Faraday Cage for Car?

[ryan112ryan]

I have read many mixed things about weather a car will or will not be susceptible to an EMP attack. There seems to be allot of uncertainty about it.

I am particularly concerned when it comes to my car. While most cars are skinned in a metal shell (which some claim would protect it), my car is simply a cage, where there are some holes that are too large to block emp. I drive a Smart Car and all the body panels are 100% plastic, which surrounds the safety cage. In addition my car has about every electronic bell and whistle you can get.


I was thinking of making retrofitting my one car garage into a Faraday cage. Basically metal sheeting on all sides, top and bottom. weld the seams and I would have to figure out a door. I would line the floor with rubber paint just for good measure.

Thoughts? Suggestions?

[AwakenedPatriot]

How you going to recharge it if there's an EMP?

[Grevlin]

Originally Posted by AwakenedPatriot

How you going to recharge it if there's an EMP?

That is a painful question...

Now, I've considered the same option- but I don't think you need sheet metal and welding. Aluminum foil, chicken wire, or metal screen-door sheeting should do the trick. (chicken wire is a little iffy to me)

You need to do all 6 sides inside the garage with ZERO large holes or gaps. Watch out for the garage door and edges, entry doors, attic access panels etc. Run a bunch of ground wires from various spots, preferably into the ground outside.

The car MUST be sitting on an insulator like a rubber mat. Anything in the garage should be shielded as long as it is not touching the metallic material on the walls. -- I wonder if the garage door opener remote would work with a properly shielded garage...

Big problem I'm working on: EMP waves travel and build along long stretches of wire and cable. My garage door opener is plugged in and sits right above my truck. An EMP wave could travel along the power cords and zap the truck.

Its a work in progress - I model everything in my head until it's right, then cook up a shopping list, and then do it.

Any and all advice would be helpful.

[patcash]

Interesting concept! Would the tires serve as insulators? My garage door has an emergency handle that lets me get the door open if the power is off.

[stevegee58]

Originally Posted by AwakenedPatriot

How you going to recharge it if there's an EMP?

SmartCars aren't electric, they have normal gasoline engines.

A "whole car" Faraday Cage would be quite a project but doable if you use metal screening instead of sheet metal. I've seen DIY plans for small FCs where they use copper screen but I'm not sure that's necessary.

OK, I just found another thread where someone linked to a copper screen supplier. Bottom line is it's about $600 for a 100' roll of 48" wide screen.

[Grevlin]

I've also considered this:

Get one of those car covers. Stitch together the metal screen material into a similar shape (using thin metal wire) and the use non-metallic thread to stitch it to the outside of the car cover. The car cover would provide strength and structure as well as insulation between the car and metal screen. You would need a flat metallic layer under the car so when you cover the car, the edges of the cover rest on the ground on top of the that floor layer. This would give you a complete shell around the car. Run a ground wire from the cover and the floor layer.

The problem with this, is it's tedious to cover the car while it's inside your garage - and you are more likely to get lazy one day.

I wonder how this would sell if I were to market it... Could have different sizes for cars, trucks, bikes, generators etc...

[cranky1950]

Originally Posted by ryan112ryan

I have read many mixed things about weather a car will or will not be susceptible to an EMP attack. There seems to be allot of uncertainty about it.

I am particularly concerned when it comes to my car. While most cars are skinned in a metal shell (which some claim would protect it), my car is simply a cage, where there are some holes that are too large to block emp. I drive a Smart Car and all the body panels are 100% plastic, which surrounds the safety cage. In addition my car has about every electronic bell and whistle you can get.


I was thinking of making retrofitting my one car garage into a Faraday cage. Basically metal sheeting on all sides, top and bottom. weld the seams and I would have to figure out a door. I would line the floor with rubber paint just for good measure.

Thoughts? Suggestions?

Unless you drive a vette or a bricklin, your car is mostly faraday cage. All you need do is run ground straps from the frame. Of course that'll fry your butt if the car gets struck by lightening.

[Grevlin]

Originally Posted by cranky1950

Unless you drive a vette or a bricklin, your car is mostly faraday cage. All you need do is run ground straps from the frame. Of course that'll fry your butt if the car gets struck by lightening.

The window openings, wheel wells, and gaps around the engine are too big - the faraday cage needs to be a complete shell with any gaps being VERY small. The size of hole lets in that size wavelength. I would be comfortable with no holes larger then 1 or 2 centimeters.

[ryan112ryan]

Originally Posted by stevegee58

I've seen DIY plans for small FCs where they use copper screen but I'm not sure that's necessary.

OK, I just found another thread where someone linked to a copper screen supplier. Bottom line is it's about $600 for a 100' roll of 48" wide screen.

Why do people talk about copper screen? From looking into it it doesn't have to be copper, is there a reason why people gravitate to copper screen.

the other consideration is that screen has holes in it, while small, I would think solid, but thin, would be safer. There is some talk of EMP being as low as a Hertz, which might be an issue with the screen/mesh.

[ryan112ryan]

Originally Posted by AwakenedPatriot

How you going to recharge it if there's an EMP?

All gas I average 47 mpg with two people and my trunk full

[ryan112ryan]

I found this quote from this website: http://www.futurescience.com/emp/emp-protection.html

I don't know how credible this is, of course he makes it sound like he know what he is talking about, but I always stay on the side of caution with survival situations, second guess are sometime a death wish.

What are people's thoughts? this would be way more convenient than a whole cage.

When I was working at a broadcast transmitter site that had an unacceptable level of electromagnetic radiation from the FM broadcast antenna into the area at ground level where the vehicle was commonly parked, I had a carport built with copper screen imbedded into the roof of the carport. The reduction in electromagnetic radiation beneath the carport was quite dramatic -- as actually measured using professional equipment. Since nuclear EMP comes in from a fairly high angle, it is likely that a similar arrangement, but using aluminum screen, would reduce the EMP substantially, possibly enough to protect vehicles and other large items stored below the shielded structure. In the case of the carport that I had built, I grounded the imbedded screen because I knew that the wire leading to ground would not act as more of an antenna than a ground for the shield. Although most small faraday cages should not be grounded because of the "accidental antenna" problem, if a carport shield can be well-grounded at all four corners, then a direct wire going to a ground rod at each corner would probably be a good idea.

[stevegee58]

Originally Posted by ryan112ryan

Why do people talk about copper screen? From looking into it it doesn't have to be copper, is there a reason why people gravitate to copper screen.

the other consideration is that screen has holes in it, while small, I would think solid, but thin, would be safer. There is some talk of EMP being as low as a Hertz, which might be an issue with the screen/mesh.

You're right, it doesn't have to be copper. Copper is used in commercial screen rooms because it has the highest electrical conductivity, second to silver. I'd bet aluminum window screen would probably work. 'Course how would you know until an EMP attack?

Regarding the holes in a screen: yes, some energy would get in but you would have greatly attenuated it nonetheless. My own reading says that most of the energy is distributed throughout the lower frequencies between 3 Hz and 30 kHz. The mesh of a screen would completely block energy at these frequencies. In fact the mesh openings would have to be feet across to let these in.

A solid surface would work but it's unnecessary.

[bestairet]

I've noticed quite a few old containers from container ships that I've wondered if they could be used or retrofited as a faraday cage. If so a car, truck and a great deal of electronics and supplies could be stored there.

[stevegee58]

I'd bet a cargo container would work admirably. You just have to make sure the doors are electrically sealed. I haven't looked at one closely but I'll bet the doors have rubber or vinyl gaskets. These would have to go and be replaced with something that electrically connects the doors to the container itself.

[cranky1950]

Originally Posted by Grevlin

The window openings, wheel wells, and gaps around the engine are too big - the faraday cage needs to be a complete shell with any gaps being VERY small. The size of hole lets in that size wavelength. I would be comfortable with no holes larger then 1 or 2 centimeters.

Still the ECU and harness are surrounded by metal and grounding the frame will protect it. The pulse is going to grab the body and travel to ground. It's not like it's going to climb in the windows and search until it finds electronics if anything it'll pass through line of sight.

[Grevlin]

Originally Posted by cranky1950

Still the ECU and harness are surrounded by metal and grounding the frame will protect it. The pulse is going to grab the body and travel to ground. It's not like it's going to climb in the windows and search until it finds electronics if anything it'll pass through line of sight.

I sincerely hope we don't put that to the test. I'm gonna put up some extra precautions- just in case.

[ryan112ryan]

Originally Posted by cranky1950

Still the ECU and harness are surrounded by metal and grounding the frame will protect it. The pulse is going to grab the body and travel to ground. It's not like it's going to climb in the windows and search until it finds electronics if anything it'll pass through line of sight.

Remember that in my case, the body of the car is 100% plastic.

Anyone have any theories on just putting a layer of mesh above car?

[stevegee58]

Originally Posted by ryan112ryan

Remember that in my case, the body of the car is 100% plastic.

Anyone have any theories on just putting a layer of mesh above car?

It won't work. The item to be protected has to be completely surrounded by an electrically conductive envelope. The EMP generates an electric field that completely "coats" everything. Placing a shield between the EMP source and your items won't do it. A metal car body won't do it.

The only way out besides a proper Faraday Cage is to keep the car underground somehow.

[theyeti]

Originally Posted by ryan112ryan

I have read many mixed things about weather a car will or will not be susceptible to an EMP attack. There seems to be allot of uncertainty about it.

Thoughts? Suggestions?

Found this thread a little late but I think this is a good topic so I thought I would jump in anyway.

The threat of an EMP or non-nuclear electromagnetic pulse such as a High Power Microwave attack against the U.S. is thought by some to be growing along with worldwide access to newer technologies and the proliferation of nuclear weapons. I did have one relevant U.S. Army Engineering Pamphlet in my collection concerning this subject and I’ll post it to the Survival Files section under the title: EMP & Tempest Protection for Facilities - EP 1110-3-2.

I am also looking for another reference concerning this subject and would appreciate it if anyone could point me toward or post a digital copy of the FEMA, Electronic Pulse Protection Guidance, CPG 2-17, Volumes I, II, & III.

In all the literature I have read most cars are resistant to EMP, in tests using nuclear weapons as well as during more recent tests (with newer cars) with EMP simulators. I assume that when these reports use the word resistant because sometimes a given car will run and sometimes it won’t. However, cars with plastic or fiberglass bodies are the most susceptible to EMP damage and cars with lots of computer controls (read smart car) will have an increased likelihood of damage as well. Probably the only way to be sure other than shielding the car as you suggest or buying a pre electronic ignition diesel would be to buy spare electronic ignition parts (which might be a lot of parts) and keep them inside a Faraday box.

As far as the garage Faraday cage goes the rub is that there can be no electrical wiring allowed to pierce the foil/mesh shield. I am pretty sure that no AC powered equipment such as lights, radio antennas, or even garage door opener antennas can come into the room from outside unless they are filtered or also covered by the shielding you use. The file I am posting is a little technical but should be able to answer your questions in greater detail I just have not looked at it in a while.

By the way, hope you don’t have a pacemaker.

[Sagembob]

Originally Posted by cranky1950

Unless you drive a vette or a bricklin, your car is mostly faraday cage. All you need do is run ground straps from the frame. Of course that'll fry your butt if the car gets struck by lightening.

Have not even seen a Bricklin SV-1 in a long time. Nice reference for a car guy.