EMP question.

[DIM TIM]

I was not real sure which forum to post this one under, so I'll put it here tosee if someone has the answer to it, and if any of you moderators feel compelled to move it, I'll understand your decission.

 

I read, and sometimes do posts on survival and preparedness boards all over the web. Many folks are concerned with these subjects since 09/11/01, and the Katrina hurricane, as well as a host of other possible disasters and events.

 

One thing that I have noticed on a number of these boards is the concern over terrorists getting hold of a couple nukes, mounting them on a couple of rocket launchers aboard a few cargo ships, and launcing them high into the atmosphere above the country to be detonated, and killing all our electronic dependent items for life as we know it with the resultant EMP pulse.

 

A lot of folks make posts on some of these boards about building a Faraday Cage of sorts, from materials of all sorts to store their electronic items, to keep them safe from the pulse.

 

Some of them run from surplus ammo cans, to metal paint cans that you can buy from Lowe's, to galvanized metal trash cans, and even metal garden sheds.

 

While I can see the reasoning behind their posts, I still wonder if any of these would really work, and so I post this for discussion. I have a technical degree in Industrial Electronics, and a basic working knowledge of the principle of the workings of the Faraday Cage, but I would tend to think that with the knowledge that I have seen expressed in some of the posts I have read, that there must be at least one person out here that knows what will and what won't work.

 

So is there a solution to this that the average person could use to protect their items, and what would work that they could fabricate themselves if so ?

[timo]

I think it doesn't take a science degree to figure that a group of terrorists is more likely to get take their nuke to a major city to blow it up there than to launch one to space to disrupt electricity. Not to mention that my computer has died of less spectacular reasons before. And if the evil communists invade your country then there's more to worry about than not being able to access facebook. In effect, I think there is no need for you to protect against an EMP attack.

I am afraid I do not understand how EMP is supposed to work, either. But I would be interested how the pulse intensity compares to having my mobile lying on my laptop.

[Mr Skeptic]

Right, I can't see terrorists using an EMP to nuke our satellites, for which they'd need both an intercontinental ballistic missile sort of vehicle, when they could more easily nuke Washington and leave our news network intact to cover it real good. I mean what kind of terrorist goes after satellites?

 

As for that affecting anything on the ground, EMP bursts do follow the inverse square law and in addition the atmosphere will block some of the higher energy radiation. Maybe they can reboot your computer, but I doubt that. If they used an EMP bomb (non-nuclear) over a major city they could make a mess I guess.

[Moontanman]

Actually a high altitude nuclear detonation is more damaging than one close to the ground due to interactions with the earths magnetic field and the effects of the earth absorbing the EMP when it is close to the ground.

 

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

 

The relatively small magnitude of the Starfish Prime EMP in Hawaii (about 5600 volts/metre) and the relatively small amount of damage done (for example, only 1 to 3 percent of streetlights extinguished)[8] led some scientists to believe, in the early days of EMP research, that the problem might not be as significant as was later realized. Newer calculations[9] showed that if the Starfish Prime warhead had been detonated over the northern continental United States, the magnitude of the EMP would have been much larger (22 to 30 kilovolts/metre) because of the greater strength of the Earth's magnetic field over the United States, as well as the different orientation of the Earth's magnetic field at high latitudes. These new calculations, combined with the accelerating reliance on EMP-sensitive microelectronics, heightened awareness that the EMP threat could be a very significant problem.

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Merged post follows:

Consecutive posts merged

very funny

[DIM TIM]

Ok...just for clarification, there is no need for an ICBM for delivery. A Scud Missle on a mobile lancher mounted on the deck of a cargo ship would be able to get a warhead high enough to work, and I'm sorry to hve to be the one to point this out, but everything that is using a transistor, diode, micro chip, etc, and is not hardened [ protected ] is going to be rendered inoperable and worthless. And I do mean EVERYTHING. To borrow a phase......." more bang for the $buck$ "

 

Autos [ from the early 70's to the present ].......DEAD.

 

Modern jet aircraft.......will drop right out of the sky.No gliding to an emergency landing, because they don't work like that.

 

Communications.......pfffffffffttttttt nothing, nada, zip......ALL FRIED.

 

UTILITIES.......Water, Sewer, Phone, Electricity.......GONE.

 

And don't look for any of them to be back in use anytime soon, because I have done my homework on this stuff.

We are talking years, and in some cases.......decades. Hell, Congress released their big 200 page report on the subject just a couple of years back, and the pictre that they paint is not good at all for us.

 

So what about my questions in my original post for this thread, would any of the measures work to shield items packed inside from the effects of the pulse ?

 

As an Electronic Tech., I am not 100% sure, becase I have no good, solid evidence as to how the propigation of he way that the wave works, or any of the numbrs required to do the math for the shielding.

My best guess, with the information that I have, and with my available knowledge of electronics is, that if the items to be protected were wraped in foil, in their original boxes, and then wrapped in heavy plastic, and then placed into a metal container that had no air gaps or holes, and was properly grounded to an Earth ground, then the charge from the wave should be run off to ground, and should have no effect on the items stored in the container.

 

But this is just speculation on the problem, by virtue of the limited knowledge I have of the numbers, and the effects of how the wave works, and the properties of the wave.

Edited April 2, 2010 by DIM TIM
spelling and punctuation

[michel123456]

As much as I know this thread was considered seriously by the army 25 years ago. It was considered as a strategic first move in case of regular war, in order to disorganize the ennemy. No wording for terrorist at the time. The only problem with that move was not to disorganize yourself as well.

I remember that all instruction was given the old way, making all calculations with paper & pen, running telephone wires for kilometers between positions (no cell phones), no electronic ignition, etc. I don't know what happen today.

[DIM TIM]

As much as I know this thread was considered seriously by the army 25 years ago. It was considered as a strategic first move in case of regular war, in order to disorganize the ennemy. No wording for terrorist at the time. The only problem with that move was not to disorganize yourself as well.

I remember that all instruction was given the old way, making all calculations with paper & pen, running telephone wires for kilometers between positions (no cell phones), no electronic ignition, etc. I don't know what happen today.

 

That seems to be the main problem now, I had hoped to get an educated answer to this one, but nobody seems to take the POSSIBLE threat of determined terrorists who are actively seeking to purchase nuclear devices , even as I write this reply, seriously.

 

Of course, nobody would have thought that a group of them would hijack commercial airliners, and use them as weapons of mass destruction either.

 

There is a perception among many Americans, that these people are stupid, and not truly capable of someting as complex as a stratigic first strike.

Oh sure... they might get their hands on a few small nukes off of the Black Market, and MAYBE they could get them into the country and set them off, but the death toll would be small, and then we would just go and destroy them all, because the government will take care of it. ( This is the thought of some people in this country even now )

 

The truth is....... these people hate ALL of us. They will do whatever it takes to inflict as much death and destruction upon as many of us as they can.

 

That is why this is a real possibility as a terrorist threat to ALL of us. If you have any doubt as to this, then I ask you all to consider this.............

 

 

For longer than I can remember, people have been sneaking across our borders, and smuggling all sorts of contraband into our country as well. So I will concede to you all, that the possibility exists, that they could sneak a nuke into the country, and set it of in the center of a major city, killing thousands, and causing terror to millions. BUT.............

 

If they got their hands on 3-4, they could do as I posted at the start, and launch them from the decks of cargo ships, just outside the territorial linits of our country ( international waters ), in The Atlantic Ocean, The Pacific Ocean, and The Gulf of Mexico. They would not need large ICBM missles, just the simple SCUD missles that they have access to right now. They would launch them from just outside our territorial limits, and in a matter of minutes, they would reach the altitude needed for maximum yield, and detonate, because we have no real missle defense against an attack of this sort.

 

The resulting EMP bursts would blanket the entire country, and then all of the effects that I mentioned in my second reply and querry on the subject, would happen to the entire country. (Biggest Bang for the $Buck$ )

 

The resulting death toll from the effects of the pulse, as well as the chaos and barberism that would follow, would cause a single strike against a major city to pale in comparison. Seems that SOME people don't take too kindly to having their lives and their world turned upsidedown, and some of them will take whatever YOU might have, if it means that they will live to see tomorrow. And they won't care if you live or not. Desperation will make even the most civilized persons on the planet to do WHATEVER it takes to survive.

 

The reason that I asked in my original post as to whether or not that the shielding methods that I mentioned would work or not, was because some people in this country realize that, if some electronic devices could be made to survive, ( communications gear, power generation equipment, etc, ) then the few of them that put back some of this equipment, would be able to keep their families, groups, community, etc, better able to make it through what would lie ahead.

 

If any of the described methods of shielding would work, I had planned to put back a good supply of the FRS and GMRS radios, chargers, rechargeable batteries, and a couple of power generation sources, to be given to our local police department, and county sherrif's office, as well as a few for my own family to use. And another set of items that I thought would be of good use, would be a spare set of controls and computer module for my Chevy Silverado.

 

As a matter of fact, if any of the shielding methods would work, I had even thought of bringing this posted thread to the attention of the sherrif's office, the local police, local fire department, and the local chapter of CERT, and the city public works department as well, so that they might consider this threat, and prepare for the possibility themselves.

 

SOOOOOOOOOOOOOOOOOOOOOOO...........I come back to my original question. WOULD ANY OF THE TYPES OF SHIELDING THAT I MENTIONED IN MY ORIGINAL POST WORK ?

 

As I stated in my second reply, as an Electronic Technician, within the limits of my knowledge of how the EMP pulse works, and the numbers for the math, then it would seem possible, but I have no way to test this, and the physics involved is beyond my knowledge. So this is why I asked here. Surely with all of the well educated individuals that post here, and all of the persons with degrees in higher mathmatics and physics, surely there is at least ONE person out here that has the answer to this question. Maybe not.

 

It is possible that my answer could come from a more unlikely source, but the odds are in my favor, that I would more likely find it here. So, even if YOU ( whoever that may be ) read this post, and don't know the answer, try to think about this, and ask around to all of your friends and colleagues. Maybe one of them would know the answer to this one, and then you could pass it along. There are a great number of people in this country that would love to know the answer to this one, myself included.

[Mr Skeptic]

Well I can tell you that the military don't take kindly to the possibility of their critical equipment being wiped out in a single attack. Military hardware is specifically hardened against EMP weapons. Of course a strong enough EMP at close enough range will still take them out, but they have prepared for the possibility. I think also that our optical networks would survive an EMP. Anyhow, if you want some real numbers I think one of the folks at the military might be able to help you.

 

Navy Electromagnetic Pulse Assessment Group

[DIM TIM]

WELL, I tried. Thought for sure that I would find my answer here on the forums, but just like I said in my last post, my answer came from an unlikely source.

 

I want to thank you Mr.Skeptic.

 

Your link did not even come close to helping me find the answer, but through a series of trial and error searches on some wild tangents that were somewhat related, I was able to find what I wanted to know.

 

Thought for sure that it would have come from here or your link, but hey, I'll take what I can get, and I was even able to come up with some mathmatic calculations, and even a description of the required elements to get the needed results for the protection that I was looking for.

 

Who would have thought ?

[Mr Skeptic]

The problem really is that your question was a very specialized engineering question, one that several people (just probably none here) have already calculated. It's not like many of us here can simulate a nuclear blast.

[DIM TIM]

Thats OK, Your link was still a great help, because as I stated in my last post, I found my answer on a site that was off on a stray tangent from there.

 

I would have never thought to look at that particular site myself, but thats OK, I found my answer, and that was what really mattered.......By the way, in case anyone is interested, a few of the shielding methods I described would probably work, as long as the outer container is properly grounded. The one mentioned about using a galvanized metal trash can showed the best promise. All inner packages would be best left in their original packaging, and then wrapped inside a few sheets of heavy duty aluminum foil.

 

Seems that the can would absorb and pass at least the first 99% of the pulses energy to ground, and the foil around the packaging would handle the last little bit.