The client and operator of the Mont Blanc Tunnel, GEIE-TMB, granted the contract to Eiffage’s Énergie Systèmes branch for installing a new, sustainable ventilation system.
As part of a Franco-Italian consortium of experts, Eiffage’s VES (Ventilation des Espaces Souterrains) specialists substituted the tunnel’s fan accelerators with minimal disruption to operations.
As leader of the assigned consortium to design and build the new tunnel ventilation system, Eiffage Énergie Systèmes developed gas pedal fans that will be employed just when the tunnel requires clearing smoke.
This device enhances smoke extraction via hatches located in the tunnel vault, then sends the smoke into the stale air ducts placed under the roadway, where it is expelled to the outside.
Guillaume Planchenault, VES project manager, stated: “Before deploying the gas pedals in series, we built a prototype with Howden, in order to demonstrate the future device’s reliability. Replacing the fan-accelerators is an essential component of the fire-safety system, enabling smoke stratification to be maintained to facilitate the evacuation of users via safe shelters located at approximately 300 m intervals.”
The consortium operated to design, manufacture, and install 76 gas pedals with a very high level of performance (reportedly a 30% growth thanks to the solution delivered), nearly ten months ahead of plan.
Nevertheless, the Mont Blanc Tunnel is a single-tube two-way tunnel, measuring 11.6 km in length, and links France and Italy in approximately ten minutes. It was commenced in 1965 and features 37 secure, pressurized shelters.