Air curtain facilitates evacuation in underground emergency This air curtain, developed by France`s Centre Scientifique et Technique du Bâtiment (CSTB), or Scientific and Technical Building Center, makes it possible to safely evacuate passengers from a fire occurring in an underground train corridor or a road tunnel. The system uses air from the polluted area to push back the polluted front so that fresh air can flow into the corridor or tunnel. According to its developer, the air curtain system can replace two-door air locks. The technique involves blowing air from the ceiling to create a dynamic vault between it and the floor. Combined with a stationary vortex, this virtual vault acts as a barrier that can withstand important differences in pressure while people are being evacuated. Additional information may be obtain from Alicia Ronan at the French Technology Press Office in Chicago at (312) 222-1235, fax: (312) 222-1237.