The Mont Cenis Base Tunnel, a monumental engineering feat poised to redefine transportation between France and Italy, is a testament to human ingenuity and collaboration on an international scale. At 57.5 kilometers in length, this twin-tube tunnel is not only the key infrastructure asset of the Lyon-Turin railway project but also the world’s longest railway tunnel upon completion.
One of the primary motivations behind the construction of this tunnel is to overcome the challenging terrain posed by the Mont Cenis mountain range. Currently, trains traversing this route face steep gradients of up to 3%, requiring multiple locomotives to haul freight up to an elevation of 1,300 meters. Moreover, the existing Fréjus Rail Tunnel, inaugurated in 1871, poses safety concerns and operational limitations due to its single-tube design. The Mont Cenis Base Tunnel, with its flatter gradients and modern specifications, promises to alleviate these challenges significantly.
The benefits of the tunnel extend far beyond operational efficiency. By facilitating smoother rail transport between France and Italy, the tunnel is expected to stimulate trade and commerce, fostering economic growth in the region. Additionally, the reduction of approximately 1 million lorries annually from the roads translates into a substantial decrease in carbon emissions, contributing to efforts to combat climate change.
The construction process of the Mont Cenis Base Tunnel is a complex endeavor that requires meticulous planning and execution. Splitting the work into multiple construction lots allows for a targeted approach to address the diverse geological conditions encountered along the tunnel route. From granular soils to high-strength rock masses, each segment presents unique challenges that necessitate tailored excavation methods.
Tunnel boring machines (TBMs) play a crucial role in excavating the majority of the tunnel’s length, with seven TBMs deployed to excavate 85 kilometers out of the total 115 kilometers. However, in sections where TBMs are not economically viable or where ground conditions are unsuitable for mechanized excavation, drill-and-blast techniques are employed. The New Austrian Tunnelling Method (NATM), characterized by its integration of surrounding rock formations into the tunnel support structure, proves invaluable in navigating challenging terrain.
Safety remains paramount throughout every phase of the project. The Mission S strategy, emphasizing shared responsibility and continuous improvement in health and safety practices, underscores the commitment to safeguarding the well-being of the workforce. With an anticipated peak of 4,000 workers on-site during construction, stringent safety protocols and collaborative efforts are essential to mitigate risks effectively.
Despite the formidable challenges posed by the project’s scale and complexity, stakeholders remain resolute in their determination to adhere to the project timeline and budget. Strategies aimed at incentivizing efficiency and fostering competition among contractors underscore the collective effort to ensure the timely completion of the Mont Cenis Base Tunnel by 2032.
In conclusion, the Mont Cenis Base Tunnel represents a triumph of human endeavor and collaboration, promising to revolutionize rail transport between France and Italy while setting new standards for sustainable infrastructure development.