on Water in the Tire:
"The air inside the tire would expand to a certain degree, but
not enough to actually burst the tire. There was probably some moisture inside the tire, which was heated to boiling.
That would really drive up the pressure. If you assume that only air was inside the tire, it would require a lot of heat to even double the
original pressure. But think of the amount of steam you can generate from even a small amount of
In motor racing it is very important to have optimum control of tire
pressure. The people responsible for the tires take precautions to keep any moisture out of the tires, which minimizes the pressure increase due to rise in temperature."
on Gas in the Tire:
"I think you will find it was the gases in the tire that exploded. When I first started welding in 1969 there was a bulletin about a similiar accident. Apparently there are explosive gases exuded by the rubber and glue. Never weld on a wheel that is not separated from the tire."
Brad Warren on Tire Repair Kits:
"The tractor-trailer tire may have contained a volatile gas such as butane or propane, commonly used in quick-fix flat repair kits. These fuels can be compressed into a "stable" liquid form in a small can, and expand to inflate a car tire. All the more reason for these two poor souls the receive a Darwin Award!"
on Split-Rim Tires:
"Truck tires are sometimes mounted on split-rims, a one-piece locking ring that is split to fit between the rim and the bead of the tire. The split-rim ring is the only thing holding the tire to the rim.
Such tires are placed in a protective cage when inflating, in case the split-rim ring slips and causes the tire to "explode." I have heard of exploding split-rims punching holes through cinderblock walls. My guess is the heat from the torch caused the ring to expand and slip."