Refresher on EMP please

[Barms 98]

If we discussed this in detail can someone link?

 

I'm really concerned about what gets affected and what doesn't. So anything with a circuit or transistor is inoperable, right? So do batteries still work? How about battery powered flashlights? How about a battery powered LED lantern. I figure the least i want to have survive is a light. If at least I know I got a lantern and a gun I can start thinking about what else to EMP protect.

 

Thank you.

[A-Tech 8]

If you're that dependent on electrical devices, build a faraday cage.

[Pythagoras 2]

Physics PhD student here, so I may not have the most practical advice but I can tell you what's going on.

 

When a disaster-style, high-above-the-country EMP occurs, it's basically a big "surge" in magnetic field that moves down toward the ground (if you want to Google it, this "surge" is called "a change in magnetic flux"). When magnetic flux changes near a wire, it causes an induced current to flow in the wire. If this induced current is bigger than the wire can handle, the wire melts. So the EMP is basically like hooking up your electronic device to a WAY TOO STRONG power source and blowing the circuit. (Ever plug too many hair dryers in at once? You'll draw too much current and blow the circuit...only your device has no fuse box/circuit breaker, so the wires just melt.)

 

So the question comes down to two factors: how big is the EMP, and how small are your wires? A transistor has really tiny metal "wires" that are practically just painted-on metal, so computers die real easy. But your jumper cables are pretty big and handle fairly large current, so they'll probably be fine. What we're interested in is, what falls in the middle?

 

You have to take stock of your equipment and look at how small the wires are. The smaller they are, the more vulnerable to EMP. I wish I could give you a rule of thumb, but I don't know one off the top of my head: it would depend on how big the EMP is, kind of like how different fallout shelters are rated to different levels of nuclear blasts. But I will look into this.

 

 

On the bright side, you can protect your devices VERY EASILY by storing them in a Faraday cage (a metal container that blocks the magnetic field from reaching the wires). You don't need to buy any fancy/expensive prepper BS, just use an old school metal garbage can with the lid on tight and seal it with conducting tape. Hell, you could wrap a shoebox in aluminum foil... More info here: http://www.thesurvivalistblog.net/build-your-own-faraday-cage-heres-how/ , or just Google "build a Faraday cage" for tips.

 

 

 

As for your specific list:

-Batteries are fine, they don't have wires in them.

-Flashlights depend on the gauge of the wires inside, as discussed above. Avoid anything with a green silicon "circuitboard" in it because it will have the really tiny wires. Sounds dumb, but plenty of flashlights have em cuz they're cheaper to make that way. Note: an all-metal flashlight like a Maglite should act as its own Faraday cage (SHOULD... I have not tested this myself) and thus protect the wires within. Like we needed another reason to choose MagLite reliability, lol.

-Lanterns also depend on wire gauge, see above about flashlights. But most lanterns are made of plastic, so you don't get that self-shielding effect with them.

 

Hope this helps! Who knew a physics degree would actually be USEFUL for something?

[checko 180]

What good are our devices if they fry the source of our electric?

 

Sent from my Xoom using Tapatalk

 

 

[A-Tech 8]

What good are our devices if they fry the source of our electric?

 

Sent from my Xoom using Tapatalk

battery and generator

[Sota 1,191]

Just another reason to keep around the 197 MGB with points style ignition in it.

[Barms 98]

Okay so to be on safe side keep the battery powered lantern in a cage. Thanks.

[Malsua 1,422]

I've done quite a lot of reading and discussing EMP over at one of my other forums over the years.

 

A nuclear EMP has multiple pulses, and there's an entire breakdown of what and how it inducts current, but the bottom line is that most unshielded equipment will go belly up.

 

The upside is that there are some cheap things you can do.   

 

If you have an old microwave oven, you can store items in it that you'd like to be protected.   A handheld radio, maybe a HAM set, etc.    Surprisingly, metal ammo cans will probably also perform the same functin. 

 

Also, it is entirely possible that you will be shadowed from the main pulse of an EMP, specially if it's not lit off at high altitude, like for example, a Boeing 777 flying at 45,000 feet over Manhattan when the EMP is detonated.

 

Suprisingly, a car is a pretty good faraday cage and some will survive.  60s era cars will be unaffected entirely.

 

Many generators that aren't plugged into anything should also survive, but anything plugged into the wall probably won't. The wiring is one big antenna.

[Vlad G 345]

I think most people overstate the EMP threat. 

 

First of all, what gets destroyed depends greatly of the wave lengths, angles, etc involved.  EMP wepons are pretty hard to make to begin with, probably US and Russia are the only people who know how to do it even halfassed because no weapon was ever tested explicitly for it. Sure, Starfish Prime had a bit of a "oops" about it, and then we blew up some more generic nukes to see what happens when we do it at the edge of space, but we never let one go that specifically designed for EMP.  Think how many thousandths of nukes we've blown up to perfect our arsenals, so it might take some time to make a EMP nuke that works. 

 

Even if you did manage to make one, you probably need an ICBM to get it into place to make it effective. That means US/Russia/China for all practical purposes. Guess what, if anyone shoots one at the others, it is global thermonuclear war time, as nukes are nukes and all the subs in the world will have a missile ejaculation party quickly followed by all the bad 60's end of the world movies. It makes no sense to launch an EMP attack at a supper power instead of a plain nuclear attack because you are going to get nuked anyway, so you might just well go all out.

 

Sure rogue nation number 12 might be able to build a small nuke, but one that works for EMP or that they can let go at the right spot to work? This is prepper fiction fantasy. Why bother? They might as well nuke DC for a lot cheaper if terrorism is their goal, its not as if the US military across the world would be disabled by EMP and not be able to respond with extreme prejudice.

 

Then you have Carrington event solar flare thing. 

 

We have two known examples of it in the age of electricity. First we have he 1859 storm that everyone is afraid of, which realistically it wasn't that bad. Sure, telegraph lines cooked off, but they would because they are long wires, effectively very long electromagnetic receivers.  The small devices at the end, the actual telegraphs did not fail by enlarge. Thing is though, these were the very early days of electricity and wires, we didnd't know  that much about designing things correctly, adding simple devices such as fuses, breakers, grounding, etc. 

 

The second one was in 1989, which knocked some satellites offline resulted in a 9h blackout in Canada. this was a X15 class solar flare, in theory much smaller then the estimated Z class Carrington event, but it was a pretty direct hit. Most of the damage was done due to tripping breakers. The long power lines overloaded, the breakers tripped, and when that happens at a large scale it takes some time to bring stuff back online. Actual physical damage to infrastructure was relatively small, a few transformers cooked off,  but damage to small electronics was probably zero, the costs of stopping stuff for while is not really the issue here. 

 

Would a Z class flare today we would certainly have grid problems. We would probably lose quite a few transformers here and there. I would be worried about nuclear plants when they are cut of from the grid and need to cool the pools. I would be worried about riots, food distribution, fuel distribution, etc. 

 

What would not worry about at all is small devices in your home or around it. They don't have enough wire to gather that much charge, and realistically they haven't been damaged in past events. I know that prepper literature uses EMP as the boogie man, but I suspect that is because it a convenient trope.  It is a easy way to say "everything is broken" without having to really explain it, it is a convenient way to move the world back to pre-industrial status without actually working in the premise.  There is some truth to its concerns, but the stuff you own is the least of the concerns. Can your car have issues? Maybe, but cars can withstand direct lighting strikes without even stalling so probably they would be fine. Your cell and hand radio will probably be fine. I wouldn't worry about Faraday cages, and a heck of a lot more about food and fuel supply which are far more likely to be affected in a grid down scenario.  Ask yourself what happens when the water pumping station runs out of power. Ask yourself what happens if the water stops flowing and sanitations stop working. 

 

Your hand held devices hidden in the microwave would probably be rather pointless, and would have probably been fine anyway. 

[mechman 0]

Steve Harris discussed this on the Survival podcast.  I forget exactly his explaination but in the end its not going to happen and anything you try to protect is pointless anyway.  I dont recall the eposide but it was really a good explaination. 

[Old Glock guy 1,127]

I heard somewhere that a microwave oven is a good Faraday cage. I had an old clunker I was going to get rid of, but decided to save it. It seems to work. When I place my cellphone in it and dial it from my house phone, it doesn't ring.

 

My concerns are, first how will I know that an EMP is coming, to put my stuff in there?

Second, will it really work?

And third, if the grid is fried, what use is the stuff I've saved (as checko noted above).

[Spike 7.62 0]

Stop wasting your time worrying about an EMP. It will never, ever happen, period. Radiological fallout is more realistic, prep for that instead.

[NEAHS 11]

[mipafox 438]

 

I think most people overstate the EMP threat. 

 

First of all, what gets destroyed depends greatly of the wave lengths, angles, etc involved.  EMP wepons are pretty hard to make to begin with, probably US and Russia are the only people who know how to do it even halfassed because no weapon was ever tested explicitly for it. Sure, Starfish Prime had a bit of a "oops" about it, and then we blew up some more generic nukes to see what happens when we do it at the edge of space, but we never let one go that specifically designed for EMP.  Think how many thousandths of nukes we've blown up to perfect our arsenals, so it might take some time to make a EMP nuke that works. 

 

Even if you did manage to make one, you probably need an ICBM to get it into place to make it effective. That means US/Russia/China for all practical purposes. Guess what, if anyone shoots one at the others, it is global thermonuclear war time, as nukes are nukes and all the subs in the world will have a missile ejaculation party quickly followed by all the bad 60's end of the world movies. It makes no sense to launch an EMP attack at a supper power instead of a plain nuclear attack because you are going to get nuked anyway, so you might just well go all out.

 

I agree partially. The people that say everything will be fried by any EMP attack are not correct. "It Depends."

 

But it does not take any sophistication to pull off such an attack. Any nuke causes an EMP. Heck, large conventional explosive blasts cause EMPs. This is not like an Enhanced Radiation Bomb. Nuke=EMP, big nuke =Big EMP, nuke at proper altitude = maximum affect. But altitude is not even required.

 

We don't know where it will go off or how powerful it will be. FEMA had public predictions about nuke targets in the 1980s and 1990s. Even if they were only 50% correct, they could have helped preparedness if our nation was like the smarter ones and prepared for nuclear war. But that is not what we are talking about. We don't have so much as a guess where or what or how an EMP attack might be conducted. And, even worse, we wouldn't know what it would do if we even knew all the particulars.

 

We only know what is on our end. Conductor length, voltage sensitivity, and shielding. Clearly, solid state devices such as microcircuits have the lowest tolerance, and if they are connected to long conductors, they have the highest risk. On the other end of the scale are things like motors and such, that could only be damaged by an EMP if they were vulnerable to the smallest common transient and were connected to the grid. (Not including VFDs or associated PLCs of course).

 

Even the most sensitive common equipment (within reason) would therefore be safe if entirely enclosed within metal (ammo can/aluminum foil) and not connected to any external conductors/circuits.

[Vlad G 345]

Sure, all nukes generate EMP, its just that for most the radius of EMP effect is roughly the same that of oh-my-god-my-skin-is-on-fire-put-it-out-put-it-out .

 

Think of all the nukes on film and all the electronics on ships and so on, Those things weren't shielded because we didn't even know about it.  To get large scale EMP that has significant effects you need to a specific type of weapon detonated at very high altitudes, like the edge of space.

[Spike 7.62 0]

Sure, all nukes generate EMP, its just that for most the radius of EMP effect is roughly the same that of oh-my-god-my-skin-is-on-fire-put-it-out-put-it-out .

 

Think of all the nukes on film and all the electronics on ships and so on, Those things weren't shielded because we didn't even know about it. To get large scale EMP that has significant effects you need to a specific type of weapon detonated at very high altitudes, like the edge of space.

Absolutely correct.

 

Consider this.. Our policy is to nuke into oblivion anyone who nukes us. Who is going to totally sacrifice themselves just to turn off half our electronics? Who would be SO mad at us that they launch nuclear ICBMs, BUT NOT be mad enough to target anything except your cell phone or car battery... That sounds pretty dumb, right? Our enemies have nuclear capability. If they deliver the weapon via missile they won't waste it on an EMP effect, they will actually physically destroy their target. Our less sophisticated enemies have no vehicle to deliver the weapon so it will be a ground-level detonation, again physically destroying the target. As pointed out, anything affected by EMPs by the actual use of a nuke will also be severely damaged and contaminated, if not entirely destroyed.

[mipafox 438]

Sure, all nukes generate EMP, its just that for most the radius of EMP effect is roughly the same that of oh-my-god-my-skin-is-on-fire-put-it-out-put-it-out .

 

Think of all the nukes on film and all the electronics on ships and so on, Those things weren't shielded because we didn't even know about it.  To get large scale EMP that has significant effects you need to a specific type of weapon detonated at very high altitudes, like the edge of space.

Now we agree less. It does not require a specific type of weapon. Like I said, this is not like an ER weapon.

 

I already addressed that area of effect is altitude dependent. That is not a tough nut to crack.

 

It is not in any way a sophisticated attack.

[Vlad G 345]

Err .. dude .. nuclear weapons are a sophisticated thing to begin with, other wise every Tom, Dick and Harry would be nuking each other off the planet. I know they are "old" tech but there is a massive barrier to entry.  You are overestimating the ease of generating such a thing. I again remind you, that not even the US or Russia really understand the issue in depth, and have never really even conducted tests specifically aimed at this.  It is all theoretical, based on a couple of accidentally observed effects. 

 

You are making it sound as any if any mud hut engineer can figure out how to calculate optimal detonation height for a untested nuclear device and build a missile that can take it to roughly the height of ISS and then detonate it just the right way... 

 

If your theory is correct how come you still have internets to tell us about it?

[Smokin .50 1,907]

I remember viewing a documentary on Net Flix about the Cold War testing of Nukes (actually almost a dozen of them).  I remember watching the part about a Nuke test causing a blackout on the west coast.  Narrator mentioned that the effect wasn't planned for.  I've watched EVERY documentary known to exist on nuke testing.  From what I can extrapolate, neither side wants to create an EMP device, since you still have to protect your own equipment from its' effects, say during an invasion, when forces would be ready to advance from a perimeter.  Which is why the Communist Chinese designed "gas masks" for their horses and Cavalry soldiers to wear as they charged directly towards the exploding nukes with the reigns in one hand and Chinese machine guns firing-away in the other (also in the documentary).  Then we secretly built the Neutron Bomb in Turkey so we could save the real estate and the oil assets if we deployed it.  After-all, no sense in making what's left of your enemy and/or their country useless after a "superior, high-order detonation", lol!

 

The whole EMP scenario is like letting the Genie out of the bottle.  No way to control pin-point accuracy, or to predict solar flare effects in combination with deployment.  No way to do it in the upper atmosphere without everybody knowing about it.  No way to test it without damaging your own observation equipment.  At least not cheaply enough to keep it a secret in this day-in-age.  Let's hope that the Genie stays in the bottle...

[Shawnmoore81 623]

I just hope my eotech survives

[Vlad G 345]

I remember viewing a documentary on Net Flix about the Cold War testing of Nukes (actually almost a dozen of them).  I remember watching the part about a Nuke test causing a blackout on the west coast.  Narrator mentioned that the effect wasn't planned for.  I've watched EVERY documentary known to exist on nuke testing.  From what I can extrapolate, neither side wants to create an EMP device, since you still have to protect your own equipment from its' effects, say during an invasion, when forces would be ready to advance from a perimeter.  Which is why the Communist Chinese designed "gas masks" for their horses and Cavalry soldiers to wear as they charged directly towards the exploding nukes with the reigns in one hand and Chinese machine guns firing-away in the other (also in the documentary).  Then we secretly built the Neutron Bomb in Turkey so we could save the real estate and the oil assets if we deployed it.  After-all, no sense in making what's left of your enemy and/or their country useless after a "superior, high-order detonation", lol!

 

 

You are thinking Trinity and Beyond, scary little documentary. The accidental EMP case was in the Pacific, it was called Starfish Primed and it affected parts of Hawaii. 

[mipafox 438]

 

Err .. dude .. nuclear weapons are a sophisticated thing to begin with, other wise every Tom, Dick and Harry would be nuking each other off the planet. I know they are "old" tech but there is a massive barrier to entry.  You are overestimating the ease of generating such a thing. I again remind you, that not even the US or Russia really understand the issue in depth, and have never really even conducted tests specifically aimed at this.  It is all theoretical, based on a couple of accidentally observed effects. 

 

You are making it sound as any if any mud hut engineer can figure out how to calculate optimal detonation height for a untested nuclear device and build a missile that can take it to roughly the height of ISS and then detonate it just the right way... 

 

If your theory is correct how come you still have internets to tell us about it?

You seem to be confounding a few different things.

 

If you have nukes, there is no special magical calculation or detonation in just the right way involved in pulling off an EMP attack. Other than the Teacher's Union of New York City getting a suitcase nuke from Ukraine as a contribution for the 2014 campaign season, anybody that has possession of nukes can pull this off. The nukes are overwhelmingly the hard part.

[Vlad G 345]

If you have nukes, there is no special magical calculation or detonation in just the right way involved in pulling off an EMP attack. 

 

You are simply wrong. Would please provide some background for your information.  Again, every nuke generates some form of EMP, but not every nuke generates the same kind or size of EMP. Even more important for EMP to be real danger the nuke needs to be detonated at very high altitudes, like in Starfish Prime. 

[Smokin .50 1,907]

You are thinking Trinity and Beyond, scary little documentary. The accidental EMP case was in the Pacific, it was called Starfish Primed and it affected parts of Hawaii. 

 

Thanks!  Just looked it up.  This was the one I was thinking of.  Now I remember all about it.  Antique radios weren't affected, but transistorized, well that was another story.  Radio, navigation, everything was affected.  One report spoke of street lights being out as if it was a minor inconvenience, but failed to mention aircraft in flight, ships at sea, etc.  LOTS of hidden damage for only a 1.4 MT device at 250 miles elevation!  A thousand miles of effects, possibly more.  A Genie has been let out of the bottle that night!  

[Vlad G 345]

Thanks!  Just looked it up.  This was the one I was thinking of.  Now I remember all about it.  Antique radios weren't affected, but transistorized, well that was another story.  Radio, navigation, everything was affected.  One report spoke of street lights being out as if it was a minor inconvenience, but failed to mention aircraft in flight, ships at sea, etc.  LOTS of hidden damage for only a 1.4 MT device at 250 miles elevation!  A thousand miles of effects, possibly more.  A Genie has been let out of the bottle that night!  

 

All true, but just for some perspective on what 250 miles up means, the international space station orbits at 205miles up. We are talking about ICBM land.  Mir was at 242, and not all the space shuttles could reach it, Columbia being older just didn't have the engines to make it there. 

 

What I'm saying is that just because the US, Russia and China can get booms at that height, it is not a trivial endeavor. 

[Smokin .50 1,907]

Certainly not trivial!  

 

In checking today about the test, I noted that a previous launch vehicle (the first attempt, also with a Thor ICBM) had to be destroyed by the Range Safety Officer initiating a self-destruct order which was then radioed to the launch vehicle.  The resulting explosion rained-down nuclear material upon the launch site on Johnston Island and the entire Pacific Ocean area for MILES around it, leading to widespread nuclear contamination in what was one of the very first "Dirty Bombs" in history.

 

Most folks who aren't "Space Junkies" like us, never realize that every launch vehicle ever fired from the Cape has scuttling charges built-into it and a radio receiver dedicated to receiving the self-destruct signal from the Range Safety Officer.  The order for such signal transmission would be given if the launch vehicle would veer off-course beyond a suitable correction.  And that includes every manned space flight!  During the Challenger Disaster, when the SRB's separated prematurely from the launch vehicle due to the explosion at throttle-up, the SRB's were still firing, and so had to be scuttled before they could fly over land and fall to Earth killing the good people of Florida.....  

 

Getting back to EMP threats:  Personally I believe the greatest threat is a Dirty Bomb comprised of fissionable materials salvaged from rusting hulks of what used to be Soviet Attack Subs, as well as other such things.  I do hope our people at Langley are ever vigilant..........

[HavocMan 13]

I just hope my eotech survives

 

I'm surprised it works now, LOL ... couldn't resist.

 

 

 

Someone further up mentioned that they were worried about a nuke plant going high order after getting knocked off the grid.

 

Don't worry. Getting knocked off the grid is no biggie. Instead of using its steam to drive its generators, the plant will just vent it all.

 

In addition, and speaking in general, power plants are hardened sites - and not just nuke plants. EMP? Big Whoop.....

 

Problems arise when a nuke plant somehow loses access to its source of cooling water. Even then, there are multiple levels of containment.