Four Letters Re: EMP Preparedness and Countermeasures

Dear Mr Rawles:
I have been enjoying your SurvivalBlog very much. I am new to these kind of web sites but have been of a preparedness/survivalist mindset all my life. I served in the US Navy for seven years as an Avionics Technician on both fixed wing (FA-18 Hornets) and rotor wing aircraft. Part of my training encompassed electromagnetic pulse (EMP) and its effects on aircraft and how to properly maintain and repair them so as to not compromise their ability to withstand EMP should it occur. Now that I have been out of the military for some time I have been researching [through] the Internet to find practical examples of how to harden modern microchip-laden automobiles so they might withstand an EMP attack. There is very little info out there from a practical hands on approach but I have come up with a workable method to harden most vehicles fairly economically. One of my biggest questions is, might there be a market out there? Would people care to prepare their cars and trucks in this manner? The government has been largely silent about EMP and its danger to the civilian sector and terribly unprepared in the DOD arena as well, from what I gather. I’m thinking that only a few of the survivalist folks might be interested in having their trucks/cars prepared against EMP and the rest of the population will scoff or gamble it will turn out okay. I also read that the EMP threat is not diminishing since the fall of the USSR but if anything it is getting greater with the possibility of smaller more efficient bombs designed specifically to radiate EMP that terrorists will surely not ignore. Any input or ideas out there would be appreciated. thank you. Keep up the great work. – Ross W

JWR Replies: Yes, there would definitely be a market, since you would be filling a need that heretofore no company has supplied for the civilian world. If your EMP protection solution is not too expensive, you are sure to find hundreds of customers. I wish you well with this venture. It sounds like a winner. (Talk about pent-up market demand!) Once you are ready to put your product(s) on the market, let me know and I will do my best to help you get the word out there to folks that will have both the interest and the means to make a purchase.

Mr. Rawles,
I’ve been reading SurvivalBlog for awhile and have read much on protecting equipment from EMP. I’m confused as to what would constitute as sufficient protection. The blog has articles on the effects of EMP, but I couldn’t find any how-to subjects. I’ve read anything from wrapping car computers in tin foil to thicknesses of conductive metal that is grounded. Is there a set of guidelines or can you or the readership comment on this? (That is, how to properly configure an ammo can for EMP protection for radios/electronics, modifications to make for your gun safe, et cetera.) Thanks, – Paul

JWR Replies: Unfortunately, I can’t issue any blanket guidelines that will protect any piece of electronics that is kept plugged-in to a grid power outlet. Radios receive some protection from zener diodes attached to external antenna cables, but that isn’t a panacea. Vehicular electronics are safer than power grid-connected electronics, but still at risk. If left unplugged and disconnected from external antennas, most radios will be fine, except for close proximity nuclear detonations. In a perfect world, everyone would have three to five redundant radios, with just left one plugged in, and all of the spares stored in practical Faraday Cage type enclosures, such as steel ammo cans or a steel gun vault. But for most of us that are on a realistic middle class budget, the best that we can hope for is one spare of each radio. At least keep that one spare in an ammo can! To make an ammo can into a more efficient Faraday cage, its original rubber gasket should be replaced with braided wire, as explained in a September, 2006 SurvivalBlog letter. OBTW, I also recently posted details on how to EMP-protect a gun vault that has an electronic (key pad entry) lock mechanism.
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Sir,
Do you have any theory about a high altitude EMP in the northern most part of the US? Would it affect Anchorage, Alaska? Would mountains and the curve of the Earth block it? I don’t think we are on the “grid”, shared electric power with the Yukon Territory but there may be a old telephone line still plugged in to the South 48, does that count for a EMP? Although, Alaska’s Air Force bases would be important military targets for a threat from a Pacific nation if times get tough.- Edventures (in Alaska)

JWR Replies: First, let me reiterate that in most terrorist nuke scenarios, EMP will be quite localized. Even if terrorists were to set off a nuke in an airplane at high altitude (highly unlikely, since their main goal is to see news footage of blast damage and panic on the ground), the EMP effect would be limited to the line of sight (LOS) from the detonation. (As explained in one of my SurvivalBlog posts in October 2005, and reiterated in April, 2007.) And even a very high altitude burst would be limited to about 280 mile line of sight. However, keep in mind that EMP can also be carried beyond line of sight (BLOS), via coupling through any linear metallic objects that can act as an antenna. These include phone lines, power lines, and even railroad tracks. The coupled EMP could conceivably travel many hundreds of miles. The bottom line: In Alaska you should be safe from the EMP generated by most anticipated terrorist use of nukes, but in the event that nation states start tossing around nukes, all bets are off.

James:

Why isn’t there an EMP category on your site? A while back, I inquired about back-up computer modules for vehicles and other means of protecting vehicle electronics, but you didn’t post it.. – Stephen F.

JWR Replies:
Sorry about the delay, but I was saving up a few letters regarding EMP to answer all at once.

I have been filing most of the EMP letters and articles under the “NBC” category. I suppose that I should indeed create a more precise EMP category. To find most of the archived EMP articles and letters, just do keyword searches on the words “Faraday” and “Coupling” in the “Search Posts on SurvivalBlog:” window in SurvivalBlog’s right hand window.

It is prudent to store spare microprocessors for each of your vehicles, especially if you live within 100 miles of any anticipated nuclear target. The spares should be stored in steel ammo cans, which make a decent Faraday Cage–effectively protecting their contents from most conceivable EMP events.

Since spare motor vehicle microprocessors are fairly expensive to buy brand new, you might consider finding used ones and auto wrecking yards. The most important spare microprocessor (or microprocessor box) to acquire is a Electronic Control Module (ECM), which control the ignition system. (Note that the terminology for this module will vary, depending on the vehicle’s maker.) Some cars and trucks also have a Powertrain Control Module (PCM) and other s even have discrete microprocessors associated with the fuel system. Without all of these intact, your vehicle might not run. In essence, the newer the vehicle, the greater its vulnerability to EMP. Not only is he sheer number of chips needed to run a car increasing, but the gate sizes of those chips is simultaneously getting smaller. (Now “sub-micron” size gates are commonplace!) Both of these factors add to EMP vulnerability with each new model year rolling out of Detroit, Stuttgart, Seoul, and Tokyo. Consult your local dealership mechanic for details on the microprocessors needed for each make and model of vehicle. Your mechanic can also let you know if it is feasible to retrofit your vehicle with a traditional (rotor and condenser) ignition system.