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Flash to Bang by blackrams
Started on: 04-15-2021 07:44 AM
Replies: 18 (304 views)
Last post by: theogre on 04-18-2021 07:32 PM
blackrams
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Report this Post04-15-2021 07:44 AM Click Here to See the Profile for blackramsSend a Private Message to blackramsEdit/Delete MessageReply w/QuoteDirect Link to This Post
Just for fun, ever since I learned how to do it, I have always tried to estimate the distance of lightning from my location. So, I pay attention when I see lightning and start counting the seconds to determine that distance. Just a mental game I play.

Have had quite a few thunder storms rolling through this Spring, so I've had a few interesting lightning storms to observe. Tonight, my house shook and brought me out of a dead sleep. The thunder and lightning was intense. Even the dogs were scared. Actually, I thought it was a pretty cool demonstration of Mother Nature's power.

Looking out to the back yard onto the neighbor's property a bit later, I realized why that massive sound woke me up. One of my neighbor's trees was smoldering and there wasn't much left of it. Additional and continuing lightning is what allowed me to see that tree. The tree will not survive and I got a good reminder of how powerful lightning can be. Will get my chainsaw and tractor out and help him when it quits raining.

I have been in aircraft before that were struck by lightning, a couple of times while in flight and once while the UH1 was sitting on the ground. Interesting experiences.


 
quote
This technique is called the "flash-to-bang" method, and it can keep you safe during rainy summer weather. The National Weather Service recommends taking cover if the time between the lightning flash and the rumble of thunder is 30 seconds or less, which indicates the lightning is about 6 miles away or closer.

This method is based on the fact that light travels much faster than sound through the atmosphere: Light travels at 186,291 miles per second (299,800 km/s), whereas the speed of sound is only about 1,088 feet per second (332 meters per second), depending on air temperature.

For metric-system conversions, follow this method: Sound travels at about 340 m/s, so multiply the number of seconds you counted by 340, and you'll know how many meters away lightning struck. A three-second count, then, would place the lightning strike about 1,020 m away, or roughly 1 km.


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2.5
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Report this Post04-15-2021 03:17 PM Click Here to See the Profile for 2.5Send a Private Message to 2.5Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
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Originally posted by blackrams:

I have been in aircraft before that were struck by lightning, a couple of times while in flight and once while the UH1 was sitting on the ground. Interesting experiences.

Rams


What happens during those instances?

[This message has been edited by 2.5 (edited 04-15-2021).]

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blackrams
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Report this Post04-15-2021 03:48 PM Click Here to See the Profile for blackramsSend a Private Message to blackramsEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by 2.5:


What happens during those instances?



Well, normally the crew chief needs to change his underwear............
If you mean what happens to the inflight aircraft, no damage in either instance.
But with the grounded UH1, the rotor system (blades) had to be replaced along with the skids.
In neither situation was a crew member hurt. We weren't grounded.

Rams

[This message has been edited by blackrams (edited 04-15-2021).]

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TheDigitalAlchemist
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Report this Post04-15-2021 05:24 PM Click Here to See the Profile for TheDigitalAlchemistClick Here to visit TheDigitalAlchemist's HomePageSend a Private Message to TheDigitalAlchemistEdit/Delete MessageReply w/QuoteDirect Link to This Post
Reminds me of that scene from poltergeist...


Life is more exciting when lightning is around...

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Report this Post04-15-2021 07:17 PM Click Here to See the Profile for Jake_DragonSend a Private Message to Jake_DragonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Spent over 30 years living in the Florida, lightning capital of the world.
Its funny they had an airbag manufacturing plant just down the road from us.
They would close up and send everyone home if they got even the hint of rain.

After the third explosion they closed the place. lightning is kind of a big deal when static can blow up your work place.
It also didn't help decapitating kids in booster seats.
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Report this Post04-15-2021 07:50 PM Click Here to See the Profile for OldsFieroSend a Private Message to OldsFieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
One time when my wife and traveled, I watched a bad storm in the mid west from above the clouds. I told her that if aliens came here and saw that, they would say move on nothing could live here.
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Report this Post04-15-2021 07:53 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
I had 2 "struck" my house many years ago...
One we think hit the house and/or well 2 feet from the house. Fried phones, deep well water pump, and few other things.
Other hit a tree ~ 20 feet away and piece of same hit the house.

Again years later hit a tree a few yards away when parked my car in a park during a storm. Rain was too hard to get out or see to drive.

You may think flash and huge boom is instant... Nope.
Flash and Huge Zapp sound Hundreds x louder then shorted out 120 or 240vac then Short Fast Boom if any.
Why? You too close, IE @ Ground Zero, to have the big shockwave that makes the boom.

If you been near 13,500vac or higher shorting out like tree falling or Squirrel kill themselves on High Tension wires... That zapp sound is close to noise level. But this might sound more like a big welder because because many breakers/fuses won't blow right away.
I have seen this happen several times before Asplundh and other tree trimmers chopped out a lot of trees here in Power Co right of ways.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)


The Ogre's Fiero Cave

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blackrams
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Report this Post04-15-2021 09:56 PM Click Here to See the Profile for blackramsSend a Private Message to blackramsEdit/Delete MessageReply w/QuoteDirect Link to This Post
Yeah, back when land lines were the norm, I was sitting in the living room next to the phone watching TV and lightning hit the aluminum land line box on the outside wall. The bang was enormous, the phone actually jumped off the chair side table beside me. Scared the hell out of this 10 year old.

Never been the same since. Land Lines scare me.

Rams
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Report this Post04-16-2021 07:52 AM Click Here to See the Profile for cliffwSend a Private Message to cliffwEdit/Delete MessageReply w/QuoteDirect Link to This Post
I was on I-20, heading East, to Dallas from Midland, TX. The Wife called. As we were talking, I hear an Earth shattering BOOM. Followed closely by an Earth shattering scream from the wife.

Lightning hit one of our trees, 10' from the house.

When I got home days later, there was a one inch wide strip of tree bark peeled from the top to bottom of a 30' tree.
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blackrams
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Report this Post04-16-2021 01:11 PM Click Here to See the Profile for blackramsSend a Private Message to blackramsEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by cliffw:

I was on I-20, heading East, to Dallas from Midland, TX. The Wife called. As we were talking, I hear an Earth shattering BOOM. Followed closely by an Earth shattering scream from the wife.

Lightning hit one of our trees, 10' from the house.

When I got home days later, there was a one inch wide strip of tree bark peeled from the top to bottom of a 30' tree.


Dang!!

Two things came to mind:
First, what did you do to make you wife that mad and second, I had no idea she could do that!!!

Rams

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Report this Post04-16-2021 02:08 PM Click Here to See the Profile for maryjaneSend a Private Message to maryjaneEdit/Delete MessageReply w/QuoteDirect Link to This Post
Bark is usually 'blown' off the trunks and limbs as the energy from the strike instantaneously boils off the moisture in the vascular layers of the tree. (assuming the tree is not dormant) Steam pressure builds up in the blink of an eye and sends large chunks of bark flying quite a ways from the tree. Happens more on a rough barked tree like pines and oaks than on a smooth barked tree. This is also wht generally kills the tree, as the vascular cambium ( xylem and phloem cells) and cambium cork a bit farther inside the bark is all ruptured by steam pressure. The xylem and phloem cells are the part of the tree that transport nutrients up and down from roots to leaves and vice versa. Often, only one side of the tree will die, as the damage doesn't always involve the full circumference of the cambium layers.

(a good bit of the noise heard when lightening hits a tree is the steam explosion)

[This message has been edited by maryjane (edited 04-17-2021).]

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Report this Post04-17-2021 03:25 AM Click Here to See the Profile for HudiniSend a Private Message to HudiniEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by blackrams:

Just for fun, ever since I learned how to do it, I have always tried to estimate the distance of lightning from my location. So, I pay attention when I see lightning and start counting the seconds to determine that distance. Just a mental game I play.

Have had quite a few thunder storms rolling through this Spring, so I've had a few interesting lightning storms to observe. Tonight, my house shook and brought me out of a dead sleep. The thunder and lightning was intense. Even the dogs were scared. Actually, I thought it was a pretty cool demonstration of Mother Nature's power.

Looking out to the back yard onto the neighbor's property a bit later, I realized why that massive sound woke me up. One of my neighbor's trees was smoldering and there wasn't much left of it. Additional and continuing lightning is what allowed me to see that tree. The tree will not survive and I got a good reminder of how powerful lightning can be. Will get my chainsaw and tractor out and help him when it quits raining.

I have been in aircraft before that were struck by lightning, a couple of times while in flight and once while the UH1 was sitting on the ground. Interesting experiences.
Rams


My aircraft has been struck 3 times. Once in the F111 and twice in the A320. Interestingly, if my current aircraft is struck it is my fault and I will be punished. The logic is simple, if you were not flying near thunderstorms you would not have been struck. Actually running a scheduled airline that flies into areas with storms does not make a difference. “You should have diverted”

Rams: Do you have lightning rods on your house? These are absolutely required for me after witnessing a fire inside the walls of my parent’s house due to a strike on the TV antenna around 1976 ish. The lightning jumped from the antenna cable to the household wiring and lit the paneling on fire on the inside. 16 year old me was shaking like a leaf as I grabbed a pot full of water to douse the flames as they started climbing the drapes.



This is the type of damage a strike can do.
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blackrams
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Report this Post04-17-2021 09:57 AM Click Here to See the Profile for blackramsSend a Private Message to blackramsEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Hudini:


My aircraft has been struck 3 times. Once in the F111 and twice in the A320. Interestingly, if my current aircraft is struck it is my fault and I will be punished. The logic is simple, if you were not flying near thunderstorms you would not have been struck. Actually running a scheduled airline that flies into areas with storms does not make a difference. “You should have diverted”

Rams: Do you have lightning rods on your house? These are absolutely required for me after witnessing a fire inside the walls of my parent’s house due to a strike on the TV antenna around 1976 ish. The lightning jumped from the antenna cable to the household wiring and lit the paneling on fire on the inside. 16 year old me was shaking like a leaf as I grabbed a pot full of water to douse the flames as they started climbing the drapes.



This is the type of damage a strike can do.


Interesting damage on those aircraft. I've not experienced that (with the exception of the UH1 that was on the ground).

No, my home does not have a lightning rod attached/installed. Looked into that and found so many differing opinions, I wasn't sure it was the way to go. Some say it's the only thing that will protect a house from a lightning strike, others say it provides a lightning rod for more frequent events, drawing strikes. It didn't lower my home insurance so, that was the deciding factor. But, we also don't have any TV antennas or other similar metal objects sticking up from the roof so....................

Anyone else have lightning rods installed on their homes?

Edited: In fact, I took steps to remove potential lightning drawing things from close to the house. Not just or really due to the threat of lightning strikes, I removed some of the trees that were close to the house. Didn't like the damn things anyway. While I'm not a tree hater (like some of our other well known members), I don't like trees that touch or over hang a structure. They always end up doing some kind of damage even if that's just clogging up gutters or busting foundations.

Rams

[This message has been edited by blackrams (edited 04-17-2021).]

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cliffw
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Report this Post04-17-2021 03:38 PM Click Here to See the Profile for cliffwSend a Private Message to cliffwEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by blackrams:
Dang!!

... what did you do to make you wife that mad ...


Let me count the ways.
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Report this Post04-17-2021 06:20 PM Click Here to See the Profile for OldsFieroSend a Private Message to OldsFieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
We had them on the house, barn, and on the two story chicken houses on the farm. Don't know of any strikes on them. I live next door and have been hit twice in the last 40 years. Don't have lightning rods on the house or garage. The first one blew up the transformer and all three lightning arrestors on the pole. It also tripped all the breakers on one leg in the service. We think it forked and hit the TV antenna that was mounted on the lawn on a steel pole on the opposite side of the house. I say this because the flat cable from the antenna to the TV was vaporized. All that was left where the cable went across the porch and under the window was two parallel stains! The TV and VCR were the only appliances that died. The lineman said he had never seen all three arrestors blown before. We were at work at the time. The second one just roached the phone line between the last two poles. We don't know when that happened. The wire rusted in two later on.

Marc
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theogre
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Report this Post04-17-2021 09:21 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Hudini:
Do you have lightning rods on your house? These are absolutely required for me after witnessing a fire inside the walls of my parent’s house due to a strike on the TV antenna around 1976 ish. The lightning jumped from the antenna cable to the household wiring and lit the paneling on fire on the inside. 16 year old me was shaking like a leaf as I grabbed a pot full of water to douse the flames as they started climbing the drapes.
Very Likely because antenna and wiring to it was installed wrong.

Most outdoor antennas have no earth ground from whatever mounting.
Most wiring don't have grounds either except maybe at the device(s) inside.
...Almost no-one used any protection for "flat twin wire" 300Ω for old TV's or 50Ω Coax for CB Ham and other radios.
...Mosty only "pro's" properly ground 72Ω Coax before entering a building.

Example: Cable Co's have these to ground a service before enters a home etc.

Ground wire to bottom 7/16" head bolt.

Is a ground and MoCA blocker/filter
(May have top ground point plus MoCA blocker attach to that. depend if Cable "tech" has above or just a blocker.)

Most antennas including Sat Dishes still don't have grounds from mounting hardware. So in a heavy storm the static generated alone can kill many devices. Good luck if it gets struck.

And this can happen even w/ buildings w/ lightning rods because:
Antenna at or above the rods.
Antenna is on another building or "telephone" pole.
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maryjane
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Report this Post04-18-2021 02:20 PM Click Here to See the Profile for maryjaneSend a Private Message to maryjaneEdit/Delete MessageReply w/QuoteDirect Link to This Post
And most ground wiring isn't large enough to dissapate all the joules in a strike either.
My TV dish does have a gound cable, attached to the dish base on one end and a 5/8 diameter 8' long copper coat rod driven 7 1/2' into the ground. (It hit a rock or would have been driven the full 8' in)
Neither the solid core ground wire or rod will handle all of a normal lightening direct strike's energy except for the fact that the strike is of such short duration, usually less than 1 ms.

I was indirectly struck by lightening in my teen years while working on a barbed wire fence. Have no idea where (how far away) the strike actually took place as that fence was tied into others but there were plenty of steel posts elsewhere in the fences and they didn't provide enough pathway to ground to prevent me from being knocked off the fence. An average bolt of lightening releases high millions to 10 billion joules.

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blackrams
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Report this Post04-18-2021 02:44 PM Click Here to See the Profile for blackramsSend a Private Message to blackramsEdit/Delete MessageReply w/QuoteDirect Link to This Post
I have disposed of many a cow and a horse or two that got directly stuck by lightning or were in contact with a barbed wire fence while back on the ranch. It ain't pretty and stinks to high heaven if disposal isn't done quickly.

Rams
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theogre
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Report this Post04-18-2021 07:32 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by maryjane:
And most ground wiring isn't large enough to dissapate all the joules in a strike either.
My TV dish does have a gound cable, attached to the dish base on one end and a 5/8 diameter 8' long copper coat rod driven 7 1/2' into the ground. (It hit a rock or would have been driven the full 8' in)
Neither the solid core ground wire or rod will handle all of a normal lightening direct strike's energy except for the fact that the strike is of such short duration, usually less than 1 ms.
The large ground for lightning rods often fry when hit too.
The small grounds for antennas etc dissipates the static on whatever to try to prevent them getting hit.

Quick overview of antenna grounds...
How To Ground an Outdoor TV Antenna Per NEC by Antenna Man
https://www.youtube.com/watch?v=5aey9rCC5Gs
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