Afghan Bridge Update and Sad News

Hi Everyone.
Thanks for all the help and advice on the Bridge Project. It's currently on hold, as the FOB Mayor wants to see if we can score some
honest culvert from an Engineer Unit rather than build some. Works for me.
On the 12th, we lost two good men and had a third badly injured courtesy of an IED. If I've figured the time zones right. it would still have been Memorial Day back home.
I have been wondering if there is any way to inductively couple enough current to prematurely detonate these suckers. Maybe an R/C car with a rotating coil sort of thing. My knowledge of electricity pretty much ends with "Don't stick coathangers into the wall socket". I know that high-tension lines will sometimes induce power in fences running parallel to the lines. Could this effect be useful against pressure plate IEDs at a range of a foot or so? If any one has any thoughts on the subject, no matter how bizarre, I'd love to hear 'em. (Other than "Just Leave." While effective, it's not in the cards.)
Way smarter people than me are working on this I'm told. I thought I'd bring it to the attention of some of the smartest people on the net. If anyone knows where Fitch Williams hangs out now, he'd be a good one to ask, too.
In closing, we can't remember our fallen in the traditional way until deployments end. If anyone would care to hoist a glass in salute, I'd be grateful. Godspeed guys.
Thanks,
Ken
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In article
snipped-for-privacy@yahoo.com wrote:

Time tested method is to herd sheep over the area. The Russians used troops that lacked dicipline.
Free men own guns - www(dot)geocities(dot)com/CapitolHill/5357/
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nick hull wrote:

May be they did, may be they did not. But what they would definitely say - "get the hell out of this country, it's not yours".
C.
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Sorry to hear about your loss. There is nothing that comes to mind that you can do that is easy and works 100%.
i
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snipped-for-privacy@yahoo.com wrote:

If you hooked that R/C system up to a humvee with realistic looking passengers, maybe that would work. AKA Bait.
I suspect that jamming to deny the trigger signal is being used along with freq sweeping to try to trigger IED a head of convoy.
If you see an afghan walking down the road, offer him a ride. Gage his reaction.
Try to win the hearts and minds of the locals. They know things.
Thank all of you for your service.
Wes
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Ken,
Wes wrote:

This sounds like a remotely triggered device. Is that the threat, or does "pressure plate" mean they trigger on contact?
Have we recovered and disarmed live bombs? It would all depend on the sophistication and variations in design. My guess is that they are contact activated and we simply need something other than our soldiers to push on them. That could take the form of a computer operated and armored ATV or something to go ahead of you, at least in the open areas.

Ditto!
Bill
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I'm reminded of WWII era mine-bashing tank accessories - a drum on long arms in front of the tank, with many pieces of chain, and the whole drum spun up to beat the ground and clear a swath. For pressure-plate type detonators, that should do as well as anything, and should be a known (if not current) technology. Presumably the drum takes some damage, and is made to be cheap and easily replaceable.
I suspect there are several problems with reliably getting the damn things to go off with electricity or magnetics. Presumably, at the silly end of the scale, you could keep tossing neutron bombs and that ought to fix them, but with somewhat problematic side effects. As there are going to many variants, finding something that will manage to set off one is not likely to manage to set off others, and anything that will have enough energy to possibly pull it off is probably going to take something more like a remote-control humvee to have enough power to run it. Then you have the problem of remotely controlling something that is actively trying to send out a huge amount of interference (so perhaps it's controlled via cable, not radio), and the effects of that interference on communications, etc.
--
Cats, coffee, chocolate...vices to live by

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On Sun, 18 Nov 2007 10:44:23 -0500, Bill Schwab

http://en.wikipedia.org/wiki/Mine_flail http://en.wikipedia.org/wiki/Hobart%27s_Funnies
Unfortuatly..most IEDs are command detonated, least thats the word I get from the sand box.
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
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Yep. That's the word we get from Iraq too. 'Round here, the pressure plate varients are by far the most common. Construction varies, but it goes like this... Take an explosive device, anything from homebrewed explosives to antique British and Russian A/T mines. Fuse with electric blasting cap. Bury mine to varying depths. Build a pressure plate from anything conductive which happens to be in the bomb-maker's reach that day. Bury shallow. Connect a couple D-Cells via some scavenged wire, and...wait.
Pressure plates are generally around 18-24 inches long and from 1 to 8 inches wide. Insulators between the plates are anything that won' conduct too much electicity; from pieces of goat hide to bits of rubber. Pressure plate assy. is usually water/sand proofed in some manner. Goat hide, plastic bags, truck innertube, pvc pipe, etc.
Since the pressure plates are generally large, shallow, and not electrically shielded, I was hoping to target them with an induced current. Not as easy as I was hoping, I see. If it were simple, somebody would have figured it out already. Sigh. We'll keep working the problem.
Thank you all for your help and support!
Ken
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On Mon, 19 Nov 2007 01:33:35 -0800 (PST), snipped-for-privacy@yahoo.com wrote:

Google on "mine flail". They should work just dandy on a pressure plate mine.
Should be something a craft shop could put together in a week or so. Mount it on the front of a bulldozer or similar.
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
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I wonder what a big vibratory soil compactor on a boom would accomplish?
Wes
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You mean besides putting one vibratory soil compactor into low earth orbit? 8-O
Call NORAD so they can track the trash... On second thought it probably won't make escape velocity, but "What goes up must come down" still applies. It's got enough mass to go right through whatever house or car roof it lands on. Headache!!
That's the nifty thing about a mine flail, the arm is just far enough away that it should remain attached and mostly undamaged. You'll lose some of the chains and flail weights in the BOOM!, but they won't go nearly as far.
--<< Bruce >>--
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How well do the thermal imaging night-vision cameras work in the field? I built some telescopic lenses for them, about the size of a gallon paint can with black Germanium front elements, but never heard anything good or bad about them from the field.
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Ken,

What about a metal detector? Or might that set some of the damn things off?

Again, thank you!
Bill
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snipped-for-privacy@yahoo.com wrote: (...)

(...)
I like your first idea a lot, Ken.
> I have been wondering if there is any way to inductively couple enough > current to prematurely detonate these suckers.
If you knew the electrical resonant frequency of the initiator, you could aim a parabolic dish off a boom in the front of a vehicle. A high power transmitter tuned to that resonant frequency would drive several 10's of megawatts of ERP down into the cap, bypassing the trigger. Dishes and transmitters are cheap!
--Winston
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On Mon, 19 Nov 2007 01:33:35 -0800 (PST), snipped-for-privacy@yahoo.com wrote:

Metal pressure plates that big and buried shallow would be very easy for a metal detector to find, and the detector could be desensitized so it didn't pick up miscellaneous small bits like shrapnel etc.
A metal detector would be small enough and light enough for a small R/C vehicle to handle, and they draw very little power.
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On Mon, 19 Nov 2007 10:05:24 -0500, Bill Schwab

Very, very unlikely. There's no closed circuit in the described IED in which to induce current, and the field of a metal detector is very weak.
The only way I know of that an EM field can fire a squib is if it's high enough in frequency (and powerful enough) to induce enough resonant RF current in the squib leads. Resonance doesn't require a closed circuit. That'd be at least UHF in frequency, and at least a couple of watts of power -- and then only if the metal pressure plate doesn't act as an effective RF shield. Metal detectors typically operate at kilohertz or low megahertz frequencies.
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My understanding is that the frequency needed depends on the length of the wires going to the det. And that about 27 MHZ is about right.
Dan
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snipped-for-privacy@krl.org wrote:

The idea is to cause inductive heating of the of the squib, yes? There is no current path via the leads unless you can convince the enemy to install (say) a capacitor across their series switch.
--Winston
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wrote:

At RF frequencies where the squib leads form a half-wave dipole, no other current path is necessary. The squib itself would be the current path and electrical load. 27 MHz would require rather long squib leads, as might be found in mining, construction or demo setups. Twisted parts don't count much, but eventually they must separate enough to engage a switch and battery within an IED.
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