Saturday, September 11, 2010

EMP is High Noon Then We Descend Into Darkness

Protecting Ourselves from EMP
Leaving the technical stuff to the techies* let's look at what you can do to protect your electronic stuff from EMP (Electro Magnetic Pulse) without spending a lot of money. (*techno stuff for the techies is at the bottom of this article.)

Faraday Cages
Faraday Cages can be as simple as a grounded aluminum foil or metal mesh around the electronic device(s) to be shielded or an entire room or building so shielded. The cooking chamber of your microwave oven is a Faraday Cage in case you were wondering what all those little lines on the glass door are for.

The simplest Faraday cage for small appliances (like the hand cranked/solar radio you plan to use in an emergency) is the cardboard box they came in plus a slightly larger box completely covered in aluminum foil and grounded with a shielded (plastic coated) wire such as you have laying around like cut from the charger of that last generation electronic device you tossed, half the cord from that old lamp you threw out or maybe some speaker wire leftover from installing your stereo. Strip the last few inches of plastic to expose the copper wire then tape the metal part of the wire directly to the aluminum foil on the outside of the larger box. Then attach an alligator clip to the other end of the wire.

Make sure NONE of the aluminum foil (or wire mesh) extends into the inside of the larger box. Place the electronic device(s) still in their original (or other) cardboard box(es) so that there is only cardboard to cardboard contact within the larger box. You want a small space or non-conducting material between the outer Faraday cage box and the inner box(es) with vulnerable electronics.

Obviously it would be a pain in the arse to be taking everyday use items in and out of your Faraday cage every time you want to use one of them, and there's no guarantee that the Electro Magnetic Pulse won't come while you've got them out so you'll probably want to protect just the emergency stuff like that crank/solar emergency shortwave radio that listens to broadcasts from around the world located on frequencies between 1700 kHz and 30 MHz.

If you have a store room for emergency supplies you might consider stapling chicken wire or other metal mesh to its walls, ceiling and door then add your spare light bulbs, crank/solar emergency radio and solar battery charger.

Putting your emergency generator in a chicken wire lined shed might be a bit much, but maybe not.

I'm currently trying to force myself to read by One Second After by William R. Forstchen and finding the plot progression painfully slow. The protagonist jumps from facts to conclusions with all the deliberate speed of a leaping tortoise as he slowly realizes the implications of EMP.

I know it's a novel and he's (presumably) trying to introduce the concept of EelectroMagnetic Pulse to his readers, but com'ON!

If the lights, TV, radio and 99.9% of vehicles in your town suddenly died would you expect to see people wondering around wondering what happened or would they be out trying to buy food hand over fist and buying (or stealing) horses and mules?

With the 18 wheelers out of commission how much would old Nelly and an old hay wagon be worth?

Here's some links for those who want to know more:

World Band Radio

Faraday cage

Mythbusters build a Faraday cage

* EMP Shielding for Techies
"The purpose of the electromagnetic pulse (EMP) protection system is to protect critical electrical systems from the effect of intense electromagnetic (EM) effects caused as a result of an explosion. The frequency spectrum may extend from below 1 Hz to above 300 MHz. The high-altitude EMP produced by an exoatmospheric nuclear explosion is the form of EMP commonly of most interest because of the large area covered by a single bomb. This high-intensity EMP can disrupt or damage critical electronic facilities over an area as large as the continental United States, unless protective measures are taken in the facilities. The development of such protective measures involves grounding, bonding, and shielding."
US Army TM 5-690/c5

To Comment on this article E-Mail Me Unless you specifically ask me not to, I'll post your reply here in the blog so everyone can read it. Of course I'll remove your last name, email address and any other specific information for privacy purposes.