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Old 05-28-2015, 11:36 AM   #23
Civicsman
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KSAGAL's answer, "just go home and get out of the rain" is good advice, but the The original post specifically asked, "but what is safe if you get caught in a storm on your seg? Common sense says avoid if at all possible.. But some of these storms are coming up pretty fast and I'm not always that close to either home or shelter, so safety tips would be welcome." (emphasis is mine).

So this thread is about what to do if one gets caught in a lightning storm while Segging. "Just glide home" is not a valid answer to that question, and is not a strategy that is suggested or promoted by anyone who has actual knowledge of lightning events.

I don't know whether every electromechanical engineer has a good understanding of the properties of electricity. I personally know of many "field engineers" who are educated as repair technicians, not engineers, and, perhaps surprisingly, may not have a good understanding of electricity. This lack of understanding does not mean these people are not permitted to have "Field Engineer" on their business card, or that they are unable to make a living....at the right type of job. However, when I lay out the reasoning behind crouching on the balls of one's feet, if one is exposed in the open to lightning, and it is dismissed without any technical reasoning to support the dismissal, the facts lead me to wonder whether the electrical issues are understood.

Yes, I said it was a "theory", but the question isn't whether taking the squatting pose does as advertised, minimizing high current from a nearby ground strike directly through the body (it clearly does), but rather whether it is a better safety strategy than laying flat on the ground. Laying flat minimizes the likelihood of being struck directly, but crouching on the balls of your feet, with feet touching, minimizes the through the body damage of a nearby earth strike. I gave both safety strategies in my original post, and the reasons behind them.

What followed was not a discussion of potential life saving strategies, but rather repeated attempts to dismiss the need for taking any precautions. This is based, in my opinion on a completely inaccurate perception of lightning strike statistics, and how they apply to someone who is actually caught in the open in a lightning storm, coupled with refusal to consider what lightning experts (referred to as "bureaucratic scientists") consider to be prudent actions.

Below, I've reposted my first response. It's still the only real advice in this thread for Lily (or others), unless you count "just ignore the storm and glide home".

Quote:
...Tires or other rubber items do very little to protect one from a lightning strike. What helps in a car is the metal body, which acts as a Faraday cage. Lightning that strikes a vehicle travels through the metal wrapper and to the earth below. On the bottom side of the car, it either travels through the tires (there's lots of conductive carbon in those "rubber" tires") or arcs directly to the earth. Remember that lightning has already arced down from the cloud. It can certainly arc another foot from the bottom of the car to the ground. If you don't touch the metal parts of a car inside, you'll likely be OK. Aircraft get struck all the time.

With an approaching storm, you must get OFF the Seg and get away from it. Standing upright, it's like you are standing on a ladder. You're a prime target for the "leaders" which are looking for the easiest path to the earth. Don't shelter under trees, as they can sometimes quite literally explode when hit by lightning, driving splinters of wood into anything nearby.

If you are caught in a storm with lightning and you really have zero shelter, such as being in a field, crouch down with your arms wrapped around knees, and feet positioned so that they touch each other. It's better to do this in a depression in the earth, if you have the option. There are arguments that say laying down prostrate is a better solution, but I subscribe to the "potential difference" theory. Lightning which strikes the earth electrifies the area around. The point of strike has the highest instantaneous voltage with respect to the earth, and the voltage drops as the distance increases from the strike point. If lightning strikes the earth near to you, and your feet are far apart, there will be a large voltage across your body, and electrical current could flow through your body. This might actually be worse that being struck directly. With your feet close together, there will be relatively less voltage across your body. BTW, there seems to be agreement that umbrellas are good for shedding rain, but you don't want to be holding one in a lighting storm.

Most storms don't come out of nowhere and start flinging off lightning bolts within seconds or minutes. It takes time for the storm to build. Get yourself a good warning application, such as Storm for iPhone, which notifies you when lightning or precipitation are approaching. If you're going gliding in storm season, maybe make a plan for where and how you would shelter safely, and, perhaps pack a folded plastic trash bag for rain protection.

My research says that if the lightning flash-to-thunder time is less than 25 seconds, you're already in the potential danger area for a lightning strike.

Last edited by Civicsman; 05-28-2015 at 11:41 AM..
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