MONT BLANC FIRE SAFETY

This article describes the testing procedures used on the newly renovated Mt. Blanc tunnel, which reopened after three years of work in the wake of a fire that killed 39 people. Tests were designed to measure the effectiveness of new safety equipment and designs, especially the ventilation and smoke-clearing systems, refuge chambers, and rescue and safety training of tunnel staff. Fire tests were constrained by need to avoid damaging the new equipment while still subjecting it to severe challenges. A cold-smoke test measured how well the ventilation would handle a large cloud of smoke similar to that produced by general burning materials. Tests were also carried out with low-intensity fires, high-intensity fires and fires with destratified smoke. Shallow metal pools filled with fuel were used to simulate the fires. All fires were set at one location to reduce the amount of cleaning and refurbishment needed, and delicate equipment was sequestered by panels lined with insulating materials. Firefighting equipment navigated the smoke filled areas using thermosensitive video cameras. Results indicated that smoke extraction and conduction isolated the smoke and shelters were kept free of smoke even when their doors were open.