Testing the effects of EMP on automobiles

[69hurstolds]

Hutch's build post had a couple of tangent posts about EMP and cars. Rather than muck up his thread, here's the latest quote about it that I figured I'd steer it to a new discussion thread:

spidereyes455

Actually I don't think so. It would also burn out any primitive ecm in our cars ,and while they can run without it you can't get it to run without an ignition system and since the HEI module would also be fried unless you converted to points your dead in the water.

According to some testing in the link below, it's not quite so simple. At low EMP pulses, cars aren't affected or simply need a restart or battery disconnect to reset. Very few examples were totally disabled. It must be noted this was for cars which the newest was 2002. I personally believe that if you were close enough to an EMP event (nuke) that you're probably going to have much more to worry about than your car dying while driving. According to this writeup, the automobile manufacturers have been testing their own vehicles against EMP as well. Of course, they don't release any information on it, though. A good read if you have the time. Again, inconclusive.

EMP Effects on Vehicles - Futurescience.com

Electromagnetic Pulse and vehicles. The sparse evidence about how motor vehicles would react to a high-altitude nuclear EMP.

www.futurescience.com

I did find this comment slightly amusing on why car manufacturers wanted to ensure EMP issues didn't kill the cars.

For example, they wanted to make sure that a driver's day wasn't ruined because the car's airbag went off in his or her face while going 65 mph just because the guy in the next car dialed up a cellular phone, a trucker used his CB radio or they drove past a radio station.

 

[69hurstolds]

And here's a slightly surprising test result from Russia's EMP testing at high altitude back in 1962. NON-electronic parts can be damaged if the EMP was at high enough rates.

This illustrates that even vehicles without an electronic ignition or other electronic components are not completely immune from EMP.

 

[81cutlass]

I was told by my HS physics teacher that cars, as long as they are metallic bodied, act as Faraday cages and disperse the electrical energy to the farthest part of the body, protecting any electronics that are electrostatic sensitive by putting them inside as a protective barrier. Basically cars are inherently EMP resistant since the ECM's are faraday cages and the bodies are too.

Basically, think of those tesla coils you played with in class that had that 1ft diameter steel ball and the belt that rotated under it, the belt would build up static charge and you would get a foot or so away and you would get shocked.

If you were to make a giant tesla coil and stand inside the ball, you would never be shocked. That is because the electron energy is trying to get as far away from itself as possible (think trying to push two + poles of a magnet together). That sheet metal .060" thickness is enough for all the excess electrons to move to the OD of the sphere since the surface area of the OD of the sphere is just slightly larger than the ID of the sphere.

Same things apply to the ECM steel or aluminum case and the body of a car. The EPM pulse is just a giant wave of electro-magnetic radiation. The faraday cage idea applies to the body of the car and any radiation that is transfered into the car tries to get as far away from itself as it can, so it goes to the far outside surface of the car away from where the electronics are.

Also, he mentioned that since cars are on rubber tires and rubber is a great insulator, EMP's are likely to not get into cars since they are not grounded and theres no real desire for the energy to go into the car and eventually ground itself, to well, ground.

However, this is all the theory and real world deviates a lot. A car is not a perfect sphere, giant EMP pulses don't really exist, and so many other things in life would suck if you get hit by a serious EMP way before cars not running.

 

[pontiacgp]

This is really interesting but for my Jeep with the way the electronics screw up all time I would probably not notice getting hit with EMP's

 

[69hurstolds]

Nuclear bomb EMP is the one that needs worrying about. Like mentioned earlier, nobody really knows and with nuclear blasts, there's so much more to worry about during that kind of an event. And even if YOUR car works, where would you go? If even just a few cars crap out on the highway all at the same time, there's going to be major pileups blocking roads for miles and miles. But that glass windshield and the plastic dash will NOT stop EMP from getting to the wiring and electronics in the dash. So a car isn't likely to survive outside unshielded. It's already been proven via EMP simulators that most cars WILL get some effect from low level EMP, let alone a big nuke pulse. The paper does delve into someone making EMP shield kits with an EMP car cover thingie. That's still no guarantee if you don't have a good food source since the grocery stores and gas stations will be out of commission.

The paper states that even the EMP experts aren't sure what would happen. It's a fun read, since the guy doesn't write like a scientist, but it covers some things about EMPs that you may not think about.

 

[Gonzo1970]

You would bring this up while I'm reading a post-apocalyptic EMP Nuke series... lol (Bruno Miller - Cloverdale Series)

It does bring up some things people don't really think about. Airplanes just falling out of the sky.. Trains stop.. Trucks stop.. Supplies such as food/water/etc. dry up.. No pharmacy's for silly things like maintenance meds.. Pretty much everything goes to hell in a handbasket in about a week.. basic infections turn deadly.. the new currency is bullets.. Interesting and frightening at the same time.

-Gonz

 

[rfpowerdude]

Yes, I have a points distributor on the shelf. It would help. And vacuum tube radio gear. And vacuum tube guitar amps. When the apocalypse hits, I will be able to communicate across the world, drive on roads and jam on my guitars via diesel gen set (also with no electronics). LOL (at least until I run out of diesel)

Yep total chaos. Without bullets or arrows, one pretty much guarantees their demise...

 

[Dayzedandkonfuzed]

I thought a faraday cage had to be grounded...? Car tires don't ground well.

I keep an HEI distributor and 10si alternator in an insulated steel ammo box under my shed. Only cuz I had spares and why not? But I get what 69hurstolds said, where would you go? Guess I better find a 4x4!

 

[rfpowerdude]

I'm gonna build a gyro copter like the guy in Mad Max...

 

[mikester]

Arent military vehicles shielded against an EMP ? I know the diesel generators are.
Ive also been told that the book to read about an EMP is One Second After.