Hi Jim.
Just felt the need to re-emphasize the point you made with regard to Mr. Yankee’s ideas about an improvised fallout shelter.
First, I applaud his view that one should not count on being able to pull together an adequate expedient shelter when the need arises. As simple in theory as it seems, in practice, few would end up with a shelter they would want to rely on to save the lives of their loved ones.
Second, as far as the point you made, Jim, it is indeed very important to over-engineer any sort of structure that will be bearing the loads necessary for a fallout shelter.
I need to point out that I want to do everything in my power to encourage folks to buy or build their own shelters, whether it is from us or not. Why? I feel it’s very possible that the number of adequate shelters in the USA will go a long way toward defining our future viability. So I always hesitate to discourage folks in any way when they talk about what they feel are good, easy shelter ideas … but really are simply short cuts that as you pointed out could end up killing them.
To anyone thinking about this, if you’re going to build your own fallout shelter, then be darn sure it is built to last for decades under the most stressful conditions you can imagine. (Better yet, under conditions a structural engineer can imagine.) If it turns out you need to spend any time at all in your shelter, you sure don’t want to be thinking about how you cut some corners to save a few bucks, or that you did just enough to probably hold up when you have to start topping off the loads.
A “for instance”: There are a lot of arm-chair, Internet shelter designers who like to propose grand designs for underground shelters made of storage containers. Bad idea! They may look great as you are backfilling and burying them, but they are not built to withstand subterranean forces. They will catastrophically fail at some point–probably sooner than later. Believe me, if they would work, there would be plenty of us selling them as bargain-basement solutions.
As I said, I want to encourage folks to do the best they can to provide a decent shelter for their loved ones. It’s important, and when you get it done well, it’s peace of mind that you can’t otherwise buy or manufacture. If you’re going to do it at all, do it very, very well.
Besides the need for Mr. Yankee to think seriously about shoring up his floor overhead and perhaps his walls, I’d ask him to try not to get too clever with what it is that will serve as his shielding mass. Salt will work, as will any material (including air), but the key is how much will get the job done? I suspect that one would need a whole lot of salt to provide the needed mass.
A quick rule of thumb many can benefit from when looking at how well to shield their survival space: Shielding that reduces gamma ray intensity by 50% includes .4 inch of lead, 2.4 inches of concrete, 3.6 inches of packed dirt or 500 ft of air. One should aim for 10 times the halving protection using these guidelines when constructing your fallout shelter … such as 36 inches of earth or 24 inches of concrete or 4 inches of lead (not practical) or say, 12 inches of concrete and 18 inches of earth. This is a minimal level of protection, I feel. Of course, overkill in shielding is great as long as the supporting structure is built to withstand it. – Vic at Safecastle
Hi Jim,
I applaud Mr. Yankee for starting to think about constructing a Fallout Shelter. Over the past few months, I have been giving some consideration to the very same thing. But, after researching various “expedient” shelters such as the one described by Mr. Yankee (available in FEMA publications), I came to the conclusion that these are inferior, last minute, “make do” constructs. Given the time available to plan, it just makes sense to do the job properly.
Time and Space
I am constantly amused at how little time people think that they will be spending in a fallout shelter. Somehow, they seem to equate a nuclear incident with that of a passing thunder storm/tornado. The problem is that while a storm does its thing and moves on (or dies out), a nuclear event has two components: The Blast and the Fallout. What most folks do not realize is that it’s the Fallout that is “the gift which keeps on giving” (gamma radiation). And, in most cases, people will need to create Fallout Shelters to protect and shield themselves from the gamma radiation contained in the Fallout. Those who live in target rich areas should consider building a Blast Shelter.
Figuring on a minimum of two weeks (but more likely a month) in the shelter to allow the radiation to taper off, leads one to consider not only providing for clean Air, Food, Water, Clothing, Beds; but also Sanitation, Exercise, Entertainment. Now, add an average family of four people into the equation and things become more interesting.
I am reminded of the old gag question: “How many college students can you fit into a telephone booth?”
A 12’x 8’ (and what height?) basement room is not going to be enough physical space to handle the family and all the other things they will need for the duration in the shelter. – Douglas in CT
Dear Jim,
I believe Mr Yankee is unclear on his terminology. Concrete or other mass won’t stop fallout. Air filters stop fallout, which is radionuclide particles. These generally precipitate out in a few hours/few days. A good soaking of the surrounding ground with soap solution will wash them into the soil and lessen the danger of inhalation/contact (from stirring up the dust). The reason nuclear residue from weapons is dangerous is because of its high energy. At the same time, that high level of radiation means it has a short half life. There are long term risks of cancer and such, but the immediate risk is quite controllable. An expedient method is to tape windows shut and use dryer lint between screens as air filters, drawing up from under a cover. A sprinkler over the intake to create a water curtain will improve effectiveness. Obviously, HEPA filters are preferred, if available.
Direct radiation (Which is what I believe he means by “fallout”) is stopped by concrete, compacted Earth or other dense materials such as lead. Most modern military warheads are efficient enough that exposure to lethal levels of radiation means one is already within the radius of overpressure or thermal blast. Obviously, improvised devices are not so clean, and there is danger near the edges of an explosion where one can be exposed to dangerous levels. He is correct that food cans won’t stop such radiation. On the other hand, metals will. Lead is the classic choice, but gold, silver, copper (you might see where that is going) and even steel are of some effect, as is the mass of the house and any outside walls–radiation travels in straight lines, and if the blast is directly overhead, you won’t feel a thing. Copper plates overhead, with a layer of brick or such, plus the outside walls of the house, a berm, trees, nearby terrain features or intervening buildings will all absorb some of the radiation front.
I would recommend against storing materials one plans to use so they can double as shielding. The shielding can absorb neutrons and re-emit them as ionizing radiation. This is very unhealthy. The copper, lead or steel used as such needs to be avoided after the fact, especially on the blast side. It would be a decent gesture not to trade such materials off to the unsuspecting to get sick and die from.
I agree on over-engineering and then covering with concrete or compacted Earth. Something mentioned here before that is quite affordable is a used CONEX box, which is designed to take high weight on the edges and corners. A fairly simple bracing atop it (Any mechanical engineer or even a good construction contractor should be able to calculate what’s needed) will support more than enough mass to act as shielding. This can be planted outside the basement with a drainage bed of gravel underneath, accessible from inside, and reducing the risk of the house collapsing atop the shelter. – Michael Z. Williamson