Background

On a warm, sunny, winter day in the Appalachians, a log truck was in line to be unloaded at a forest product mill’s woodyard.

Personal Characteristics

The truck driver was in his fifties and was considered thoroughly trained and had no known previous accident history. He was wearing the personal protective equipment required by the woodyard.

Unsafe Acts and Conditions

The truck driver came into the mill with a flat tire (very low pressure) on the outside right rear axle of his log trailer. The trailer was fully loaded, and as the driver had driven approximately 70 miles from the woods to the mill, the tire was very hot from travel. The driver decided that while he had to wait in line to be loaded, he would pull off to the side and try to pump up the flat tire.

Accident

As he pumped up the tire and the air pressure built up, the tire exploded on both sides. The explosion left two ten-inch-long gashes on the sidewalls.

Injury

Fortunately, the driver was standing to the side of the tire and was not injured. However, the loud “boom” of the exploding tire echoed around the neighboring hills and could be heard above the sound of the mill operation. It scared the driver quite severely.

Recommendations for Correction

• Commercial truck drivers should complete daily walk-around inspections of their rig, including the tires.
• Before leaving the logging job with a full load, a quick check of the tires for leaks and wood chunks or rocks jammed between the tires is a good safety practice.
• Tires should be inflated to the proper pounds per square inch (PSI). Driving on an underinflated or flat tire can cause excessive heat to build up and weaken the tire sidewalls. This in turn can cause the tire to disintegrate while on the road or cause a tire failure/explosion if reinflated.
• OSHA’s Wheel Chart Booklet (https://www.osha.gov/Publications/wheel/wheel-chart-booklet.pdf) advises to “NEVER reinflate any tire that has been operated in a run-flat or underinflated condition (i.e., operated at 80% or less of recommended operating pressure). Demount, inspect, and match all tire and rim components before reinflating in a restraining device with the valve core removed.”
• It is inadvisable to try to inflate a tire on a fully loaded log truck or trailer. If it is believed that a tire can be inflated safely on the rig, wait until the trailer has been unloaded and ensure the tire is cool. (An inexpensive infrared thermometer can be used to check tire temperature from several feet away.)
• Always stay to the side and a safe distance away when inflating a tire to reduce the injury risk if the tire explodes. (Use of a clip-on air chuck with a remote gauge helps with “driver distancing.”) Wear eye protection.