Garbage truck fires are never ideal, but they are usually not catastrophic. When a fire broke out on December 6 in the back of a garbage truck making its Friday rounds through the Chicago suburb of Arlington Heights, the fire department responded within five minutes. Firefighters saw flames shooting five feet into the air out the back of the truck, and they prepared to put the fire out using hoses and water. Four minutes after their arrival on scene, however, the garbage truck exploded in rather spectacular fashion, injuring several firefighters and police officers, damaging several homes in the vicinity, and scattering debris through the neighborhood.
The truck, it turned out, was powered by compressed natural gas (CNG), stored in five carbon-fiber-wrapped cylinders on the roof. The cylinders had pressure relief valves installed that should have opened when they reached a temperature between 212° and 220° Fahrenheit (100°–140° Celsius). This would vent (flammable) methane gas into the atmosphere, often creating a powerful flamethrower but keeping the tanks from exploding under the rising pressure caused by the heat. In this case, however, all the pressure relief devices failed—and the CNG tanks exploded.
Fire officials now believe that the whole incident began when a resident improperly disposed of a lithium-ion battery by placing it in a recycling bin.
Original Article Published at Arstechnica
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