My Thoughts On: EMP information

Jerry D Young

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The formatting is all essed up in the text post, so I am attaching the .pdf of the article for easier reading.

My Thoughts On: EMP information

Now, I am not an electrical engineer, and never having been exposed to an EMP, and not having access to the still secret reports on EMP the government has, this is all just my opinion, based on years of research, using the most reliable sources I have been able to find.

This is a group of posts I have made at various times in various prepper forums. I did try to eliminate duplicate information, but I am pretty sure there is still some here.

EMP/HEMP is a controversial subject. It has been discussed many time in many venues. And there is much difference of opinion about the subjects. I have researched it for many years. Still, I strongly recommend that everyone do their own due diligence research on the subject. Do not take my advice as the last word on the matter.

During the 1950s and 1960s, during some 20 nuclear weapons tests conducted by the US and the Soviets, the effects of Electromagnetic Pulse were first observed. While much of the information is still classified, it is known that these detonations at 30 to 50 kilometers above the surface affected electrical power grids.

It must be noted that during the atomic testing in the 1950s and 1960s there was not that much recorded damage. But there were some recorded happenings.

Some 300 street lights were fused and burglar alarms that went off in Hawaii during Pacific tests. In the Soviet Union 570 kilometers of telephone wire fused and a power station burned down. This was caused by a 300-kiloton warhead detonated at 290 kilometers of altitude. The radio frequency range of these types of EMPs was in the 15 to 250 megahertz range.

The effects from a Coronal Mass Ejection or CME that hits the earth with just the right conditions will affect the electrical grid. On March 10th 1989 a massive CME erupted from the sun and it hit the Earth two days later. At 2:44 AM on March 13th the Quebec power grid went down from the loss of a transformer due to electrical currents coming from the ground. Shortwave radio went down and satellites lost command control. The blackout affected over 6 million people. But, the power was back on in 9 hours or so.

In 1859 Richard Carrington was observing the sun and detected large solar storm activity. A large CME was recorded. On September 1st and 2nd the European and North American telegraph systems were affected and failed.

I am one of those that believes that EMP/HEMP are credible threats. Also, CME induced EMP. Dealing with the possibility is part of my preps. I have not gone hog wild. I do not have a copper enclosed room. Well, not yet, anyway.

So here goes.

EMP, while a known effect of nuclear detonations, and producible by other means, is a difficult subject for preppers. Yes, it does exist, but will it be as catastrophically damaging as some say, or more a non-event, as others say? Will it, or even can it, actually be effectively used? These are tough questions for a prepper.

There are actually two major factors involved in dealing with EMP. The actual possible damage to electrical and electronic equipment and how we as preppers will deal with the aftermath of that damage.

If the damage is slight, with a loss of power for a few days, and some damage to some especially sensitive computer based electronics is one thing. Most unprotected electronics inoperable and irreparable, modern vehicles with electronic or computer chips in them going dead where they happen to be, and a total long-term collapse of the grid with the resulting collapse of modern infrastructure is another thing entirely.

For the first situation we will just shrug, and go about dealing with whatever it is that caused the EMP, whether a natural cause, or an EMP attack that failed, or some other attack with nuclear weapons that did not produce a destructive EMP.

The second situation is the kicker. The results of a successful EMP attack or event goes far beyond the loss of some electronics. Our discussions of what will happen if the grid goes down for an extended period of time addresses that problem. And it is already a scary one without the addition of the near total lack of modern transportation if the EMP does, in fact, incapacitate the vehicles. The same goes for the loss of much of our communications system, that would otherwise allow for coordination of the recovery.

Even without major destruction from other forms of attack, as would probably be the case in a HEMP attack, the loss of those two infrastructures will be debilitating to the country as a whole. For us, as preppers, we will most likely be in a position to take care of ourselves for a much longer term than the rest of the society, with those resulting problems. It could be one of the worst disasters we could face.

That is not to say that we cannot protect some of our own systems from EMP. Just like that it is a known fact that nuclear weapons, especially built electronic weapons, and very large CMEs can generate EMP, it is a known fact that electronics, and especially electrical items, can be protected from the EMP effects.

Fortunately, the CME induced EMP is significantly different from nuclear induced or electronically induced EMP in that it will not affect computers and such that are not connected to a power grid or long antenna. Only long runs of cable will be affected in that situation, such as the power grid and some above ground communications wire cabling systems.

There is no doubt that preparing for the worst effects of EMP, even on a small scale, if they turn out to be effective to any significant degree, can be rather expensive, depending on the degree of protection you might want for various electronic items. Protecting some radio gear does not have to be expensive and will allow preppers to maintain communications with each other. Owning an older model vehicle without major electronics, or converting one to that state, will most likely eliminate local transportation problems for preppers.

Having those capabilities can increase the problems of other people becoming upset with us for having them, when they do not. But that is another subject.

How does one go about protecting against EMP, other than having an old vehicle? A Faraday cage was developed by Michael Faraday in 1836 as an experiment to the properties of conduction of AC energy. It turns out that this Faraday Cage is an effective means to protect some electronics from EMP. And there do exist some electronic components that can be used to protect in use equipment to a fair degree.

There are several ways to protect potentially sensitive electronics. Here is my list:

1) Faraday cages. (some as described above)

2) In a well-designed underground bunker or home.

3) In a well-designed earth sheltered above ground structure.

4) In deep caves/underground mines.

5) In underground caches fairly deep.

6) In an all metal, reinforced floor, no/very small metal screened openings, with every component correctly electrically bonded together, room.

7) Wrapped in two or more sets of grill foil & bubble wrap and placed in a protective box or cabinet. (Fairly small items)

8) An all metal container with continuous metal to metal bond along every seam, without any gaps or holes larger than the equivalent of 20opi mesh, will act as a Faraday cage. If it is totally isolated from any sort of ground, including being close to anything that is grounded, does not need to be grounded itself.

For communications gear, that can be put away for long term storage, it is actually fairly inexpensive and easy. Box the item in cardboard, wrap the box in bubble wrap, wrap a layer of heavy duty aluminum foil around the whole thing, and then repeat the bubble wrap and foil wrap layers twice more, and finish off with a final layer of bubble wrap and put the big ball into another cardboard box and place in a metal cabinet of some sort.

Generators, for instance, can be put on insulators inside a large steel box and a lid with a metal mesh gasket can be bolted on, and the box put on pallets to insulate it from the ground.

Every container, to be an effective Faraday Cage, must be protected all the way around, and on the top and on the bottom. You can put solid sheet copper all the way around a building, and over the roof, solidly connected at all the joints. But if there is no protection under the floor, solidly connected to the copper walls, it is not a complete Faraday Cage.

The same goes for doing a Faraday cage with penetrations for air, water, sewer, electrical, communications, etc. Anything. It can all be done, but there are very specific techniques to do so.

If a Faraday container has any type of ground connection, such as sitting on a concrete garage floor, or on a basement floor, it should be grounded. But that is a highly specialized process, and I would suggest than any moderate size Faraday cage or box or trash can be placed on a good insulating mat of some type. If there is no type of connection with the ground, and there is a good airspace or insulation between the cage and any grounded surface, no grounding is needed.

The problem is that if there is any grounding, then appropriate grounding is paramount.

Any Faraday cage that is close to a grounded item, or in any way is even partially grounded due to siting, must be well grounded. Far more than a simple 8' grounding rod and #6 wire to the thing. Grounding for EMP enclosures is not all that difficult, or even expensive, but it must be done just so.

For simply storing electronics and electrical gear, either do it individually, or collectively, with a sealed container that will be opened only after risk of EMP is past. Or to take out something and then reseal to the same standards as originally.

Plastic EMP bags have been mentioned for protection of some electronics from EMP. I do not quite trust them myself. They look like electronic component static discharge protection bags. If that is the case, then I am not sure if they would be enough protection.

For some small items like my backup prepper cell phone/laptop computer, that need to be kept handy but protected, I use these products:!products/c1i41

There is even some limited use of the items in specific circumstances while in the cages. And though it does not say to, I put the items in bubble wrap, just to keep the metallic parts of the items isolated from the metal mesh.

Going much beyond these relatively simple solutions becomes more and more expensive and difficult, though doable. But do you want to spend the money and make the effort? That is a huge investment in both to protect against something that may or may not happen at all, and even if it does happen, may not be nearly as destructive as some people believe. It will be up to each of you to decide for yourself just how much you want to prepare for the actual EMP effects on your electrical and electronic gear. The preps for the affect a major and effective EMP attack will have on society are pretty much a given. They are the same preps we are all making now, for all the other disasters.

This is a complex subject, with no easy answers. For more information there are a few respected, and generally considered reliable, sources of information.

One of these is the US government, in its various publications on the subject that are not restricted, such as TR-61, TR-61A, and TR-61B that are available, sometimes, on-line. I have copies of the publications, and will loan them out to anyone that wishes to peruse them, upon the guarantee of their return in good condition by the borrower.

A couple of newer publications are the 2008 EMP Commission Report: and the 2010 National Academy of Engineering Report on Nuclear Dangers:

Another, much easier to use source of information, one that I have obtained information from, is Jerry Emanuelson at

Another source, that I often refer to, is the book EMP – Protect Family, Homes, & Community, by Donald R. J. White. I also have this book and will loan it out under the same conditions as the government publications.

Some additional notes on EMP:

Almost all nuclear weapons produce an EMP spectrum. Some much more than others, of course. However, a nuclear HEMP device does not have to be 'big' or expensive. The most effective EMP devices are relatively simple fission devices (or 'atom' bombs), with some enhancements, not the complex thermo-nuclear fission-fusion-fission devices (or 'hydrogen' bombs) used in today’s warheads.

A few kilo tons of power to a few hundred kilotons of power is all that is necessary for these EMP enhanced devices to generate the massive electro-magnetic pulse that can destroy much (but not all) of our electrical system and electronics devices. Compared to blast weapons, EMP weapons are pretty cheap.

These lower yield, specially constructed devices are, by far, the highest producing types, when considering total investment, material usage, delivery possibilities, shielding, transport, and a few other things.

Though megaton plus devices produce more EMP in total, the other destruction they cause tend to outweigh the EMP, because they are too expensive and difficult to deploy in the manner in which maximizes the EMP effects. Which is a high altitude burst at the edge of the atmosphere to take advantage of the enhancement effects of the magnetosphere and chemical composition of the upper atmosphere.

So, small devices, high in the atmosphere, that have no effect on the ground under them except the EMP, can take out electronics and the electrical infrastructure over a huge area, with no direct physical damage.

Railroad tracks can carry enough of the EMP to affect things otherwise out of range of the direct effects, depending on the direction of the tracks to the direction the pulse is spreading, and how long the tracks are.

EMP does penetrate into the ground, depending on its strength. Deep enough to interact with underground metal pipes and metallic cables. And like RR tracks, the current can be dangerous some distance away from the point where the EMP has charged them. But we are talking only two or three feet, unless right under or very near the EMP source.

Every container, to be an effective Faraday Cage, must be protected all the way around, and on the top and on the bottom. You can put solid sheet copper all the way around a building, and over the roof, solidly connected at all the joints. But if there is no protection under the floor, solidly connected to the copper walls, it is not a complete Faraday Cage.

If you use an ammo can, remove the rubber gasket, polish the groove and the can edge. Install a flexible copper mesh gasket or stainless-steel mesh gasket in place of the rubber one. That will make the coverage complete. Without it, there is a 1/4" or so gap between the lid and the bottom, even though they are grounded together by the hinge. There has to be continuous coverage and connection to all the parts of the ammo can.

It is best to line the can with thin plywood or non-conductive hard foam to keep anything inside from touching the metal. I would still do the bubble wrap/foil for each individual item, however.

Much the same applies to metal garbage cans used as Faraday Cages. Though the lid will fight tightly, and will have electrical continuity with the can, that does not mean that there are not gaps in the electrical seal of the lid to the can. It is best here to use a metallic mesh gasket to ensure there are no gaps that could act as slot antennas at some frequencies.

One way to make a gasket is to get some automotive door gasket strips, long enough to be a friction fit inside the garbage can lid, and wrap it with several layers of heavy duty aluminum foil. This will make a suitable gasket that will last for several open/close cycles, and can be refreshed as needed with new aluminum foil.

There are a few things that come up regularly. Here are my responses to them:

1) Just use a microwave oven with the cord cut off as a Faraday Cage – No. Is not a good Faraday Cage, even if the cord is left on, the power blades pulled and the ground blade plugged in.

2) Use a cell phone to test your Faraday Cage – Better than no test. If it rings, you do not have a Faraday Cage. But even if it does not ring, that is no guarantee that the Faraday cage is effective.

3) Faraday Cage has to be solid metal/A Faraday Cage has to be copper sheet metal – No, it does not. Not either one. Copper is best, and is easy to work with to get good electrically solid joints. But 20 OPI (openings per inch) copper or aluminum screen, if bonded properly, will work just fine.

4) Removing batteries from sensitive electronics, or unplugging them will prevent EMP damage – No, it will not. The EMP induces current in devices with sensitive electronics. Being connected to a power line does make it worse, and disconnecting is good, but it will not stop the pulse if the device is sensitive and otherwise exposed.

5) Photovoltaic solar panels are susceptible to EMP/Photovoltaic solar panels are not susceptible to EMP – I simply do not know. I do know the associated wiring is susceptible to EMP

6) Solar PV panels cannot be protected from EMP, if they are susceptible – Yes, they can. Using 20 OPI copper mesh, two layers, a base can be put down, the panels and electronics installed, and then two layers of the 20 OPI copper mesh can be placed over the panels, shifted slightly off center of each other, and draped down to connect all the way around with the copper mesh on the ground. The power line leading from the unit must either be disconnected, or run in metallic conduit to an EMP protected power distribution box inside. If that distribution box has appropriate EMP protection, then things will be safe.

7) There is no way to protect an entire house from EMP – Yes, there is. It is not particularly difficult or even expensive. But it must be done during construction, and like all Faraday cages, every Faraday component must be bonded to the adjacent ones, with no gaps. EMP – Protect Family, Homes, & Community explains the process, as it does the PV panel protection process.

8) You can line a garage with chain link fencing and ground it and protect everything inside the garage – Chain link fence is not an adequate Faraday cage. A Faraday cage does not have to be solid material, but mesh must be 20opi or small openings.

9) There is no point of using a Faraday cage, since you just as easily put your electronics inside your home and just unplug it. Only stuff connected to long lines will be affected – I do not believe this is true. It does depend on the source of the pulse, and the actual item(s) in question. An event with an E1 component in the pulse will affect disconnected electronics such as TVs and computers. The EMP from a coronal mass ejection (CME) does not create much of an E1 component, therefore disconnecting items from long runs of wire or other conductive elements will protect them.

On a discussion about EMP/HEMP on one of the prepper forums:

I usually stay out of the EMP/HEMP discussions because of so much incorrect and misunderstood information about it.

From my research, since I have no practical experience with EMP:

1) All it takes for a major EMP is a simple fission device, of low power (10kt - 20kt) with an appropriate casing to enhance the EMP effects, especially E1, detonated outside the atmosphere. This actually gives more EMP bang for the buck than Fission/Fusion/Fission hydrogen devices.

2) Some things won't be damaged, due to sheer circumstance.

3) Many things can be shielded, even sensitive ones.

4) A Faraday Cage does not have to be solid metal.

5) A Faraday Cage does not have to be copper.

6) It is much simpler to protect stored equipment than equipment in use. Triple insulate individual items with aluminum foil and bubble wrap, with no gaps in the foil, place in a stout container, and put it on a shelf away from anything that could conduct EMP close to it.

7) Grounding is a double-edged sword. Do it right and maintain it properly and it helps. Do it incorrectly or let it degrade, and it makes things worse.

8) Solar panels and their associated gear can be protected from EMP, but it is spendy. Two layers of 20 openings per inch copper mesh surrounding the entire Solar Power system will do it. Above the panels, down the sides of the structure and under the floor. All 6 sides. At about $5.34 per square foot of mesh. If you keep the room or building small, it can be done. But all six sides must be shielded adequately, and all input and output lines must also be shielded appropriately.

9) There are cheaper ways to protect large spaces, but they are a matter of scale and don't make much sense unless one is building a new place, or specifically retrofitting a single room or small building.

10) If these whole house or single room methods are done, they must include shielding for input and output lines of all types, including air handling, water, sewer, electrical, phone, telemetry, etc. And everything must have a continuous bond, including the floor or under the floor. Windows can be shielded the same way as the solar panels. Two layers of 20 openings per inch copper mesh, bonded all the way around the window frame to the shielding of the building.

11) Some solar events can produce E1 currents in earth's atmosphere, but they are the one in a hundred-million-year type events. Some solar events do produce E3 currents on the surface of the earth and can do great damage to the grid.

As I mentioned before, EMP is a controversial subject. So, people will know they need to seek other opinions, and do their own research, I will first list the controversial elements of the subjects, the subjects being EMP/HEMP and EMP/HEMP protection. And then I will post some of the Tips, Tricks, Hints, and Kinks that I know to deal with them.

The controversial elements:

1) Does EMP even exist?

2) Can a CME cause EMP/a CME is the same thing as an EMP/CMEs do not cause EMP

3) Does EMP even pose a danger to us, at the levels it exists?

4) If it is a danger, just how great is the danger?

5) Even if EMP is a danger, a HEMP device is not really possible, and if it is will not be a big one.

6) If it is a big danger, is there even anything we can even do about it?

7) If it causes widespread damage and takes down the grid for a long period of time is there even a need to protect radios and other communications gear since on one else will have any, anyway?

8) If we can protect things, just what can we protect and how much will it cost/not much is needed to protect things and it is cheap.

9) Just put things in an old microwave oven with the cord cut off/A microwave radio will not work as A Faraday Cage

10) If we have to use a Faraday Room, it has to be solid copper/other metals will not work/mesh will not work.?

11) A Faraday has to be grounded to be effective/A Faraday cage should never be grounded.

12) Solar PV cells are not affected by EMP/Solar PV cells will be destroyed in an EMP, PV panels cannot be protected against EMP.

13) You cannot protect a whole house/a generator/your vehicle from EMP.

Okay. There you have some of the questions and statements that cause the controversies. I am not going to get into my opinions of and explanations about them here. (Now, isn’t that a surprise!) I am just going to give a couple of tips, tricks, hints, and kinks for those that do think the EMP problem exists, that one can be a problem, and that there are ways to protect gear that they think will be useful after an event.

This applies to radios and associated communications gear, and computers, cell phones, and other fairly small consumer electronics.

To protect smaller items from an EMP/HEMP event:

1) Put the item in a sturdy cardboard box of appropriate size and tape it closed.

2) Wrap the box in bubble wrap (thinner stuff with small bubbles is ideal) and tape it closed.

3) Wrap that package with heavy duty aluminum foil (Reynolds Grill Foil is best), making sure to not puncture the foil anywhere, and be very careful to make solid, tightly folded seams.

4) Add another layer of bubble wrap.

5) Add another layer of foil.

6) Add another layer of bubble wrap to protect the top layer of foil.

7) Place the package into an appropriate sized cardboard box and tape it closed.

8) Place the box in a metal file cabinet, metal storage cabinet, purpose built metal container, or some other container to protect it physically.

That item is now protected from EMP unless the device is right on top of you.

Some have recommended using a GI ammunition can to protect small items. If you want to do that, here is what I suggest:

1) Clean up the can inside and out and paint it if there are any bare metal areas.

2) Remove the rubber gasket from the lid.

3) Line the inside of the can with cardboard, all four sides, the bottom, and the lid.

4) Sand paper or emery cloth the gasket groove to bare metal.

5) Sand paper or emery cloth the rim of the ammunition can to bare metal.

6) Buy (or make) a metallic or other conductive gasket the right size to fit the gasket groove of the lid.

7) Place the items to be protected inside the can. (For extra protection, you can do the bubble wrap/foil technique on the items before putting them inside, but with only a single layer of foil.)

8) Close and latch the lid. There should be at least some resistance to the latch if the gasket is adequate.

Some useful links and suggested reading (some are already listed in the body of the article):

The Mobile Solutions metal mesh, magnetic strip closed, Faraday bags I prefer:!products/c1i41


Copper wire mesh:

A couple of other potentially useful sites:

This double-sided foil vapor barrier could be used to create a full-room Faraday cage, or even used, if installed properly to create a 6-sided bonded edge box during the home construction, with appropriate window, door, vent, and other penetration treatments, to have a full EMP resistant home.

US Government publications:

TR-61, TR-61A, and TR-61B

I have not found them on-line. I do have copies of the publications, and will loan them out to anyone that wishes to peruse them, upon the guarantee of their return in good condition by the borrower.

A couple of newer publications are the 2008 EMP Commission Report: and the 2010 National Academy of Engineering Report on Nuclear Dangers:

Another, much easier to use source of information, one that I have obtained information from, is Jerry Emanuelson at

Another source, that I often refer to, is the book EMP – Protect Family, Homes, & Community, by Donald R. J. White. I also have this book and will loan it out under the same conditions as the government publications.

20 OPI copper mesh specifications from TWP Inc. website.

(Not related to member twp.)





Mesh Size

20 per in

20 per 2.54 cm

Wire Diameter

0.016 in

0.4064 mm


0.034 in

0.8636 mm

Opening Microns



Opening %



Weight / sq. ft

0.3900 lb

0.1771 kg

Just my opinions.


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