ElectroMagnetic Pulse (EMP)—What’s your Plan B?

Back in September 1985, when I lived on Long Island, NY, I experienced Hurricane Gloria which left 750,000 of us without electrical power for as long as 11 days (I experienced only 7 days without power).

Fortunately, I had some emergency preparedness with an oil lamp and a Propane barbecue became our stove, as we had to cook all our meats before they spoiled. My neighbors did the same and we all shared our meals that day and talked and laughed and thanked God that this was the worst thing that happened to us. Many others near the shore lost their homes, lives and possessions.

We were able to read books made from trees and play board games made of cardboard, paper, and plastic. There was no phone service (We had landlines and not many cell phones in 1985—Radio Shack had one that was about $1,000 and looked like a Walkie-Talkie) and gas stations could not pump gas out of the ground (See my articles on Puerto Rico’s power losses: Hurricanes and Power distribution system architecture: Puerto Rico and Tesla wants to re-build Puerto Rico’s Power system infrastructure.)

We actually had conversations with each other face-to-face!

There was an emergency battery-operated radio with a crank handle as well that would power the radio when the battery ran out of power. During an EMP event there would probably not be any working electronic components in such a radio. Computers were still in their infancy and modems were around 300 bits/second—they didn’t work either without electricity.

If we are to design EMP protective systems, we need to have a knowledge of amplitude and time dependence of the EMP as a function of distance from various kinds of explosions, as with multiple, various yields , various fission-to-fusion ratios and various explosion altitudes.

An EMP is a high intensity electromagnetic pulse having broad frequency spectrum covering from low frequencies to the VHF and UHF bands. EMP is still a serious threat to the electronic systems and communication systems.

A Nuclear explosion will emit gamma rays within nanoseconds. These gamma rays will travel downward and reach denser atmospheric layers at a 20 to 40 km height. At the pancake-shaped zone, called the deposition region, Gamma rays will strip electrons from the air molecules. This process is known as the Compton Effect

Free electrons will initially move in an average radial direction from the initial detonation point. When in the presence of the Earth’s magnetic field, electrons will be deflected giving a transverse component to the current, that in turn, will produce a radially high-amplitude pulse of electromagnetic energy which will propagate towards the surface of the Earth.

The EMP will react with all metallic conductors which act as resonating antennas. This electric field strength may be billions of times greater than normal radio communications; however, harmful effects on humans are not very likely.

Protective systems can be:

1 Shielding in buildings/Faraday cages

2 Shielding of cables

3 Transient protectors

4 Ground and equalizing potential

5 System separation/partitioning

6 Preparing for repair

7 deploying non-electric systems

8 Simulation

An EMP-shielded cable (Image courtesy of Reference 1)

An EMP-shielded cable (Image courtesy of Reference 1)

EMP energy coupled can destroy semiconductor elements, even inside equipment which renders system malfunction.

Because both lightning and HEMP have strong electric and magnetic field components, it is necessary that the screen material should provide good shielding effectiveness for both an electric field and a magnetic field. A steel plate can provide better magnetic screen effectiveness than an aluminum plate.

For a high-power microwave and ultra-wideband EMP, it is only required that the screen material have good electrical shielding effectiveness due to the small magnetic component. On the other hand, the higher the frequency, the more difficult the aperture design will be. If the aperture is greater than 1/100 of a wave length, it will lead to a relatively high energy leak.

The main paths through which EMP enters sensitive electronic information system include ‘front door’ and ‘back door’. Examples are for a shipboard electronic information system, the front door includes different types of antennas located on the decks and mast for communication, radar, and reconnaissance. The back door can be doors and windows of cabin, apertures and slots, and link cables for equipment.

What’s your Plan B? Please share it with us.

Stay tuned for an excellent paper on EDN regarding EMP protection techniques by api technologies corp.


1 A SURVEY OF SWEDISH NUCLEAR ELECTROMAGNETIC PULSE (EMP) RESEARCH, G. Dahlen, K. Daxberg, L. Hoglund, B. Sjoholm and M. Wik, Research Institute of Swedish National Defence (FOA)

2 Nuclear Electromagnetic Pulse (EAAP) and Associated Effects, Manvai Wik, Defence Materlal Administration Electronlcs Directorate, IEEE Antennas and Propagation Society Newsletter, Stockholm, Sweden, June 1987

12 comments on “ElectroMagnetic Pulse (EMP)—What’s your Plan B?

  1. D Feucht
    October 1, 2018


    My Plan B was to move out of the target zone of North America to Central America.

    For those not convinced that an EMP attack, whether from the sun or an atomic (not thermonuclear) bomb at low-earth altitude, is a serious possibility I recommend a book that will widen an engineering perspective on the fragility of modern technology, especially electronics. I have discovered recently author Dmitry Orlov, a Russian-American engineer. His book is available on Amazon dot com or more directly from his website at cluborlov dot com titled Shrinking the Technosphere . Then to really get into the mood for the collapse of civilization read his book, The Five Stages of Collapse . It is realistic gloom and doom with a Russian flair and Russian-style dark humor.

    Plan B needs to be taken seriously. Engineers at the least should know enough to stock their houses with modest preparations for collapse of the electric power grid. Without electricity, we are truly back in the early 1800s, yet modern society is not configured to survive in the 1820s. But the Amish will be okay, and “the meek will inherit the earth” – along with some preppers.

  2. Steve Taranovich
    October 1, 2018

    Hi Dennis,

    There will be no nukes over Central America.

    Thanks for your insights and interesting references for our audience

  3. softy
    October 10, 2018

    This isn't a comment that pertains to the 'EMP – Plan B' blog post, But I just noticed that there's no way to comment on the “Flash Polls” that show up here (take for example, the one on AI that's showing up next to this EMP blog post).  They seem to be the products of low-IQ high school students, are ridiculously simplistic, and have no value whatsoever.  How about you bloggers lobby the people in charge of the website to eliminate them?

  4. Andy_I
    October 11, 2018

    Unlike you, we did have telephone service after Hurricane Gloria.  Telephones used wires, and even though those wires are above ground here, most were OK.  All it takes is one downed power line to render an entire neighborhood without power; but the phone service remained intact and working unless YOUR wire was broken.  But those were the days, and now they have electronics in the phones, and electronics (demultiplexers) in the wires between the Telco office and your home, or electrical/optical converters and glass instead of wires, and I hear rumors that many of those Telco offices may have disposed of the battery backup systems that kept them running without commercial power.

    We survived the week after Gloria.  The gas lines were unaffected so we could cook, and had hot water, but no heat.  I went to work every day where I designed electronics, then came home to a cold, dark house with no electronic entertainment.  It was a strange week.

    You've probably seen the dire warnings about the Carrington event which was a huge solar flare in 1859 which, if it happened today, might wipe out significant electrical infrastructure.  I have mixed feelings about whether those warnings over-exaggerate and prey on fear.  However, yes it is possible, it could happen at any moment, in any political climate, and not involve any nukes.

    I do some radio communications (both ham radio and emergency communications for others) and we were told (by the gov't) to read and study some guidelines about EMP preparedness, what things we can do to make our radio equipment more robust.  I need to work on that.

    Many folks assume that all electronics that isn't inside a Faraday cage is instant “toast” if an EMP occurs.  It's a fear that's been promoted by movies and TV shows.  It makes a good plot device, but it's not reality; there are no absolutes.

    EMP preparedness is similar to good lightning protection.  They both get into your electronics via anything that looks like an antenna — any connecting wire.  The key is to understand the paths the electrical pulse current will take, and provide paths that go around instead of through.

    Even a non-magnetic aluminum plate gives magnetic protection, but not at DC.  Being a “pulse”, an EMP isn't DC.  That's why Faraday cages can be made out of copper or aluminum.

    My biggest fear about an EMP-like event, is its effect on commerce — especially the food supply.  When grocery stores become empty, all bets (for a civilized life) are off.  Most of us aren't farmers.

  5. Andy_I
    October 11, 2018

    I wish they would bring back black text (font color).  So many websites seem to be going to grey instead of black, including this one!  YUCK!

    Some are more obvious and annoying than others.  I'd rate this one about in the middle on that spectrum, it's medium-gross.

  6. Steve Taranovich
    October 15, 2018

    @softy—I create and put these polls online to get the pulse of the audience on various hot topics. Sometimes simplistic points like these tell a great deal without getting into a tremendous amount of details–that's what polls are about.

    Readers cannot comment because it is a simple poll, but I am glad you commented in this blog. I do value reader response and I value your inputs. When the Planet Analog site is re-designed soon, I will ask to have comments added to the polls

  7. softy
    October 15, 2018

    @steve.taranovich:  “Getting the pulse” using such simplistic polls doesn't gather any valuable information.  Nobody with valuable input on the topics will interact with the polls.  The people who do interact with them comprise a self-sorted group of people who think that simplistic responses are worthwhile.  This gives a skewed analysis by virtue of the fact that the statistical input comes entirely from people who don't have any valuable perspectives.  This sort of thing makes Planet Analog appear to be moving in the direction of becoming a soap opera.

  8. cyliax
    October 15, 2018

    one of my vehicles has a diesel engine with mechanical injection pump. it does have a solenoid based fuel shutdoff valve, but that can be circumvented to get it running. it will also run on waste oil, as well as various vegetable oils, as long as it is in a fluid state so it can be pumped through the injection pump. the challenge is starting it, since I don't have a compressed air starting system. I could make sure that I park at the top of the hill so I can bump start it if necessary… an EMP event would bring a whole new perspective on “boot strapping”. 

  9. Steve Taranovich
    October 15, 2018

    @softy—Well, we disagree, but thanks for your input and opinion

  10. SergioQ
    October 27, 2018

    The people who do interact with them comprise a self-sorted group of people who think that simplistic responses are worthwhile.  This gives a skewed analysis by virtue of the fact that the statistical input comes entirely from people who don't have any valuable perspectives.  This sort of thing makes Planet Analog appear to be moving in the direction of becoming a soap opera.

  11. Steve Taranovich
    October 27, 2018

    @SergioQ—I think that our audience of 41 people who replied to the 'simple' Flash Poll would have something to say in reply to your remark that they are “people who don't have any valuable perspectives”.

    Your comment is condescending in the least and if you do not have any good technical commentary, then please continue to watch this 'soap opera' as you call it and look closer to all the rest of the tech content on this site with excellent, insightful, and technically revealing commentaries by some of these same people that you have judged.

  12. EdwardThirlwall
    February 26, 2019

    I am sorry you had to encounter such a devastating time of your life though it occurred a long time ago. The memories must still be very much present but they are also the best teacher. Experience makes you a tougher person to prepare for whatever that may come your way next regardless of their intensity. In such a situation, preparedness is key and to know what to expect in the worst possible scenario, is to know how to react.

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