Three Letters Re: The Simple Reality of EMP — Different Than You Might Expect

Dear JWR,
I read the EMP article by Andru and thought it very well done with one minor correction in the power generation area (worked in the nuclear power industry for 20 years before changing careers). The EMP E3 pulse is very dangerous to the transformers in the transmission and distribution system, and hydro-electric and nuclear will also be severely affected. Commercial generators of any output run at 8,000-10,000 volts which is fed immediately to step up transformers to feed the transmission system. The most common voltage for the transmission system is 250,000 to 500,000 volts (3 phase) which reduces amperage and therefore reduces line losses. The power goes from the power plant through the transmission system to one of the many interchange grids which direct and control where the power is going to. The power is bought and sold in commodity markets by these interchange systems. Even if you live next to a power plant its output will go through the transmission system first, and then to a series of step down transformers in the distribution system before finally being delivered to the customer. Much of the time my home power was not supplied by the power plant I lived next to and worked at.

The transformers are the weak link. A severe solar storm can induce currents that will destroy them (this has happened). Safety interlocks may not work as the pulse can increase current too fast for the breaker to trip before the contacts get welded shut or else it can cause winding damage before it trips. As Andru says the extent of the damage will be the problem. None of the high tension step up/step down transformers are made in the US anymore. And the lead times for their manufacture are measured in years. I expect in such a scenario desperate measures will be taken to produce transformers (or repair them – very difficult and not possible if the damage is severe enough).

If we suffer an EMP attack plan for the power being off for years. I would suspect that power recover would be prioritized in the major metropolitan areas as that is where most people and industry are. The rural areas will probably be the last to be worked. This is standard operating procedure (SOP) for power restoration, you do what brings the most people back online first. – James J.

Mr. Rawles,
Mention was made in your blog of an article entitled, “EMP 101 – A Basic Primer” concerning the results of an EMP attack on the United States. The article was written by William R. Forstchen, the author of the novel One Second After.

I followed the link and read the article. For the most part it was very informative, especially the part about all modern airliners being “fly by wire” and controlled by computers. From my aviation background I know that the control surfaces of most large aircraft today are simply too large to be moved around by the pilot’s own strength, as they were in aircraft designs up to the 1950s. Still, it was a graphic reminder that most large aircraft today are completely dependent on their on-board computer systems to operate. There is no “manual backup”, just another spare computer system that could possibly also be damaged in an EMP incident.

But there was one section of his article discussing advance preparations to mitigate the effect of an EMP blast that I did not understand. That was the paragraph:

“An off the shelf purchase of hand held two way radios by every local police, fire, sheriff, and emergency response department in the country would mean, that if then properly stored along with a large stock pile of batteries that within minutes after an attack, a nation wide network of communications would be back up and running. This can not be emphasized enough, that proper communications and what the military calls “command and control,” will go a long step towards maintaining public order.”

I’m not quite sure what Mr. Forstchen is referring to with the term, “off the shelf purchase of hand held two way radios”? If he is referring to the commonly available Family Radio Service (FRS) and General Mobile Radio Service (GMRS) walkie-talkies that use AA and AAA batteries, then he is not aware of their severe limitations. FRS radios only have 14 UHF channels and 0.5 watts of RF output power. The GMRS radios have 22 UHF channels and typically around 2 watts of RF output power.

Both radios operate on relatively low power and on UHF frequencies, a combination that will limit their effective range to a few miles typically. At best perhaps 10-miles with the higher powered 2-watt GMRS radio (don’t believe the advertising hype on the package). The UHF frequencies do a better job of penetrating building walls, but they don’t propagate as far as VHF signals. They provide “Line of Sight” operation – if you can see the other person in the distance, you should be able to reach them on the radio.

Based upon these obvious limitations, I don’t understand where the author comes up with the statement that equipped with these consumer-grade walkie-talkies, “within minutes after an attack, a nation wide network of communications would be back up and running.” With their short range and limited channels, it is impossible to create a “nationwide network of communications”. When used from inside a vehicle, the range of the low power FRS radio can be measured in feet! Usually the range is only a few car lengths, which makes for limited convoy use. In addition, the limited number of available radio channels will ensure a pandemonium of signals and the resulting radio gridlock reminiscent of the peak of CB radio activity in the late 1970s. This is especially true when you realize that every man, woman, and child could potentially be attempting to communicate on these same channels with their personally owned FRS or GMRS radio. The public service functions will no longer be operating on radio frequencies reserved and licensed exclusively for their use.

If the author is referring to the purchase of additional two-way radios of the type already in use by police, fire, sheriff, and emergency response departments, then he is unaware of how they operate. Most “business band” or “professional” hand held radios have a RF output of 5-to7 watts. They are still limited in range by their inefficient “rubber duckie” flexible antenna, frequency band, and power output. The only reason they seem to operate so well over many miles of varied terrain is because of the supporting infrastructure, mainly the radio repeater system. The radio repeater extends the range of the low powered hand held radios by retransmitting their signal [typically] from a mountaintop repeater site. A network of repeater stations located on high terrain can vastly improve the coverage of a hand held radio, providing excellent range throughout a county or even an entire state depending on the size and extent of the repeater network.

Unfortunately, the weak link in all of the radio systems used by public service agencies is their radio repeater system. With all the repeater stations off the air due to EMP damage (or even a lightning strike) the entire radio network falls apart. Most public service radios are programmed to operate exclusively through the repeater system. If the repeater system is down, the radios no longer work. Sometimes a sheriff’s department will have their radios programmed with a “car-to-car” channel, which is a simplex frequency where the radios transmit & receive on the same frequency (without the need for a repeater radio). But these “direct” channels are very few, and are often the only simplex channel available out of a radio system with five or more radio channels. To provide adequate coverage over a large city or county, all the normally used channels are duplex frequencies going through the radio repeater system. An additional limitation is that each public service function is limited to their specific allocated and assigned radio channels. The radios are pre-programmed by a radio technician at his shop. The radios are not field programmable by the user.

In addition to this vulnerability, professional two-way radios use rechargeable battery packs – usually Nickel-Cadmium or Nickel-Metal Hydride. The sealed battery packs are designed to work with a specific model of radio. The radios do not use AA, AAA, C, or D-cell batteries. So unless there is a back room filled with chargers and a person assigned to keep all the spare batteries charged up and rotated out of the charger at all times, there is no simple approach to having charged batteries ready to go to support a stash of spare radios. In fact, most public service agencies can barely afford the minimum number of portable radios needed to equip all their personnel. There is no budget for an additional stash of spare batteries and radios.

The only radio service I know of that has the flexibility to adapt in a “repeater down” situation is the Amateur Radio Service. Instead of specific frequencies or channels, “Ham” radio operators are allocated entire radio bands to operate on. The VHF and UHF radios used in the Amateur Radio Service can be user programmed to operate on any desired frequency within a radio band, and all will switch to simplex operation at the press of a button. Manufacturers of ham radio equipment often offer an optional alkaline battery case for use with their hand held radio models. While looking like the typical Nickel-Cadmium (NiCd) battery pack from the outside, these battery cases can be opened up and AA batteries inserted into the slots. The battery case is then attached to the radio the same way as the regular NiCd battery packs do. This allows the ham radio operator to stockpile a stash of spare AA batteries for use during an extended power outage that prevents the usual recharging of the NiCd or Nickel-Metal Hydride (NiMH) battery packs.

So, unless you are a ham radio operator, expect a long delay before normal radio communications are restored. Due to the limitations and vulnerabilities of public service two-way radio networks, reestablishing a nationwide network of radio communications is going to take time. Sincerely, – Bruce C.

Andru’s outlook about EMP is in part misleading. The main item that Andru got correct is that an EMP attack will be more devastating that any other attack on America. I am an engineer and have read the Critical National Infrastructures (CNI) Report and this report is based on educated opinions without large scale testing since large scale testing has not been performed due to banning of nuclear testing. Localized EMP testing generally wipes out the electronics depending on how close the EMP generator is to the electronic equipment. It is all supposition as to the amount of damage that an EMP attack will create but it is know from a nuclear weapon test in 1962 that was 800 miles from Hawaii and the EMP created damage to Hawaii even with the minor amount of [microcircuit] electronics existing at that time. Think what the damage would happen in our electronics world of today.

Nuclear Electromagnetic Pulse by Jerry Emanuelson: “Although nuclear EMP was known since the earliest days of nuclear weapons testing, the magnitude of the effects of nuclear EMP were not known until a 1962 test of a thermonuclear weapon in space called the Starfish Prime test. The Starfish Prime test knocked out some of the electrical and electronic components in Hawaii, more than 800 miles away.

When the 1.44 megaton W49 thermonuclear warhead detonated at an altitude of 248.5 miles (399 km), it made no sound. There was a very brief and very bright white flash in the sky that witnesses described as being like a huge flashbulb going off in the sky. The flash could be easily seen even through the overcast sky at Kwajalein Island, about 2,000 km. to the west-southwest.

In a phenomenon unrelated to the EMP, the radiation cloud from the Starfish Prime test subsequently destroyed at least five United States satellites and one Soviet satellite. The most well-known of the satellites was Telstar I, the world’s first active communications satellite. Telstar I was launched the day after the Starfish Prime test, and it did make a dramatic demonstration of the value of active communication satellites with live trans-Atlantic television broadcasts before it orbited through radiation produced by Starfish Prime (and other subsequent nuclear tests in space). Telstar I was damaged by the radiation cloud, and failed completely a few months later.

EMP is a potentially massive, severe problem that can essentially devastate our nation. America as we know it can not survive even a moderate EMP attack. Society will collapse.

The EMP pulse flows through the air at the speed of light until it hits antennas, power lines, cabling, etc. then the pulse flows through this cabling at the speed of light into the electronic equipment and the electronics fail.

[Here is a roughly analogous event that is illustrative:] Our television cable system was struck by lighting and all electronics that were on and all electronics that were off and that were connected to the TV cable were fried. Similarly, EMP will fry any unprotected electronics. The only way to protect your electronics is to have the equipment inside an adequately grounded Faraday cage (metal box) that does not have power or cabling running into it. Your electronics that are not in use should be stored in a grounded Faraday cage everyday.

Even if repair parts for your electronics were available, how would you obtain the repair parts since there will be no mail or transportation services. If you have an auto that still runs after and EMP attack, the last thing that you will wish to do is take your vehicle out and show everyone that you have an operating vehicle.

We are acquiring extra [CPU] “brains” for our diesels and SUVs. We also are acquiring carbureted vehicles.

Even if an EMP strike only caused the death of 10% or our population (30 million citizens) just how do you survive this as a nation? Prepare for EMP and pray that it does not happen.

Severity of potential failures: From least to greatest [Some causative details and conjecture deleted by JWR, for brevity]

1. Swine Flu – World Wide – Population loss 1 to 10% – could trigger Item Number 3.

2. Civil War – America – Population loss of up to 40% – could trigger Item Number 3.

3. Financial Collapse – World Wide – Population loss up to 40%. Loss of 50+ years of progress. Will probably lead to nuclear war or EMP strike. No economy remains.

4. EMP Attack – America – Population loss of up to 80% – No economy remains.

5. Nuclear War – World Wide – Population loss up to 60%. No economy remains.

Regards, – TD