A 63-year-old worker was fatally injured when the lock ring on a wheel rim he was mounting off-road truck tires on dislodged, causing the lock ring to strike him.
U.S. Mine Safety and Health Administration (MSHA) investigators determined that the mine the worker was employed by failed to correct known defects on wheel rims and didn’t properly train workers on the task.
Ring shot through the air, killed worker instantly
On April 9, 2023, Filemon Ortiz was working for South Pittsburg Stone at the South Pittsburg Stone #2 surface sandstone mine in Marion County, Tennessee.
Ortiz was assigned to help his foreman mount eight regrooved truck tires on wheel rims. The method for mounting the tires involved placing the interior protective liner of the tire over the rim and then installing the inner tube inside the tire.
Once the inner tube was installed, they fastened the lock ring inside the rim and filled each tire to 70 pounds per square inch (psi). The tires could be filled to 120 psi, but the mine operated the trucks at a lower pressure to prevent blowouts from rough terrain. Ortiz and his foreman didn’t use any methods to restrain the wheel assembly in case it malfunctioned.
The two workers were about 20 feet away from the first wheel assembly when they began installing the tire on the fourth wheel assembly. As they worked, the first wheel assembly’s lock ring dislodged, propelling the ring into the air. Ortiz and his foreman heard the loud “pop” as the ring shot into the air and both men turned to see what happened. When the lock ring came down, it struck Ortiz, killing him instantly.
The foreman called 9-1-1 and instructed other workers who came to the incident scene to stay back in case another wheel assembly malfunctioned. Emergency responders arrived a short time later and pronounced Ortiz dead at the scene.
Investigators found wheel assemblies had obvious problems
MSHA investigators found that there were multiple problems with the wheel assemblies Ortiz and his foreman had been working on, including:
- the rims weren’t verified to be compatible before the tires were mounted because the manufacturer’s markings were illegible
- rust and rounded edges were observed on the interior of the lock ring, preventing the ring from properly seating on the rim
- damaged rim components that should have been discarded were being re-used while mounting the tires
- use of improper tools, such as a normal hammer rather than a proper rim mallet
- failure to use lubrication on the rim before mounting the tire, and
- failure to follow proper procedures for inflating the tires once they were mounted.
These were all obvious problems that a thorough examination of the rims would have revealed, according to MSHA. Further, the mine didn’t have a tire cage or other restraining device to place wheel assemblies in to prevent such an incident from occurring.
Ortiz had 10 years of mining experience and had helped his foreman in mounting truck tires before during those years. However, investigators learned that Ortiz was never properly task trained to perform this job.
Wheel assembly moved offsite to prevent similar incident
MSHA found that there were two main root causes, including the mine operator’s failure to:
- correct defects on rims that could lead to the creation of a hazard, and
- task train miners on how to properly mount tires on rims.
To prevent another fatal incident, the mine has removed all two-piece wheel rims with lock rings from the workplace. Wheel assembly has also been moved offsite and will be conducted by a tire technician. This is noted in the mine’s safety training plan so miners are aware that the task is no longer conducted onsite.
