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High voltage wires versus branch
March 1, 2010 8:14 AM   Subscribe


 
No leaves on the branch, no trees tall enough close by. It looks like they threw that branch up there. Maybe the solution to catching people doing criminal acts isn't to put cctv cameras everywhere, but just give them out to idiots so they can record themselves.
posted by stavrogin at 8:19 AM on March 1, 2010 [4 favorites]


Every time I see a video like this I wonder what the electrical grid would look like if it had been designed during an era when safety/money ratio was a little higher.
posted by DU at 8:21 AM on March 1, 2010 [1 favorite]


Saw this on http://amasci.com/amateur/physvids.html , and yeah.... punk kids.
posted by Wanderlust88 at 8:21 AM on March 1, 2010


SPOILER

The high voltage lines win.

/SPOILER
posted by WinnipegDragon at 8:21 AM on March 1, 2010 [7 favorites]


First I thought: Oh shit, why are they standing so close?
Then I thought: Wait, yeah, they probably threw that branch up there. Idiots.
Then I realized I answered my first question.
posted by Plutor at 8:22 AM on March 1, 2010 [2 favorites]


"The high voltage lines win."

That would only be true if the branch fell down on the dumbass kids who did this for lulz.
posted by majick at 8:24 AM on March 1, 2010 [1 favorite]


I guess Wanderlust88's observation makes this a double? Either way, cool video. I'm curious why it just stopped so suddenly and didn't continue to spark and flame until the branch was completely removed from the lines.
posted by The Winsome Parker Lewis at 8:24 AM on March 1, 2010


I'm curious why it just stopped so suddenly and didn't continue to spark and flame...

I assumed they tripped a breaker and thus cut power to some section of their town.
posted by DU at 8:26 AM on March 1, 2010 [1 favorite]


oh oh can I add my current favorite high-energy youtube video? It's a substation switch opening without an arc interrupter.
posted by kiltedtaco at 8:26 AM on March 1, 2010 [9 favorites]


I have, through no creation of my own, seen a high voltage discharge probably similar in size and proximity to the one in the video. The difference was I saw mine at night, and wasn't expecting it. For about 2 seconds all I could see was light and think, "Wait a second, portals aren't real... ... RUN!"
posted by 517 at 8:29 AM on March 1, 2010 [1 favorite]


It's good to know teenagers are still out there doing stupid shit that could leave large percentages of the bodies horribly charred just for the lulz.
posted by The Straightener at 8:30 AM on March 1, 2010


I'm curious why it just stopped so suddenly and didn't continue to spark and flame until the branch was completely removed from the lines.

From living in a neighborhood where this happened regularly as a result of weather and lots of trees, I can tell you it stops because the breakers protecting that line trip and turn off the power. Usually the breaker attempts to re-close itself a couple of times, then gives up.

Then you just wait for the men in the utility truck to show up, remove the branch from the line, and radio in to have the breaker closed manually. It's sort of cool when you are a kid. Not so much when you just want to heat something up for dinner.
posted by FishBike at 8:30 AM on March 1, 2010 [1 favorite]


they forgot the marshmellows
posted by pyramid termite at 8:34 AM on March 1, 2010


Yeah, once the branch actually burst into flame, the resultant plasma allowed current to flow freely between the wires, which resulted in a huge current spike, which resulted in the power line circuit protection breakers tripping.
posted by Salvor Hardin at 8:35 AM on March 1, 2010




Yeah, once the branch actually burst into flame, the resultant plasma allowed current to flow freely between the wires, which resulted in a huge current spike, which resulted in the power line circuit protection breakers tripping.

Wait, fire can conduct electricity?????
posted by exhilaration at 8:41 AM on March 1, 2010


It's good to know teenagers are still out there doing stupid shit that could leave large percentages of the bodies horribly charred just for the lulz.

I occasionally miss the feeling of immortality that comes with being a teenager. Of course, I also occasionally look back at being 18 and go "Goddamn, how was I that stupid?"
posted by Pope Guilty at 8:42 AM on March 1, 2010


Fire doesn't exactly conduct electricity, but if you heat up a gas until the electrons dissociate from the nuclei and flow freely, then you have a plasma, which conducts pretty well.
posted by echo target at 8:46 AM on March 1, 2010 [4 favorites]


well, it's not exactly the fire that conducts electricity. The fire heats the air so much that the O2 molecules (among others) dissociate into free oxygen radicals, individual O atoms floating around. Those have a charge, so they let charge flow through them.

OK, it's exactly the fire that conducts electricity.
posted by Fraxas at 8:47 AM on March 1, 2010 [2 favorites]


fyi, that's a great example of a Jacob's Ladder!
posted by gigbutt at 8:47 AM on March 1, 2010


I'll bet 5 favorites that branch wins. NOTHING CAN DEFEAT BRANCH!
posted by Mister_A at 8:48 AM on March 1, 2010 [8 favorites]


High voltage wires versus branch
I don't think the branch ever really had a chance. It seems like it would take a heavy branch with, say, a tree or something to bring down supremely badass wires like those.
posted by uraniumwilly at 8:52 AM on March 1, 2010


Here's another fun, related video gets really good after about 3:30.
posted by squarehead at 8:55 AM on March 1, 2010 [7 favorites]


Whoa, that Bellingham tree video is incredible. It not only explodes, but then goes quiet to lure victims in and explodes again!

And only about 10 blocks from where I used to live.
posted by DU at 9:02 AM on March 1, 2010


Branch: It's no inanimate carbon rod!
posted by blue_beetle at 9:10 AM on March 1, 2010 [2 favorites]


At the end the lines are no longer conducting power, and the branch is still there. I call that a win for branch, however temporary.
posted by idiopath at 9:12 AM on March 1, 2010 [5 favorites]


Be good in this life kids, because this is exactly what happens to your body when YOU'RE SENT TO HELL.
posted by gwint at 9:13 AM on March 1, 2010


When you are sent to hell, someone makes a 60 second YT video that goes slightly viral for a week.

Sounds about right.
posted by DU at 9:16 AM on March 1, 2010 [1 favorite]


well, it's not exactly the fire that conducts electricity. The fire heats the air so much that the O2 molecules (among others) dissociate into free oxygen radicals, individual O atoms floating around. Those have a charge, so they let charge flow through them.

What? O radicals are uncharged. What is generated is likely a plasma, which is predominantly oxygen/nitrogen ions along with electrons, continually combining and re-ionizing, that allows the current to flow.

Some light reading for you.
posted by lalochezia at 9:20 AM on March 1, 2010 [3 favorites]


Actually, after the fire goes out I think branch does a pretty good impression of carbon rod.
posted by Rhomboid at 9:24 AM on March 1, 2010 [1 favorite]


I assumed they tripped a breaker and thus cut power to some section of their town.

I think it's more likely that the resistance in the branch got to high as it turned to ash. In fact, I would imagine that that's the reason the plasma became the prime conductor. And after the plasma arc died, there was no more conduction.

What? O radicals are uncharged. What is generated is likely a plasma, which is predominantly oxygen/nitrogen ions

Ions are atoms.
posted by delmoi at 9:27 AM on March 1, 2010


Wait, fire can conduct electricity?????

That is exactly how the flame sensor works in many home gas furnaces. The flame sensor is just a plain steel rod that extends into the flame. A small voltage is applied to the rod. In the presence of a flame, a tiny amount of current flows from the rod, through the flame, to ground at the gas jet. The current flow indicates the presence of a flame. Without a flame, no current flows. Sometimes if your furnace fails to stay lit, all you need to do is polish up the sensor rod and the flame jet with emery cloth to remove a build up of corrosion that insulates them. The flame current sensor in furnaces is different from the thermocouple sensor that is in many gas water heaters. The flame sensor is a passive device that requires an external voltage source to generate the current. The thermocouple sensor generates its own voltage.
posted by JackFlash at 9:30 AM on March 1, 2010 [5 favorites]


And after the plasma arc died, there was no more conduction.

And why would the plasma arc die, once it is conducting?
posted by DU at 9:32 AM on March 1, 2010


Uh, I wouldn't say it works exactly the same. The thermopile works via the thermoelectric effect across a temperature differential in solid metal, whereas here we're talking about ionized gas atoms.
posted by Rhomboid at 9:36 AM on March 1, 2010


(And to be more exact, the thermoelectric effect does not require "flame" at all, just a mere temperature gradient, even a few degrees.)
posted by Rhomboid at 9:38 AM on March 1, 2010


ericb

OMFG

That is all
posted by Windopaene at 9:42 AM on March 1, 2010


Bonus question: Why was the plasma arc blue?
posted by evidenceofabsence at 9:56 AM on March 1, 2010


The branch is flying!
posted by Blazecock Pileon at 10:02 AM on March 1, 2010


My favorite: High Voltage Cable Inspection by Helicopter .

OMG
posted by Blazecock Pileon at 10:08 AM on March 1, 2010


Bonus question: Why was the plasma arc blue?
posted by evidenceofabsence at 11:56 AM on March 1 [+] [!]


'Cuz it's baby left town, uh-huh, oh yeah....
posted by WinnipegDragon at 10:17 AM on March 1, 2010


And why would the plasma arc die, once it is conducting?

Well, Here's a video of another arc, which dissipates after a few seconds. Obviously it's possible. Why wouldn't it be? If the arc gets interrupted somehow, and there's not enough charge to create a new one, it should go away.

My theory is that something like this happens:

1) Branch starts conducting with r1
2) Branch bursts into flames, which conduct at r2 > r1, creating a self sustaining arc
3) branch stops conducting, leaving only the arc, which (as you can see) travels away from the branch
4) arc gets interrupted, leaving no conductor between the two branches.
posted by delmoi at 10:20 AM on March 1, 2010


Actually, after the fire goes out I think branch does a pretty good impression of carbon rod.

Coincidentaly that's also my porn name.
posted by scalefree at 10:30 AM on March 1, 2010 [1 favorite]


here's another switch-open arc 343kv.

Oh and I just found this out the other day, but before incandescent light bulbs people used Arc Lamps based on the same principle we see here, but they were actually too bright to be used in the home. Interestingly, they were actually more energy efficient then the incandescent.
posted by delmoi at 10:34 AM on March 1, 2010


Here's my favorite high voltage video.
posted by Rangeboy at 10:37 AM on March 1, 2010


Here's another dissapating arc.
posted by delmoi at 10:46 AM on March 1, 2010


These videos are so cool! But are also mildly freaking my out for my (electricity and magnetism) physics lab today.
posted by Solon and Thanks at 10:49 AM on March 1, 2010


Why was the plasma arc blue?

Well my chemistry is really terrible but I think the color depends on the properties of the gas relating to its ionization energy. Since the atmosphere is about 78%/21%/1% Nitrogen/Oxygen/Argon, you'd expect it to be dominated by Nitrogen's blueish tint.
posted by Rhomboid at 11:16 AM on March 1, 2010


Can I ask a stupid question? Shouldn't those lines be insulated or something?
posted by JHarris at 11:25 AM on March 1, 2010


Its not practical to insulate high voltage lines, because insulation is a function of the dielectric constant of the insulating material (which is mostly constant) and the thickness. When you're talking about tens or hundreds of thousands of volts that means serious thickness. Look up at a power line and you'll see that it's suspended from the tower structure by stacked porcelain insulator discs or knobs. Those stacks can range anywhere from six inches to several feet. The length required corresponds to the voltage. And that is just to hang the line at one point; for total insulation like we're accustomed to with regular power cords and whatnot you'd have to encase the power line in a two foot diameter chunk of porcelain for its entire length.
posted by Rhomboid at 11:46 AM on March 1, 2010 [1 favorite]


As a kid, I used to think power lines had an insulated coating like household wiring does until the day when Butchie Boacher took a bicycle chain and whipped it up into the wires out front of his house. That sucker started to drip molten steel until it blew the circuit and knocked the power out for blocks around. The cops are still looking for Butchie.
posted by Ron Thanagar at 11:50 AM on March 1, 2010 [3 favorites]


Also, remember that touching just one conductor doesn't create a path for any current to flow (assuming that you're not also touching anything else, like the ground) which is why birds can sit on power lines all day long and those dudes in that video can just pop out of a hovering helicopter and hang from a live power line. Legend has it that the spacing between the two conductors was chosen to be wider than the wingspan of the largest wild birds, but that might be apocryphal. And in a lot of cases there is a non-conducting guywire installed at a higher elevation than the power lines whose job is to shield the power line from things like falling branches.
posted by Rhomboid at 12:06 PM on March 1, 2010


No no, this is an ongoing Eastern European Powerline Shorting meme.

Also Budget Rent a Car.
.
posted by billb at 12:07 PM on March 1, 2010 [1 favorite]


Electricity
Nature's Ninja
Invisible

Deadly.
posted by Mister_A at 12:12 PM on March 1, 2010


why would the plasma arc die

It tripped the breakers.

- Damp branch steams, slowly carbonizes
- Carbon path completes, branch flames
- Air discharge begins (carbon ions, mobile freed electrons, very low ohms.)
- Voltage value plummets (volts appear along power lines,) branch goes dark.
- Distant breakers blow, everything stops.
posted by billb at 12:15 PM on March 1, 2010


Did you see what happened? They broke the wires and the smoke got out. Damn kids.
posted by From Bklyn at 1:18 PM on March 1, 2010


Rhomboid: (And to be more exact, the thermoelectric effect does not require "flame" at all, just a mere temperature gradient, even a few degrees.)

We are talking about two different kinds of sensors. A gas water heater uses a thermocouple (thermoelectric) device to generate voltage based on a temperature gradient. This is because gas water heaters have no power supply connection.

On the other hand, the sensor for many gas furnaces is a passive steel rod that conducts current through the flame using an internal power supply. A furnace only works when power is supplied so a thermocouple is not necessary. The flame sensor is not a thermoelectric effect and requires a flame to conduct the current. A steel nail would work just as well.
posted by JackFlash at 1:44 PM on March 1, 2010


Pope Guilty : I occasionally miss the feeling of immortality that comes with being a teenager.

As I begin to approach my 40s I sometimes wonder if maybe I wasn't actually fast enough getting away from some of those fuses or electrical "projects" and I'm actually still 17 and going through an ...Owl Creek Bridge/ Jacob's Ladder moment.

Because, seriously, I did some stupid shit and by the laws of averages, I should be dead a couple of times over.

And the world has certainly gotten weird enough that questioning my sanity and perceptions at times feels warranted; having a life-lived-flash-on-the-deathbead seems like a reasonable possibility I should consider now and again.
posted by quin at 2:01 PM on March 1, 2010 [2 favorites]


A wearable Saunt Bucker's basket!
posted by Stylus Happenstance at 3:13 PM on March 1, 2010


Sometimes when a branch falls on a feeder line, nothing happens except a quiet buzzing sound. A similarly sized branch to the one in the video fell from a neighbor's tree a couple of months back and sat on the line doing that for weeks before the power company bothered to come out and remove it, despite being notified.

At night when I was standing out in my back yard the noise was very obvious. For a while I thought it was my neighbor's new (stupidly bright!) yard light going on the fritz. Then one day as I was walking on the street under the power lines I was able to hear the buzzing noise above me, looked up, and lo and behold, a branch!

It probably didn't trip the breakers because it wasn't resting across two phases of the power line. It was conducting between one phase and the tree, and obviously not that well. I wondered what would happen if the guy's dog pissed on the tree, though..
posted by wierdo at 4:43 PM on March 1, 2010


Back in the day, before arc interrupters I guess, instead of switches high voltage nodes had a piece of metal that was clipped in line on the circuit. There was an insulated handle like a broomstick attached. If you needed to switch off that circuit, you stood back holding the end of the broomstick and walked slowly backwards until the arc broke.
posted by StickyCarpet at 7:04 PM on March 1, 2010


going through an ... Owl Creek Bridge / Jacob's Ladder moment

I see what you did there.
posted by intermod at 8:07 PM on March 1, 2010


I found this power transformer explosion that reverberates along the lines back in December, after a tree weighed down by a blizzard kinetically exploded near me. There was a flash such that I thought a nearby electrical line had contacted a different tree, but the fire department couldn't find anything wrong with it. The next morning I saw the evergreen that had broken. The flash was as bright as an electrical explosion, but I only saw it in my peripheral vision. I was 20 feet away, compared to 50 feet to the other tree.
posted by dhartung at 10:51 PM on March 1, 2010 [1 favorite]


Back where I grew up/where my parents live in Florida, I lived on a man-made island with a really really dumb electricity grid. It essentially had two sets of high-voltage wires running over the bridge for the entire island: one set branched left, one branched right. At the junction where these split (maybe half a block from my house), just over the bridge, there was a massive transformer on either set. Invariably, during hurricane season, one of these transformers blew (and a few times actually blew up, sending twisted burnt hunks of metal all up and down the street that we thought was SO COOL), sending exactly half of the island into darkness for about a day while we waited for the storm to stop and the power guys to come out and fix it. By the third or fourth year of us living in that place everyone in our house and probably on the block knew that arcing plasma sound.
It was one of our routines, a bit of a ritual even: Lights flicker, bzzt-zapt-bzzzt-kaBOOM, flash of blue light in the street, darkness. If it wasn't raining that hard, all neighbors come outside to tell each other what they all already know. Light Candles, stepdad makes coffee on the gas stove. Like Clockwork.
posted by The Esteemed Doctor Bunsen Honeydew at 2:50 AM on March 2, 2010 [1 favorite]


Well, I know what I'm picking next time I play rock, scissors, high voltage wires.
posted by sebastienbailard at 3:47 AM on March 2, 2010 [1 favorite]


I was having coffee at a friend's house when there was an incredibly loud noise from outside that sounded pretty much exactly like you'd expect a huge AC discharge to sound - a sudden enormous ripping rending BUZZ that lasted maybe half a second.

We all poured out of the house to look for the cause, and eventually found it about half a block away around the corner. There, lying on the ground at the bottom of a power pole, was the top half of a crow. It was still steaming, and it looked very surprised.

As the parent of a male teenager who has just crashed two cars in quick succession, I often find myself thinking about that half crow. I swear, they should be buried in the back yard at 15 and not dug up again until they're 25.
posted by flabdablet at 9:52 PM on March 2, 2010 [1 favorite]


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