BIKES AND LIGHTNING

 

There have been several cases of motorcyclists hit and killed by lightning. Because a car is comparatively safe in a thunder storm, there is a misconception that its safety lies in the fact that it is on rubber, and by extension, that a motorcycle is safe for the same reason. However, if you consider that a bolt of lightning travels several kilometers between the clouds and the ground, a few centimeters of wet rubber isn't going to help at all.

The reason why a car is safe, is because it forms a cage (scientifically it is called a 'Faraday' cage) around you. The electrical charge collects around the outer surface of the car, leaving the occupants unharmed. A bike, and some other vehicles like convertible cars, do not form a cage around the occupants, leaving them vulnerable to lightning strike.

Here are a few safety steps you can take if caught by a thunder storm:

  • Know the weather forecast before heading out.
  • If lightning threatens, try to find the relative safest location possible.
  • Avoid tall objects, especially trees.
  • Squat low if caught in the open.

Know the weather forecast for that day. If there is a high chance of thunderstorm activity, you may want to curtail your riding activities on this day.

  • If you see threatening skies in the distance and you are passing a safe location, you may want to stop at this safe location and wait the storm out. This is especially true for motorcyclists who are in remote areas and safe locations are few and far between. Remember, lightning can strike many miles away from the rain area of a thunderstorm.
  • If you can turn around and get away from the storm, do it.
  • DO NOT ride into or near a lighting storm.

If you cannot find a safe location, some areas outside may be somewhat safer than others:

  • If an overpass is available, seek shelter under the overpass. DO NOT go near steel girders. Move away from your bike. Remain on the dry surfaces if possible. Overpasses are engineered structures and are likely to be properly grounded. Although an overpass is likely to be higher than the surrounding landscape, if it is struck by lightning, the electrical current will likely be channelled safely into the earth’s surface.
  • Look for a bridge over a stream, culvert, railroad crossing or any other type of bridge. Stay away from water, stay away from any metal surfaces (however, be alert for rapidly rising water if under a bridge which crosses a stream).
  • High tension wires: If high voltage electrical tension wires cross the road, you may want to seek shelter directly underneath these wires. Do not get too close to the large metal towers which hold up these wires (stay away at least 20 meters). Electric companies design these high tension wires for lightning strikes. If lighting should strike the wires or towers, the current is designed to safely go deep into the ground.

    IMPORTANT: None of the above recommendations (overpasses, bridges, high tension wires) guarantee safety from being struck by lightning. However, it is likely that these recommendations are safer than being caught "out in the open". Of course, the best thing to do is to find a safe location before lightning threatens.
  • REMEMBER - Do NOT seek shelter in an UNSAFE BUILDING. Picnic shelters or other open roadside shelters are NOT safe during lightning activity.

If you find yourself caught completely in the open and lightning is occurring within 10 to 15 km of your location, it is strongly suggested that the best thing for you to do is STOP riding, get off of your motorcycle, find the lowest area possible (small ditch/culvert, etc), and get into the Lightning Desperation Position.

  • Motorcyclist should move at least 20 meters away from their bike.
  • DO NOT CONTINUE TO RIDE if lightning is occurring! Once lightning is within 5 miles of your location, it is suggested you should stop your ride. Motorcyclists have been struck and killed by lightning while riding in lightning storms.

The Lightning Desperation Position

Squat down, keep your feet together, keep other parts of your body off the ground, close your eyes and cover your ears.

If you are caught in the open and lightning is nearby, the safest position to be in is crouched down on the balls of your feet. Keep your hands over your ears and do not allow other parts of your body to touch the ground. Keep your feet as close to one another as possible.

Why is it important to crouch down on the balls of your feet? The reason why is that when lightning strikes an object, the electricity of the lightning discharge does not necessarily go straight down into the ground. Quite often the electricity will travel along the surface of the ground for quite a large distance. The electrical current likely varies widely from place to place, even over a small area.

This phenomenon is known as a "side flash". Many people who are "struck" by lightning are not hit directly by the main lightning channel, but are affected by electrical current of the side flash as it travels along the surface of the ground. By keeping the surface area of your body relative to the ground to a minimum (that is, keep your feet together and do not allow any other part of your body to contact the ground, you can reduce the threat of the electricity travelling across the ground from crossing your body and injuring you.

A more technical description of this phenomenon is called ground potential. If a flash occurs nearby and your feet are separated AND the electrical current is different between your two feet, then the electrical current will try to equalize across your feet. What this mean is the electric current will travel through your body to equalize between your two feet (it will do this by travelling up one leg, across your lower abdomen, and then down the other leg). The greater your feet are from each other the greater the ground potential could be (even a few extra inches can make a big difference). If your feet are together, then the ground potential between your two feet will likely be less, and the current will likely not travel as much through your body. This safety measure only helps for a lightning flash that strikes nearby, and not a flash that directly hits you - it is important to note that if you are in this position and the lightning strikes you directly, then there is a high probability that you will be seriously injured or killed. It is good to know, however, that there has never been a documented case of somebody being injured or killed while in the lightning desperation position.

How Far Away is Lightning From Me?

To estimate the distance between you and a lightning flash, use the "Flash to Bang" method: If you observe lightning, count the number of seconds until you hear thunder. Divide the number of seconds by 3 to get the rough distance (in kilometers) the lightning is away from you. If you count to 10, the lightning hit roughly 3km from you.

You should be in a safe location if the time between the lightning flash and the rumble of thunder is 30 seconds or less.

Remember, prevention is better than cure – if the weather looks bad, rather don't take the bike.

NOTE: This article is heavily based on an article I found on a website, the URL of which I have unfortunately lost. I would like to credit the original author. If you are the author of the original article, please contact me so that I can either credit you, or remove the article if you so prefer.

 

© Dries van der Walt, 2008. Click on 'About' to see copyright information.

 
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