You have to take your pain in patience to circulate between the Neuchâtel coastline and the Val-de-Travers. The Clusette tunnel is completely closed to traffic from July 7 until the end of the month. In question, sanitation and security work. The main reason for this closure is the replacement of a portion of the road which had swollen following water from water. “It swells all over the road and we need all the width to work,” justifies the chief of the office of constructions and road arrangements of the canton of Neuchâtel, Alain Koenig
From a security point of view, cable crossings have also been dug throughout the length of the tunnel.
Problematic watercomers
These sealing problems do not date from yesterday. Made in the 1970s and located on the sides of a karstic massif, the clusette tunnel is prey to arrival of water which weaken the structure of the tunnel. “At the time, concrete was not waterproof and cracks were created,” recalls the engineer and project manager Phillipe Steudler.
To overcome this problem, several solutions have been studied. The variant chosen is the installation of draining bleeding, a sort of trenches dug inside the wall of the tunnel, allowing the flow of water and its evacuation. A necessary repair because these influx of water presented risks. “Ice cubes were present on the walls and degraded the road” notes Philippe Steudler.
With climate change, water from water may be greater but less frequent. From now on, thanks to the work, the infiltration will be captured and then evacuated.
A sustainable and safe tunnel
The Clusette tunnel now meets the security requirements in force. Six emergency exits leading to the recently built security gallery were installed throughout the tunnel (there was none before the work). To limit the risk of fires, cameras and smoke detection systems have been set up.
The tube connecting the valley to the coast is also a lasting. All the excavated materials have been recycled ”underlines Alain Koenig.
The Clusette tunnel will reopen on traffic at the end of the month. In the meantime, a deviation is in place by the Col de la Tourne. The complete renovations of the structure will be completed in the fall of 2026.
