Hugh and James:
I’m missing something regarding EMP protection measures, and I could use some help.
I have researched EMP, how it’s created, and the common frequencies of EMP. I’ve looked into its relative intensity based on creation mode, altitude (in the case of nuclear devices), and the extended effects attributed to conductive networks. I understand what a Faraday cage is and how it works. And I’ve read numerous articles, lots of forum comments, endless opinions, a quantity of engineering documents, and several much learned evaluations on protecting against EMP.
So here’s where I keep running aground: Protecting from EMP is, at its base, a simple affair. You provide a conductive shell around what one wishes to protect. Grounding that shell, or not grounding, is a subject of debate. However, my experience with electronics indicates that if the shell is doing its job, grounding it is not a problem. It may or may not be required, or even useful, to electrically insulate sensitive contents from the conductive shell. That answer depends on to whom that question is addressed. But consensus seems to indicate that it can do no harm.
Steel is an electrically conductive material, not as conductive as copper or gold but quite conductive nonetheless. So why not use a steel drum to protect against EMP? Drums are available in “open head” design in which the entire “head” or end of the drum is removable and can be reinstalled with a suitable circumferential or “ring” clamp. The clamp is available in two basic styles: one using a bolt and nut to clamp the drum head (end cap) and drum together, and one with a locking over-center handle. I have seen both types in which the clamping band overlaps at the bolt or the locking handle, ensuring greater than 360 degree coverage of the joint between drum head and drum.
If additional protection is warranted, and I suspect it’s not possible to have too much, a circumferential ring of conductive tape (the aluminum stuff duct workers use that seems much liked in the EMP protection community) wrapped over the surface of both drum head and drum prior to securing the head with the clamping ring should provide that level of protection.
The drum heads are usually equipped with a gasket around the rim, which could easily be removed and replaced with a conductive material, such as steel wool, wood stove door gasket, et cetera, should simple, tightly clamped metal-to-metal contact between ungasketed drum head and drum not be sufficient.
In short, I can find no reason why a steel drum could not be used as an EPM protection measure. They’re readily available in multiple sizes, from 16 gallons to 30 to 55 gallons. The over-center circumferential clamp arrangement allows for fairly rapid access. They can be stood vertical or laid horizontally in racks. They can be stacked several drums high if vertical. Properly closed, they’re waterproof, vermin proof, dust proof, in fact pretty much a barrier against whatever form of contamination one may commonly encounter.
So why do I not see frequent mention of inexpensive steel drums for use as EMP protection measures? What am I missing or not understanding? – NK
You’re not missing anything. Most people are not used to seeing them. They just don’t think of them They think smaller, like in 5-gallon increments. A steel drum does come with its own set of issues related to its size and weight, especially when full of stuff. But they are an excellent option. If you have the type with the metal band to seal the lid, you don’t even need the tape. The lid and drum usually do not have paint on those edges. If they do, it’s easy to remove. About the only thing that you really can’t use them for is direct burial.