I started in the electrical field when I was 18. I'm now 24 and fully licensed. That being said, for the past four years or so, everytime I drive by a substation (now that they stand out to me as more than just some skeletal frame) I find my mind wandering about what it would be like to create a direct short on the incoming lines.

Naturally, I would never act on such an impulse. But, I can't seem to fathom a way that it could be done with relative safety in regards to personal harm. It seems to me that any way you do it would leave you dangerously close to the blast radius with no time at all to flee.

Any ideas?

Howver, I find myself of a more relaxed moral persuasion than youself. Therefore, I would have no problem shorting out the main lines if it served my purposes. Blackouts can be useful in a variety of situations.

The problems are more theoretical than might be supposed:
There are a variety of sizes of substation. Some might be easily and safely tampered with. Some might be less so. I imagine voltages above the 50kV range would be immensely dangerous at a distance with arcing, etc. being an issue.

The obvious answer at mid- and lower high- voltages would be a thrown sturdy chain. After trials, I can confirm that a 3 - 4 ft. chain can be thrown within 6 inches or so at 50 foot ranges with practice.

However, I don't know the separation of terminals on the substations you mention so a metre or so may be too far apart to contact the 2 leads.

Do you have any dimensions for the separation of the lines in a large substation? For that matter, would 50 feet be anything like a safe distance to be with a high-tension line short taking place?

Has anyone actually seen HT lines shorting out in RL or in video, and the local effects? The best I can match is 5 cows killed stone dead under a tree at some 100 - 150 feet by lightning from my aunt's front porch swing (!!!!!).

Hmmmmmm, just off the top of my head. Bow and arrow, model rocket or Line throwing gun to launch a long, non-conductive line over the mains. With a long enough line you could just haul a length of chain or bare cable over the mains from a safe distance.

The safe distance would depend on what type sub-station your dealing with. A "distribution" sub-station with line voltages in the area of 12,000 volts or a "main feed" sub-station with line voltages in the 30,000 to 50,000 volt range.

Hmmmmmm, just off the top of my head. Bow and arrow, model rocket or Line throwing gun to launch a long, non-conductive line over the mains. With a long enough line you could just haul a length of chain or bare cable over the mains from a safe distance.

Unless one used monofilament or something similar, most everything is going to have some moisture content - even a kiln-dried 2x4 has ~14% moisture - and, at those potentials, fry. This will generate a lot of carbon, which is conductive.

I don't have any dimensions on hand. This was more of a spring board question, so that i could find a general idea that I feel I can work with.

I doubt 50ft. would be safe for high tension. The transformers in many power stations are quiet large and I've seen much smaller ones explode and throw a surprisingly large ball of fire.

A three to four foot chain would probably be long enough for smaller stations. Larger ones may be farther apart. I'll ask around at work and try to come back with some dimensions.

I have considered the bow and arrow method before, but never went far enough to think of it as a hauling method. I stopped short at using it as the means of hauling, which left me worrying about the arrow surviving the blast and possibly ending up as some type of evidence.

Several militaries around the world use a similar idea by dropping large amounts of steel foil out of dispersion containers over power stations. After these bombs are dropped, it looks like the stations are covered in spider webs.

Maybe a couple of large chains with wieghts on the ends, bolo style, dropped from an ultrlight would work. It would need to be a heavy set of chains though.

The closest distance you can safely approach an electrical line is the length of the insulator.

So, if the line is hanging from an 8 foot long insulator, no part of you can get closer than that without getting zapped.

When the maintenance techs at work have to replace a blown fuse/transformer assembly in the substation, they set it in a sort of hydraulic jack that is part of the substation. The part they replace is a large cube about 3x3x4 feet with pins in the top. The jack is raised after a timer goes off allowing the men plenty of time to get out of the area. Sparks really fly when that thing plugs in. This then is how you service a substation...

Using this principle, how can you raise up your conductor without you being near? Maybe some hydrogen filled balloons tied down by a water bottle with a leak. Maybe throw a rope over the overhead metal structure. Maybe get one of those remote controlled blimps and drop a bunch of aluminumized chaff (mylar?) over the area. Maybe improvise some sort of telescoping hydraulic or pneumatic tube that holds a chain, have two of these, turn on the water/air and the chain rises up slowly but surly until...

A thin wire would short it, once it starts conducting the plasma arc will keep the current flowing until a fuse blows somewhere else in the grid and cuts it off. You could easily fly such a line over using a spool of thin wire and a rocket, with a long fuse. Wear rubber boots :)

Wear rubber boots :)
For lines in the tens or hundreds of kilovolts you're going to need more than that. Transmission voltages usually range from 138,000 to 765,000 volts, but can be even higher. Distribution voltages can range household current 120/240 volts up to 69,000 volts.

At voltages like that, even disconnected lines can pick up enough voltage by induction from nearby lines to kill.

The voltage across ground is roughly 1000 volts per meter, so the chance of problems with rubber boots is non-existent. Obviously if you touch the lines you die! But the boots will mean the sudden appearance of electrical potential across the ground will not fry your legs.

How about a harpoon approach? Fire an "anchor" (Think anvil launching) and have it pull a few dozen feet of Aviation wire over the Wires? Peg the end of the wire into the ground near the Tube/mortar. Don't have to be anywhere near it when you fire your "Wire short-er out-er" (Fuse lit would be easiest and probably safer seeing as Electrical ignition just sounds dangerous... don't want to be connected to 100 feet of copper wire... ).

My idea would be to take a coil of 1/8" steel cable from home depot, hook it to a model rocket and fire it over the lines at a 45. Throw a nice tri-hook from your local fishing store, the bigger the better, on the end and let the sparks fly. :cool:

I think the cable is too heavy for the Model rockets and It would throw it off balance...

Also wouldn't 1/8 vaporize at that much voltage/amperage?

Yes, but plasma is conductive as well.

There is a reason they put big fences around substations.

It has a lot less to do with how much damage you can do to the grid and a lot more to do with how much damage the grid will do to you.

Remember last year's French riots? Caused by the deaths of two Muslim teenagers seeking only to hide from the police in a substation.

A simple pipe mortar, firing a large lead fishing weight (a pound or more), pulling a thin braided steel cable over the lines, will do the trick.

Cost? Less than $100 for everything new. Free if you scrounge.

I was about to say that NBK, the mortar from your Book that is freely available off the ftp.

Otherwise, why not something like salt water fired from one of those pressure cleaners? Or something bigger that gives a short burst of water (we are trying not to kill ourselves at the same time correct?)

Maybe even possibly a home made catapult (if you cant make/get your hands on a mortar) with a lead/steel weigh and high tensile steel wire?

A stream of water wouldn't maintain coherence very long with hundreds of thousands of amps of current passing through it. It'd likely flash boil into a cloud of steam. Steam isn't very conductive.

I've heard of mylar kites flying into local distribution lines and blowing them, but those lines are orders of magnitude less powerful than the transmisson towers that march across the country from the dams.

those lines are orders of magnitude less powerful than the transmisson towers that march across the country from the dams.

And the steam plants, NG turbine plants, lastly the nuclear plants.

I think I made my warning fairly clear, but a bit more information may be in order (use it at your own risk).

Birds will land on transmission lines carrying less than 50K volts. Over that, birds stay away because it's physically unpleasant to be around that much voltage.

If birds shy away you might want to also.

For anyone interested in watching a substation going up...

http://video.google.com/videoplay?docid=7703052748770170847&q=electrical+arc+substation+fire&hl=en

I personaly like the chain throwing idea, but perhaps another, less obvious approach is possible. Generaly, overhead utility transformers are filled with an oil to prevent internal arcing, perhaps a rifle round near the bottom of the case would allow the oil to leak out and expose the terminals and start arcing. I'm not sure how much oil is in substations, but the larger transformers, I expect, would depend atleast somewhat on a liquid insulator. Someone with a tatste for mayhem should give this a try, roll up on a substation and give a few rounds to some of the more expensive looking components and see what happens.

I wouldnt be supprised if a round penetrated a big diode or some form of capacitor and started a nice little campfire.

At midnight Dec 31 1999 i pulled a 24 gage copper wire over a 110,000 kva power line with 500 foot of monofilament fishing line.

All that I got was a bright blue green lightning bolt to ground and the power did not go out. RATS!

I was hoping everyone would think Y2K had struck.

DO NOT TRY THIS AT HOME. I am a electrician with over 30 years high voltage exp. and the proper training. This state would not let me take there new electrician licensing test. Due to my being off work due to being disabled and non union. SCREW THEM. Now I will take there workmans comp till it is time to retire.

ATLAS #11
If you shoot a big substation transformer at the bottom or open the drain. It will over heat hours later and then blow.

The large MV/HV trasformers which I have seen are equipped with an oil level switch; if the oil level goes too low (due to a leak) the input power is tripped automatically before any arcing/shorting out happens.:(

Fishing line? That sounds like fun even though the power didn't go out...

In distribution lines, Isn't the top one live? If you did the same trick with them wouldn't it short it out to the lower ground line and keep the arc going? It would be better to do it next to a wodden power pole or something that can carbonize and conduct nicely after the coper is vaporized.

It would take a significant ammount of juice to keep an arc from the line to ground going... Mabye doing the same thing with the fishing line and copper wire would work on substations though.

SF use EFP's to attack the large ground transformers by blowing a hole in the bottom, causing the oil to drain out and turning off the power, whether by overheating or tripping a safety.

But they also usually follow up with a thermite grenade into the oil pool to set it on fire. :)

Whatever you do don't spill oil from transformers. Old one transformer oil contain cancinogenic compounds, as for the new types they invented to replace the old ones I don't know. It seems to me a to high price for a common prank that some people start to die from cancer decades from the prank event from poluted water supplies.

For anyone interested in watching a substation going up...

http://video.google.com/videoplay?docid=7703052748770170847&q=electrical+arc+substation+fire&hl=en


Yikes.

Anyway, I have a pretty simple idea which I'm suprised nobody has mentioned yet... A significant volume of powdered graphite, bought as solid lubricant for locks and bolts, wrapped around a burst charge and lobbed over the fence with a time fuse. I mean, the US dropped a whole bunch of these exact things during Desert Storm onto substations, grids. I think a hospital got shut down because of one of these and a whole fuckload of people died.

It wasn't graphite dust, but carbon fiber tape on spools, dispensed by CBU's over the electrical yards, that did the trick.

Ok, so let's look at this logically. You want to take down a mains voltage or higher system with a thin wire? That's not going to happen. The current will blow pretty much anything you can throw at it. In the larger cases, even a big steel chain is going to melt.

I've seen a substation pole transformer lose a wire or two in a storm, and it arced to the wet ground for hours, the fuses *never* blew! The power company turned it off. And that's a pole that was probably only at a few thousand volts and amps.

The main distribution lines are up at 125,000V or even higher, depending on pylon height and other things. These are serviced "hot" either from a gondala that travels along the wire with the men in it, or from a helicopter that, obviously, is far above the ground (indeed, above the wires!)

These wires are as thick as your arm and copper or aluminium. You are not going to blow the circuit breakers, as the "fuses" are capable of carrying a few thousand amps, which is more than most copper rods can cope with. Heck, just your main fuse at home has a 100A at 240V limit, in the UK. I've never blown one of those. Even a 30A fuse is near impossible to kill off, I've fried a multimeter probe by accidentally having it set to Amps and sticking it in a mains socket, and it simply blew the steel probe tip to bits.

Think of your arc welder. Odds are, that is rated to between 50A and 250A, and then consider what that does to a sheet of thin steel.

Many, many carbon fibre strands/ribbons are needed to do anything, hence the hundreds of pounds of them dumped at once.

To bring the pylon down would be easier. A wooden pole pig could be chainsawed through in a few moments, or you could use an auger bit to drill a few holes such that the first storm or a big banger brought it down. Apparently, the IRA used shotgun slugs to take out enough wood that the poles fell down in NI when they wanted that effect.

A steel pylon would be far harder. I'd suggest cutting the legs at the base to weaken them a lot, then figure out some way to cut the wires. They are soft, so a saw on a string might work. But then you have time and proximity issues. Cutting a 6" bar of copper or aluminium from a few hundred feet isn't easy, and cutting all 6 or eight or whatever would be near impossible without some neat little robots or something.

Why not just rig up a large steel pipe to several ceramic insulators to sit on the wires (maybe wired with something non condutive around the wires so it dont fly off during det), they sell many different kinds specifiically for wire , then have some small explosive charge to break the ceramic insulators and some of the insulation on the wires , you could remote det this from some distance and not get fried . Why even short it out just blow the damn thing up , simple , relativly safe , with the same end result minus the light show unless that is your goal , IMHO simplicity is always best .

I don't know how well it would work on these high-tension lines, but a certain CIA handbook suggests a cable-cutting charge which uses a simple counterweighted charge that is hauled over with a simple, ingenious cord/ring pulley system. Anybody who's read it will know what I mean, if not, I'll find my PDF of it for y'all.

I worked for a HV switchgear company briefly. The circuit breakers were designed to "Bang" in and out 3 times in a attempt to burn the short off the lines.
USE
The interval between the breaker tripping, resetting and retripping is about 30 seconds. I'd guess it should'nt take that much of a short to trip medium 36KV lines. Remember that natural shorts are tree branches. A bike chain or stretched bed spring should be ideal.
PARAGRAPH
The situation of throwing something over the lines and watching fireworks for a hour should not be posible, as after the third attempt the switchgear stays open and needs manual resetting by an engineer. Even if the switchgear failed and stayed closed it is backed up by another bigger circuit breaker down the grid.
BREAKS
A rare occurance is cascade failure, (as happened in europe last year) whereby most of Belgium, parts of France and Germany all blacked out. The systems are cleverly designed to prevent this, but it would be great fun discovering how to cause one.
NBK
Sorry just remembered something. You could shoot the ceramic insulators as they are damaged very easily, even by airgun pellets. Although I believe some companies use a sintered vulcanised rubber/ ceramic compound now to stop this.

I remember doing this as a kid with my old 30-30 lever action rifle. Shooting the ceramic insulators was a lot of fun, and since I lived in a very very rural area, it was easy to hop on the trusty dirtbike and speed away after the damage was done. I am sure we pissed off the power company!

As far as shorting the system -- I think NBK is on the right track, some sort of chaff-type bomb would do the trick.

However -- and I say this from experience -- anyone would do well to be as FAR AWAY from the substation as possible to avoid all sorts of trouble or physical injury.



Sorry just remembered something. You could shoot the ceramic insulators as they are damaged very easily, even by airgun pellets. Although I believe some companies use a sintered vulcanised rubber/ ceramic compound now to stop this.

A long time ago (40yrs), Me and a friend found hundreds of aluminum disposable pie pans behind a bakery. There also just so happend to be a substation about 100 yds away. We naturally could not resist the temptation & each threw about a 1 ft stack over the fence. Shee-it, It scared even us & knocked power out at the K-Mart next door (one of the first). We tried to do it again the next day while a friend waited in the store to shoplift when the lights went out but couldn't get lucky again. Was fun, only wished it would have been dark, He,He,He

Here's what .mil uses.
http://www.fas.org/man/dod-101/sys/dumb/blu-114.htm

Something like this dropped from a RC aircraft should be safe enough, and effective if the main ingredient can be improvised.

This is just an expansion on the mortar and cable idea:

Picture that game where a string with a weight on each end are tossed at a frame, and the object is to have the string wrap around the bar and stay on.

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

Two mortar tubes strapped together, at a slight angle from each other, with the bottoms touching. A hole is drilled through the bottoms of both tubes where they touch, so that the charges ignite almost simultaneously.

The mortars are each loaded with a heavy ball, connected by 50-100 feet or so of wire rope.

Fire this at the lines so that the balls have separated far enough to stretch out the cable, and wrap it around all of the lines. with enough force, the cable might be able to pull the hanging lines into direct contact, allowing that max possible current to flow in the actual lines before the whole deal melts or fuses blow.

Just had a think about this. Just use detcord! Throw/fire a line over, then tie your reel of detcord to one end, and tow it over. Detonate at will, cutting all the HV lines at the same time. I'd stick a few wraps around the base (or weaken by cutting in advance) at the pylon, and the weight distribution change combined with the damage might even pull the whole pylon down.

We used to have powercuts occassionally due to people shooting the ceramic caps on the lower voltage lines. I think the biggest pylons are tall enough that they are out of range for a legal limit air rifle in the UK (12ft-lbs)