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This is a discussion on Emp within the Space & Defense Technology forum, part of the Global Defense & Military category; I have been trying to understand the real dangers of an EMP attack on the US. I understand that many ...


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Old August 29th, 2009   #1
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I have been trying to understand the real dangers of an EMP attack on the US. I understand that many military systems are hardened and that almost no civilian systems are. I have seen conflicting information on the impact of an EMP on cars and trucks. Some info says that all cars and trucks not protected by a Faraday cage would become immobilized. Other info says that the car itself is a Faraday cage. Still other info says that only older vehicles with points have a chance of working after an EMP if not protected by a Faraday cage. What are the real facts regarding cars and trucks and an EMP?
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Old August 29th, 2009   #2
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I have been trying to understand the real dangers of an EMP attack on the US. I understand that many military systems are hardened and that almost no civilian systems are. I have seen conflicting information on the impact of an EMP on cars and trucks. Some info says that all cars and trucks not protected by a Faraday cage would become immobilized. Other info says that the car itself is a Faraday cage. Still other info says that only older vehicles with points have a chance of working after an EMP if not protected by a Faraday cage. What are the real facts regarding cars and trucks and an EMP?
I doubt mechanical systems could be affected directly through an EMP detonation/release. It is the processor supported/ driven systems that will get affected.
Maybe the head lights could blow out dont know for sure

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Old August 29th, 2009   #3
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Older cars would almost certainly be unaffected, but items in the newer cars, things like your sat nav, would break.

As long as you have a normal starter, not a button or keyless system, it should start and stop ok.
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Old August 31st, 2009   #4
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Originally Posted by Byrnezie View Post
I have been trying to understand the real dangers of an EMP attack on the US. I understand that many military systems are hardened and that almost no civilian systems are. I have seen conflicting information on the impact of an EMP on cars and trucks. Some info says that all cars and trucks not protected by a Faraday cage would become immobilized. Other info says that the car itself is a Faraday cage. Still other info says that only older vehicles with points have a chance of working after an EMP if not protected by a Faraday cage. What are the real facts regarding cars and trucks and an EMP?
I've read the other replies & it got me thinking.....


Have you tried here ???

Electromagnetic pulse - Wikipedia, the free encyclopedia



Also, I remembered that discovery did a program with a section on it, in 2006 as part of the series 'Future Weapons'. Here's a link....
Future Weapons: EMP Bomb : Video : Discovery Channel Channel

That will pretty much ruin your day...

Hope this helps..

SA
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Old September 5th, 2009   #5
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Originally Posted by Byrnezie View Post
I have been trying to understand the real dangers of an EMP attack on the US. I understand that many military systems are hardened and that almost no civilian systems are. I have seen conflicting information on the impact of an EMP on cars and trucks. Some info says that all cars and trucks not protected by a Faraday cage would become immobilized. Other info says that the car itself is a Faraday cage. Still other info says that only older vehicles with points have a chance of working after an EMP if not protected by a Faraday cage. What are the real facts regarding cars and trucks and an EMP?
A Faraday cage is a space surrounded on all sides by electrically connected conductor materials (metals, alloys...) - hence the word "cage". It doesn't have to be very elaborate, in fact it can be rather crude and still protect from electromagnetic waves. A car's carcass is such a cage, that is one of two (and the main) reasons why you're safe in your car from lightning strikes (second - insulation from ground). Same goes for EMP pulses. But since a lot of electrical stuff is located under the hood in the front or elsewhere not inside the car's cage, it's susceptible to EMPs without deliberate construction against such interference (which should be very simple to accomplish).

All the electrical systems can be affected, including the vehicle's computer.

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Old September 5th, 2009   #6
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A Faraday cage is a space surrounded on all sides by electrically connected conductor materials (metals, alloys...) - hence the word "cage". It doesn't have to be very elaborate, in fact it can be rather crude and still protect from electromagnetic waves. A car's carcass is such a cage, that is one of two (and the main) reasons why you're safe in your car from lightning strikes (second - insulation from ground). Same goes for EMP pulses. But since a lot of electrical stuff is located under the hood in the front or elsewhere not inside the car's cage, it's susceptible to EMPs without deliberate construction against such interference (which should be very simple to accomplish).

All the electrical systems can be affected, including the vehicle's computer.

Cheers
I always thought the Faraday's Cage had to be grounded to protect electronics from an EMP. Also EMP energy ranges across a significant portion of the electromagnetic spectrum " Frequency or Wavelength". In particular Microwave/Radio waves and x-rays wouldn't thy pass through the windows and damage electronics inside.
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Old September 5th, 2009   #7
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I always thought the Faraday's Cage had to be grounded to protect electronics from an EMP. Also EMP energy ranges across a significant portion of the electromagnetic spectrum " Frequency or Wavelength". In particular Microwave/Radio waves and x-rays wouldn't thy pass through the windows and damage electronics inside.
Nuclear blast EMP is a complex event with several components to it, but the effect would be greatly reduced even if the cage is not grounded , although grounding helps.
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Old September 6th, 2009   #8
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Nuclear blast EMP is a complex event with several components to it, but the effect would be greatly reduced even if the cage is not grounded , although grounding helps.

I fully understand how EMP weapon's work, both HEMP and HPRF. I was just wondering how you came to the conclusion that putting the "electrical stuff" in side the car would protect them from any type of EMP. Do to the fact that the car has large holes (windows) in it?
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Old September 6th, 2009   #9
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I fully understand how EMP weapon's work, both HEMP and HPRF. I was just wondering how you came to the conclusion that putting the "electrical stuff" in side the car would protect them from any type of EMP. Do to the fact that the car has large holes (windows) in it?
A car's cage is a Faraday cage, and as such will reduce E&M effect and spikes in electrical field, windows or not.
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Old September 7th, 2009   #10
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A car's cage is a Faraday cage, and as such will reduce E&M effect and spikes in electrical field, windows or not.

A cars cage act's as a Faraday's Cage yes .So does the steel frame of a building or a wooden house for that matter.But nether protects from EMP devices. There is a very big difference between Electrostatic discharge and Electromagnetic radiation.
The body of an automobile will do nothing to protect electronics inside from EMP And depending on the size and design may actually magnify the affect. The only way to Harden a vehicle from EMP is to isolate the vulnerable electronics as much as possible . Shield them with conductive mettle or a conductive fine screen.Then shield all wires and censers connected to the electronics. To do this in the average automobile would cost more the vehicle itself. Most new vehicle have hundred of censers that are connected to the control module for diagnostics. You maybe able to eliminate some but most are there for emissions so can not be removed by law at least in the US.Thats why most hardened vehicles have only the basic instruments and amenities, Aircraft are much more complicated.
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Old September 7th, 2009   #11
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A cars cage act's as a Faraday's Cage yes .So does the steel frame of a building or a wooden house for that matter.But nether protects from EMP devices. There is a very big difference between Electrostatic discharge and Electromagnetic radiation.
The body of an automobile will do nothing to protect electronics inside from EMP And depending on the size and design may actually magnify the affect. The only way to Harden a vehicle from EMP is to isolate the vulnerable electronics as much as possible . Shield them with conductive mettle or a conductive fine screen.Then shield all wires and censers connected to the electronics. To do this in the average automobile would cost more the vehicle itself. Most new vehicle have hundred of censers that are connected to the control module for diagnostics. You maybe able to eliminate some but most are there for emissions so can not be removed by law at least in the US.Thats why most hardened vehicles have only the basic instruments and amenities, Aircraft are much more complicated.
First of all, a wooden house or anything else that is not conductive cannot make a Farady cage and has no effect on anything of the sort. You're right that a Faraday cage protects fully against electrostatic fields but you should know that it also significantly protects against E&M and you are wrong to say it does nothing, and, no, a Farady cage cannot amplify EMP. And since we're talking about EMP from a nuclear blast there can be a strong electrostatic discharge as well, so the car's cage definitely helps. And when you talk about providing a mesh or a fine screen as protection - that is also a Farady cage, just with finer mesh, the size of which is irrelevant for the electrostatic discharges (a car does just fine), and there's only a very small percentage of the E&M spectrum (a small part of the radio waves spectrum) of EMP that cares about whether it's a mesh or the whole car that is acting as the cage, and for the rest of it (with larger wavelengths) a car's cage is just as good as a fine mesh. Now, I don't know the breakdown of a typical EMP radio wave spectrum by frequencies but assuming it is not preferential to its highest frequency tail (where a mesh would be better) then what I described above is true.
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Old September 7th, 2009   #12
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First of all, a wooden house or anything else that is not conductive cannot make a Farady cage and has no effect on anything of the sort. You're right that a Faraday cage protects fully against electrostatic fields but you should know that it also significantly protects against E&M and you are wrong to say it does nothing, and, no, a Farady cage cannot amplify EMP. And since we're talking about EMP from a nuclear blast there can be a strong electrostatic discharge as well, so the car's cage definitely helps. And when you talk about providing a mesh or a fine screen as protection - that is also a Farady cage, just with finer mesh, the size of which is irrelevant for the electrostatic discharges (a car does just fine), and there's only a very small percentage of the E&M spectrum (a small part of the radio waves spectrum) of EMP that cares about whether it's a mesh or the whole car that is acting as the cage, and for the rest of it (with larger wavelengths) a car's cage is just as good as a fine mesh. Now, I don't know the breakdown of a typical EMP radio wave spectrum by frequencies but assuming it is not preferential to its highest frequency tail (where a mesh would be better) then what I described above is true.
I Didn't mean to poke you in the eye. Actually I said a wooden house act's as a Faraday's cage. When a house is struck by lightning the electricity travels down the exterior walls to the ground and the occupants are unharmed?(Not unlike a Faraday cage).
I do apologize for saying the body of the car does nothing That was an incorrect statement. It is affective for a portion of the E1 and all of the E2 stage,E3 a none player here. I would think a vehicle like a cargo van with the windows at only one end would amplify an EMP unless it was grounded. As fare as the spectrum thats debatable but the people who know don't talk about it. I still don't think the body of a car is effective enough to protect the electronics inside. at least we agree to disagree.
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Old September 7th, 2009   #13
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I Didn't mean to poke you in the eye. Actually I said a wooden house act's as a Faraday's cage. When a house is struck by lightning the electricity travels down the exterior walls to the ground and the occupants are unharmed?(Not unlike a Faraday cage).
I do apologize for saying the body of the car does nothing That was an incorrect statement. It is affective for a portion of the E1 and all of the E2 stage,E3 a none player here. I would think a vehicle like a cargo van with the windows at only one end would amplify an EMP unless it was grounded. As fare as the spectrum thats debatable but the people who know don't talk about it. I still don't think the body of a car is effective enough to protect the electronics inside. at least we agree to disagree.
It seems that you're referring to different components of the EMP blast with E1-E3 (I'm not familiar with the names), and you summed it up correctly (I know of three different components and that's probably what E1-E3 are). But as far as windows in a car or a truck - it shouldn't make any difference, as long as there is a general, even partial conducting cover over all sides of its insides. The purpose of the conducting shell around a volume of space is to keep the electric field out and any shape will do, even if you take 4-5 wires and wrap them once around something that will be enough to eliminate any static electric field, so even if you have an open Jeep (I do) with a frame on top it should be enough for the purpose. As I mentioned before, this works for radio waves too, up to certain frequencies (with wavelengths above ~1m order).

What you said about a house diverting a lightning strike - that is due to a grounded wire running from the top of the building down into the ground and can be achieved with a single straight wire - a cage is not needed. This is different from a Faraday cage, which not only diverts an electrical discharge but also keep electrical fields out of the cage, so in case of a major electrical field blast an average house would probably be penetrated more or less freely.
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Old September 7th, 2009   #14
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Yes the three stages E1 Gamma radiation interacts with electrons
E2 Electromagnetic pulse similar to Lightning E3 restoration of magnetic field.

When I was building my house it was struck by lightning.It was only rough framed no wiring or pluming. The workers were inside not ten feet away. No one was heart. The house had a little damage. I didn't see it but afterward I asked if it was raining it happened before the rain.
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Old September 17th, 2009   #15
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Yes the three stages E1 Gamma radiation interacts with electrons
E2 Electromagnetic pulse similar to Lightning E3 restoration of magnetic field.

When I was building my house it was struck by lightning.It was only rough framed no wiring or pluming. The workers were inside not ten feet away. No one was heart. The house had a little damage. I didn't see it but afterward I asked if it was raining it happened before the rain.
hey um couldnt you induce a short wave length emp by putting oh say a pipe wrench or somthing conductable between two transformers and also would it be effective enough to take out a grid from shorts in th electric system in a big city for atleast a minute before it is back up
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