I ask this here because it is obviously outdoors and TexAgs has always had the answer.

It has to do with where it is safe to be in case of a lightning strike.

Situation- at my kids baseball game last night, the lightning detector goes off. I believe it measures electomagnetic interference and then sounds a horn.

Anyway, the horn goes off and the ump said standard procedure was to go under a pavilion and wait 15 minutes to see if the game would be cancelled.

I told my team to stay in the dugout. The pavilion is an open air pavilion with posts on the 4 corners. The dugout is basically a chainlink fence enclosure with a metal roof.

Me reasoning was based on Faraday's cage. Where the lightning hits the fence and travels around it.



I know, I know "Being safe would be leaving!"

I'm just asking all those smarter than me (and there many) if my reasoning was correct.

I convinced the team parents to stay in the dugout, but there were some blank stares when I began giving my reason based on electromagnetic shielding.

So, TexAgs Outdoors, what say you?

I am no expert but I don't think you could call an enclosure made of chain link Faraday's box.

Getting into the cars would be better, wouldn't it?

Canyon, maybe. That was part of my "leaving would be better"

But cars work off the Faraday Cage principle, too.

How about more of a real life example. I took off work early to go crappie/white bass fishing with my roommate. It was raining when I got there, but I thought, "I can suck it up he'll be here any minute with my rain coat." (fyi, the wuss never showed)

It started raining harder, getting windy, some lightning getting closer until ultimately lightning hit a willow tree on the opposite bank of the river (maybe 30 yards across and 50 yards down). Despite being drenched like a drowned rat every hair on my body stood at straight attention, I IMMEDIATELY got a headache and I couldn't see out of my right eye (from the flash) for about 15 minutes. I decided maybe it was time to vamoose.

My question is, what gave me the headache? Blinding flash of light? Electricity in the air? Pure exact timing coincidence?

(by the way, I caught about 4 crappie in 40 minutes, no keepers)

For the OP:

quote:

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Safe Buildings

A safe building is one that is fully enclosed with a roof, walls and floor, such as a home, school, office building or a shopping center. Even inside, you should take precautions. Picnic shelters, dugouts, sheds and other partially open or small structures are NOT safe.

Enclosed buildings are safe because of wiring and plumbing. If lightning strikes these types of buildings, or an outside telephone pole, the electrical current from the flash will typically travel through the wiring or the plumbing into the ground. This is why you should stay away from showers, sinks, hot tubs, etc., and electronic equipment such as TVs, radios, and computers.

Lightning can damage or destroy electronics so it's important to have a proper lightning protection system connected to your electronic equipment. The American Meteorological Society has tips for protecting your electronics from lightning.
Unsafe Buildings

Examples of buildings which are unsafe include car ports, covered but open garages, covered patio, picnic shelters, beach shacks/pavilions, golf shelters, camping tents, large outdoor tents, baseball dugouts and other small buildings such as sheds and greenhouses that do not have electricity or plumbing.

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Edited for this:

quote:

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Coach of Outdoor Sports Team

You are a manager of a little league team and have a game this evening at the local recreational park. The weather forecast for the day calls for a partly cloudy skies, with a chance of thunderstorms by early evening. You arrive in your vehicle while the kids arrive with their parents. Once arriving at the park, you notice the only buildings are the the restrooms, an enclosed building. Shortly after sunset, the skies start to cloud up and you see bright flashes in the sky to the west. The local radio station mentions storms are on the way.

In this case, the safest locations are the vehicles the kids came in or the rest rooms. You should have a choice of allowing the kids to go back to their vehicles or bring everyone into the restrooms. It is important NOT to stay in the dugouts as they are not safe place during lightning activity. Once at a safe place, wait 30 minutes after the last rumble of thunder before going back outside.

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From here:
http://www.lightningsafety.noaa.gov/outdoors.htm


[This message has been edited by KRamp90 (edited 4/24/2008 11:31a).]

i actually have an issue with both of the places during a lightning storm.

the best place for those kids was in their parent's vehicle.

tell the parents not to leave, send the kids to the cars, and wait for the all clear.

seeing what lightning can do to things and animals and people...you would not have convinced me to keep my kid in the dugout with you, he would've been in the car.

I think if you were surrounded mostly by metal, you would be fine...might be deaf, but youd be alive. The car would be safer in my opinion anyway.

Thanks for the replies.

First, there was no lightning. I'm not sure what the detector senses or how sensitive it is. Something sets it off and it monitors the area for 15 minutes and sounds an all clear or cancel.

I guess I made it sound like we had lightning hitting the trees and dugout all around us. We actually never heard or saw any lightning.

I wasn't trying to convice anybody to do anything dangerous. Heck, the only thing they were worried about was walking to the car if it started raining.

No EE's out there to chime in??

Sean, your headache was more than likey caused by vasoconstriction, meaning that blood vessels and capillaries constricted (somehow being triggered by the electricity). This is also how caffine and nicotin headaches work, and a big trigger in migraines.

I.Y.A.C.Y.A.S. '91

My lightning story...

When I was in the Army in Georgia, we took shelter from an afternoon thunderstorm in some wood bleachers under a metal canopy. The drill sergeants made us stand so we wouldn't fall asleep.

Lightning struck the mercury vapor light on the light pole next to the canopy, arced over into the metal bleacher framework, came out the other side and went down a parking barrier made of steel cable and 4 X 4 posts. It shattered 17 posts as it ran down the cable and arced into a jeep and took out a tire. This happened faster than you could blink your eye.

Most everybody was OK except 7 seven guys that went down. Seems they were standing on the metal bolts connecting the wood bleacher rows to the metal frame. Thank goodness they weren't setting on the bolts! (Which I think about to this day 33 years later)

We dragged their stuporous bodies back up the hill to the barracks and all 7 went in the hospital overnight for observation.

I think the Faraday cage concept is valid, but I wouldn't want to bet somebody else's kids on it working.

My Lightning story

I was a kid of 6 or 7. I was sitting on a metal chair eating breakfast in my Grandfathers seacoast home in New Hampshire. There was a thunderstorm going on and I was sitting about five feet from a screen door. I got up to put my cereal bowl in the sink when lightning came through the screen, struck the chair I had just vacated, traveled through the kitchen, entered the den, knocked out the TV, went through the window behind the TV and flopped around in the wet grass for a few seconds.

[This message has been edited by swampstander (edited 4/24/2008 8:25p).]

Here is the problem with the dugout (I am equating to caves which I know more about). First off the metal doesn't completely surround. In fact it might initially create a strike point. DEEP caves can be safe in a thunderstorm, shallow caves can get you cooked because you can't get away from the entrance. I am equating a dugout to a shallow cave. From the stike point, electricity radiates either vertically or horizontally through the the medium (water, sandy soil). The electricity travels right along the surface. If you are remotely close to the strike point, there is a chance that the electricity will simply travel/arch through the open air space from one side to the other.

I'm not an EE, but that is the general idea behind why dugouts/shallow caves are bad.

"Our nation’s continued prosperity hinges on our ability to solve environmental problems and sustain the natural resources on which we all depend.” John McCain November 22, 1996
"I recognize the right and duty of this generation to develop and use our natural resources, but I do not recognize the right to waste them, or to rob by wasteful use, the generations that come after us."
- Theodore Roosevelt, speech, Washington, D.C., 1900



[This message has been edited by ursusguy (edited 4/24/2008 8:55p).]

More good points.

Ursus, I use the term "dugout" in the historical sense.

It really is enclosed. It looks like a chainlink dog kennel with a metal roof. It has chainlink gates on each end. It is on a concrete slab and the metal poles are, I assume, going about 1 foot in the ground.

In fact, it looks just like the picture I first posted. I actually think it is a perferct Faraday Cage.

Again, I'm not going to test my electromagnetic theories with someone's kid. I'm not that stupid.

I'm asking more from a hmmmmmm perspective. It drives my wife crazy I "have to know" something.

quote:

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First, there was no lightning. I'm not sure what the detector senses or how sensitive it is. Something sets it off and it monitors the area for 15 minutes and sounds an all clear or cancel.

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speaking as someone who has had to deal with the sensors....

they detect lightning...

if the detector went off, it means it detected lightning within a mile of where the field is.

you dont have to see it for it to be there

it could've been cloud-to-cloud lightning and it would still detect it.

The thing constantly monitors and would continue to give a detection alarm if it stayed in the area.

When the monitor detects lightning further out for 15 minutes, it blares the all clear alarm.

i cannot believe someone affiliated with the fields allowed y'all to stay in the dugout. they should know better...

the lightning detector at our youth baseball fields has distance settings.

It detects lightning and an LED lights up for:
1. 1 to 3 miles
2. 3 to 6 miles
3. 6 and over

You can sometimes watch the lights and get a decent idea of what is happening relative to your location. Example... the "6 & over" light keeps flashing, then for a few minutes it moves to the "3 to 6" range, then it moves back to "6 and over". In this example you can be pretty sure that storm has passed you by.

http://en.wikipedia.org/wiki/Faraday_cage

after seeing your picture I guess it might work, I wouldn't want to try it though.

[This message has been edited by AggieCowboy (edited 4/25/2008 8:29a).]

The wiki article is correct. Farraday cages must have a mesh that is smaller than the wavelength of the energy source they are intended to shield from.

The main problem that I could see being in the dugout would actually arise in a fancier facility. If it were a true dugout with concrete floors and walls (below grade) the posts for the above ground chainlink would likely not be grounded. Your run of the mill little league park though is a slab poured around poles set in the ground.

Next question is whether or not there would exist a danger of the concrete exploding as the electricity surged into the poles and reinforcing steel in the slab.

The pavilion (staying near the center) would be safe. The poles will be sunk fairly deep and be well grounded. Also if that is the location determined by park policy, it might have a lightning protection system installed.