- Author
- Braun, E.
- Title
- Report of Fire Tests on an AM General Metro Bus. Final Report.
- Coporate
- National Bureau of Standards, Gaithersburg, MD
- Report
- NBSIR 75-718, June 1975, 21 p.
- Distribution
- Available from National Technical Information Service
- Keywords
- arson | fire retardants | flammability | flooring radiant panel test | standards | urethanes
- Abstract
- The Center for Fire Research at the National Bureau of Standards has conducted a study of the fire safety of a bus supplied by the Washington D.C. Metropolitan Transit Authority. The objectives of the work were: (1) to determine the minimum ignition from source necessary to initiate a fire in the bus, and (2) to determine the means by which a fire, once started, is most likely to grow and spread. A series of small-scale laboratory tests were run in addition to the three full-scale tests. Tests showed that accidental ignition by a cigarette or dropped match is unlikely. However, the seat can be ignited with one or two matches, if applied at the proper location, as by an arsonist. In full-scale tests, ignition of the seat occurs readily with the following ignition sources: (1) a small bag of paper trash on the seat, (2) a newspaper under the seat, or (3) if the contents of a can of lighter fluid is poured on the seat. Fire growth and spead in the bus in primarily through involvement of the seat cushioning. Fire spreads from seat to seat with little direct involvement of other interior materials. In all three tests, between one and two minutes after the urethane ignited, dense smoke filled the bus space seriously reducing visibility. Spread of fire beyond the seat of origin is not necessary for the level of smoke to be formed.