Would Your Car Run After A Solar Or Nuclear EMP?
The following quote is the report on the EMP Commission testing of vehicles from pages 115-116 of the EMP Commission Critical National Infrastructures Report:
The potential EMP vulnerability of automobiles derives from the use of built-in electronics that support multiple automotive functions. Electronic components were first introduced into automobiles in the late 1960s. As time passed and electronics technologies evolved, electronic applications in automobiles proliferated. Modern automobiles have as many as 100 microprocessors that control virtually all functions. While electronic applications have proliferated within automobiles, so too have application standards and electromagnetic interference and electromagnetic compatibility (EMI/EMC) practices. Thus, while it might be expected that increased EMP vulnerability would accompany the proliferated electronics applications, this trend, at least in part, is mitigated by the increased application of EMI/EMC practices.
We tested a sample of 37 cars in an EMP simulation laboratory, with automobile vintages ranging from 1986 through 2002. Automobiles of these vintages include extensive electronics and represent a significant fraction of automobiles on the road today. The testing was conducted by exposing running and nonrunning automobiles to sequentially increasing EMP field intensities. If anomalous response (either temporary or permanent) was observed, the testing of that particular automobile was stopped. If no anomalous response was observed, the testing was continued up to the field intensity limits of the simulation capability (approximately 50 kV/m).
Automobiles were subjected to EMP environments under both engine turned off and engine turned on conditions. No effects were subsequently observed in those automobiles that were not turned on during EMP exposure. The most serious effect observed on running automobiles was that the motors in three cars stopped at field strengths of approximately 30 kV/m or above. In an actual EMP exposure, these vehicles would glide to a stop and require the driver to restart them. Electronics in the dashboard of one automobile were damaged and required repair. Other effects were relatively minor. Twenty-five automobiles exhibited malfunctions that could be considered only a nuisance (e.g., blinking dashboard lights) and did not require driver intervention to correct. Eight of the 37 cars tested did not exhibit any anomalous response.
Based on these test results, we expect few automobile effects at EMP field levels below 25 kV/m. Approximately 10 percent or more of the automobiles exposed to higher field levels may experience serious EMP effects, including engine stall, that require driver intervention to correct. We further expect that at least two out of three automobiles on the road will manifest some nuisance response at these higher field levels. The serious malfunctions could trigger car crashes on U.S. highways; the nuisance malfunctions could exacerbate this condition. The ultimate result of automobile EMP exposure could be triggered crashes that damage many more vehicles than are damaged by the EMP, the consequent loss of life, and multiple injuries.
As is the case for automobiles, the potential EMP vulnerability of trucks derives from the trend toward increasing use of electronics. We assessed the EMP vulnerability of trucks using an approach identical to that used for automobiles. Eighteen running and nonrunning trucks were exposed to simulated EMP in a laboratory. The intensity of the EMP fields was increased until either anomalous response was observed or simulator limits were reached. The trucks ranged from gasoline-powered pickup trucks to large diesel-powered tractors. Truck vintages ranged from 1991 to 2003.
Of the trucks that were not running during EMP exposure, none were subsequently affected during our test. Thirteen of the 18 trucks exhibited a response while running. Most seriously, three of the truck motors stopped. Two could be restarted immediately, but one required towing to a garage for repair. The other 10 trucks that responded exhibited relatively minor temporary responses that did not require driver intervention to correct. Five of the 18 trucks tested did not exhibit any anomalous response up to field strengths of approximately 50 kV/m.
Based on these test results, we expect few truck effects at EMP field levels below approximately 12 kV/m. At higher field levels, 70 percent or more of the trucks on the road will manifest some anomalous response following EMP exposure. Approximately 15 percent or more of the trucks will experience engine stall, sometimes with permanent damage that the driver cannot correct. Similar to the case for automobiles, the EMP impact on trucks could trigger vehicle crashes on U.S. highways. As a result, many more vehicles could be damaged than those damaged directly by EMP exposure.
It is important to note that the latest model of car that was tested by the U.S. EMP Commission (as noted in the quotation above) was a 2002 model car. Since 2002, the number of microprocessors in cars and the reliance on microprocessors in all motor vehicles has increased greatly. Also, the sensitivity of the electronic circuitry to EMP has increased due to the use of smaller electronic components designed to operate on lower voltages.
Automobile manufacturers have also done EMP testing on their own at the EMP simulator at the White Sands Missile Range in New Mexico. There was a news release from the White Sands Missile Range web site about this testing. Since that White Sands statement disappears from the web occasionally, I have reproduced it below.
Electromagnetic pulse testing
Testing at White Sands involves much more than firing rockets and missiles. In fact, in the past few years, one of the missile range's labs has done considerable testing for the automobile industry.
First of all, the military is very concerned about the battlefield survivability of its communications systems, vehicles, computers and other electronically based systems. If someone were to explode a nuclear bomb in the upper atmosphere, one of the byproducts of the blast is a very powerful electromagnetic pulse covering millions of square miles. This pulse induces an electrical charge in material which conducts electricity -- like the components of a computer or battle tank.
If the pulse is strong enough, the electronic components can be fried or severely damaged. It is very possible, then, to have such a high altitude nuclear explosion from which personnel will suffer no ill effects but they may be out of business because none of their electronic gear will work.
At White Sands, the Nuclear Effects Directorate has the capability to simulate and evaluate the various effects of a nuclear explosion -- including the electromagnetic pulse. For example, when the Abrams was being developed as the U.S. Army's main battle tank it was put through extensive electromagnetic testing at the missile range. Its electronic components were protected by various "hardening" techniques during development so they would survive very powerful pulses. The test and evaluation done at White Sands validated the adequacy of the "hardened" design.
Electromagnetic pulses and fields exist in our everyday lives, but are much weaker than the ones found on a battlefield. For instance, kitchen appliances and televisions produce electromagnetic fields. Citizen band radios and cellular phones all radiate electromagnetic pulses when they are transmitting. Even garage door openers emit weak electromagnetic pulses when they are used.
These devices can interfere with one another if they get too close to each other. This is why most airlines do not allow passengers to operate computers, stereos and other electronic devices when the plane is landing and taking off. The emissions from these electronic devices could interfere with sensitive electronic gear on the airplane.
Automakers were concerned about common sources of electromagnetic radiation in relationship to the airbag mechanisms, anti lock brakes, computers, etc. found in most cars today. 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.
So, the missile range has subjected computer chips and whole cars to all kinds of electromagnetic radiation in order to prove that such devices will not fire unintentionally.
When the testing first started several years ago range officials thought it was a good story and asked the automobile companies if the range could invite the news media out. The answer was a firm, "No."
Not only can we not tell you much about the testing, at the request of the companies, but range personnel report the automakers sometimes arrive with their cars wrapped in brown paper so no one can see them. Apparently some of the cars are advance models and manufacturers don't want anyone to see the new designs until the appropriate time. Secrecy wears many hats and is certainly no stranger to business.
At a time of cuts in the military this commercial testing has been welcome at White Sands and contributes to maintaining the current workforce.
(The above release was last modified by the White Sands Missile Range Public Affairs Office on April 8, 2010.)
Today's automobiles have published standards for electromagnetic shielding, but there is not much consistency in shielding requirements. You can check this list from Clemson University for a partial list of the many and varied standards for electromagnetic shielding of automobiles. Most automobiles and trucks have a similar appearance, at least close enough that we can tell when a object is an automobile or a truck just by looking at it. When it comes to wiring and electronics, however, the differences are much more striking. This fact makes generalizations about vehicles and EMP very difficult. Even if every make and model were tested on one occasion in an EMP simulator, the EMP sensitivity could be changed dramatically just by moving a wire or by changing the way that a cable is routed. This makes statements about the EMP sensitivity of any particular make and model nearly meaningless. This is why you will not find a listing anywhere of which makes and models of vehicles are EMP resistant.
As I pointed out on another page on this web site, retrofitting an automobile to make it EMP-resistant is a project that would be too difficult and expensive for most people. For those who want to try, the only authoritative document that I know to be available is one called "EMP Mitigation - Protecting Land Mobile Vehicles from HEMP Threat Environment" which was published in March 2011. They keep moving their web library, so I cannot link directly to it. To find this document, go to the Protection Technology Group page, then click on the Media Library link at the top of the page. On the Media Library page, click on White Papers. Scroll down on the White Papers page until you get to the article that you want. The article specifically applies to military vehicles, but has relevance to commercial vehicles as well. Note that the part of the referenced article that refers to bonding of "all metallic structures to a single point ground system" is referring to an electrical chassis ground on the vehicle,not to an earth ground.
Some additional suggestions for making vehicles more resistant to EMP can be found on pages 118 and 119 of EMP - Protect Family, Homes & Community, 3rd edition by Don White and Jerry Emanuelson.
The easiest way to retrofit some EMP protection into an automobile is to use the snap-on ferrite cores described in the EMP Personal Protection Page. These snap-on ferrite cores can be snapped on over all kinds of unshielded bundles of electrical wiring in an automobile or truck. You will have to go through the wiring on your automobile thoroughly to determine the size of the snap-on ferrite core that you will need to order. So this will involve going through an inspection of your car's wiring twice: once to measure the size of each bundle of wires, and again to install the snap-on ferrite cores after your order arrives. The snap-on ferrite suppression cores are not a perfect solution. They will only help to suppress (but not eliminate) fast voltage transients on the bundles of wires that are accessible to you.