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Lightening and barb wire...


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If lightning were to strike a fence how far away would it be deadly? Assuming steel posts.

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While it may destroy the fence or the charger , it will "look" for the first opportunity to arc to the ground rod (s). Hard to say how far it would go before it dissipates to ground.

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With steel posts I'd think maybe not as far a wood posts. But that's a lot of juice to dissipate depending on the strike. And you never know what instant it is going to strike again or where. My advice is not to touch a fence if you hear thunder.

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Not a direct comparison but it will go a ways.

About 25 years ago we have a neighbor who for something to do feeds between 2 to 4 Holstein dairy calves. Has a outdoor lot which happens to sit on top of a 2 line major natural gas pipeline for Panhandle Eastern. One day he came home from work and there laid the 3 calves, deader than a stump. Had the vet look at them to figure out what happened. He surmised it was electrocution. No power lines in this field. No anything with that amount of juice to drop them. It didn't storm there that day, though there were Thunderstorms about that day. The theory is lightning hit something on the pipeline and traveled it. We think the calves were reaching through the fence when it happened, ( the bodies were right on the fence) fence got energized and it was lights out. 

Its just a theory with no proof but lack of any other cause leaves us with that theory. 

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We lost a stock cow that way too.  She was laying with her head between the wires.  A neighbor boy died when struck driving the tractor in the farmyard when I was little.  Here on the plains we have a healthy respect for lightening!

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2 hours ago, axial_al said:

We lost a stock cow that way too.  She was laying with her head between the wires.  A neighbor boy died when struck driving the tractor in the farmyard when I was little.  Here on the plains we have a healthy respect for lightening!

I would guess you do. I am surrounded by trees so at least it helps 

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We had 3 guys killed in the 80's in southern Ill. A bad storm came up and we shut down and went in, they did not show up and the superintendent and I went looking. They were working about 1/2 mile behind us wrapping welds. Corner said lightening struck the pipe. 

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Many years ago, had the neighbors mule die when the tree it was tied to was hit.  Sad day because he was a share-cropper and that mule was his total source of power for his farm. Poor folks suffer the most!

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have lost several chargers to lightening storms over the years, lost one horse, best one I ever owned too, how come it never strikes the bad ones? 

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Back in the mid 80s when I was in 8th or 9th grade lightning got a flag pile between buildings when we were changing class. It blew a small chunk of concrete through both ankles on a girl walking up the sidewalk. Run I guess through the rebar in the concrete and blew a big chunk out probably 100'away. Another kid was opening the door and it burnt his hand. 

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Back to Mader's question. Lightening does whatever it wants to do. It could probably be deadly a mile away or survive it close by. I mean it jumps miles out of the sky. Do you really think that it matters if it is wood or steel posts? Or how close to the ground rod it is? As an electrician, I have seen some strange stuff. Everything from every electronic device in the house fried, but no other detectable damage to outlets ripped out of the wall breaking the wires in the process. I have seen multi-thousand dollar surge arresters completely destroyed and cheap ones that did the job. It goes where it wants and does what it wants. I was standing by my garage door with my hand on the track. I was standing bare footed on damp concrete enjoying a much needed rain. Lightening struck several hundred feet away and I got a good jolt. Way worse than 120v ever. I felt lucky to still be standing. 

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Many years ago on a Labor Day weekend, wife and I were working in the yard when a storm came up here in Northeast Nebraska.  We headed into the house (twas after 5PM) and into the shower to clean up after an afternoon's work.  Our shower was in the basement over a cast iron drain.  She cleaned up and I got in the shower and just soaped up when lightening struck somewhere.  It sounded like a rifle shot in the basement and the lights blinked out and came right back on.  I was caught with water running over me body from the shower head that had the telephone ground wire fastened to the iron pipe as a ground.  I became part of the conductor for the strike from the showerhead through the water heading for the cast iron drain in the floor.  I felt the electricity come from the floor to my knees.  I yelped, shut off the water and sat down on the cool concrete floor soaking wet and went into shock.  She wanted to haul me off the hospital, but I convinced her that I was OK.  I tingled for a couple of hours after that, but the next morning I drove an 8 foot ground rod beside the foundation and grounded the telephone line to it.      

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5 hours ago, sandhiller said:

1086607084_awesomefencelightning.jpeg.54ba2dd1759cff4fafc2743bbea4316a.jpeg

Wow! Way cool photo!

My old house got struck. I came home to find little charred bits of my electronics all over the living room. The only thing that survived was the old tube color TV. I'm quite glad I wasn't home for that show.

Flying along at night we get quite the view of lightning. It's mostly filtered by the clouds but it will go on for miles.

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1 hour ago, New Englander said:

Flying along at night we get quite the view of lightning. It's mostly filtered by the clouds but it will go on for miles.

One time I remember seeing cloud to cloud lightning. It was pretty cool. Bet your view is much better than my little passenger window 😁

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On 7/8/2020 at 10:09 PM, oldscoutdiesel said:

Many years ago on a Labor Day weekend, wife and I were working in the yard when a storm came up here in Northeast Nebraska.  We headed into the house (twas after 5PM) and into the shower to clean up after an afternoon's work.  Our shower was in the basement over a cast iron drain.  She cleaned up and I got in the shower and just soaped up when lightening struck somewhere.  It sounded like a rifle shot in the basement and the lights blinked out and came right back on.  I was caught with water running over me body from the shower head that had the telephone ground wire fastened to the iron pipe as a ground.  I became part of the conductor for the strike from the showerhead through the water heading for the cast iron drain in the floor.  I felt the electricity come from the floor to my knees.  I yelped, shut off the water and sat down on the cool concrete floor soaking wet and went into shock.  She wanted to haul me off the hospital, but I convinced her that I was OK.  I tingled for a couple of hours after that, but the next morning I drove an 8 foot ground rod beside the foundation and grounded the telephone line to it.      

This topic brings up a memory my wife had as a little girl, she would travel by train down to valley city ND from BC. with her grandmother, the first thing her granny would do is walk around pouring water on all the lightning rods around the house, whenever a storm would go through they would go upstairs and watch from a bedroom window the light show and wonder if the heavy clouds would turn into tornados during a storm.

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Some locals here rushed to get the washing off the line (wire strung between two trees) in a storm. As she grabbed the washing the tree got struck by lightning, killing her. Her husband survived with burns. 

So I would assume you would either need to be touching or very close to the wire for it to kill you. 
 

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I saw it hit a pine tree. I was almost blinded by the flash. All the bark blew off one side; I assumed it boiled the sap and the steam blew it off.

As for the original question: I would bet it depends on the soil moisture/conductivity.

When we've had lightning strikes on planes it's been various degrees of destruction. Years ago at the airline we used to see it quite often. DC9s seemed to have the most in my memory; could be because they did the short hauls with the most TO/LDGs. We had to identify the entrance and exit wounds. On the 9 it seems often struck just below the windscreen with exit on a wing tip. Maintenance action included checking magnetic compasses, all control surface bonding straps, static dischargers, and all radios. I saw one that had every static wick blown off to a stub. The biggest problem we had was when we couldn't find an exit wound. That meant it may have exited through an engine and if so, crossed a bearing, which could set it up to fail later.

On our business jets we've had several strikes in the last couple of decades. One blew the paint off the fuselage along a seam, arcing a bunch of rivets and another did similar plus taking out the radome bonding strips.

I think we saw lots of strikes back in the '70s as crews would fly much closer to storms than we do now. Airlines simply fly way more and have schedules to meet so they're going to have lots of strikes anyway. Present guidance is no closer than 5 miles taking off/landing and 20 miles min from big ones enroute. Top 1000' for each 10 knots of wind, so if the storm tops off at 35,000 and the wind is 100kts at FL350 then the storm can be crossed at FL450, something we may be able to do but no airliner is likely to. More than likely it's a big detour around, generally on the upwind side as hail can blow out the top and fall in clear air on the downwind side.

Thunderstorms get lots of respect, not just for lightning.

That said, the strikes we've suffered were in relatively clear air in excess of the 5 mile requirement, all while approaching to land.

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Neighbor had a pickup struck. No one was int at the time. Fixed everything obvious but fought electrical gremlins for two years before they finally traded it off.

Not sure how much cattle against a fence had to do with this but a neighbor lost 99 head of yearling steers that bunched up in a fence corner during a storm. 

I found another cow yesterday morning one back leg pointe forward the other straight back, sure she was lightning struck.

Storms have had a lot of lightning in them this summer, more grass fires than normal, I could do with less.

 

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Had a customer call in one day and state his new tractor would not start. Sent service truck to farm, as mechanic was walking up to tractor he noted something in field. Part was antenna, to his credit he stopped and picked it up thought about everything and did a walk around. From bale spear to ground noted a hole blown in field, then from each tire same thing out about a foot from wheel rim. Ground strap from cab to rear axle had a part number sticker melted. Sent rollback out to bring tractor in. Insurance adjuster came and said do not even think about repairing tractor. CaseIH said the same thing. 

Insurance company sold tractor and we forgot to remove dealer decal, huge mistake as some bloke in Florida bought it and started calling in. He had no close dealer to work with, always wonder where it went from there????

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