospects (benefits and advantages)

In the next few months, we will be commissioning the excavation works on Italian territory, which will result in the award of 100 per cent of the route. Then we will have about 10 years of work ahead of us, comprising civil engineering works, equipping the tunnel and pre-operational work, before operation.

More specifically, today we are entering a new phase, which will lead us directly to the operation of the line: between the end of this year and the beginning of 2022, we will be putting out to tender all the technologies necessary for the operation of the railway tunnel. We will be placing all the installations and technologies out to tender in a single invitation to bid worth €2 billion: this will be another fundamental step because it means planning the future use of the tunnel, as well as generating new economic benefits.

The construction of the Lyon-Turin line is part of the development of the European networks, and when the line will be fully operational, it is estimated that more than one million lorries will no longer travel across the Alps, reducing CO₂ emissions by three million tonnes per year. The benefits that the project will bring also concern the creation of a greater freight interchange between Italy and France, but also an increase in the number of passenger trains, shorter travel times (e.g. Paris-Milan in four and a half hours instead of about seven hours) and a series of possible origins and destinations on different European routes.

The long-term strategic objective is to create the ‘European metro’, ‘bringing closer’ European cities and encouraging rail transport, which will reduce greenhouse gas emissions. The rail link that is being built should be seen in terms of interconnections, focusing on the fact that it has an impact on 18 per cent of the European population, in regions that account for 17 per cent of EU GDP. To support the economic development of these territories, an efficient and green infrastructure is essential.

There are various estimates of the economic impacts of the Lyon-Turin line during construction and when fully operational. It has been calculated, for example, that cross-border projects bring the greatest benefit to the European economy, with a multiplier three times greater than the average for the nine TEN-T corridors.

Finally, the real major multiplying benefit of the new infrastructure is the elimination of the Alpine bottleneck, which penalises not only the Lyon-Turin section (for 300km) but the entire Mediterranean Corridor of 3,000km and, pro rata, the 30,000km of the entire European network. It is on this scale, including from the energy point of view, that the base tunnel will have its full effect.