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Project nachonaco
01-13-2010, 09:13 PM
I have a character who is trying to break into a maximum-security facility.

So I had this idea of her hooking a car battery's tweezers (for lack of a better word because the actual word is not coming to me) to one of the fences and shorting it out at least long enough for her to climb up and down.

She would also be wearing rubber gloves and boots.

I did ask my history professor, who was an electrician in the Navy and she said she thought it would be plausible but that I should check just to be sure.

Sarpedon
01-13-2010, 09:22 PM
It would be more reasonable to simply attach a jumper cable to the fence, and the other end to a grounded object, rather than to one's car battery. This would probably wreck one's car.

Note this would cause the breaker to trip, and probably would sound an alarm. The power would remain off until someone comes by, removes the cable, and switches the breaker back on.

Also note that a high security facility might have more than one layers of fences.

Project nachonaco
01-13-2010, 09:24 PM
It would be more reasonable to simply attach a jumper cable to the fence, and the other end to a grounded object, rather than to one's car battery. This would probably wreck one's car.

Note this would cause the breaker to trip, and probably would sound an alarm. The power would remain off until someone comes by, removes the cable, and switches the breaker back on.

Also note that a high security facility might have more than one layers of fences.

Whoops.

Should've mentioned that the battery is NOT in a car. Which probably makes quite a big difference.

Sarpedon
01-13-2010, 09:28 PM
The cords that connect the battery to the car are part of the car, not the battery. The battery has only the positive and negative ports, to which the wires attach. Where I live, most people have jumper cables, which are portable cables that should do the trick. The only issue is whether the cable is able to carry enough voltage to trip the breaker, which I don't know.

archerjoe
01-13-2010, 09:46 PM
After looking at some high-tech security fences (http://www.total-fencing.co.uk/high-security.htm), your idea doesn't seem feasible. Check out the "anti-climb" fences. Also, how does she get over the razor-wire at the top of the fence? Lastly, the guards were alerted by other sensors triggered by her merely approaching the fence.

Wayne K
01-13-2010, 09:49 PM
A battery isn't going to blow out an electric fence. Actually, the opposite is more likely. Your hero should go after the power supply. The generator or power line.

PeterL
01-13-2010, 10:11 PM
I think that a better idea (and somewhat more dangerous, but who cares, since she's already trying to break someone out of prison) would be to use a power distribution cable from pole to the fence. If there were a 220 line, then that probably would fry the power supply to the fence, and it might fry other systems that would be on the same service. As long as she doesn't become grounded, it wouldn't hurt. It would raise the suspense level, because it probably would kill her, if she messed up.

BillPatt
01-14-2010, 08:41 AM
Lots of potential for problems here.

I believe the OP meant the large alligator clips on standard jumper cables. Here's a few things to consider:


There may be many phases of power running along the fence. Taking the typical US 480 residental line as an example, three 'phases' of power split off of such a line, 120 each. The voltage across two phases are 220v. Consider, then, the three conductors coming off the pole could be all hooked up to the fence. So cutting or bridgine one would still leave the fence 'hot'.
Being grounded or not, in such a scenario, is irrelevant. You'd have to ensure that you are not part of any conductive pathway between any phase and the the ground, as well as any phase and another. You could be standing on a block of rubber and still fry yourself.
In a high security fence, there are proximity sensors based on body capacitance scattered in the grounds leading up to the fence, as well as video gear.
Don't forget infrared. The cams would be able to image you via body heat.
Even if you bridge the power leads, there could easily be capacitance sensors that will detect cut mesh or bridged power leads

How is such a system defeated? There are several methods:

Kill the power at the source. Downside: The screws know something's up, and go into lockdown. There's also batteries, standby generators, dogs.
Bollix the computer. Downside: Takes a computer guy, the security computer is probably very well protected, redundant computers.
Suborn the guard. Make sure the guard you want is covering for you when you make your move. Downside: scheduling, double-cross, accident.
Diversion. Ram a bulldozer, truck, tree into the fence. When everyone's off investigating, slip in the other side. Downside: increased alertness, lockdown.
Social Engineering. I like the way that Steve Perry did it in his Matador series: keep triggering the security system with false positives until they shut it down. Do this on a maximally unpleasant night (gale, blizzard) and you've got a (mostly) free pass. Downside: reliance on uncertain human factors, lockdown, duty-struck guard.
Good luck! I hope this helps.

RobinGBrown
01-14-2010, 12:45 PM
I have a character who is trying to break into a maximum-security facility.

So I had this idea of her hooking a car battery's tweezers (for lack of a better word because the actual word is not coming to me) to one of the fences and shorting it out at least long enough for her to climb up and down.

She would also be wearing rubber gloves and boots.



http://darwinawards.com/

jclarkdawe
01-14-2010, 06:28 PM
As well as Bill Platt's concerns (all of which I share), let's look at what happens when power goes out to a fence section.

1. Lock down. Although it will take a few minutes for the guards to get all the inmates in their cells, all of the doors will be locked. It will be next to impossible to move around, even for the guards. Every door system in a prison is a double lock, which means one door has to be locked before the next one opens.

2. Exterior guard immediately heads to the scene. As well as probably the SWAT team.

3. Tower guards get ready to shoot.

4. Fencing is on different circuits, so the other row of wire (that's at least one, more likely two) is still live.

5. Climbing this wire is next to impossible. Wire cutters are a better choice, but you're still going to be a while cutting through.

6. You have to know when the inmate is out of his cell in max. Most inmates are out only an hour or so a day, and a lot of prisons vary the time to complicate planning.

Escapes from maximum security tend to happen from high tech/high money approaches (like a helicopter) or during transfers. This would be marginally possible from medium security, depending upon how the prison was laid out. From maximum security, disconnecting the power from the fence is just a small cog in the total security system.

Best of luck,

Jim Clark-Dawe

Michael_T
01-15-2010, 08:44 AM
Perhaps have him re-route the current in the fence through a wire that has less resistance than the fence. So in that location the fence will be dead, no alarms will go off, nobody has to know. You can just take wire cutters and go through.

RobinGBrown
01-15-2010, 12:57 PM
Perhaps have him re-route the current in the fence through a wire that has less resistance than the fence. So in that location the fence will be dead, no alarms will go off, nobody has to know. You can just take wire cutters and go through.

Thats a great way to get electrocuted, probably three times.