As part of a Franco-Italian consortium of experts, Eiffage’s VES (Ventilation des Espaces Souterrains) specialists replaced the tunnel's fan-accelerators, with minimal disruption to operations.
As leader of the appointed consortium to design and build the new tunnel ventilation system, Eiffage Énergie Systèmes developed gas pedal fans that will only be used when the tunnel needs clearing of smoke.
This device improves smoke extraction through hatches located in the tunnel vault, then sends the smoke into the stale air ducts located under the roadway, where it is expelled to the outside.
"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 evacuation of users via safe shelters located at approximately 300 m intervals," explained VES project manager Guillaume Planchenault.
The consortium managed to design, manufacture and install 76 gas pedals with a very high level of performance (reportedly a 30% increase thanks to the solution provided), almost 10 months ahead of schedule.
The Mont Blanc Tunnel is a single-tube, two-way tunnel measuring 11.6 km in length, which connects France and Italy in around ten minutes. It was inaugurated in 1965 and features 37 secure, pressurized shelters.
