Internal EMP Shielded Generatorby Walton McCarthy

Power is Everything

Life support in an underground shelter depends on electrical power. Just like a house, water has to be transferred by an electrical pump, air has to be moved and filtered, people need light to operate in, radios need DC power, and laptops, DVD players, etc. require charging power. Manual air blowers work well for short term shelter durations but for long-term disaster environments, manual blowers are not recommended since they may not be able to be powered by the elderly, disabled, injured, young children, people who smoke, etc. It should be used as a backup only.

Solar Power

Solar panels consist of many diodes so they are vulnerable to EMP but the solar panels can be stored inside an EMP shielded enclosure so they are protected. Aluminum foil does not work as an EMP shield for all frequencies of any real intensity. The solar charge controller is also very vulnerable to EMP so it must be placed inside an EMP shielded enclosure either for normal operation or a backup can be stored in an EMP enclosure and removed and installed after an EMP event. The shelter solar system should not be connected to any structure that is connected to the grid. It must be isolated from the grid. Although there are a few EMP fuses promoted by some companies, these fuses do not stop all the EMP frequencies to the standards of EMP shielding MIL-STD-188-125. If a shelter is not shielded to this standard, it is not EMP shielded. Different EMP frequencies requires different dB or decibel attenuation. The disadvantages with solar panels is that they can be seen for miles away and they are subject to theft and vandalism. Therefore the military will not rely on solar power except in some cases for battery maintenance.

Generator Power

Generators are designed to be used outdoors and if they are connected to a shelter they should be underground where the intake and outlet air does not mix with the shelter air. This is a simple method but has two disadvantages. First, it is subject to theft which is a common occurrence even in peace-time. It is extremely hard to service in any kind of nuclear fallout, chemical agent, or biological agent environment. Wearing a chemical suit with bulky gloves to replace an air filter element is cumbersome and time consuming and is hot climates is almost impossible.Internal generators require extensive engineering and testing but it is the best method to supply power in severe environments if it is properly designed and it is the only method accepted for military shelters. NORAD Shelter Systems is the only shelter manufacturer in the country that uses an internal isolated EMP shielded generator. The diesel generator is housed in an EMP shielded aluminum enclosure and the air entering the enclosure first travels through an EMP shielded vent and when the spent air leaves the generator enclosure it again travels through an EMP shielded vent. The gaskets around the access door must have EMP shielded gaskets and the exhaust pipe must be designed for high temperature from the diesel exhaust. All the air entering the generator for cooling and combustion must be filtered to the same specifications as human breathing air and at many times the volume of air required for shelterists. In smaller shelters with up to 50-60 shelterists, the generator usually operates 3-6 hours per day to charge a battery bank. In larger shelter systems, it is more efficient to operate the generator 24 hours per day and alternate between two separate generator systems. Diesel generators are the only type that should be used since diesel generators consume 1/3 less fuel than an equivalent gasoline generator and diesel fuel is combustible but not flammable.

Walton McCarthy is a mechanical engineer with 40 years’ experience in designing and installing over 1,400 underground shelters and the author of PRINCIPLES OF PROTECTION, The US Handbook Of NBC Weapon Fundamentals and Shelter Engineering Design Standards, 6th edition 2013, 740 pp. Brown Books. This book sets forth the definitive design standards for underground nuclear, biological, chemical, and EMP shelter engineering. The book was written with help from experts from the US Department of Defense, US Department of Energy, Strategic Applications International (SAIC), Oak Ridge National Laboratories, Nuclear Engineering Laboratory from the University of Illinois, Brookhaven National Laboratory, Chemical Division of Edgewood Arsenal, US National Bureau of Standards, and the US Defense Nuclear Agency. This is the book that the US Government should have written with tables showing actual radiation doses based on the distance from ground zero and the size of the nuclear weapon. It is considered the bible in the underground shelter industry and used by engineers and architects around the world.


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