Electro Magnetic Pulse - Major step in any endgame

[MadMichigander13]

Everyone:

One thing we need to keep in mind is if a hostile nation detonates a megaton-class thermonuclear device 300 nmi above Kansas; it would throw the entire Continental US, as well as much of Canada, and Mexico back into the mid 19th century (I think we can figure out how a fight with an uneffected opponent would play out.) The inductive pulse from such an event would slag any semiconductor (read: transistor) based eletronics almost instantly. So, folks should be thinking of how to store/cache such equipment in a manner to protect it. The only way I know how is what is known as a 'Faraday Cage'. You have an outer surface that is highly conductive, no gaps, openings sealed with conductive cushon (RFI seals), the inside electrically insulated, and connected to an earth ground,

[TacAir]

Everyone:

One thing we need to keep in mind is if a hostile nation detonates a megaton-class thermonuclear device 300 nmi above Kansas; it would throw the entire Continental US, as well as much of Canada, and Mexico back into the mid 19th century (I think we can figure out how a fight with an uneffected opponent would play out.) The inductive pulse from such an event would slag any semiconductor (read: transistor) based eletronics almost instantly. So, folks should be thinking of how to store/cache such equipment in a manner to protect it. The only way I know how is what is known as a 'Faraday Cage'. You have an outer surface that is highly conductive, no gaps, openings sealed with conductive cushon (RFI seals), the inside electrically insulated, and connected to an earth ground,

I, for one, would be interested in your source for these statements.

[banghowdy]

interesting.

[KnightoftheRoc]

we need a popcorn smiley
srsly

[Doctorr Fabulous]

Does this mean my ACOG won't work?

[-----P-----]

Everyone:

One thing we need to keep in mind is if a hostile nation detonates a megaton-class thermonuclear device 300 nmi above Kansas; it would throw the entire Continental US, as well as much of Canada, and Mexico back into the mid 19th century (I think we can figure out how a fight with an uneffected opponent would play out.) The inductive pulse from such an event would slag any semiconductor (read: transistor) based eletronics almost instantly. So, folks should be thinking of how to store/cache such equipment in a manner to protect it. The only way I know how is what is known as a 'Faraday Cage'. You have an outer surface that is highly conductive, no gaps, openings sealed with conductive cushon (RFI seals), the inside electrically insulated, and connected to an earth ground,

I, for one, would be interested in your source for these statements.

I know the 1987 version of Nuclear War Survival Skills from Oak Ridge National Laboratory talks about how "A coordinated enemy attack may include the detonation of a few submarine launched ballistic missle at high altitudes over the United States within a few minutes of the launching of hundreds of SLBMs and ICBMs. Such high altitude bursts would produce EMP effects primarily intended to knock out or disrupt US Military Communications. These EMP effects could also knock out the public power necessary to sound sirens and could put most unprotected stations off the air." It also states that, according to Janes Weapons Systems at the time, most Soviet SLBMs had a yield of 100 kilotons to one megaton.

That information is 25 years old, and i would also be interested to see a source about a single weapon doing the job.

Pseudo Edit: http://www.doh.wa.gov/ehp/rp/factsheets ... ecpuls.htm They actually mention it here. 1.4 megatons being the magic number.

[abelru]

Does this mean my ACOG won't work?

No, silly... Simply means you will need to replace your ACOG's cr123's with the ones you stored in your Farraday cage. You did store your cr123's in your Farraday cage, right????

[Boyscoutdreams]

Ok, I know I don't know anything about the sizes of these bombs, but isn't 300 megaton kinda big? I thought the current high yield was only around 30 megaton.

[-----P-----]

The largest ever tested by any nation was an estimated 50 megatons, with a weapon that was too large to be delivered on a target. The largest US test was around 15 megatons. High yield weapons like that were used in strategic bombers to compensate for the fact that dropping them by parachute made them fairly inaccurate, so you made them destroy a larger area. Ballistic missiles are limited in weight, which limits the size of the warhead(s) that can be carried on board, but they are much more accurate, so a large yield isn't needed. *That I know of* and I'm no expert, 1 megaton is on the high side nowadays for missiles.

And as a reference, Fat Man (the bomb we dropped on Nagasaki in WWII), had a yield of about 21 Kilotons. So even with a warhead yielding 100 kilotons, you have almost 5 times the explosive power of that one.

[JesterODX]

Ok, I know I don't know anything about the sizes of these bombs, but isn't 300 megaton kinda big? I thought the current high yield was only around 30 megaton.

300 was the distance up not the mega ton.


It was always in our war plans to detonate several missles at high altitude for an attack on the soviets. They're communications systems back in the 70's and early 80's was so jinky it would have done fairly well. But by the mid and late 80's they said the systems had been upgraded enough that it would only do limited damage to civilian systems.

[Tater Raider]

Everyone:

One thing we need to keep in mind is if a hostile nation detonates a megaton-class thermonuclear device 300 nmi above Kansas; it would throw the entire Continental US, as well as much of Canada, and Mexico back into the mid 19th century (I think we can figure out how a fight with an uneffected opponent would play out.) The inductive pulse from such an event would slag any semiconductor (read: transistor) based eletronics almost instantly. So, folks should be thinking of how to store/cache such equipment in a manner to protect it. The only way I know how is what is known as a 'Faraday Cage'. You have an outer surface that is highly conductive, no gaps, openings sealed with conductive cushon (RFI seals), the inside electrically insulated, and connected to an earth ground,

The thing to keep in mind is that if there is an airburst nuke for EMP then you've got much, much bigger issues, like WW III. US reponse to any WMD attack has always been stated as we will reply with WMD.

Can you guess which WMD?

So yeah, WW III. A below grade fallout shelter makes a good faraday cage and you will be needing one if any nukes start to fly.





Having said that, my long term plans include a fallout shelter. It's lower on the priority list than food and water though. I suggest we prep for the likely then move towards the "We're all gonna die" stuff, but that's me.

Here's some video on the Tsar Bomba:

[crypto]

Does this mean my ACOG won't work?

To the OP: I'm guessing you're new here. Theres probably been 2 dozen posts on EMPs here in the last year or so, you may want to use the search function to post in one of those.

[TacAir]

It was not my intent to harsh on the OP, rather, ask him (or her) to share the source of their information. EMP is a pet bug of mine being 'done to death' in damn near every post-apocalyptic tale of late. Don't get me wrong - I'm the guy that smashed the Earth with Alien space junk.... but, still a little knowledge is not a good thing.



I found a site where the fellow has quite the bug over EMP and has posted, literately, a metric crapton of data, excerpts - and some opinion. I found it to an interesting read, well worth my time. The graphic above came from that site.
I am NOT saying this site is in any way Canonical on the subject, but the site owner has amassed quite a collection about EMP. Much of the 'real' data on the effects of atmospheric nuke bursts dates from the early 60s - and the comm systems of today bear little resemblance to the systems of yesteryear.

http://ed-thelen.org/EMP-ElectroMagneticPulse.html\

As noted by others, an EMP strike is about the last thing I worry about. Then again, I do own a PRC-109 with a GN-58 - about the 'hardest' piece of commo gear I know of... for fun! It was used extensively by US SOF types in SEA in the camps.

Have fun.

[-----P-----]

I wasn't intending to be snippy myself. If I came across that way, I apologize. According to the link you posted, my source wasn't entirely accurate anyway...

Thanks for sharing that TA. Lot's of interesting stuff on that site... There goes my work week.

[KJ4VOV]

we need a popcorn smiley
srsly

Here, use mine. It's imported.

[Tater Raider]

It was not my intent to harsh on the OP....

I wasn't intending to be snippy myself.

FWIW, nor I. I use cynical humor & sarcasm a bit but no harm intended. I do, however, like to put things in a bit of perspective. After a lot of debate here and research done on my own the above post was mine.

Just like every other free opinion, worth every penny you paid for it too.

[CryHavoc]

The thing is, the longer the wiring, more amperage gets ramped into it. So theoretically, you can unplug all of your electronics and they might not get fried by the EMP. If you knew it was coming.

http://blog.alexanderhiggins.com/2011/0 ... net-69021/

http://blog.alexanderhiggins.com/2011/0 ... war-41021/

There's a lot of knee-jerk reaction to this. So what if China is making EMP bombs? They've made nuclear bombs for over half a century and haven't used them. So has the U.S.

I'd be more worried about a CME (Coronal Mass Ejection) causing an EMP than another country. The sun doesn't care if you want to retaliate against it.

[Tater Raider]

If you knew it was coming.

That would be quite the trick, wouldn't it?

I'd be more worried about a CME (Coronal Mass Ejection) causing an EMP than another country. The sun doesn't care if you want to retaliate against it.

Agreed. EMP is diferent on a CME as well (different properties on E1, E2, and E3 radiation) and with CME you will have warning.

[Boyscoutdreams]

I'm also under the impression that a CME would also be a stronger EMP than any man made ones and would cover the entire planet, not just the hemisphere of impact. Unfortunately I am not positive of the facts and am still learning.

[Big and Daft]

Here is a quote from THIS THREAD:

Answers from a physicist follow:

I'll start with the grounding question, because that's the easiest to answer: Doesn't help a bit. All that matters is that the metal container is conductive and doesn't have gaps (ammo cans are bad at isolating from UHF on up because that rubber gasket only leaves the lid connected to the body at the ends, and that allows radiation in if the wavelength is short enough). If you're concerned about direct lightning hits, then having the can connected to ground could attract lightning to it, especially if it's much above ground level. I'd leave it ungrounded.

The paint can sounds like a great solution for anything small enough to fit inside. Since it's designed to make an airtight seal, you know you have metal-to-metal contact all the way around the edge of the lid. Trash cans aren't very good on that point -- the lid probably only touches the can at a few points, leaving long (also thin, but it's the long part that matters) gaps, so RF can get inside. They, like the ammo cans, will still protect well from low frequencies (such as indirect lightning effects). Insulation on the inside isn't really necessary (the whole point of the Faraday cage is that currents only flow on the outside surface), but I suppose it can't hurt.

Radios are a fine way to test isolation. It's better if you can control the signal strengths involved and have some basis for comparisons, so you can get an idea of how much attenuation the can provides. The point about testing at high frequencies is valid -- in all but a very very few cases, low frequencies will always be better-isolated than high frequencies. The microwave, I think, is one of those few counterexamples -- it's a resonant cavity tuned to one specific frequency (2.45 GHz), and the edges of the door are positioned at natural zero-current areas for that frequency. At any other frequency, the fact that the door isn't electrically connected to the body around most of the edge allows some RF through.

As for what frequencies matter for what sort of threats, it's time for numbers. Starting with the lowest, and therefore easiest for a Faraday cage to handle:

• Solar flares and resulting geomagnetic storms: Hundredths of a Hz. Complete non-issue for anyone but the guys running the power grid and pipelines. Small risk of surges on the power lines themselves from transformer failures, but absolutely no RF risk (i.e. if it's not plugged in, it doesn't give a damn).
• Lightning: Mostly below 1 MHz. That means wavelengths of hundreds of meters, so anything that more or less surrounds your electronics will protect from the electromagnetic waves (i.e. the indirect effects that extend hundreds of meters from the strike). Direct hits from the strike itself are nearly impossible to protect against, since a lightning strike can easily blow a hole through something like an ammo can. But those follow conductors, so don't store your Faraday-protected electronics next to that wire running to the old TV antenna on your chimney. For testing in this frequency range, try an AM radio tuned to the strongest station you can find.
• Nuclear EMP: Worst below 100 MHz, but significant up to several hundred MHz. Wavelengths as short as several inches. This is where things become demanding. Gaps of several inches in length may allow RF to penetrate into a Faraday cage. Making sure the lid contacts the body around its whole circumference, or at least every inch or two, is important. To test isolation for this sort of thing, try at least UHF (FRS/GMRS radios operate around 460-470 MHz, which is a good example).
• Non-nuclear EMP bomb: Up to several GHz, perhaps tens of GHz. Wavelengths down below an inch. Damn hard to shield against, but short-ranged and, in my opinion, not likely to be seen unless you're on the wrong end of a serious attack from a high-tech power. If you're still concerned about it, then look to absolutely, completely seal your Faraday cage. Consider soldering the lid on to that paint can. Testing at cellphone/wifi frequencies would be a start, but threats could go well beyond that frequency range. There just isn't much consumer hardware that uses frequencies this high.

In fact, there is a lot of good information all the way through the thread - well worth a read.

[KJ4VOV]

Here is a quote from THIS THREAD:

Answers from a physicist follow:

I'll start with the grounding question, because that's the easiest to answer: Doesn't help a bit. All that matters is that the metal container is conductive and doesn't have gaps (ammo cans are bad at isolating from UHF on up because that rubber gasket only leaves the lid connected to the body at the ends, and that allows radiation in if the wavelength is short enough). If you're concerned about direct lightning hits, then having the can connected to ground could attract lightning to it, especially if it's much above ground level. I'd leave it ungrounded.

The paint can sounds like a great solution for anything small enough to fit inside. Since it's designed to make an airtight seal, you know you have metal-to-metal contact all the way around the edge of the lid. Trash cans aren't very good on that point -- the lid probably only touches the can at a few points, leaving long (also thin, but it's the long part that matters) gaps, so RF can get inside. They, like the ammo cans, will still protect well from low frequencies (such as indirect lightning effects). Insulation on the inside isn't really necessary (the whole point of the Faraday cage is that currents only flow on the outside surface), but I suppose it can't hurt.

Radios are a fine way to test isolation. It's better if you can control the signal strengths involved and have some basis for comparisons, so you can get an idea of how much attenuation the can provides. The point about testing at high frequencies is valid -- in all but a very very few cases, low frequencies will always be better-isolated than high frequencies. The microwave, I think, is one of those few counterexamples -- it's a resonant cavity tuned to one specific frequency (2.45 GHz), and the edges of the door are positioned at natural zero-current areas for that frequency. At any other frequency, the fact that the door isn't electrically connected to the body around most of the edge allows some RF through.

As for what frequencies matter for what sort of threats, it's time for numbers. Starting with the lowest, and therefore easiest for a Faraday cage to handle:

• Solar flares and resulting geomagnetic storms: Hundredths of a Hz. Complete non-issue for anyone but the guys running the power grid and pipelines. Small risk of surges on the power lines themselves from transformer failures, but absolutely no RF risk (i.e. if it's not plugged in, it doesn't give a damn).
• Lightning: Mostly below 1 MHz. That means wavelengths of hundreds of meters, so anything that more or less surrounds your electronics will protect from the electromagnetic waves (i.e. the indirect effects that extend hundreds of meters from the strike). Direct hits from the strike itself are nearly impossible to protect against, since a lightning strike can easily blow a hole through something like an ammo can. But those follow conductors, so don't store your Faraday-protected electronics next to that wire running to the old TV antenna on your chimney. For testing in this frequency range, try an AM radio tuned to the strongest station you can find.
• Nuclear EMP: Worst below 100 MHz, but significant up to several hundred MHz. Wavelengths as short as several inches. This is where things become demanding. Gaps of several inches in length may allow RF to penetrate into a Faraday cage. Making sure the lid contacts the body around its whole circumference, or at least every inch or two, is important. To test isolation for this sort of thing, try at least UHF (FRS/GMRS radios operate around 460-470 MHz, which is a good example).
• Non-nuclear EMP bomb: Up to several GHz, perhaps tens of GHz. Wavelengths down below an inch. Damn hard to shield against, but short-ranged and, in my opinion, not likely to be seen unless you're on the wrong end of a serious attack from a high-tech power. If you're still concerned about it, then look to absolutely, completely seal your Faraday cage. Consider soldering the lid on to that paint can. Testing at cellphone/wifi frequencies would be a start, but threats could go well beyond that frequency range. There just isn't much consumer hardware that uses frequencies this high.

In fact, there is a lot of good information all the way through the thread - well worth a read.

I'll second that. Bunsen knows his stuff, and straightened out some wrong information I had, as well as providing additional information of interest.

[MadMichigander13]

Everyone:

One thing we need to keep in mind is if a hostile nation detonates a megaton-class thermonuclear device 300 nmi above Kansas; it would throw the entire Continental US, as well as much of Canada, and Mexico back into the mid 19th century (I think we can figure out how a fight with an uneffected opponent would play out.) The inductive pulse from such an event would slag any semiconductor (read: transistor) based eletronics almost instantly. So, folks should be thinking of how to store/cache such equipment in a manner to protect it. The only way I know how is what is known as a 'Faraday Cage'. You have an outer surface that is highly conductive, no gaps, openings sealed with conductive cushon (RFI seals), the inside electrically insulated, and connected to an earth ground,

I, for one, would be interested in your source for these statements.

Well, I believe there is a book 'One Second After' which discusses the effects on the general public after an EMP event (heard about it on Sean Hannity a couple of years ago). I first learned about it in an aricle in Science Digest over 20 years ago. And a good reference is Mr. Gary Smith's testimony/presentation to the House National Security Committee "Electromagnetic Pulse Threats" made on July 16th 1997. This is a phenomena that was discovered in 1962 by accident during an exo-atmospheric nuclear test (Starfish Prime)

[Doctorr Fabulous]

Another good source is current DOD/DOE testing on modern vehicles, in which most vehicles either didn't react, or shut down, but were able to re-start. Take a look at the other threads linked. One Second After was fantasy, based somewhat in reality, but not entirely.

[MadMichigander13]

Ok, I know I don't know anything about the sizes of these bombs, but isn't 300 megaton kinda big? I thought the current high yield was only around 30 megaton.

The biggest device ever deployed was the Soviet "Tzara Bomba" (King of Bombs) rated at 100 Megatons, and was so large it had to be conformally mounted on special TU-95 Bear bombers (couldn't be carried internally.) The largest nuclear detonation was the clean config of this monster which was 57 Megatons.