The danger of a tire explosion is greatest
after the machine stops, because of the
loss of the cooling effect of the circulating
air due to wheel rotation.
Explosions of air-inflated earthmoving tires
have resulted from heat-induced gas com-
If smoke, excessive heat, the smell of
bustion inside the tires. The heat
burning rubber or hot brakes, or other
generated by welding or heating rim com-
indications of bead burning are noticed,
ponents, external fire, or excessive use of
take action to prevent personal injury.
Move the machine to a remote area, but
A tire explosion is much more violent than
only if it can be done without endangering
a blowout. The explosion can propel the
the operator or other personnel in the
tire, rim, and final drive components as far
as 460 m (1500 feet) or more from the ma-
chine. Both the force of the explosion and
Remove all personnel from the area
the flying debris can cause personal injury
where the machine is located.
or death, and property damage.
Although the risk of an explosion is very
low, the hazard is very great, particularly
with large tires used on wheel tractor-
All personnel should be made aware of
this danger and the actions to take to min-
imize the risk.
Heat from any source is transferred to
Normally, the burned bead causes loss of
air, and the tire goes flat without hazard to
anyone in the vicinity.
Bead burning can result in the release of an
explosive gaseous mixture inside the tire.
In some cases the gaseous mixture inside
the tire ignites. The internal burning
Do not approach a tire closer than the out-
causes a rapid increase in pressure,
side of the area represented by the shaded
resulting in a violent tire explosion. The
area in the above drawing.
explosion produces a blowout at the tire
bead which reacts against the machine to
propel the tire, rim assembly and final drive
components a considerable distance from