I'm Olaf Knezevic, Engineer with WorkSafeBC. Tires can explode with devastating force,
causing injury or death. I'm going to describe three serious tire accidents. In the first accident, a worker was killed
while removing a tire from a log stacker. This stacker's tires are mounted on rims made
up of several pieces, including an inner and outer rim. 16 bolts hold together the inner and outer
rim. 48 larger bolts attach the entire rim to the stacker's hub. To get the wheel off the stacker, the worker
removed most of the large bolts while the tire was still inflated to about 90 psi. The remaining bolts had weakened over time
and could not handle the pressure. They sheared off or stripped. The outer rim and tire blasted towards the
worker, who was facing the tire. The worker was crushed between the tire and
his truck. The tremendous force of the impact can be
seen in the damage where the tire and worker hit the truck. In a second accident, a worker had just repaired
a crack in the rim by welding the rim with the tire still mounted but deflated. After completing the weld, the worker reinflated
the tire. The heat from the welding caused some tire
decomposition, which produced flammable gases. When the worker inflated the tire, the additional
air led to a fire inside the tire, causing it to explode. The huge force of the explosion separated
the tread into 4 flaps, folding them over. One flap struck the worker, causing fatal
injuries. In a third accident, a worker was inflating
a new tractor tire that he had just mounted on a rim. The tire and rim were laid flat on the ground
and the worker was positioned over the tire. The bead of the tire would not seat. To force the bead to seat, the worker kept
adding air. It was too much. The bead burst over the rim flange, catapulting
the worker and tire into the air. The worker fell back down, hit the concrete
driveway, and sustained serious injuries. The tire continued upwards and struck the
underside of the shop canopy. Death or injury could have been prevented
in all three accidents by the following safe work practices. With a multi-piece rim, always fully deflate
the tire before loosening the wheel nuts or bolts. When inflating multi-piece rim and tire assemblies,
always use a suitable restraining device, such as a safety cage, a safety T-bar, or
safety chains. This is also a safe work practice for single-piece
rim and tire assemblies. Keep out of the trajectory when handling or
inflating tires. Inflate tires to the recommended pressure
using a clamp-on air chuck and an in-line valve and gauge. The hose should be long enough to allow the
worker to keep out of the trajectory. Safe tire servicing requires proper equipment,
training, and procedures. Refer to the tire manufacturer's instructions
for more safe work procedures and remember to always work safely.
