TL;DR: Slight tangent, why don’t electric fences work on toddlers?
Three weeks back I was at a family event on a working dairy farm. Next to the yard was a small pen holding a few yearling steer surrounded by 2 stands of electric wire. Nephew’s 2 year old is wandering the yard with the other little people when he takes interest in the “puppies.” He grabs the fence, lifts it away, and walks into the pen. Moms panic and dads laugh in their beers. Host’s children race for the controls to shut them off to get in. Fortunately a teenager was next to the pen and was able to climb in through the feeder to grab the urchin before the steer used him as a toy. I recall two or three other preschoolers over the years with the same ability. I always assumed it to be their shoes.
Probably only the top wire is electrified.
I doubt my golf partner would have pissed up to a four foot wire. But I suppose it’s possible that the bottom wire of a four foot fence may not be electrified.
Sent from my XT1635-02 using Tapatalk
Electricity follows all paths; it just follows the low-resistance paths more than the high-resistance ones.
And yes, it’ll flow through the urine in your bladder, but it’ll also flow through all the rest of you. From the electricity’s point of view, a human body is all saltwater.
If you’re going to get all Kirchoff, sure. But if you’re going there, then you’ll have to also agree that most of those paths are so minor as to be utterly negligible.
This is a pretty common arrangement for electric livestock fences.
Because having only a top wire electrified is cheaper to build, and much easier to maintain – most maintenance is removing weeds that grow up to the fence and short circuit it, and those are mostly near the ground, not a top wire. And an electrified top wire is sufficient to keep animals away from it. A big problem is animals leaning on it as they reach over to try to graze on the other side* – that tends to break down the fence and also increases the danger of an animal getting tangled up in the fence. Better they always stay a bit away from the fence, and electrifying the top wire accomplishes this.
You often see fences with an electric wire on top, sometimes along a wooden top rail, and a different, more sturdy type of fence below that, like woven or welded wire squares, or wooden post-n-rails (or lots of similar fences in plastic or fiberglass materials now).
- This tendency is one origin of the phrase “the grass is always greener on the other side of the fence”.
Except that the “paths” aren’t discrete. It’s not like you can draw a zero-thickness line representing the shortest path from the tip of the penis, through the perineum, and down the leg, and expect that all of the current is going to be restricted to that zero-thickness line. It’ll be spread out over some characteristic width, and that characteristic width (say, the width of the path that contains 90% of the current) will be fairly thick. Sure, the amount going through, say, the heart is going to be quite small (since the heart is pretty far off of the direct route), but through the bladder, like Velocity asked about? Yeah, that’ll probably be non-negligible.
Treat is as a solid body problem - It’s largely true, if not a homogeneous solid body, you can (theoretically) examine current flux throughout. Some areas are going to by high flux. Many will be very low.
Bar owners have been rigging up electric fences in alleys for generations to stop drunks pissing on the building. You need a couple hundred feet of copper wire to run along the base of the wall and a car battery for power, although you’ll probably want to spring extra for a deep-cycle marine battery for convenience and service life.
You also need a fence charger. A car battery isn’t going to do anything by itself.
My ancient mechanical fence charger would run for many months on a 6v lantern battery, so a car battery is serious overkill.
It’s a myth.
Once cannot get electrocuted via the electrical current “climbing” the urine stream.
I actually tried this, peeing on an electrical cattle fence in West Texas a couple of years ago at my uncle’s ranch outside of Abilene.
And…yeah…I admit I had had a couple beers.
LOL
A roommate in college described his visit back to Holland, where his cousins persuaded him to piss on an electric fence for controlling cattle. One guy hid at the corner and turned it off while his cousins demonstrated, and then turned it on for him. He mentioned the word “pain”. However, no permanent damage.
I have been zapped by an electric cattle fence in suburban Toronto. I was climbing over, and put the rubber sole of my shoe on the wire. The throbbing shock went up my leg. I assumed I had wet shoes or a hole in the sole or something. I thought I was safe wearing a rubber soled running shoe.
I have also accidentally touched an incompletely plugged in 120V plug from an extension cord while feeling around in the dark when I was a kid (about 9 years old). Throbbing pain all up my arm. MUCH worse than the cattle fence.
Your anecdote doesn’t invalidate other poster’s experiences, like:
http://boards.straightdope.com/sdmb/showpost.php?p=20264878&postcount=11
Nope, both strands electrified. Cattle are not the brightest bulb in the mammal family but they can figure out crawling under a fence to reach that one blade of grass just out of reach. Raised in farm country and have seen it done. Another situation I’ve seen was a single electric strand around a pony pen. Yes the power was on 24/7 or they’d be all over the neighborhood.
There’s no such thing as a perfect insulator, and it’s quite possible that the shock passed through the rubber of your shoe. Which is not to say that the rubber was useless: It probably still mitigated the shock considerably.
Which is probably why the live plug hurt more, since you were touching it directly, and didn’t have anything mitigating it.
I have a two-strand (upper and lower) electric fence around my hog pasture. Fence controllers (which supply the pulsed shocks) have outputs measured in joules and range from 0.5 - 15 joules.
A 0.5 joule fence I will test by touching the back of my hand, but I’d rather not be near a 15 joule fence.
Regarding energizing different strands, when I have piglets out there I only energize the bottom wire, about 3 weeks later I turn on the top wire, and about 2 weeks after that I just shut the whole thing off. They’ve learned not to go near the fence at that point.
I guarantee you from sad and embarrassing experience that this is utterly not true 
^^^^ This is what I always think of when I see electric fences! Ha!