Jul 18, 2007 at 2:36 pm #1224180
@quoddyLocale: New York/Vermont Border
I was just reading a Trail Journal for July 9th from "Thirsty" in which he's blown off his feet by lightning 30' or less away. He happened to be walking with metal poles and I began to wonder, "how much safer, if at all, are carbon fiber poles in these circumstances?". Any definitive information on this? This hits close to home since hiking in the same spot in just over two weeks.Jul 18, 2007 at 2:38 pm #1395808
Why not call up Fibraplex and ask them? Oh, and don't forget to post the answer. :)Jul 18, 2007 at 3:08 pm #1395817
This calls for a test. Volunteers?
Maybe it wasn't such a good idea to be walking in a thunderstorm? Hmmmm?Jul 18, 2007 at 3:10 pm #1395819
@quoddyLocale: New York/Vermont Border
Fine idea! I wrote and had the answer in less than five minutes. Here it is:
There is essentially no difference in safety. Carbon is less conductive than metal but it is still conductive. People are also conductive. Lightning will tend to strike the highest (or closest) object, not the most conductive. For safety, don't be the highest object near a lightning storm or near a tall object.Jul 18, 2007 at 3:33 pm #1395821
Good to know. Thanks, John!Jul 18, 2007 at 9:40 pm #1395870
Unless you're shorter than your hiking pole, or holding it over your head, I don't expect there is any difference.
Really high voltages exhibit very strange, often difficult to predict behavior. Your body is a pretty good antenna for lightening in and of itself. Adding a parallel path through your relatively skinny arm and wrist through 2 right angles (which fast transient charges, such as lightning strokes don't like) down to the ground has more resistance than the straight shot from your head through your stouter body, through thicker thighs and down both legs and feet. (no personal comments on anyone's phisique intended)
It won't really matter if your boot soles are rubber, if the lightening can jump a couple of miles through the sky, it won't even notice the air gap created by 2 inches of vibram rubber.
MikeBJul 19, 2007 at 5:27 am #1395896
I don't disagree with what you've said regarding unpredictability, or 2 miles vs. 2 inches of rubber, but for the sake of discussion…
I have heard that most of the time lightning won't strike you directly, but will instead run along the (probably wet) ground. The highest risk of injury concerns heart stoppage, which is why the recommended position is balled up, with feet together underneath you and no hand touching the ground. If you have two poles planted, you have just advertised a path through your heart. Perhaps grip material is more relevant than pole material.
It's also important to note that many people who are hit by lightning are NOT getting rained on at the time, as lightning can travel quite a ways out ahead of a storm.Jul 19, 2007 at 7:37 am #1395903
The Mountaineer’s manual says to avoid height, depressions (never understood this), trees and positioning yourself as one of the tallest objects in a wide open space. Kevin adds, “Maybe it wasn't such a good idea to be walking in a thunderstorm?” So what do you do on the trail when a thunderstorm passes over the area you occupy?Jul 19, 2007 at 7:50 am #1395910
In a thunderstorm, if at all possible, get off any summits and ridges, stay out of shallow caves and crevices (a depression would be a pronounced low spot of limited dimensions—-not a valley), if your campsite isn't under the immediate vicinity of tall trees or on a pronounced high spot (say a scenic high point above that lake), that would be a good place to hang out while it blows over. I say don't walk bcause you may be passing into one of the above "higher risk" zones. Just hunker down under the protection of your hardshell or under tarp or fly and enjoy the light show.
If carrying climbing equipment, I deposit it away from where I'm hanging out—-this is more out of custom (aka common sense?) than scientific evidence—although I once had St.Elmo's Fire dancing on the head of my ice axe. Classic…
Must get coffee, now…..Jul 19, 2007 at 9:06 am #1395916
@leadfootLocale: Middle Virginia
There was a quick segment about this on the Weather Channel not long ago. They said if you're out hiking, to find an area where most of the trees are of the same height, ditch your poles, crouch down, raise your heels off the ground (try holding that for any time!) and close your eyes, cover your ears. They advised not to lay (lie?) flat because your heart will get zapped if lightening hits the ground. I guess because the heart conducts energy and is in direct contact of the ground.Jul 19, 2007 at 10:18 am #1395924
That would be standard practice if there are close strikes about you. You need not do this for an entire storm! You'll miss out on the fun. :-)>
Yes, entire parties have been taken out by electricity being conducted a distance through rock!Jul 19, 2007 at 10:22 am #1395926
Doesn't matter what you're carrying, if you're close enough for a strike to have that effect, it's going to have that effect. Mother Nature always wins when she chucks a lighting bolt <s>at you…</s> at anythingJul 19, 2007 at 10:28 am #1395927
Don't be too fatalistic—-one can at least practice safe bolt dodging. :-DJul 19, 2007 at 11:59 am #1395943
@scottalanpLocale: Northern California
I seem to remember Backpacker mag recommending the grove of trees of similar size…and not being exposed or on a ridge…and in addition, placing your sleeping matt under your feet as you crouch. I am not sure if a foam pad is going to insulate totally but it may help?
I personally would stay away from the base of the trees too. I recall seeing a sequoia as a kid that had been hit…and the bark had been gauged off about 8 inches wide from somewhere up high to nearly the base of the tree!Jul 19, 2007 at 6:31 pm #1395989
The real trick is to not be in a bad spot when the lightning starts. Lightning has killed people inside houses as well as in the wild.
The trick about getting low in the terrain, squating and putting your feet together is to minimize the electric field and voltage gradient when the bolt hits. Putting your hands over your ears and opening your mouth is to minimize the sound on your ear drums.
I've also seen very tall pine trees that have a nice swatch from the top to the bottom where lightning traveled, and have seen 1 tree that exploded. Wouldn't want to be near that one.
MikeBJul 19, 2007 at 7:09 pm #1395992
@joshleavittLocale: Ruta Locura
Carbon fiber poles have a very high electrical resistance, I applied 12V DC @75 amps to a carbon pole (at the cut ends) and read .25 amps running intermitantly through it. An aluminum pole will transfer the full 75 amps instantly.
For a refernce I ran the same Volt/Amps through a piece of fresh cut green wood, which barely registerted.
I have run EDM's (electric discharge machining)where copper and/or carbon/graphite electrodes are used to precisely "burn" away metal. The copper electrodes burn hot and fast, and wear away quickly. Copper electrodes easily conduct, but dont hold good accuracy because of the wear factor. The carbon/graphite electrodes burn hot(you need more amps though), but slow, and dont wear as faster, but easily loose grounding because they have a much higher electrical restance than copper.
So my opinion is that if your trekking poles were the only route for the electricity to travel, then you would most definitely be better off with carbon, all other variables aside.Jul 19, 2007 at 7:23 pm #1395996
"For a refernce I ran the same Volt/Amps through a piece of fresh cut green wood, which barely registerted."
Sounds like my traditional bamboo hiking pole, at 190 grams, is safer than aluminum in thunderstorm season. And similarly, carbon fiber tent poles are safer when you've already pitched the tent and don't want to move camp.Jul 19, 2007 at 7:35 pm #1395999
Interesting results, you indicated the CF resistance of 48 ohms, and aluminum of .16 ohms.
The issue is the conduction relative to a parallel path, such as your body or the air. Air will ionize and breakdown to a virtual 0 impedance, the human body, depending upon the connection points, voltage and current involved can be 10 ohms (OM) to 1K ohms (OM).
When you're talking about lightning, you're in a fast transient, ionized environment which behaves very differently than static DC circuits or measurements. If you hat is the highest point around an otherwise flat area in a lightning storm, it isn't going to make a difference if you do or don't have poles: You're a reduction of arc potential of about 2 million volts: The current and voltage are there and you're likely going to be part of a microsecond circuit.
MIkeBJul 19, 2007 at 7:37 pm #1396000
If your trekking poles were the only route for the electricity to travel, then you are basically screwed:
Lightning Facts Excerpted from Strikealert.com
Voltage in a cloud-to-ground strike is 100 million to 1 billion volts
Lightning reaches 50,000 degrees Fahrenheit
The average lightning strike is six miles long.
A cloud-to-ground lightning channel can be 2 to 10 miles long.
Differentiating between carbon fiber and aluminum in the above situation is like cerebralizing how much better a piece of cardboard is than a tissue paper in the middle of Hurricane Katrina…
EDIT: Mike Barney beat me to it… pointing yet again that great minds think alike! :)Jul 19, 2007 at 7:58 pm #1396001
Yes and no. The thing is, lightning will (usually) follow the easiest path it finds. If one path is a hiker with carbon poles and another 500ft away is a nice tall tree, it might "choose" the tree rather than the hiker. I'm not saying this is measurable but it IS the reason that lightning rods exist. If you give a more attractive option, it's more likely to go that route than some other. So you certainly aren't going to avoid being hit if your number comes up, but I'd rather swing things in my favor by NOT poking aluminum shafts into the ground during a lightning storm. Ideally, you'd surround yourself in a metal cage to wait out the storm. Chances are, neither of us will be struck anyway, but you never know!Jul 19, 2007 at 8:25 pm #1396006
@butukiLocale: Kanto Plain, Japan
I love reading these intellectual discussions about how to withstand a brush with God. It's like an ant frantically trying to decide between hiding under a leaf or a pebble as Godzilla's foot is bearing down upon her.
That being said, how about a wire mesh dome tent? From what I learned at the Science Museum in Boston electrickery runs only along the outside of the mesh… you can place your hand safely on the inside of the mesh. And the wire mesh would serve another purpose… that of keeping bears from gnashing you into mush; you would at least still be recognizable!Jul 19, 2007 at 9:04 pm #1396015
@robertm2sLocale: Lake Tahoe
Personally, I climb the highest tree and yell: “Blow winds, and crack your cheeks! Rage! Blow!” I rip off all my clothes and tear my white hair, which the impetuous blasts with eyeless rage catch in their fury, and make nothing of. I scream, “You cataracts and hurricanes spout till you have drowned our steeples! You sizzling lightning, singe my white head! And thou, all-shaking thunder, strike flat the thick rotundity of the world! You sulph ‘rous and thought-executing fires, advance couriers of oak-cleaving thunderbolts, crack nature’s moulds.” Then they drag me back to my safe, padded room.Jul 20, 2007 at 6:10 am #1396041
@aroth87Locale: Missouri Ozarks
This has nothing to do with the topic at hand but when I saw the subject "You're little more than a complex impedence" I had horrible flashbacks to Circuits. I was just praying imaginary numbers weren't going to be present when I opened the topic. Thank you for sparing us from turning a simple conversation about being safe in a lightning storm into something involving phasors and complex impedance. :D
AdamJul 20, 2007 at 7:11 am #1396046
@jshannJul 20, 2007 at 7:58 am #1396047
Good urls… Points to note:
"Don't touch metallic objects like ice axes, crampons,tent poles or even jewelry"
"Stay away from metal objects, such as fences, poles and backpacks. Metal is an excellent conductor. "
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