Three Essential Safety Actions When Heavy Wheeled Equipment is Struck by Lightning


Do you know what action to take if a piece of your heavy wheeled equipment is hit by lightning or comes into contact with an electric transmission line? What you do could save serious injury.

When equipment is energized by a lightning strike or contact with a transmission line, that energy takes the path of least resistance to the ground, which are the steel ply cords found in most radial tires. This energy creates heat that can weaken the internal components of the tire and compromise its integrity.

Furthermore, heat of this magnitude can turn any moisture inside the tire to turn into steam which can quickly increase the inflation pressure beyond what the tire can safely handle.

Unfortunately, there is even more to this story. Heat can also cause pyrolysis which is essentially when the chemical bonds in the rubber compounds begin to break down. Pyrolysis is the thermal decomposition of materials at elevated temperatures in an inert atmosphere. It involves a change in chemical composition and is irreversible. The word is coined from the Greek-derived elements of pyro “fire” and lysis “separating.”

This can take place very quickly or over several hours, but the result is the same – the inflation pressure exceeds the ability of the weakened casing to contain it. The problem is, pyrolysis gives no outward sign that the tire has been energized with electricity.

So, you could be dealing with a loss of air pressure that renders the tire inoperable and creates dreaded downtime. At worst, you could be dealing with a ticking time bomb that causes enough force to injure or even kill someone on the equipment or standing nearby.

When lightning strikes your equipment, or it comes into contact with an electric transmission line, you should take these three vital actions:

  1. Get everyone away from the equipment immediately.

    Pieces of large tires have been found as far as 1,000 feet from the equipment following a catastrophic failure due to pyrolysis.

  2. Stay away for at least 24 hours.

  3. After at least 24 hours, scrap all the tires on the equipment.

    Again, you may not be able to see the damage that has been done internally to the chemical bonds.

Please feel free to leave a comment below if you have questions about heavy equipment and lightning strikes…or if you would like to learn more about the full line of Triangle OTR radial and bias tires.

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