With all the discussion of EMPs lately I`m curious what will NOT be damaged... and what can be done to limit the damage or eliminate EMP damage totaly.

Will flashlights work?
Will ALL cars be broke or just ones with computers?

If things do stop working is it perm. or temp? If both (which is my guess) how can you tell which items will die for good, and which you can plan to use in case of an EMP?

Diesel vehicles will still work as long as they do not have any sort of microprocessor to contol the starter and/or fuel injection pump. That's one of the reasons why the military uses diesel vehicles. The Humvees, deuce-and-a-halfs, FMTVs (I think), and larger trucks have mechanical injector pumps and very simple glow plug systems. A diesel engine, once it is started, will run forever as long as it has a diesel fuel supply. The extremely high compression ratio causes the fuel to autoignite continuously. There are no ignition parts to wear out or be disabled by EMP. Also, I have heard that electronics using vacuum tubes instead of ICs and transistors, like old High Frequency HAM radios, should still work. The Soviets are still flying some older jets that use vacuum tubes in some of their systems.

Figure on anything electronic not working perminantly until it can be repaired with non blown parts. Think of EMP as a voltage/current spike, so it would have the same effect on electronics as blowing a fuse. First, an old non computerized diesel has less basic electronics then a gas engine, so like mentioned you are better off with that. Also, chances are the starter setup may go bad, so you need to be able to push/roll start the vehicle, so you need a manual transmission. Also, remember that chances are your A/C, Headlights, Radio, Interior lights, Gauges, wipers, ect may or may not work.
Now, as to basic electronics. I've read that LEDs, fuses, batteries that are regulated, ect would be bad if the pulse is big enough, so don't count on your flashlight either. The good news is you can protect your equipment with a faraday cage, they are simple to make and protect equipment quite well. The goverment has quite a few buildings surrounded by a faraday cage, so it is possible to surround your house or garage in one if you had the time, money, and energy. <img src="/images/graemlins/smirk.gif" alt="" />

Faraday cage... I`ll have to look into them <img src="/images/graemlins/smile.gif" alt="" />

Great info guys.

Basically, if it has any integrated circuits, they won't work. I'm not 100% on the CR123s and LEDs that Paul mentioned in the WoW thread, but I wouldn't bet on them working. As they say, the factory smoke would be let out.

The "personal electronic age" will come to a screaching halt in areas effected by a pulse. As I said in the WoW post, anything with a fuel injector, gone. Digital anything, kaput. That includes most modern furnaces, water and fuel pumps, elevator controllers, emergency lights... Oh, and a lot of pacemakers will be pretty messed up.

What will work: old cars, small motors (like some ATVs, but most of your new ones are injected not carbed), older generators. Becuase even the older infrastructure has been fitted with computer controls, most areas will be reduced to a 3rd standard of living in a heartbeat.

Forturnatly, EMP is not that easy to make, contrary to what various plans on the web claim. Actually, it is really easy, but big enough to be usable is a trick. Easiest way is to detonate a nuke in the ionosphere. We supposedly have various non-nuke EMP devices in our military inventory, but supposedly we have direct energy weapons and antigravity craft to. *rolls eyes*

Oh, and I should mention this: part of why diesel is used for military purposes is becuase it isn't as likely to explode. That's been US policy since WWII. I doubt anything in out vehicle inventory would survive a pulse if it wasn't buried.

Oh, and I should edit this with protection information, as Todd requested. Dig. Dig deep. Dig deeper. Armour is part of why NORAD is in a mountain, the other part is EMP. You will want a lot of dirt and/or water around you if you want something to survive an EMP strike.

There are other ways to do it. The faraday cage was big for a while during the cold war, but protection costing X dollars could be defeated by a larger pulse, costing Y dollars. And X woudl be much greater than Y. But if you can buy an old missile silo, or a silver mine, or a salt mine, you might be able to do just use earth sheilding. Just remember, everything has to be sheilded. Any antennas are going to have to have big honkin' (yes, that is a technical term) diodes on them to prevent a backwash of the pulse.

Bascially, EMP is a really big radio friequency spike. when RF hits metal, it creates electricity. That is why you can turn a florescent light on just by getting close to a radio tower. The resulting electrical spike is just like any other in an electical system.

Todd, you might as well buy rad and chem suits. :P

A faraday cage, for those that don't know, is a big metal box, which is grounded. Anything in the box is fully self contained. That way, when an external electromagnetic signal (like an EMP pulse or your neighbor's pirate radio broadcast) passes by, and is turned into an electrical impulse, it just goes in a safe direction. Of course, a big enough pulse won't matter.

Oh, and most of us own a faraday cage, we just don't know it. <img src="/images/graemlins/smile.gif" alt="" /> If your computer has a metal frame and metal side panels, rather than the flimsy, cheapy, artsy fartsy all plastic jobs, it will function as a faraday cage. But that is becuase older computers made a lot more noise from an EM point of view, and it had to be contained.

I'm going to be contrary here. There is a lot of hype and spec flying around at the moment about EMP that is not completely accurate, to be charitable. I can offer objective and hard facts, but instead of saying "trust me", I'll do a little checking to see if there is more accurate and objective information readily available on the internet and get back on the thread if I find some open source info to share.

Tom

PS - AFAIK CR123 batteries have no internal electronics and are strictly primary cells. Secondary cells (rechargables) MAY have internal electronics - most don't - but certainly some recent lithium chemistry secondary cells do have internal electronics. Easy to check and if you don't know the answer, you probably aren't using batteries with internal electronics.

Any protection a faraday cage may afford, no matter how big or small, is seriously compromised if a metal conductor passes through it. The conductor can be a power line, communications circuit, or utility pipe or conduit. You will find that any real government hardened building has no metal of any kind passing through or to it. Their communications are fed by strictly fiber opti cables with no shielding.

That also nullifiies the affect of a faraday cage on a metal cased computer due to the power and porting circuits passing through the body.

Do not ask me how I know.

Hi,

I've been lurking for awhile and only recently decided to register. I agree totally with the above post. EMP's are one of those things that Hollywood probably does better than reality. I'm getting my PhD in chemical physics and have been working with quite a few nuc engineers this summer. Every so often over lunch this type of topic comes up. Consensus among us is that unless the weapon was specifically designed to maximize the resulting EMP, most of us doubt the EMP would be substantial beyond the blast radius. Unless there is some part of the problem I am really missing, the pulse should die off as 1/r^2, so its probably not that big of a deal unless you are close enough to the weapon to have much bigger problems than a busted radio.

Also, the faraday cages around secured buidings I would guess have more to do with keeping people from electronically eavesdropping than serious concerns about EMP survivabillity. Then again, this is all pretty speculative anyway...

-r

Right. My last post on the subject (long):

Let’s start with a brief definition:

http://www.absoluteastronomy.com/encyclopedia/e/el/electromagnetic_pulse.htm

Now on to some readily available internet “information”

A bit specialized, but a synopsis of some real world testing on COTS Ham gear (and the technique is not exactly news – the news is that there is COTS protection available:
http://www.geocities.com/HotSprings/Falls/1984/newfact.htm

This is an example of mostly crap info that tosses out some nearly correct mostly irrelevant info and then authoritatively leaps to some (wrong) conclusions without offering one bit of real-world verifiable information: http://www.alpharubicon.com/basicnbc/empfacts.html

This is much older information than the 1997 date indicates; I saw and touched all of those up close and personal well over a decade before that date at the source, CERL. In the early 1980s I did the construction management for their EMP generator, which when completed was (at that time) the world’s largest non-nuclear EMP generator. I have in more recent times toured much larger and more sophisticated non-nuclear EMP generators. At the time and for all practical purposes, nearly all of the testing since was to evaluate the effects of nuclear near-misses on military equipment and has virtually no useful extrapolation to the rest of the world. (doh!) It was often to test a worst-case scenario, not best case. A military formation or ship can take a sever blast and lethal dose of radioactivity but still continue to finish a specific tactical or even operational mission if the systems are all working well enough. That’s not relevant to the rest of the world for the most part, yet this is some of the root information that continues to drive the “Clad your house in tin and ground it” experts (Your house will not be standing if you need that sort of EMP shielding). Actually, a lot of these approaches had/have as much or more to do with TEMPESTizing electronics (protection from electronic eavesdropping) and serendipitously provided a brute-force protection against EMP effects (but not blast or radiation). These non-nuclear EMP generators are also not perfect simulators because the frequency characteristics of these are NOT exactly the same as that from a nuclear weapon as well as some other reasons – you can follow that fact deductively to some correct logical conclusions:
http://www.cecer.army.mil/facts/sheets/FL16.html


This is a tough call; use with caution. There is some surprisingly accurate information here AND some wildly erroneous information salted throughout as well. Worth reading if you are willing to be a little skeptical and check out some of the claims (I mean, some of it is pure crap, but there are many solid nuggets here as well as well):
http://www.aussurvivalist.com/nuclear/empprotection.htm

I can pick a lot of little nits with this, such as substituting “may” for “will” and tossing in a few “some”s in the EMP paragraph, as well as bits of the Chem section, but it’s not a bad read and he’s got the important bits close enough for you and me: http://www.survival.com/cbr.htm

I believe I can dig up some definitive scientific open-source info, but so can you and it will not be light reading. EMP is a small fraction of the total energy released, even in an enhanced weapon used the right way. It is not very relevant to survivors of a nuclear terrorist attack compared to the primary and secondary effects of the (MUCH larger) direct-effect energy releases.

In the event of an all-out nuclear attack by a MAJOR power (you’ll have fingers left over using only one hand to count), the important effects of deliberate EMP attacks again are largely irrelevant to survivors for lots of obvious reasons. If there were deliberate EMP attacks.

If a minor power with the ability to conduct a significant EMP-only attack did so, we would survive and it would probably be an act of national suicide on the attacker’s part.

It’s not worth spending a lot of effort or worry on unless you are in certain businesses (nothing to do with this forum) or have certain equipment needed to respond as a volunteer in emergencies (perhaps HAM operators, for example).

Regards,

Tom

<<You will find that any real government hardened building has no metal of any kind passing through or to it.>>

Oddly enough, I've built some of those facilities. Just in case the designers and I totally screwed up, how do you propose to get power in, water in, and sewage out? Meant kindly, as food for thought. (And we were actually doing TEMPEST stuff for the most part.)

Tom

I think the main thing is there isn't enough definative info out there for the average person. We know it will effect electronics and that is about it and we know what we read from nuclear testing in years past (like when they blew the fuses in Hawaii). I think someone needs to come up with a definative answer (in laymans terms) of what the EMP from a suitcase type dirty bomb or small nuke would do and what the EMP from one of those Korea size bombs would do (as that seems to be the current threat) and for what distance. There is more false info out there then true and the movies arn't helping. Personally, I'm planning for everything to be gone and hoping for the best. Plan for the worst, hope for the best seems to be the best option right now. <img src="/images/graemlins/confused.gif" alt="" />

ironsraven- I`m not rushing out to buy anything.. just was curious with all the hype going around what was true and what was not.. etc.. <img src="/images/graemlins/smile.gif" alt="" />

I had a client once for whom I processed a "nuclear survivor" claim. He was a commo guy in the pacific during severl of the post-war tests. Among his jobs was going abord surviving test target vessels to evaluate damage.

We got to talking about the tests, and EMP cam up one day. In those vacuum tube days, the damages to electronic equipment from EPM was -- none. Not even at Bikini (sp?) Atol, which is the shot we hung our claim upon.

Water and sewer were brought in with nonmetalic pipe. Power was the tricky part.

Hmm, maybe a close-coupled isolation transformer or two?

Theres a faint smell of eau de Y2K in this thread <img src="/images/graemlins/wink.gif" alt="" /> Every technological leap offers humanity benefits and the added worry we will become dependant on it and wind up worse off if it breaks. I'm sure some Homo Erectus eschewed cooked meat until he observed his buddies for a few meals. There is always the worry of countermeasures against our latest goodies.The Ghostdancers wore sacred shirts to stop bullets. They had a significant failure rate vs a .45-70. But today's Kevlar is a different story. Meanwhile, I have a real situation in my emergency gear closet-silverfish! ew yuck,nasty. I'm going to waste them with a chemical strike. First I have to don this black suit and sunglasses <img src="/images/graemlins/cool.gif" alt="" />

Chris, you hit it right on the head. How likely are any of us to be (a) exposed to EMP, and (b) then worry about it while running like mad? As Ayeres pointed out, there are stationary EMP generators, and maybe someone has minuturized one (Tom- yes? no? no comment?) to the point where it is readily transportable, but I put it into the same catagory as something that requires a full MOPP suit. I'm too slow to get out of the way, so I'm not going to worry.

I learned some about EMP in school, but realistically, I don't think the issue is significant enough to worry about. I just don't trust electronics becuase they don't like water and impact, which I seem to find a lot of, and batteries are heavy.

Gee whiz, didn't anybody see "Ocean's Eleven?" They took out Vegas for pete's sake! Wasn't that a portable EMP from Caltech?

Their first idea was much more practical and likely to work, which was to cut the mains with a shaped charge.

At least they got one thing right, if you try to steal from the Casinos in Vegas you will get caught. There are no exceptions, but there have been a few examples made. <img src="/images/graemlins/blush.gif" alt="" /> <img src="/images/graemlins/wink.gif" alt="" />

Thank you for taking the time to put together that response.

ETS vs. survivalism

I am wondering whether an altoids tin would act as a Faraday cage and protect, eg, a Photon microlight inside it. Also whether the aluminium body of a Surefire torch would protect its circuitry and possibly its LED.

Nope, the body of a surefire is part of the circuit. So, if EMP could/would/will blow it out, then it would travel through the flashlight body. The altoids tin on the other hand might.

Right, a faraday screen only works if it has somewhere to drain the energy off to, specifically a ground. If there isn't a huge welding wire connected to your altoids tin on one end and a copper rod driven deep into the ground on the other end, sorry, no protection. Same goes for cars, portable radios, flashlights, bicycles, cordless phones, cordless power equipment.... you get the idea.

While an EMP has a localized destructive effect on solid state circuits, it has a much broader temporary interference effect on same. You may be 50 miles or more from a major EMP event, and suddenly your flash mem stick is wiped clean, or your computers bios is gone, or your ipod has lost all your favorite songs.

Lightning is also an EMP, just not as strong as a thermonuclear detonation. Large meteors coming down through the atmosphere can also cause an EMP, though like the thermonuclear device ones big enough to blow circuits generally have much worse direct effects.

A really big problem we had with electronics aboard ship and up on hilltops was static precipitation. It is a localized type of EMP caused by the movement of dry air across the surface of the antenna. One way to isolate your antenna system without using those big honking diodes is to install a ferrite bead at the coax connection to the radio, or even inside the radio in some models. Isolators also work pretty good, though they can be defeated by static discharge.

Gosh, there are so many things that can be done. I guess them old tube jobs do still have some purpose. <img src="/images/graemlins/laugh.gif" alt="" />

EMP Electro Magnetic Pulse
By Rich “Raspy” Shawver

The way you make electricity require 3 things a conductor [Wire] a magnetic field and relative motion. A lightning strike generates an expanding [the moving] magnetic pulse or field that passes over power lines [the wire] generating a voltage spike in incoming services. The size of the spike is dependent on the strength of the field and the length of the wire involved. The resulting spike only has a duration of a very small fraction of a second but that is more than enough to damage electronic components. Circuit breakers are of no help. The spike is so short that it hits and does the damage long before the breaker has a chance to react and open. The spike resulting from a lightning strike can be 4 to 5 times as high the normal line voltage. The EMP of a nuclear weapon is exactly the same mechanism but with a much greater intensity. Depending on your distance from the detonation the field can be strong enough to generate damaging voltages in the internal wiring of the equipment.

If your equipment is hooked up but turned off, an incoming spike on the electrical power lines [and other attached lines, cable and phone] can arc over the switch if large enough. Also most electronic equipment now have circuits that have power running through them even when turned off for remote operation [even if it's not remote controlled]. Rather than building separate boards for each model companies have found it is cheaper to include many of the features on a common board. They just turn on the special features on the cheaper models.

The only safe way to keep equipment from being damaged is to enclose it in a metal structure that is grounded. The equipment has to be totally isolated from the cage and any outside connections. A structure of this type is called a Faraday Cage. A metal container [such as an ammo box] in which equipment can be stored if insulated from the container and the container is grounded will act as one. The way a Faraday cage works is the moving magnetic field strikes the cage. This starts to generate an electrical charge. As the electrical charge builds this in turn starts generating its own magnetic field that pushes back or repulses the original magnetic field. This then causes the original field to flow around the cage rather than through it. This is what keeps the EMP pulse from effecting the equipment inside the cage. While the best design for a cage is solid sheet it can be a fine mesh grid. The size of the openings in the grid is somewhat critical. If the openings or mesh size is too large the field the wires counter generate does not build up fast enough to block the field pulse. Something the size of chicken wire would be so large that there would be some leakage. The field on the cage has to build up fast enough to block the holes in the mesh. The cage does need to be grounded to dissipate the resulting electrical charge.

There are devices called lightning arresters among other names. That are sold on the market that are designed to stop or at least minimize the effects of such spikes. Many are good devices. But they are limited to the amount of protection they can supply. A large enough spike can overwhelm their capacity. While you can not shield wiring outside your own home. Inside it can and should be shielded. Some wiring is designed with shielding. This is a metallic or braided sheath surrounding the wiring. Another way is to run the wiring through EMT conduits. Both methods can be combined for better results. This shielding needs to be grounded. Just remember that this wiring is attached to wiring that is outside your control and probably not shielded.

The best way to build your shelter is to line the inside or outside with sheet metal. [Door included] The metal of the door must make electrical connection with the rest of the sheeting. For more reliability Line both inside and outside independently. A double Faraday cage. You do not have to do this for your entire house but should be done for a shelter, panic room, communication shack or a room that is a combination of any of the three. The best metal for making the cage is copper because it conducts better but any metal will work. [Gold and platinum would actually work even better but who could afford it.]

If you do run electrical or electronic conducting lines into your structure have them shielded but do not have your equipment connected to them except during actual use. I do not mean disconnected by a switch but physical distance such as pulling the plug out of the wall socket.

Remember if the moving magnetic field is strong enough the internal wires of the equipment itself can cause a voltage spike that will damage it. That is why most cars will be knocked out because the voltages would knock out any electronics. [Most cars are totally controlled by chips] That is why older vehicles [pre chip] are a better BOV. The voltages can be high enough to actually burn out the wiring itself.

I can see the question in your eyes. A car is basically a metal box wouldn’t that act like a faraday cage? If that is so how can a car be effected? Simple the box that is a car has some huge holes in it electrically speaking. That and many modern vehicles have gone to composite material mostly plastic for sheet material rather than steel to reduce weight. The engine compartment, that has much of the wiring running hither and yon to operate the engine. Plus you have the main power supply cables from the battery and alternator and they either hook into everything that uses electricity or that item does not have power. Look under the hood sometime even in the tight compartments today there are places you can see the ground. The passenger compartment has windows some real big holes in the box. Yeah, but the wires are under the dash. How much of the dash is plastic? Look at all the holes for gages and dials. In most cases the entire underside is open. Out your car in the bottom of your swimming pool. Just kidding. But if you did would the water be able to get to the wiring? If so then so could the pulse. While you could close off the engine area covering the windows with plate or mesh just wouldn’t be a workable solution. It would be difficult to say the least to see out and drive. But the local constabulary might have a comment or two.

If your only choice for a BOV does rely on electronics there is a remedy. On any car you could pull the entire wiring harness and up grade it. This would be with heavier gage wiring and using shielded wire. Get a spare set of the control modules needed for you car. Not just the computer control boxes but also the sensors and the items that are controlled by the computer. [They are also susceptible to pulse damage.] Wrap them in insulation [Electrical not temperature type I.E. rubber] and store them in a metal box. Attach the box to the frame so that it makes good electrical contact. Then do as they do to movie stunt cars. Attach a grounding strap to the frame. The strap is usually a braided copper cable that then drags on the ground. This is to dissipate and charge that builds up on the vehicle. The strap needs to be checked regularly and replaced as needed.

Yes the entire national power grid would be knocked out. While the most of the grid components them selves would be able to withstand such a pulse all the electronic control equipment would be fried. The means of operating and monitoring the system. Local power may be restorable but an inter linked grid would take a long, long time to restore.

Will your car or home equipment be affected? Mainly it will depend on luck. How far you are from the source and intervening obstacles. Even the angle that the local grid or house wiring is to the source can have an effect.

Sorry to be so long winded but it is not a simple subject and needs some explanation on the hows and whys.

Here are a couple of web sites that have a more technical explanation of how the field is generated.
http://www.geocities.com/CapeCanaveral/5971/emp.html
http://www.geocities.com/HotSprings/Falls/1984/emp1.htm

I am convinced that local release EMP devices are BS - the fantasy of paranoinacs and survivalists, in the worst sense of that term.

However, from some documents which I have obtained in litigation and cannot provide to you, I have learned that the detonation of a small nuclear (nucular, in the pronunciation of our fearlful leader) will result in third degree burns to exposed skin at a distance of 64 MILES.

I was born in '57. I went to a private schoolin Abilene, Texas with the kids of a bunch of SAC pilots from Dyess AFB. Their dads said, 'In case of air raid, get down in a comfortable possition, put your head between your legs, and kiss your ass goodbye.'

I am not frieghtened by the 64 mile stat - it just gives me one less thing to worry about. I'll be dead.

So, what's the difference between "nucular" and:

"fearlful", "possition" and "frieghtened"?

In the words of the great Steve Martin: "Yeah, I remember when I had my first beer...."

Vince

Got me that itme

> the body of a surefire is part of the circuit. So, if EMP could/would/will blow it out, then it
> would travel through the flashlight body.

I've come to the same conclusion. I think it would be fairly easy to design a hardened flashlight, though. It'd need a metal "lens cap" to shield the bulb/LED, and it'd need to not make the shell part of the circuit. But it's probably not worth it: cheaper and as effective to keep it in a metal biscuit tin when it's not being used. Don't let it touch the sides.


> The altoids tin on the other hand might.

Yep. I'm now fairly sure of this. The metal is opaque to the EMP and will sheild anything inside it. The EMP will induce current in the tin itself and in anything touching the tin, but something like a Photon Microlight which has a plastic shell keeping it away from the tin ought to be OK. The tin doesn't need to be thick, nor do small holes in it matter much, but it does need to be made of a conductor with the lid shut.

The controversial issue is whether a Faraday shield needs to be earthed. I've found several references which say it does (including some in this thread), but I don't believe them. I've also found references which don't mention it and some which flatly say earthing is not needed. I'd need to see more argument and more physics before I believe earthing is needed.

Earthing provides a favourable route to ground. If you don't earth the tin, the current will reach ground by some other route. If you are holding it, it might go to ground through you. But whatever the effect that has on you, it's not going to affect what's inside the tin. A charge may build up and take a while to dissapate, and the tin might be dangerous to touch meanwhile - but again that's about protecting people outside the tin, not the contents (and of course the danger, if any, applies to touching anything big and metal and unearthed). Aircraft can be EMP hardened and presumably are not earthed.

Some references: This was given earlier. It doesn't say earthing is required. Duncan Long is very clear about Faraday cages, says earthing is not required, and makes a lot of sense to me.

Overall, I reckon EMP shielding is an advantage for building a PSK in a tin instead of a plastic pouch. And for keeping other electrical equipment in a tin when it's not being used. Torches, GPS devices, your spare watch, I suspect simple magnetic compasses too.

Those stat.s are for the czar bombe, the largest nuc (soviet) ever test detonated (thank you History Channel), not a "small ' nuclear device, but why split hairs, if the major players start throwing nuc.s back and forth, we're all done for any way. If it comes to that, give me a couple of LARGE bottles of good wine, let the fireworks begin, and set one down right in my lap... I don't want to have to linger through rad. poisoning before I check out. On a side note, anybody else seen "Dirty War", it was an HBO movie I caught on DVD last weekend... very well researched, and VERY unsettling.

Troy

Brangdon while it is true that a faraday cage does not have to be grounded. It functions better if you drain the build up of charge to ground.

A hardened aircraft will build up a charge from an EMP burst. But they can also build up charges just from flying. These either slowly discharge to the air or when the plane lands.

The charge built up on something as small as an Altoids tin would disipate through the body. But would be so slight it probably would not even be noticed or at most a slight tingle.