EMP - the science behind it - and basic countermeasures

My plans for this thread are to, first, post some information about the science of EMP's caused by nuclear weapons.  This information will be somewhat detailed, since it indirectly influences our preparedness, and is necessary to knocking down some myths (even those coming out of government offices). I plan, at most, two postings of detailed science of this kind.

Second I plan to post some info on the expected impact of EMP's on various technologies and infrastructure. There may be several posts of this kind, especially later on, and I expect others to add to this information.

Third, I plan to post some info on countermeasures to deal with those impacts. Again, there will be a few postings from me, on this topic, and I expect others to add to this information.

(All of this contingent on the Admin agreeing to the above, of course.)

Of course! The more info the better! That's why we're all here!

TRex, I remember reading your EMP posts on the other forum on EMP's, very informative, can't wait.

I stated, in another thread, I would begin writing on the subject of EMP. I am opening a thread to rebut some persistent myths surrounding EMP, that may affect how we prepare to survive such an event.  

Recently, Bill Gertz wrote an article on the subject, and while it is good enough for the masses, we need to get somewhat more precise in order to deploy countermeasures and to make plans to deal with the aftermath.  His article referenced recently released reports from "the now-defunct Commission to Assess the Threat to the United States from EMP Attack."

Link to article by Bill Gertz
https://freebeacon.com/national-security/china-russia-building-super-emp-bombs-for-blackout-warfare/

As there are ten of these reports, and and some of them have been updated since I first reviewed them, I will rebut Gertz's article, rather than attempt to rebut the reports behind it. I suspect he is more widely read than they are, anyway.

Most of my info will be derived from my studies while I was in Air Force communications, and from Conrad L Longmire's papers. Longmire basically wrote the book on EMP, but most of his writings were classified until recently, and much of it is difficult to weed through unless you have a background in Electrical Engineering and Physics. While I can decipher almost all of it, it sometimes takes me hours to decipher and comprehend his ideas. (So this series of postings will take a while.)

As I do not currently wish to delve into the political side of the discussion surrounding this issue, I will begin my analysis of the article beginning with:

three types of EMP waves in seconds damage electronics and the strikes are regarded by adversaries as not an act of nuclear war.

"Potential adversaries understand that millions could die from the long-term collateral effects of EMP and cyber-attacks that cause protracted black-out of national electric grids and other life-sustaining critical infrastructures," the report said.  

I concur.

The attacks are regarded by enemy military planners as a relatively easy, potentially unattributable means of inflicting mass destruction and forcing opponents to capitulate.

Mostly true. Each nuclear detonation will have a signature that can be used to determine what the disign was, and therefore who designed it, but that doesn't tell with certainty who detonated it. OTOH, combining that with observations of the lauch vehicle may provide enough information for us to retaliate. Of course, this is irrelevant to those who are only interested in surviving the outcome.

EMP strikes can be adjusted in the size of the area and the intensity of the wave by detonating at different altitudes. The closer to the earth the more powerful is the pulse. The higher the altitude, the wider the area of impact.  

Partially true. Closer to earth makes a difference, particularly in the area near but not directly below the detonation, until you get below 30km (20 miles), lower than that doesn't do much to increase the strength, but still reduces the area affected. More on that later. Higher widens the area of impact, until you get to the edge of the Van Allen Radiation Belts.

"A single nuclear weapon can potentially make an EMP attack against a target the size of North America," the report said. "Any nuclear weapon detonated at an altitude of 30 kilometers [18.6 miles] or higher will generate a potentially catastrophic EMP."

While correct, this is misleading. It requires a fairly substantial nuclear weapon, to create a substantial EMP, and to create an EMP across all of N. America, a large nuclear weapon would have to be detonated considerably more than 30km.

Super-EMP bombs produce gamma rays that generate a peak EMP field of 200,000 volts per meter—enough to fry strategic communications and intelligence systems. China, Russia, and probably North Korea are said to have these arms, according to the commission. The United States has no super-EMP weapons in its nuclear arsenal.

This is THE most misunderstood item, and the statement is NOT accurate. While it is true that enhancements can be made to increase the gamma radiation, and thus the effectiveness in generating and EMP, the amount of increase is over-hyped,

Also, no matter what the gamma burst is, it can't generate 200,000 volts. The upper bound on EMP intensity isn't the strength of the nuclear weapon, but the properties of the atmosphere.

Somewhere above 30,000 volts, the dielectric strength of the atmosphere breaks down. I suspect the result would be a spectacular light show, but no further increase in the E1 component. (I haven't determined if the E2 component might break into multiple waves under these conditions, however.)
https://en.wikipedia.org/wiki/Electrical_breakdown#Gases

More later.

As I have read through the half dozen new releases from the Commission, I am impressed with how much they have learned over the past ten years.  Almost ten years ago, I read through similar reports and was a bit miffed at how little they understood the threat.

I am not the only one:
From The Hill - aprox May 2018  
https://thehill.com/opinion/national-security/387148-trumps-actions-have-been-critical-to-defending-the-us-against-an

The EMP Commission found the classified report on EMP issued in 2014 by the Joint Atomic Energy Intelligence Committee (JAEIC) is analytically unsound, and recommends recall of the erroneous Obama-era JAEIC report.

The EMP Commission likewise found assessments by the electric power industry, including the North American Electric Reliability Corporation (NERC) and Electric Power Research Institute (EPRI), erroneous and grossly underestimate the EMP threat.

The commission also recommended electric grid equipment that requires a long time to replace — such as large power transformers — be tested against system failure, and that they be hardened to a standard over 10 times higher than recommended by NERC and EPRI.

So, who are people to believe anymore?

Sounds like the left hand doesn't know what the right hand is doing.

Keep us informed TRex.

rick1 wrote:So, who are people to believe anymore?
Sounds like the left hand doesn't know what the right hand is doing.
Keep us informed TRex.

I found what I believe is the source of the myth, in a briefing to the Senate. They guy briefing them is a very learned man in many fields, but I think he was out of his element with this, and was "gee whiz'ing" himself and others.

I found a cache of some of Longmire's notes here:
http://ece-research.unm.edu/summa/notes/Theoretical.html
Number 368 is the one that details conductive breakdown of the atmosphere in an EMP event, and even he admits that it is hard to follow.

Conductive breakdown (or saturation) in the atmosphere happens somewhere beyond 30,000 volts, and I have heard numbers as high as 50,000, but I am still looking for a definitive answer. The calculus in Longmire's paper is beyond my abilities, and I think it is only representative of the idea, not the final equation.

My point is: don't let those who are scaring themselves silly scare you too.
If we stick to the basics, we can be prepared in case of the event.

Continuing in my discussion/rebuttal to the article written by Bill Gertz

I must point out that I do not mean to be criticizing Bill Gertz. To be clear, I am pointing out that the reports he gathered information from are less than precise, and may lead to erroneous conclusions. This will become more apparent in this posting.

The bombs do not require accuracy and the weapons do not require a re-entry vehicle, heat shield, and shock absorbers required for nuclear warheads detonated in the atmosphere above targets.

This is true, and is the primary reason most of us are concerned that a rogue state like N.K. or Iran, or even Al Q'ada, might launch such an attack.

The weapons can be delivered through a variety of means including satellites, long- or medium-range missile; short-range missiles launched from a freighter; from some cruise missiles and anti-ship missiles; from jets or a commercial jetliner; or a meteorological balloon.

Massively over-hyped, are the ideas that you could use a jetliner or even a meteorological balloon. A balloon would have to be rather huge. The largest I can find on the open market will lift about half a percent of the required weight. Maybe if you had one the size of the Goodyear Blimp. Using a jet would work, but the effected area would be very limited. (about 100 mile radius)

Further research into the maximum generated voltages was all but fruitless. I found a paper showing mathematically that there is a maximum, but the paper didn't attempt to actually show what that maximum is.

My next point isn't about any particular quote from the article, but would like to point out that the drawings of EMP damage radius are so simplistic as to be deceptive. Now, it may be, that when presenting this material to Legislators and Bureaucrats, in mass, the reports had to keep it simple, but for us, we need to be aware of some important points.

First point is that the EMP damage will not be uniform across an area, nor will that area be circular. The damage will be far greater near, but just South of, the detonation point, and decrease, almost linearly to the East, South, and West of that maximal damage area. To the North there will be a rapid drop at first, to almost none, and then another band of area where damage will occur. In addition, which direction wires run will affect how much of the EMP they absorb and how much damage will occur to anything touching them. To the average observer, this will be almost completely random.

The reason behind the above, is that EMP is affected by the magnetic fields surrounding the Earth, as electrons impacted by gamma radiation from the bomb tend to follow certain paths, as do the electrical fields generated in the process.

The above is important because we need to be aware that not all electronics in an area will be affected, and that the area of maximal damage is expected to be relatively small. In addition, the scenario described in the "worst case" is badly flawed.

Rather than hitting a lot of precise targets, it would be more to their advantage to hit about three places, and hit them at least twice each. Those three places would be the North of the center of Eastern U.S., North of the center of Western US and the North edge of Texas. Of course, they would probably also hit any carrier group that was out to sea.

That would still not prevent us from retaliating, as our Peace Keeper Missiles and any submarines that are out to sea are pretty much immune, as long as they are below the surface. (If they catch one as it is launched, they would kill it.) Our remaining nuclear forces would still lay waste to them. This is why the Russians and Chinese will not be likely to directly initiate such a war.

The article also completely lacks information about the E3 component of EMP. This is a result of the massive magnetic "heave" that takes place in the Earths magnetic fields, as a result of the massive energy release.

The E1 and E2 components of the EMP are instantaneous (practically) and they are the primary cause of damage to all sorts of electronics, especially radios, TV's, computers and cars. To be damaged by these waves, no connection to "the grid" is necessary, although being connected (plugged in) will enhance the chances of damage (remember not everything will be destroyed, except in a small area just South of the detonation).

The first effect of this E3 component is massive electrical surges on long wire systems such as power lines, telephone cables, and some antennas. (Fiber optics are immune, but the electronics that make them work are not.) This wave will impact a second (or sometimes a few seconds) after the first two.

This third component may cause damage beyond just the power lines, as the heat generated could cause transformers to burst into flames, which, if they are near other flammable materials (such as houses or trees) the fires could spread. A solar flare can cause similar problems, especially in Northern states.

Bottom line is that the reports are a "sales job," selling Congress and the Senate on the need to do something to protect the US from attacks of this type. Not a bad job, overall, but in an attempt to "make the sale" some parts of it are oversold, and some parts neglected.

I will begin, now, to discuss
the effects of EMP on things around us.
I plan at least two or three posts after this, on "effects."

There are multiple direct and indirect impacts of EMP. This posting will address the impacts of the E1 and E2 components. These are the components and effects that most people talk about most of the time. (E3 is also important, but I will discuss it separately)

They create surges inside and outside electronic equipment, requiring fairly short wires and conductive surfaces to do their damage. The wavelengths are from around 1.5 meters to around 100 meters, or put in a different way, they represent 200 MHz down to around 3 MHz. These numbers will become important when we begin building shields to protect our stuff.

The two most important aspects of this EMP are that it is Magnetic which means that we can discuss it almost as if it were created by a magnet, and that it weakens with distance from the center of the impact. This weakening is linear, so that twice as far away, it is half as strong. A third important aspect of it is the high frequency cut off around 200 MHz, or 1.5 meter wavelength.

(It does not weaken to the square of the distance, since we are dealing with a somewhat circular wave front, where the Gamma Rays are intersecting the atmosphere, not a spherical wave as you might think. The intersection is where the spherical radiation burst crosses the curved plane of our atmosphere, and that intersection is a circle, for all practical purposes.)

The difference between the E1 and E2 is somewhat academic, as they both arrive within less than one second of each other. The first is usually more intense, and at a higher frequency. They damage equipment by inducing high voltages and currents on conductors (wires, pipes and metal frames) which are then conducted to electronic components and circuits. At the least, these voltages and currents will interfere with the function of the circuit, or may alter data held in memory. At stronger levels they can burn the circuit and destroy it.  

Any conductive element that cuts across the path taken by the magnetic wave front will have a current induced into it, proportional the the length that the wave front "sees." A conductor lying perpendicular to the direction the front is traveling will get the maximum induced into it. A conductor pointed directly towards the source of the wave front will have very little induced current.

The real world consequence of that last paragraph is that there will be some things, seemingly at random, that will survive the EMP.

We will explore these phenomena more, when we begin shielding our equipment.

.

I'm not trying to jump to the end so to speak because I intend to read all of your threads on this, but do you think a small engine would run after a EMP attack ?? I have a 18hp briggs and stratton riding mower if the vehicles are dead I thought I could hook a trailer on it and go get my parents if need be..

Just a thought

Unless you are in that area of maximal impact, if it doesn't have electronic fuel metering of some sort it will be likely to survive. Electronic ignition is a little less likely to fail, but could, but the starter and alternator should survive.

At least that is my evaluation. I haven't run tests of my own, but have looked at a lot of tests others have run.

Edited to add: I realize there are a lot of uncertainties, and maybes in my evaluation. True, as there is nothing certain when defending against such a weapon. The best you can do is put the odds in your favor.

Here are some of the results of the last meeting with the National Infrastructure Advisory Council (NIAC) about the power grid:

https://abc6onyourside.com/news/nation-world/catastrophic-power-outages-pose-profound-risk-to-us-advisory-council-says

rick1 wrote:Here are some of the results of the last meeting with the National Infrastructure Advisory Council (NIAC) about the power grid:

https://abc6onyourside.com/news/nation-world/catastrophic-power-outages-pose-profound-risk-to-us-advisory-council-says

Thanks. I'll be reading it, with interest,
to see how much they have learned

I'm definitely interested in this thread. Great topic

Drinkthekoolaid wrote:I'm definitely interested in this thread. Great topic

If you like this thread, check this out, you can subscribe to it:

http://spaceweather.com/

Hey DK (DrinktheKoolaid) glad you found your way over here. I have invited a couple others, but you are the only one to show up, so far.

I am still in the process of reviewing the NIAC Surviving a Catastrophic Power Outage: How to Strengthen the Capabilities of the Nation document, and to steal a line from Men in Black, it is everything I have come to expect from years of government training.

E1&E2 Effects

I mentioned, in a previous posting, that the diagrams of the affected areas under a nuclear burst were over simplified. They show a simple circle of effects, but the real area is more like a series of expanding horseshoes.

The following link should take you to a picture on Wikipedia showing EMP affected area for 400 km altitude burst
https://en.wikipedia.org/wiki/Nuclear_electromagnetic_pulse#/media/File:EMP_mechanism.png


Looking at the diagram, you can see the area of maximum damage (red) is rather small and that it is completely surrounded by areas of less of the damaging magnetic pulse, Without going into too much detail, we can divide the areas under the nuclear burst into three zones. Zone 1 (the red area) is the smallest, Zone 2 (dark blue) next and Zone 3 (everything else) is a somewhat fragmented (some of it almost directly under the burst) but very widespread area.

I will be making some assumptions, first that the nuclear burst is from a moderately large nuke, around 500 to 5000 kilotons (kt) and second, that the burst occurs at a moderately high altitude of 30 to 200 miles. From these, I can give a moderately accurate forecast of what kind of damage should be expected. Nothing here will be precise, but simply an illustrated guideline, which will hopefully help define what kind of defenses (countermeasures) will be needed.

While I will be going into more detail than the government articles, I will still be remaining in a slightly oversimplified mode, for two reasons. First is that I don't want to get so technical that I lose a lot of people, and I don't want to get bogged down in too many details.

In Zone 1, the direct effect of the EMP will probably destroy or damage any unprotected electronics. In addition, because the wave is so strong in this area, a secondary effect caused by surface imperfections will induce magnetic waves inside metal containers (Faraday cages) used to shield many systems. Unhappily, every house in this Zone will experience a shock similar to being struck by lightning. That doesn't mean that all of them will burn down, but a few of them will, and many things that are not "electronic" (like motors, and generators, if connected to house wiring) will be damaged also.

In Zone 2, the direct effect of the EMP will destroy or damage most unprotected electronics, but not all. There will be, seemingly random (to the casual observer) electronic devices, including a lot of cars and trucks, that will survive.

In Zone 3, the surges become more like common lightning strikes, most electronics that are connected to wiring (anything from a power cord, to an antenna, to headphones) will be damaged, but most electronics, including cars and cell phones, that do not have wires protruding from them (even if they have a internal antenna) will survive. In this zone, it will require a few feet of wire to build voltages and currents sufficient to damage electronics. This is because, simply put, static electricity present in most homes and businesses would otherwise be sufficient to damage them. (And with cars, the electronics are partially shielded, so that nearby lightning strikes don't damage them.)

Thankx TRex, you explained that last post at my level of understanding. Now I found this article on the countries that have the capabilities of delivering an EMP and from what I read between the lines, it sounds like the U.S. is expecting one:


https://freebeacon.com/national-security/china-russia-north-korea-and-iran-set-for-electronic-pulse-attacks-on-u-s/

Argh! I want to read this thread ...  but my brain cells are dead!

Thanks for the feed back. Without that, I don't know if I am reaching anyone, or if I am completely missing the mark with my readers.

National Infrastructure Advisory Council published a study,
NIAC Surviving a Catastrophic Power Outage:
How to Strengthen the Capabilities of the Nation
https://www.dhs.gov/sites/default/files/publications/NIAC%20Catastrophic%20Power%20Outage%20Study_FINAL.pdf

My assessment:

These papers were the result of several Presidential Directives (mainly PDD-21) and laws, passed over a 25 year period, from 1988 to 2013. We are now 6 years beyond those dates and the NIAC still does not even have a handle on how big the problem is, let alone any concrete plans to deal with it. (They at least have a good grasp on the interdependencies of the various infrastructure components in Appendix E) What this paper is, is a beginning on how to assess the scope of the problem and a catalog of the various plans, programs, and agencies that are presently in place.

This paper defines the problem as being a power outage 'too big to deal with' or 'bigger than we have ever dealt with' (paraphrased from the box in page 3). They don't actually try to contend with any particular size of disaster, and don't even begin to touch on how they would respond to an outage destroying all of the nations high power transformers, let alone one that would also destroy most of our electronics, at the same time. It seems to be beyond their grasp, that it could really happen.

About as close as they get to addressing repairs to the grid is saying we need a plan to restart all of the generating systems. They don't address how to distribute that electricity or who should be the priority customers. Their apparent answer is that those details should be handled at the local levels, but they admit the local authorities don't participate in disaster planning.

To their credit, they do have several recommendations (overview on page 4, and several pages of detail afterwards), but these are things that need addressing yesterday as we are way behind the curve.
Here is an example:
Page 18 - Recommendation 5
Conduct a series of regional catastrophic power outage exercises that identify the second- and third-order cascading failures of an outage over time, as backup resources and mutual aid agreements are exhausted, and examine cross-sector supply chain and cyber risks that could delay re-energizing the grid.

Most of the serious preppers, on various forums have already done that.

Recommendations 6 and 7 in the paper are absolutely critical to dealing with the threat, and at this time, seem to be just dreams that may happen some day. Number 6 fails to comprehend the haphazard and chaotic system of petroleum and gas pipelines that feed our need for gas. In addition it seems to overlook that many of our petroleum and gas pipelines are old and feeble, and therefore, when subjected to EMP or geomagnetic storms (Carrington Event) they may subsequently blow up (due to electric currents induced by the E2 and E3 components.

Number 7 was supposed to be done after 9-11 (but there was no personal profit in it for executives, politicians, or the Deep State). Much of the impetuous for the post 9-11 communications upgrade was subverted and undermined to create profitable "improvements" for the cell phone industry. We traded our national security so that people could play Fortnight and Mortal Kombat.

To be fair to the people who were given this project, the previous administration had no real desire to address the problem. (This can be seen on page 52, as well as bottom of pg 57 and top of pg 58) And the one before it was out of its league, and didn't know it, because the studies previous to 2009 were handicapped by a flawed prejudgment that the project was of little importance (N.K. and such were not in the forefront of our planning at that time), and they thought the systems currently in place could deal with the problem. So, the real effort to deal with this issue has only been ongoing for about 2 years.

Various National Infrastructures and their interconnectedness (or interdependencies) are covered in Appendix E. This Appendix (for anyone in a leadership position in the prepper and patriot communities) is worth reading in detail. It not only covers interdependencies, but details exorcizes they have run to assess "weaknesses." While preppers don't need intimate knowledge of the various infrastructures and their interdependencies, these should provide a detailed foundation for understanding what we would be up against.

There are many things the government agencies learned during these exercises. They have great intentions, but in all likelihood it will be decades, if ever, when they can put what they have learned into realistic fixes for the real problems caused by Electronic Armageddon. Right now they are concentrating on regional outages caused by natural phenomenon, such as earthquake, volcano, or (moderately large) solar flare, or by small terrorist bands or hackers.

The US is failing, on a consistent basis, to completely fund the maintenance, renewal, hardening and expansion of our various infrastructures, and refuses to acknowledge and plan for the general deterioration that will take place over the next couple of decades. The result will be a haphazard and progressively deteriorating situation. And that is why we prep!

None of this should surprise any of us, as we are no longer "One nation under God" but rather, a splintered and tribal civilization (about half of which are mentally ill ), under the rule of a benevolent oligarchy.

The E3 component of an EMP is generated by the effect a nuclear weapon has on the Earths magnetic field, as a whole. While not a popular way of describing it, I see it as similar to a object hitting the surface of a lake. There is the initial splash, which we have already described, but then there are the waves radiating outwards across the surface.

The E3 component consists of wave lengths thousands or even millions of meters long, so it has no direct effect on electronic devices, but rather, it induces extremely low frequency energy into power lines, pipe lines, the earth itself, and the ionosphere.

This component is similar to the effect a solar flare (also known as a CME, or Carrington Event) induces into our magnetic field (geomagnetic storm) and its most important effect is damage any transformers that are still connected to power lines. In addition to the giant transformers that carry our commercial power all over the US, this current may cause some (but not all) smaller transformers to catch fire (transformer like the ones outside of people's homes and businesses are typically oil filled.)

This E3 component will have some effect far beyond the horizon, partly due to wires, cables and pipes carrying the pulse surges far from where the energy is induced into them. The surge will travel as ordinary electrical current, at extremely low frequencies, until it runs into something that it can't cross, where it will be converted to heat.

It is the conversion to heat that does the damage, therefore most (but not all, since some will not be up to the task) of the power lines will be undamaged, but whatever is connected to those lines will be subjected to immense heating. Mostly, that will be transformers, since it takes miles of line to build enough energy to damage things.

Events in 1859 and 1924 show the ability of these extremely low frequency waves to damage equipment, and even start fires. An event in 1989 (Quebec Hydro) showed the potential for this energy to trip circuit breakers or damage transformers and generators.

Destruction of the transformers and transformer stations will, most likely, kill the commercial electrical grid for almost all of us, for years to come. Hopefully, the powers to be will have a plan to route power to some emergency facilities in the interim. (There is a proposed plan for "microgrids" but I don't know it has gotten any traction in the offices of those who actually need to create concrete plans for them.)

Some effects of an EMP (or a CME) will be felt by radio systems around the world. Much like thunderstorms hundreds of miles away can cause static on radios, these events will cause interference for thousands of miles. Many kinds of radio traffic (Short Wave, and maybe Citizens Band) will be out of commission for a couple days, until the static dies out.

Satellites have a different problem. While there is virtually no E1 component above the burst (since E1 is caused by the gamma rays impacting the atmosphere), a nuclear burst will leave a cloud of radioactive debris in high orbit, and many satellites will fail after running through that cloud a few times. The radiation cloud from the Starfish Prime test killed quite a few satellites in the weeks after the test.

https://freebeacon.com/national-security/white-house-warns-of-emp-attacks-on-u-s/

Maybe they are starting to open their eyes.

I went back and reread the article and it seems that they think it might be a good idea to sit around and talk about doing something in a year or so because somebody might have a EMP type weapon.. Sigh

Ugh! This thread keeps getting longer and I still don't have the time to read & digest it all. Finally am 98% recovered from the flu (still have a lingering cough), but now we're 6 weeks away from daughter's wedding & I'm SO busy!

Just keep posting ... this may be my summer reading!

I have had some off line world matters
to take care of, so I hope to be able to
write more on this late in April.

TRex2 wrote:I have had some off line world matters
to take care of, so I hope to be able to
write more on this late in April.

Hope everything is alright. If you need any prayers PM me

Drinkthekoolaid wrote:
Hope everything is alright.  If you need any prayers PM me

Heck, I need prayers every day!

Things have settled down for now, so I will get back to this topic soon, if the Lord is willing, in a time frame that can be measured in hours, rather than weeks.

Theory and limitations of shielding and other precautions

Electronic equipment most preppers are concerned about is vulnerable to the sudden burst energy from the E1 and E2 components of EMP. Because these can be absorbed directly by circuits inside equipment, the primary method of defending them is shielding.

Connections and cords, however, should not be overlooked. Despite the popular notion that EMP will kill everything, most electronic devices that are not in the worst zone have a decent chance of survival, if they don't have any wires collecting the pulse energy and bringing it to them.

That said, no shield, or any other defense, is perfect, and there is no such thing as perfect safety.

So, what can we do to give our selves an edge? Store away critical electronics in shielded containers, when not in use, and disconnect any external wires, even inside those containers.

Now, why would we need to disconnect the wires if the equipment is in a shielded container? Because no container is perfect. Here is a little theory on shielding:

When a moving magnetic wave crosses any conductor, it creates an electrical current in that conductor, and that electrical current creates a wave opposing the one that created it. If the two were exactly identical they would cancel each other completely, but no conductive surface in the real world is perfect, so we have some remaining energy on the other side (the inside) of the surface of the container. The primary imperfections containers exhibit are gaps and surface irregularities.

There is a lot of mythology about shielding, and here, I will kill three of those myths.

1. Shielding needs to be thick. Not so. Since the wave front is a very high frequency, something known as "skin effect" limits the currents in the conductive surface of the shield to only a few thousandths of an inch.

2. Even tiny holes in the shielding will "let the EMP though." This is really neither true, nor 100% false. The reality is that small holes will let a small amount though, but that is a tiny problem, in comparison to other problems that most shielding has.

3. Shielding must be "grounded." (Think about shielding on an airplane.) Earth is simply another conductor. The objective is to have a continuous shield around the item to be protected. If your shield is a metal shed, it should be grounded all the way around, but if your container already has a good, metal, top and bottom, grounding only makes you feel better.

Next time, I will discuss the most common home made "faraday cages" used for shielding equipment.

Good update

TRex2 wrote:E1&E2 Effects

I mentioned, in a previous posting, that the diagrams of the affected areas under a nuclear burst were over simplified. They show a simple circle of effects, but the real area is more like a series of expanding horseshoes.

The following link should take you to a picture on Wikipedia showing EMP affected area for 400 km altitude burst
https://en.wikipedia.org/wiki/Nuclear_electromagnetic_pulse#/media/File:EMP_mechanism.png

Finally starting to read through this thread and TRY to digest it. The grapic is so different from anything else I've ever seen!

Thank you for this thread!!

ReadyMom wrote:
Finally starting to read through this thread and TRY to digest it. The grapic is so different from anything else I've ever seen!

Thank you for this thread!!

Yes, I am trying to defeat some of the myths that have grown up around EMP, and provide a little more precision than most of the common articles provide.

I think some of the myths are people trying to "one up" each other on describing the damage, and some of it is engineers who don't entirely understand the mechanisms in play. And maybe a little bit of political dumbing down of certain aspects so that certain people wouldn't panic. I try to go back to look at the original research (done when they actually detonated those bombs), whenever I have a conflict between how physics works and how something is portrayed. That is one of the reasons it takes me so long between postings here.

TRex2 wrote:E1&E2 Effects

First is that I don't want to get so technical that I lose a lot of people, and I don't want to get bogged down in too many details.

Thank you! I would be one of those non-technical lost people

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TRex2 wrote: In addition, because the wave is so strong in this area, a secondary effect caused by surface imperfections will induce magnetic waves inside metal containers (Faraday cages) used to shield many systems.

So those things that are in the faraday cage will become damaged? Non-unsable?

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TRex2 wrote:
In Zone 2, ...

In Zone 3, ...

Better scenario than we've heard in the past. More hopeful.

TRex2 wrote:[b]

Connections and cords, however, should not be overlooked. Despite the popular notion that EMP will kill everything, most electronic devices that are not in the worst zone have a decent chance of survival, if they don't have any wires collecting the pulse energy and bringing it to them.  

So ... if I am understanding this, so far, if we are NOT in the red zone #1, our UNPLUGGED electronics *may* survive. (Another reason NOT to leave my laptop plugged in all the time ... besides my fear of fire). BUT ... our electric grid might get damaged due to hot moving currents, transformer fires, etc. So, we would still have an option to use more of our electronic items than originally thought (when I say that I mean more than what we have stored in a faraday box, because now I'd be including some undamaged items) via alternate electric/solar options?

TRex2 wrote: In addition, because the wave is so strong in this area, a secondary effect caused by surface imperfections will induce magnetic waves inside metal containers (Faraday cages) used to shield many systems.

ReadyMom wrote:So those things that are in the faraday cage will become damaged? Non-unsable?

This is referring to the worst hit area, and in that area, it won't be unstoppable, but may be more difficult than some preppers imagine.

If you review the many videos floating around, about how to use a trash can for a faraday cage (I will be linking a few of them in the next few days) they will show how to line the inside with cardboard and use metallic furnace tape to seal the contains. These things help a great deal, especially in that inner zone, and I was trying to explain why. (Got ahead of myself on that post, I explained more on April 29th)

TRex2 wrote:Connections and cords, however, should not be overlooked. Despite the popular notion that EMP will kill everything, most electronic devices that are not in the worst zone have a decent chance of survival, if they don't have any wires collecting the pulse energy and bringing it to them.  

So ... if I am understanding this, so far, if we are NOT in the red zone #1, our UNPLUGGED electronics *may* survive. (Another reason NOT to leave my laptop plugged in all the time ... besides my fear of fire). BUT ... our electric grid might get damaged due to hot moving currents, transformer fires, etc. So, we would still have an option to use more of our electronic items than originally thought (when I say that I mean more than what we have stored in a faraday box, because now I'd be including some undamaged items) via alternate electric/solar options?  

Yes, that is what I was saying.

So, we would still have an option to use more of our electronic items than originally thought (when I say that I mean more than what we have stored in a faraday box, because now I'd be including some undamaged items) via alternate electric/solar options?

There is a monkey in the wrench, here, and I haven't researched enough to know how bad it is. EMP will damage Solar PV panels.
I need to find out more about how hard they are to protect, since so many will be depending on them for so much.

I have had some distractions lately, and because there was so much material related to this subject, I had to completely revamp my cataloging of source materials for this subject.

I still plan a short series of articles on home made and professionally made Faraday boxes or cages.  They will be chock full of links (with some commentary on each link), since I haven't built too many for my own use or experiments, and others have.

In addition, I found a PDF that gives a comprehensive treatment of the subject, at the engineering level. It apparently was something read by one of the users over at APN, and now I see where he got some of his ideas. I got into an argument with him over some details and now see that, while he wasn't quite correct, I should have given him partial credit. (Some of his ideas about Faraday cages are applicable to TEMPEST, not EMP, but the source didn't differentiate that.)

The next three or four posts I make here will be on containers that can be used, built or repurposed for shielding things from EMP. This one will be links that go to material I have read, and a short comment about the information they link to.

The following is comprised of several groups of links, with the first link in bold, being the page here on Emergency Home Preparedness that contains the next several links. Rather than bump each of those threads back to the top, I will comment on them here.


In this thread:
https://emergencyhomeprep.forumotion.com/t198-faraday-cage-general-info

https://modernsurvivalblog.com/emp/thoughts-regarding-faraday-cage-techniques-for-an-emp/
Very good background article on the subject of what would make a good container
discusses the problems, as well as possible solutions
covers trash cans, screen covered boxes, shipping containers, microwaves and ammo boxes
This article leads to an article from QST, which I need to give a more thourough read. (I should note that following guidance outlined in the QST article is much better than nothing, but I fear that it may be overly opimistic.)

http://www.utahpreppers.com/2009/02/microwaves-faraday-cages-and-emp-protection/
Short and to the point about using a microwave as a container. No real science, just a mention that the author did it.


In this thread:
https://emergencyhomeprep.forumotion.com/t834-faraday-cage-general-info

http://www.endtimesreport.com/faraday_cages.html
Interesting, though neither historically nor scientifically precise (not bad for 2009, but outdated, and wasn't written to scientific standards). Read for entertainment, but don't expect much more.

http://www.preparednesspro.com/emp-101-part-iv-faraday-cage
Would reccomend NOT reading this article, as it contains more miss-information than information, though the author is really, really, convinced of their info.

https://www.youtube.com/watch?v=uYWhTMmv6bs
This one is very good.
Disasterprepper Dr Aurther Bradley uses 500 MHz to test trash can with and without aluminum furnace tape taping was a reasonable job but only one run. While limited, this video illustrates the usefulness of this kind of container, and the need for applying tape around the lip to improve the sheilding.

Also tested a cheap EMP bag which didn't work very well, but he showed some other, more expensive bags that should work fairly well.

http://www.askaprepper.com/15-things-think-know-faraday-cages-dont/
15 Things You Think You Know About Faraday Cages But You Don’t
written mainly as click bait, but 11 out of the 15 are actuall correct
(numbers 1, 6, 8, and 13 are only half right)


In this thread:
https://emergencyhomeprep.forumotion.com/t833-faraday-cages-make-your-own

http://www.survivalistboards.com/showthread.php?t=149786
Conversation amoung the members. They didn't do a bad job, considering how little was know about EMP shielding back in 2011

http://www.backdoorsurvival.com/how-to-build-a-simple-faraday-cage-for-emp-survival/
Not bad, he gives a lot of good info, but does have a few bugs in the article.
He admits not knowing electronics, so it isn't surprising to see some errors.
First, and EMP will not affect the whole planet, unless the enemy detonates quite a lot of nukes above the atmosphere, and doing so is much more complicated than one would expect.
Second, his problem with the microwave oven (in addition to the test being somewhat questionable) was likely that he left the cord attached. This provides a route for the waves to enter the enclosure. The test with the FM radio is much better.
OTOH, the little diagram he includes about failure modes for our infrastructure is kinda neat. (It points out, to some degree, that if any one part fails, it will cascade to all other parts.)
The Trash Can? Radio waves don't like to go around corners? Well, yes and no. Here is where some things break down. This pulse wave will treat the lip of the lid as an antenna and try to radiate itself into the interior of the can.
Finally "Duct Tape" will not work for the lid. What is needed is "Furnace Tape." This is the aluminum tape (as opposed to cloth) you should use to seal your can.

https://www.thereadystore.com/diy/9713/building-your-own-faraday-cage/
This is about building, not buying. And building it to any size you desire. The jargon used in explaining the theory is all wrong, but the result isn't that bad. He very much glosses over the problem with sealing the "door" on a room sized faraday cage.

http://www.askaprepper.com/10-faraday-cages-you-can-make-at-home/
Several good ideas, none sufficiently explored, lots of dead links and click bait on site.
(Not surprising since the article is 4 years old.) The site seems more designed to drive traffic for ads, than to inform.

There are several very common items that preppers use, to create Faraday cages for their electronic equipment. I will discuss a few of them here.

The most ubiquitous protective container among preppers is the galvanized steel trash can. Cheap and pretty effective, but it has three flaws that need to be dealt with to make it much better.

First is that anything other than a completely smooth exterior will result in currents (and voltages) on the inner surface of the can, and strong electric fields that extend a few millimeters off of that inner surface.

In general, this is easy to deal with, by simply insulating the inside of the can with a half inch of cardboard or bubble wrap. A couple places that need special attention, however are where the lid fits on the top and the bottom seals to the sides. For that last one, an extra inch of insulation or not keeping your most sensitive items (like radios) along the outside of the bottom is sufficient.

The lip of the can lid acts like an antenna, trying its best to drag the EMP wave into the inside of the can. There are a couple ways to deal with this. The cheapest way is to wrap the lip with aluminum furnace tape, in such a way to make a smooth transition from lid to can. Since there could be substantial amount of current flowing across this tape, I would make sure to generously wrap a couple layers, along with making the contact surfaces between tape and can and lid generous.

Another way of dealing with this problem is to install a "seal" between the can lid and body. This consists of something like a refrigerator seal that is very conductive on the outside. The "seal" shorts the signal that is being conducted into the can, to the can body, and the ones I have seen are both more effective than I would have thought, and more expensive (they might cost more than the can).

As was noted in the previous posting, this is a relatively new subject area for preppers, so I would not be surprised to see some continuing innovation in this field.

Microwave oven. There have been way too many various reviews on this, without much science. While this is can make an expedient container, if you have a defunct Microwave. You need to remove the power cord and make sure that where the sides of the outer case are screwed together make good contact (sand the surfaces, screw them down tight, and paint them. I don't know of anyone that has done any serious testing of a microwave oven to determine how effective it is, but it would certainly be more effective than nothing.

Cookie or popcorn tin is another expedient container. This one might be useful if you are stashing a radio at a remote location, or carrying one in a car. (Doesn't create paranoia, when noticed by police.) Again, sand the contact surfaces until they are shiny, and put a bead of paint (car touch up, for instance, to keep it from rusting) around the lip, to keep good conduction from lid to body. And wrap the stuff inside with bubble wrap to keep it from touching the sides of the can. (Keeps it quiet when shaking, too.)

Ammo Box. Again, the lid to body gap needs to be taken care of. Sand the surfaces that need to contact an electrical seal or do some thorough blending with tape, and bubble wrap the contents, or make a cardboard insert to keep anything from touching the outer shell. Once closed and sealed, this can be painted, whole, for storage, or left unpainted as a transportable container to store stuff that isn't immediately in use.

Of course, if you are using it as a transportable container, and getting in and out of it regularly, you need to make an electrical seal around where the moisture seal is, or retape it each time you open it.

A better storage container could be a homemade one using a wooden box and aluminum foil. There is a good homemade container it the links that I will be posting next, and I intend to point it out.

I will probably write more about this subject, including making a storage container for spare solar panels (may not be needed, but won't hurt to be extra safe) and how to do a complete screen room build.

A word here about testing containers. I have seen signal generators used at 100 MHz and 500 MHz. I have heard of people using Cell phones, radios and Walkie talkies. While all of these tests have the right idea, none of them are perfect. Cell phone test is probably the worst, since you never know how strong the signal is from the tower, which is what rings the phone, and the frequency is a lot higher than an EMP generates. OTOH, testing with a typical signal generator at 100 MHz or an FM radio isn't completely sufficient, either since the EMP signal will have components that are substantially higher in frequency that they test, and many times more powerful. Increasing the signal generator to somewhere between 200 MHz and 500 MHz is much better. Not much can be done about intensity. The intensity of a nuclear EMP is a factor most of us won't have the ability to simulate.

There is an electrical engineer (I think) who has a website called Disasterprepper and he made a lot videos, many of them having to do with shielding in preparation for an EMP.
List of all of his videos.
https://www.youtube.com/user/disasterprepper/videos?view=0&sort=da&flow=grid

Here are some of his videos with some comment by me. The first two are the most important, in my opinion.

Introduction to EMP and Faraday Cages
https://www.youtube.com/watch?v=aMct99DiZak
May 15, 2013
A discussion of homemade Faraday cages and how to conduct a simple experiment to test their shielding effectiveness against an electromagnetic pulse. Disaster preparedness books, EMP bags,
He give a lot of good information, right from the beginning. He does a good job of describing how to wrap a box.
He mentions, however, that 'you want about 50DB of shielding' (not word for word, but at 4:10 into the video) and never gives a real explanation why that is the level you want to achieve.
At about 5:40, he tests the box with a weather radio (good idea) but when he sets the radio into the open box, it already gets marginal reception, showing that the signal at his location is already fairly weak.
Then he discuses using two way radios, and the discussion is good, but it becomes more about using layers of protection to increase the sheilding.

The reason he uses 50 DB as a "standard" is that it is a substantial amount, but yet, a goal that most preppers can manage. For 90% of us, 40 DB would be plenty, and for a very tiny percentage, 50 DB may not be enough. Using 50 DB gives us something solid and realistic, as a goal.


https://www.youtube.com/watch?v=uYWhTMmv6bs
Aug 21, 2016
This video walks through the testing of metal garbage cans and anti-static bags against a RF energy from an EMP. Recommendations include how to properly seal the cans and which bags offer best protection.
The test is well done, using the best single frequency (IMHO) for the job. Shows how inexpensive aluminum furnace tape (which he mistakenly calls duct tape).

In this, or maybe another video, he mentions the "gap" between the lip of the can and lid as the culprit, and to a minor degree, it is, but the more important thing is the jump from the lip of the lid, which essentially produces the fields that go through the gap he mentions. Smooth out that transition from lip of lid to side of can and the problem goes away.

He uses a single wrap, and I would recommend a wrap above and one below that, to improve the smoothness of the outside of the can, also, I think the additional layering may prove worthwhile in a true EMP, where the currents are much higher.

This and the above videos are the most important for most preppers, and everything he says, except for the minor items I noted, is correct.




Testing EMP Bags or Faraday Cages with Radios
https://www.youtube.com/watch?v=biTL-s0X8aI
Jan 31, 2017
This video shows how to test EMP bags (or other Faraday cage structures) without RF test equipment. Gives a test procedure (3 layers) that is valid, but I wouldn't use, simply because there are a lot better ways. (I would use distance: for instance a two way radio call from someone two hundred yards, about one block, away.)



Protect Generators and Cars from EMP
https://www.youtube.com/watch?v=CIivyKyndAE
Jul 7, 2017
Describes using conductive cloth to protect cars and generators from a high-altitude nuclear EMP attack. Cloth can be found at [link to his own store]
Testing starts at 3:11 begins telling the results of the good stuff at about 5 minutes
Does some testing around 7:15 to 7:45 but doesn't give specific results
Then goes into detail about how to sew it to shape it.
He has a sewing service that you can hire.



Faraday Cage - Chicken Wire vs Aluminum Foil
https://www.youtube.com/watch?v=9M6h1U9jgWs
Aug 9, 2017
Shows the performance differences between a Faraday cage crafted from chicken wire vs one made from aluminum foil. He doesn't say anything about it, but some of the old school radio guys used to used metal window screen with quite a bit of success.



Using Ferrites to Suppress EMP Transients
https://www.youtube.com/watch?v=uBrjr3AClAQ
Aug 9, 2017
Discussion of the different types of ferrites.
Demonstrates their use and that you need to loop the cable through it several times
he has a link to his web site where he has chosen some very effective ferrites.
I may explore this later, especially for rooms where you can operate in hostile times.


Gaskets to Seal Faraday Cage
https://www.youtube.com/watch?v=6Cbw-PaW3zI
Oct 31, 2017
Video describes how to use conductive gaskets to seal a metal garbage can (or other ad hoc Faraday cage). To order gaskets, see
https://disasterpreparer.com/?product=emp-gaskets
While these work (better than I expected), I haven't explored them much because they cost more than the trash can he is sealing with them.



Ammo Can Faraday Cage 70+ dB Shielding
https://www.youtube.com/watch?v=WQ6uI2ajKK8
Nov 20, 2017
Describes how to use a conductive gasket to get greater than 70 dB
of shielding from an ammo can. Quite impressive, in my opinion.
Does a good job of showing how to install the gasket.