EMP Protective Features of CSP Shelters

Q & A Utah Shelter Systems

My company is looking into building an underground EMP bunker to store electrical equipment and I came across your company. I was hoping to get some information and learn more about the factors to consider when building such a structure.


Dear Phillip,

Our corrugated steel pipe (CSP) structures form a natural faraday cage. We place steel grating over our steel air vents. Our hatch type doors are also constructed of steel. We would need to use a special metal clad gasket for the ‘horizontally configured’ hatch type doors if your equipment is very sensitive. We also carry EMP protected ‘vertically configured’ doors.

We would suggest that you do not run connections to the power grid unless you are prepared to install very expensive filters to the structure. We keep our shelters powered with a solar array. The electrical lines from the array enter the shelter through metal clad conduit.

Much would depend on the type of equipment you are planning to store, and its function. Radios, for instance, could not be operated inside the structure without the filters, because you must insult the protective CSP cage with an antennae, which would then compromise the faraday cage effect. We keep our radios unplugged from the antennae cable and separate the coil by several feet from the equipment when not in use, which limits the risk to the use time of the equipment. We also disconnect the outside cable from the antennae when not in use.

The depth of cover and the length and diameter of the entrances also increase the protective features of CSP structures. If your structure is above ground, you should consider increasing the steel thickness, depending on the anticipated strength of the EMP. Anticipated EMP threat levels vary with the importance and characteristics of the equipment and your proximity to military and high-risk government facilities. We are not privy to the anticipated threat levels currently being used for tests on equipment during EMP simulations, but think we have a fairly good estimate of those levels.

We recently designed a concrete NBC shelter structure with EMP protection for several rooms. The rooms were totally metal clad, and we provided special blast and EMP hardware for the air vents of the metal clad generator room. The filters for the security system and communication areas were massive and very expensive. We do have access to the company that provides these filters and designs. This was a multi-million dollar endeavor and designed for a high level EMP threat.

If you are looking for an inexpensive solution with excellent EMP protection, however, and do not plan to use the equipment during threat times, the CSP structures are very practical and easily installed.


Sharon Packer

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