Tire Inflation AccidentsTire explosions during inflation are often fatal and usually serious. The average tire has enough stored energy to lift a grown man off the ground. The most common causes are:
Bead FailuresThe weakest part of a tire is the bead wire. It most commonly breaks for the following reasons: Over Filling seldom is the cause, by itself, for tires to explode while being filled. Most manufacturers try to design into bead wire a safety margin of 8. So, the bead should be adequate in a tire designed for 32psi to contain a pressure of 256psi which is far more that most filling stations and repair shops can supply. A tire designed for 45psi (usually the highest safe pressure) should safely handle a pressure of 360psi. Yet they do fail, because the safety margin applies only to new tires in perfect condition not to tires that have been in service and subject to all kinds of normal wear and tear. Excess air pressure is more often seen in combination with other bead problems leading to inflation explosions. Improper fitting typically alleged by a tire defendant in failing to notice that the bead has hung up on the wheel well safety hump, or in failing to lubricate the bead prior to inflation, or in mismatching tire and wheel size. These are foreseeable and common misuses that could easily be designed against by the tire manufacturers, instead of simply warned against. The most common cause of tire inflation explosions is the use of a 16 inch tire on a 16 ½ inch wheel. Tire fitters often believe that the wrong size tire will not fit on a wheel and generally they are right. Wheels are made this way on purpose all except for the notorious 16 ½ inch wheel, which is responsible for more mismatch accidents than all others combined. In fact, it is not sold in Europe precisely because of the extreme difficulty of identifying the size difference, and the fact that a 16 inch tire will fit without great effort onto a 16 ½ inch wheel but, with disastrous consequences. Instead of eliminating the problem size, tire and wheel manufactures rely only on warnings to tire installers. Solutions long have been known to the tire industry. The bead almost always breaks at the same spot the inside cut edge of the splice. Increasing the wire size from the standard .038 inch to .050 would almost double the strength of each wire. Moving the inside cut edge of the splice to the outside has also been suggested by industry insiders, but not adopted. Another feasible solution is to make the bead one wire, instead of a bundle of smaller wires, so that the well known weak spot is eliminated. Sidewall FailuresThese explosions occur in steel casing tires used on trucks. Also called zipper failures, they are often associated with retreaded tires in which the used tire casing sidewall was originally weak or became damaged in prior use but not noticed in the inspection process. There is no accepted way for the tire inflator to accurately determine that a given tire will likely sustain a sidewall failure explosion during inflation. Additionally, this type of failure may occur days or weeks after inflation. Multi-Piece Rim Explosions"Multi-piece wheel" means a vehicle wheel consisting of two or more parts, one of which is a side or locking ring designed to hold the tire on the wheel by interlocking components when the tire is inflated. They are used for truck tires and are so dangerous that they have their own OSHA regulation. 29 CFR 1910.177
These regulations say it all. Is it unreasonable to suggest that these wheels not be used?
|
