EMP strike possible?

[masterspark]

Wow SheepDog! good stuff there. I have a couple of small ss hard drives in the safe with lots of info on them. the triple bag/foil method would be perfect. Maybe a vacuum foodsaver bag would help instead of ziplock.

 

[Weedygarden]

Would a well made metal shed, on a concrete pad that is grounded work?

 

[The Lazy L]

I have heard folks talk about a Faraday box to protect certain electronics but don't quite know what that entails. It would be nice to be able to have a hard drive with all my files protected somewhere.
I'm surprised more is not known about this.

Oh...IMHO...if there is a EMP it will be a considerable amount of time before the files on my hard drive will become a priority, if ever.

 

[kd4ulw]

Interesting tests of solar systems and a few other home electronics.

 

[hiwall]

One thing that no one really talks about when discussing EMP, the thermo-nuclear war that follows.
Do you really think that if we were hit with an EMP our military would do nothing? We would strike back. But let's say we didn't and we just turned the other cheek while most of the population of the USA died. Other countries would certainly invade us while we were down. Would we do nuclear strikes then after we were invaded?
And if we were taken out with an EMP, it would be open season on our allies. North Korea would attack South Korea. Everybody would attack Israel and Israel would certainly counter any major attack with their nukes just to survive. And once the nuclear ball was opened others would use theirs too. Hence world-wide thermo-nuclear war.
So when that happened I would think your I-phone not working would be the least of your worries. Watch the horizon for all those mushroom clouds.

 

[ssonb]

Thanks SD, I was working on a presentation to describe how to do what you just said and you said it very well I might add.
Your description was easy to understand.
if I had posted what I was working on I would have been responding asking the OP for clarification.

 

[CrackbottomLouis]

There are a lot of myths on the net. That garbage can storage is one of the worst. You can attenuate a radio frequency but not a DC pulse like the E1 pulse from an HEMP.
A Faraday box was originally designed to ground high voltage from a point source - like lightning by guiding the voltage around the person in the box which was actually a cage of iron bars.
Later Faraday boxes were mage of copper mesh and used to block radio emissions by grounding them. An E1 pulse is not a radio signal it is the ionization of the atmosphere and it happens in less than a nanosecond (one billionth of a second). In order to stop that fast rise time voltage change you need to use capacitive reactance. That requires a very good conductor - Gold, Silver, Copper or Aluminum - in at least three layers with a good insulator between each of the conductors and around whatever you want to protect. For small devices like a hard drive or a DVD drive you can put the drive in a zip-loc bag, wrap it in a heavy duty aluminum foil, put that into another zip-loc bag and again cover it in aluminum foil, put that into a zip-loc bag and cover it with another layer of aluminum foil. The protection comes from the layers because each layer takes longer to charge and the time diminishes the charge that is transferred. Since the pulse is gone so quickly it won't make it all the way to the device you want protected (not at any large voltage). The garbage can is steel covered in zinc - not a very good conductor and the cardboard inside is not a very good insulator. As soon as there is a charge applied to the trash can an opposite charge of the same voltage is applied to whatever is inside even if you could make the can and cardboard air tight.. There is little if any protection from the E1 pulse. It might work well for a lightning strike if the can was grounded but not for the E1 pulse.
A note about grounding. It only works when the ground is opposite in polarity and capable of dispersing the energy of the pulse. Since the E1 pulse also electrifies the ground to a depth of 30 feet, any ground wire becomes a conductor for the pulse. Never ground a device used for HEMP protection unless you are talking about a chassis ground like on a vehicle or cabinet.
Solar panels are arrays of diodes. An E1 pulse is likely going to burn them out along with any electronic controls connected to them. It is nearly impossible to protect any operating electronics from the E1 pulse. You can store spares or spare parts in properly shielded storage but if you have wires running to or from it any protection is a waste of time. A room can be made E1 proof but it takes a very complex seal on the door and a self contained air supply. The room is constructed the same way your zip-loc and aluminum storage with three or more layers between you and the outside. You will have to use batteries in the room to run electronics and the only connections to the outside of that room must go through fiber optics cables which won't transmit the pulse. Any hole in your protection removes a layer of protection. All seams must be double folded and air tight. Remember that you are not trying to exclude radio frequencies you are trying to exclude air molecules that are carrying a charge.

Thanks for the excellent post. If it's the time the "layers" take to charge isnt aluminum foil too thin? Wouldnt it charge quickly, melt the thin plastic of the ziplock? I would think thicker would be better as it would take more time to charge. Just trying to think through your info.

 

[Caribou]

I have read a bunch and have conflicting theories from the countless "experts".
As for flipping your breakers off, do you think someone will give you a call before the EMP goes off?

I would not expect a notice of an EMP but a CME is another story and quite possible.

 

[Caribou]

Any wire acts as an antenna. The longer the wire, the larger the antenna and the more power collected. If you can separate yourself from the grid you eliminate most of the power collection. If you flip the breakers you eliminate some more wire. If you unplug the appliance you eliminate all the house hold wiring as an antenna. That still leaves you with the cord and some equipment allows you to unplug that at the unit.

I don't expect the charge to be equal all over the affected area. If you are unlucky enough to be at ground zero of an EMP then too bad you'll hit full force. If you are at the periphery of the effect it will be much less. If you can reduce the effect with protection you might slide by. Much like your food supply, more protection is better. Good luck.

 

[SheepDog]

The only way to test anything against the effects of an HEMP E1 pulse is to detonate a nuclear device above the atmosphere. The above tests are using a radio source to generate the pulse and it is 5 times the rise time. That means that their test requires conductors to carry the pulse. An E1 pulse is so fast that it directly affects the very small junction of a diode or transistor that has no conductors attached. The effect of the E1 pulse is not diminished by distance either because the cause is not a radio wave it is the electrons being displaced from the molecules of the atmosphere by the Gamma particles traveling away from the bomb at the speed of light. How long does it take light to travel through the atmosphere? That is how fast the pulse is generated. It turns the air into a plasma that IS the charge.

The charge has to cover the area of the surface before it builds the same charge to the next layer. It has to be thick enough to withstand the energy - that is why we use heavy duty foil - the thick stuff used to tent a turkey at thanksgiving. The insulators have to resist the voltage - they have to have a high dielectric coefficient. The higher the coefficient the better it is. there is very little heat generated by the E1 pulse because it is so fast. The effect on semiconductors is a chemical, or molecular, change that prevents them from recovering. It is no longer a semiconductor after the pulse. This is why chips and transistors and diodes sitting in the warehouse will be affected too.

The time it takes for the charge to cover one plate and move on to the next plate and the next is long enough that the pulse is already starting to diminish so the full charge never gets through. The rise time through the capacitor starts charging very fast but as the charge gets closer to the source charge the charging slows down. When it discharges it discharges very fast at first and then slows as it approaches zero. This means that after several layers the layers will discharge to the atmosphere more quickly than the inner layers are charging. At the same time there is a phase change between the voltage and amperage. With each layer the phase is separated so the voltage is driving less of the amperage. That further diminishes its effect. This is going to get very "heady" if I try to go further and I will need diagrams and math to explain it. Those who have the background in electronics will get it but I am afraid it will just confuse those who don't.

 

[bnorth12]

There is a great deal in the public about HEMP protection. Just about every piece of US Military equipment has to be qualified to the HEMP testing Standards MIL-STD-188-125-1, MIL-STD-3023,
MIL-STD-4023, and a couple of others. There is a large amount of publicly available information about the types of mitigation required for electronics to comply with the Standards. Most of the HEMP testing standards are available as well, reading through the testing standards can give you a good idea about the mitigation strategies. Depending on the size and location of the HEMP disconnecting from the grid could be all that is needed. If you are close to the source of a HEMP turning off electronics might not be a meaningful strategy as currents can easily be induced in hardware that is not turned on. The magnitude of a hemp follows the inverse square law for power density when traveling through open space, to put it in really simple terms the further you are away from the source the lower the power of the HEMP. If you are connected to an electrical grid impacted by a HEMP distance does not give protection as the inverse square law for power density does not apply.

 

[SheepDog]

bnorth,
There is a lot of "information" on the internet about HEMP. Most of it is pseudoscience and outright wrong qwhile some of it is confused with solar EMP. The military test standards are a joke. They use slow pulses that are limited in power to levels that will not destroy equipment. They also use microwave frequencies to design "wave guide filters" that can protect against radio and radiation infiltration but they, like everyone on this planet, can't generate the E1 pulse in a lab. You have to go back to the high altitude experiments to see what the affects were and what caused them. There were very few semiconductors in use back then but even the selenium rectifiers that they used in test instruments were blown out in the early tests. Modern electronics are much more susceptible to the E1 pulse than those "bullet proof" selenium rectifiers.

The "inverse square law" is true of gravity, radio signals and most electromagnetic waves. In an HEMP (High Altitude EMP) the law does not apply to the effects because the source is not the bomb. The source is local to the ground based effects. The source of the E1 pulse is the atmosphere around you, the E2 pulse is caused by the free electrons rebounding in the atmosphere and the E3 pulse is just like a CME caused by the deflection and recombining of the geomagnetic field lines. An HEMP at 250 miles above the earth does considerably more damage over a much larger area than one at 30 miles above the earth.

One very good paper was authored by Jerry Emanuelson B.S.E.E. based on the report by the Oak Ridge National Laboratory Metatech EMP Report. The original report would be a better source and more complete (if you can get access to it) but Jerry Emanuelson shows the myths and realities of all three parts of the HEMP attack and the consequences in his 20 page document.
Another good read was written by James Carafano and Richard Weitz on what congress and the citizens of the USA should be doing to mitigate the effects of an HEMP.

 

[Caribou]

SD, the bomb goes off at 250 miles altitude in the middle of the country. You're at ground zero and I'm in Portland, OR. What differences can we expect? If I have 5 minutes notice is there anything I can do to improve my chances?

 

[SheepDog]

We can expect the world around us to go quiet. Without electronics there will be no TV, radio, phones, or computers making noise. People will come out of their homes to see if it is just a power outage and it may resemble that for a short time. Some will try to start their cars but most are likely to be unable to run. Some older cars may run but the alternators won't charge the batteries and they too will soon die.

We won't get notice - not 5 minutes or even 5 seconds. A satellite some 250 miles high, that has been in orbit for years will suddenly light up the sky. If you are outside and happen to see it, know that the damage is already done. It may be minutes or up to an hour before the grid burns and fails but all the electronics are dead by the time you see the flash.

The same thing will happen, at the same time, from San Fransisco to Bangor Maine and from the Saskatchewan to Mexico City. There are a few true believers that want to believe that the garage with aluminum siding and roof will protect their cars or that facing the car away from the flash will lessen the damage but even the ground to a depth of 30 feet will be polarized with a positive voltage of 50,000 volts per meter. If those people who have old missile silos converted to shelters have all the blast doors closed and air vents shut down they might have usable electronics. Most of the military and NASA will be blind and quiet. The aircraft and ships outside the affected area will be fine except they won't have any orders coming in through the command and control systems. The rest of the world won't know anything has happened for a couple of hours and then anyone can guess what comes next. I believe most of the world will come together to help, but I am an optimist.

 

[Caribou]

SD, I'm trying to get my head around the differences between what you are teaching and what I've learned previously so I'll ask for some clarification.

I dig a hole down 31ft and my electronics are fine but you only dig down 29ft and your's are fried? Wouldn't there be a gradual degradation of the power? You notice that I always put myself in a better position than you. This is merely a self preservation technique.

If someone had a metal sided garage wouldn't they be in better shape than someone that didn't? For example, the older alternator might survive.

There is an old joke about the Russians bragging about having the largest microchips. Not all microchips are created equal. Would there be no variation of survivability of electronics due to manufacture and location?

I agree with you 99% on the notice. I live in Alaska and don't expect to be affected by the initial strike. I expect that we would bet a candidate for a missile strike shortly thereafter. Is my theory all wet? What might I do?

 

[ssonb]

Carbon not all earth is the same, it's kinda like doing a bullet test in different density ballistic gell blocks.
And AK will be affected alright, cause nuttin will be shipped from the lower 48 for many a year! So ya better stock up now with the items that are not made in Alaska.

 

[Caribou]

Carbon not all earth is the same, it's kinda like doing a bullet test in different density ballistic gell blocks.
And AK will be affected alright, cause nuttin will be shipped from the lower 48 for many a year! So ya better stock up now with the items that are not made in Alaska.

I am sorely aware of that issue. If we have an EMP or Cascadia goes AK is in deep kimchi. A couple years ago there was a Longshoreman's strike. It started in SanDiego and slowly moved north. It was settled before it reached Seattle but I think it made Portland. I was keeping an eye on it as we would have been hurting.

 

[SheepDog]

Caribou,
It would seem to me that there has to be a gradient at some level but I have never seen anything except that the Russians had electronics and cables burn at 10 meters underground in their last test. What level is safe? I know a lot but I don't have an answer to that one.I would guess that the gradient would likely be about 15 feet from start to finish so you can bury radios at 30, 35, 40, 45, 50, 55, and 60 feet and let us know which ones work after the HEMP. OOPS... We would have to have similar radios to hear you. Mine (the one stored) is an emergency band radio and AM 40 and 80 meter SW.

 

[Caribou]

Caribou,
It would seem to me that there has to be a gradient at some level but I have never seen anything except that the Russians had electronics and cables burn at 10 meters underground in their last test. What level is safe? I know a lot but I don't have an answer to that one.I would guess that the gradient would likely be about 15 feet from start to finish so you can bury radios at 30, 35, 40, 45, 50, 55, and 60 feet and let us know which ones work after the HEMP. OOPS... We would have to have similar radios to hear you. Mine (the one stored) is an emergency band radio and AM 40 and 80 meter SW.

Thanks! What is your method of storage?

 

[SheepDog]

Caribou,
Skipped the rest of your questions...
To be any help in protection the metal envelope would have to be complete and at least insulated with high electric coefficient enclosure. A garage or shed has leaks at the ground, doors, and any windows. So, not much protection from the E1. It would protect from the E2 just the same as it would protect against lightning strikes.

The E1 pulse will easily burn any chip junction but you are right, there are some very high through-put diodes, transistors, and thyristors that would probably survive. When you have a diode rated at 1000 amps with a reverse voltage protection of 10,000 it is harder to affect it in half a nanosecond. I have a few 500 amp transistors that could likely survive the E1 pulse and a couple of 250 amp SCRs (thyristers) that would likely survive without shielding too. The problem with small devices are they are made for a half volt drop and milliamps of current. Even discreet devices like the photo diodes they used to make solar panels from were only made to handle .5 amps at full solar exposure. The new panel are made using chips with many diodes on them and the silicone panels still only produce .5 amps per cell. The germanium cells only produce .3 amps per cell in full sun. It is pretty easy to burn a junction made to handle so little current and voltage. Some of the shottky diodes used in commercial broadcast radios could make it through the E1 pulse as well as the final stage transistors but the oscillator and modulation circuits would fry. A tech could probably rig a CW transmitter with what survived but darn few people would be able to read it.

I don't believe any attack would follow an HEMP attack. With all the infrastructure down it would be too costly to use the area for anything. All they have to do is wait a few years and most of the population would die off from lack of infrastructure or support. The military would still be capable of producing a decent counter attack if anyone decided to invade. If we used an HEMP it would cripple the aggressor in the same way we were. We have subs and planes that carry weapons that could be launched into space to do a pretty good job even to a country the size of the USSR or China. No nation wants to return to before the industrial revolution. Alaska would be hard pressed to get anything shipped in but the nuclear navy might help.

 

[lonewolf]

anything is possible I rule nothing out, natural or man made.