Despite no regulatory obligation for tunnels under 500 meters, the Department has chosen to invest €430,000 in the fire safety of the Marionnaise tunnel, in collaboration with the Hautes-Alpes firefighters. This decision aims to mitigate potential difficulties for rescue services in this isolated and hostile environment, where extreme weather conditions can complicate interventions.
The project, initially budgeted at €24 million, allowed for a complete redesign of the tunnel. The arguments of Colonel Jean-Yves Brobecker and Commander Pierre-Emmanuel Feït, emphasizing that prevention costs are often lower than the consequences of an incident, convinced the Department to undertake these additional works.
Integrating this new fire defense system during construction required close collaboration between the Department's teams, represented by Lieutenant Jonathan Fanti and Fabien Dombrosio, and the design-build contractor. Intense discussions led to a compromise, taking into account technical, geographical, and environmental constraints.
This system will include two reservoirs: one of 30 m³ downstream and another of 60 m³ upstream, connected by a dry riser to facilitate the connection of pumping trucks. This setup is partly inspired by a previous project for the Roche Violette tunnel.
The works are expected to be completed by the end of autumn, ensuring rapid and effective intervention by firefighters in this complex environment. The Hautes-Alpes Sdis, co-chaired by Marcel Cannat, Vice-President in charge of roads, receives funding from the Department amounting to €8.8 million this year.
