EMP survival in case of war, extreme CME

The sheer power of EMP can fry foil, Mylar or thin wire. There's lots of experiments on youtube about microwaves and CD or foil. Similar effects should be expected with EMP just on on a much larger scale. Electronic circuit boards use copper or other metal foil, microchips have thin wires. It makes them susceptible.

The easy way to protect electronics is solid metal box with thick walls. No nearby wires or metal pipes would be an advantage. It is a good way to protect equipment that is stored, electronic supplies.

Any openings or holes in the box will act as a way for EMP inside the box. EMP leak through openings is dependent on frequency and opening dimensions. It is one of the weak points in any anti-EMP protection. Sometimes it cannot be avoided when wires or optical cables must go inside protected case. That is usually the case for shelter equipment as ventilation and lights must be able to survive multiple EMP events and be operational most of the time.

All wires need high power filters, surge suppressors. EMP protection components absorb lots of energy and produce a lot of heat during any EMP event. Thermal dissipation considerably increases price of components so that it is sometimes worth considering to leave some equipment less protected and have lots of spares in fully enclosed backup metal boxes.

Spare wires can also burn or experience electric breakdown. Wires that are used in the shelter are usually protected by metal pipes. It protects electrical installation both from water and EMP. Any pipe connection, enclosure or lid should have electric contact with casing.

Last Edited by EMPerror on 02/25/2013 04:01 PM

Anti-EMP enclosure wall thickness can be calculated from standard
[link to www.ets-lindgren.com]

Magnetic attenuation 2dB=1.3 @1kHz and 80dB=10000 @10MHz using skin effect formula.

[link to en.wikipedia.org]

Thicker material is needed for 1kHz with metals of choice (it may not be the case for every material). Wall thickness is calculated from parameters found on internet, so verify it before usage.

Common metals
Copper 0.5mm
Aluminum 0.6mm
Carbon steel 0.15mm

Carbon steel can be thinner as it is magnetic material. Stainless steel is different. There are two major groups of it, austenitic (non magnetic), ferritic or martensitic (magnetic). Metal type can be tested using magnet.

Non magnetic type offers poor protection (magnet won't stick to it). It is often used for kitchenware.
Steel 304 3.1mm
Steel 316 3.2mm

Magnetic type offers better protection and is comparable with carbon steel.
Steel 410 0.3mm
Steel 430 0.1mm

It is possible to find material parameters on the internet and make calculations for most materials of choice.

In case of emergency electronic equipment can be put into any metal dish, pot, metal trash can, barrel and enclosed with metal sheet or lid. It doesn't matter if it is not up to the standard, it will be much safer this way than to leave it in the open and with luck it may work.

When preparing in advance, wall thickness, stainless steel (if needed using magnet) can be measured or tested.

Thanks for the post, OP.

Spent $100s of dollars to have a steel box made to protect my generator from EMP. Had the maker put a cell phone into it, put lid on and dial that number. The phone didn't ring and I assumed it worked, as this was all the info I had at the time.

Assume all these thickness requirements and predicated on 'specific' wave frequencies, 'strengths' of an EMP a CME or flare. Sounds like the topic has various possibilities/results depending ON .....


Eagle

Different frequencies are attenuated differently. The higher is frequency, the higher is attenuation for metals and most conductive materials. Dielectric materials act differently and have a limit to attenuation as frequency is increased. That's why metal thickness requirement is highest for lowest frequency (1kHz). On the other hand low frequencies have smaller effects as they induce smaller currents in electronic equipment and are less of a problem (it's a problem for electric grid and long wires).

Numbers are based on standard MIL-STD-125-1 and figure 2 from the link.
[link to www.ets-lindgren.com]
It is possibly based on experimental test data. There are several sources for EMP electric field values to be sure. Info is extensive.
[link to glasstone.blogspot.com]
Electronic survivability can be found in
[link to homepage.alice.de]

It is in the region of kV/m. It depends on spectral function of EMP pulse and complete overall result needs lots of math.
If HEMP is considered electric field reaches 50000 V/m with 10000 attenuation which covers most of the spectrum, it is reduced to 5V/m and it is not enough to cause trouble.

The biggest trouble (except unknown secret weapons that are hard to predict) may be with Source Region Electro-magnetic Pulse (SREMP). Not many shelters can survive in close proximity to the explosion and this topic is usually avoided.
[link to www.fas.org]
[link to www.fas.org]
If electric field reaches 1000000 V/m > 100V/m, and this level seems survivable, it does not hold for low frequencies. Lower frequencies need greatly improved protection. Far away from explosion it may not be a problem, but close in induction region, there are different rules, some modifications are needed.
Usually there are several layers of shielding. Outer copper layer which is conductive and shields both from electric field and high frequencies. Another is ferritic inner layer that provides magnetic and low frequency shielding.

Last Edited by EMPerror on 02/25/2013 09:29 PM

Be sure to try the same test with an AM radio, as EMP has most of its energy in this frequency range and nearly zero at cell phone frequencies.

Higher frequencies in the GHz range (like mobile phone frequencies) are the target for conventional EMP bombs. Mobile phone infrastructure may be targeted this way. Much higher frequencies may be used for shelters and bunkers with anti-emp protection as holes become a weak point (look at figure 2 14 at page 18).

[link to www.fas.org]

AM radio in the box is a better way of testing than mobile phone in the box, but also cannot guarantee survivability. The best way is the way that can provide exact test numbers.

1.3 times magnetic attenuation at 1kHz hardly will do any good for protection. The only usage for it may be to test the integrity and level of protection. Higher frequencies will have better protection as skin effect gets stronger (the only exception is holes and openings). Testing can be easily done by almost anyone. All that may be needed

Multimeter that can test AC voltage at 1kHz (bandwidth is usually listed in the manual) and has peak-hold function (useful when measurements must be made in the box).
Big loop coil for signal sending. It can be made by winding multiple turns of wire into circle 1m or more in diameter.
Ferrite coil for signal measurement, to be connected to the multimeter. It needs lots of windings and ferrite core.
Any sound system, signal generator that has enough power and can be connected to loop coil (and can play long sinusoidal 1kHz tone).

Loop coil should have some resistance so that damage would not be done to the sound system. It is possible to connect resistor if needed. The goal is to get detectable signal in the ferrite coil, so by experimenting it can be done.

Once everything is connected and sending, receiving coil in place, received signal can be measured with protection and without. Multimeter has to be turned on (with peak-hold if everything is in the box and without the possibility to look at readings during test) and then it is possible to start playing 1kHz tone through air coil.

Voltage will be directly proportional to the magnetic field strength and can be used to find relationship of attenuation.

Care should be taken as the distance between coils, and preferably position should be the same during both tests. This may be a problem with protection that cannot be moved. Then measurements should be made as close by as possible by keeping the same distance between coils again.

Last Edited by EMPerror on 03/01/2013 06:46 PM

Some guidance can be obtained from here. It's obviously overkill for a homebrew installation.

MIL-STD-188-125-1

[link to www.wbdg.org]

Do you know if solid state electronic storage devices like hard drives and flash drives would stand up to an emp or would they also be fried?

Solid state is more susceptible than magnetic platters. However, if the drive is totally disconnected from everything, then you will probably be ok.

Wow! I did not know that. I actually thought it was the other way around. It makes sense though when you stop to think about it because the solid state drive is made up of a chip with delicate micro-circuits and the regular drive is a metal disc.

On an episode of the show 24, there was a company that wanted to conceal evidence of something or other and did an emp to fry all of its computers. I wonder if there really are companies that have that capacity? If so, we not only need to worry about foreign military emp's but also domestic ones.

While it's not technically EMP, here is a video and article of real-life capability:

[link to www.boeing.com]

Do a search on Boeing CHAMP for more hits.

Any microchip is at risk. Flash drives can get damaged. While magnetic drives can survive, their problem may be in electronics and it can be easily damaged.

That is actually quite scarry. Imagine being in the vicinity of the target and getting your equipment fried? Although Champ is mounted on a missle, I imagine that it can also be mounted on a drone. When the US decides to fry a domestic enemy's equipment, anyone in the area will also get hit. Not too cool if the bad guys are in a big apartment complex because the emp would likely take out everyone else's equipment too.

Modern war is using drones extensively now, and it is likely to use it even more with time. The easiest way to fight swarms of drones is through the use of conventional EMP devices. It means noone can be safe in the times of modern war as there is no way of guessing where drone fights may be happening.

[link to io9.com]
"Knocking out the computers in a hospital, or the technology in computer-guided vehicles, could lead to fatalities. And losing databases of information could lead to many more deaths in the long term. Imagine one of these drones taking out a stock exchange or a water management system. Or a computer-controlled dam."

While enclosed metal box with adequate thickness can provide protection against EMP, there is a danger of radiation. Radiation can easily damage electronics and also can create SGEMP (directly inside the box) when sudden radiation burst appears. Atmosphere usually provides good protection against radiation and far away, high altitude explosions may not be of concern.
This becomes a problem when equipment should survive close to the explosion, is kept outside the shelter. The best protection is to keep electronics away from radiation, by shielding or keeping underground, and by not making the box too big. It is also possible to use additional smaller protection containers inside the box as these add additional protection.

Last Edited by EMPerror on 03/16/2013 09:16 AM

Anyone have any idea how well a fireproof safe would work as a faraday cage?

One of the best threads I've seen in awhile! Thank you for excellent info!

EMP protection is Faraday cage, but Faraday cage may not be EMP protection.
Safe usually offers really good EMP protection if door is sealed tight, there's electric contact where it closes and no gaps are present. To improve electric contact of enclosure, conductive gasket can be used.
Safe with electronic lock or any big hole in metal case leading inside, which is covered by plastic elements, is not suitable. Electronic lock is likely to go out and there's usually metal hole where plastic battery holder sits on the inside part of the door, connected through wires. It's a direct path for EMP.

Not all conductive gaskets are suitable. EMP suitable conductive gasket of certain parameters must be able to survive 900A current according to MIL-DTL-83528 in section 4.5.16. Manufacturers usually include compliance to this standard.

[link to www.everyspec.com]

Last Edited by EMPerror on 03/16/2013 01:48 PM

Would they need to be grounded?

No, it's not needed. Grounding can only protect against electrostatic field, and EMP is alternating electromagnetic field. Metal shield is protecting against EMP or high voltages. Once grounding wire is connected, it acts as an antenna collecting EMP.
Grounding is only used for installations that have equipment dependent on grounding like antennas, wired connections.

The most dangerous for grounding is E3 also called MHD-EMP. It causes currents in the ground that also travel through electric grid, pipes. It can cause discharges, sparks, can melt ground wire or cause fire.

Thousands of nuclear reactors means no one survives the next Carrington event.

Thank-You!

I was thinking that a grounding wire would act like a lightning rod so to speak!... but, there's so many conflicting opinions!

I was thinking about using a galvanized steel garbage can
lined with cardboard inside and wrapping the items in heavy duty tin foil in layers ... plastic wrap - tin foil - plastic wrap - tin foil, etc.

Galvanized steel garbage box should provide adequate protection. Wrapping it in thick foil is reducing EMP effects by a small fraction, so it won't hurt. Foil used alone can easily melt. That's how it looks in microwave. Similar effects with EMP would be within extremely short time periods and much higher power (if it happens, electronics is gone for sure).


[link to www.youtube.com]

Foil usually provides some protection against non EMP harmful signals. Most microchips are imported and it is a good question if they have undisclosed abilities to turn off permanently once some signal is received?
Layering it won't hurt, but it is not an extremely effective way.
A well sealed chemical resisting plastic bag is a must. This way you are protecting it from harmful chemicals and radiactive particles, it can be easily submerged into decontaminating aggressive chemical (like sodium hypochlorite also called bleach or other). Otherwise you are risking loosing your electronics or making dangerous to use. There are numerous chemical plants that after EMP would run out of control and cause problems of unimaginable proportions, not only for unprotected electronics.
I've witnessed one of the biggest chemical catastrophes which happened in Jonava 1989-03-20 when 7500tons of liquid ammonia were released from a collapsed tank. Witnesses tell that sewers in the vicinity reacted bubbling and popping all iron lids high into the air. Affected area was more than 50km reaching Ukmerge within few hours along the wind, and luckily wind direction changed pushing the cloud backwards towards Jonava and then Kedainiai (also 50km away). It could have been worse. Standard activated carbon gas mask was nearly useless against it. All wildlife was fleeing the zone some 40km away, including wild rats and mice which usually avoid running in the open.

[link to en.wikipedia.org]
[link to www.xxiamzius.lt]

Only specialized gas mask can help against this chemical. Once you know your surroundings and chemical plants, it's possible to "do the math". Blind possession of a standard filtration system or gas mask may only give false sense of security. Stockpiling of changeable specialized filters can be extremely important in some areas. It is another "Big topic". It can happen that it will fail and the only option will be to run away. You can't hope to outrun a cloud or wind without transport so there won't be much time to waste. Steel or container garage can be considered. Motorcycle kept in EMP protected box can be extremely useful (even bicycle may improve chances with lots of luck). When everything did settle down it may be possible to come back and there will be a task to decontaminate everything. Improper decontamination or failure to protect assets against contaminants can lead to a waste of valuable resources and health issues. Both of these hinder chances for survival.
A small steel (it's possible to test with magnet) metal box like the one from tea, candies or cookies can provide a good protection and they sometimes can protect against EMP on their own (thickness is the key and usual tin box wall thickness is 0.23mm). Using them as an additional protection in big container (like garbage box) would only improve survivability. This way, once place must be quickly abandoned, it's possible to take the most important items with you without compromising EMP protection.

EMPerror,
Do you have any info on the North Korean 'supposed' EMP nuke yield and it's resultant effect radius for the US. Seems like a concern with US agencies, with their moving anti-missile batteries that direction.

Last Edited by uscrusader1 on 03/18/2013 09:26 AM