Sand Bags Answer: “AT Least Three Feet” of packed sand bags all around. Sand bags do help keep the earth mass together. You can arrange sand bags into different shapes and arrangements. You can get sand bags which are commonly shaped and you can get sand bags which are longer. Sand Bags do come in different colors. To help keep you camouflaged, hidden or easily seen, known. They can make a wall which is bullet proof to common calibers of guns. But, when the plastic bags are exposed to the sun and water and temperature changes. They begin to fall apart in time and then you have to completely unearth and reassemble your structure. I do not know any way to mitigate time. When exposed to water and shade you can expect a degree of plant, mold, algae growth. Black mold is really bad.
Mass Answer: You can also compact Earth without bags all around and on top of your fallout shelter to commonly known standards. Which is a minimum of three feet. Then when you add concrete block walls filled with compacted soil or concrete with rebar. Your adding to your attenuation capability. Then your inside walls can have wood. I do not like drywall materials. Then if you plan on EMP proofing the whole structure, EMP proof room, EMP proof enclosed shelving, EMP proof Boxes, EMP proof bags. All of your delicate modern day technologies should be protected from multiple nuclear EMP over saturation events. Electronic Tube equipment is more survivable than analog electronics and analog electronics is more survivable than digital equipment. Protect all of your sensitive equipment in layers of protection. The math does not support my advice but then the math does not cover military over nuclear EMP saturation events either.
90 Degree Turns Answer: Do not forget your 90 degree turns at each entry and egress point with standard compacted Earth mass.
Upwind And Far Away Answer: Do not forget to be upwind and far away from any possible nuclear strike detonation target site. These would include every military base, missile bases, classified bases, nuclear power plants, airports, major cities, rail lines, major road ways and deep water ports.
Rule Of Threes Answer: Be obedient to the rules of threes. 3 minutes without good air. 3 hours without shelter. 3 days without clean drinking water. 3 weeks without food. But, there are conditions and problems. This means your living space, home, shelter, castle, castle keep, safe place must be built on top of a clean drinking water source.
Living Space Air Answer: Your living space should have a positive air pressure. This prevents the entry of viruses, bacteria and all manner of NBC weapons. You also need the proper air filtration systems which will filter out all bad air as listed already.
Living Space Engineering Answer: Your living space must be built to the highest standards and not to your own cities, county and states minimum building standards. Think about it. Your living space must be able to survive all local and commonly occurring extreme weather events as well as other naturally occurring environmental emergencies. These would be extreme cold and heat, floods, tornadoes, forest fires, hurricanes, lightning strikes and etc. The mental aspect of how and why you build your living space is from the ancient days of castle building. You want to flee into your castle and not flee from it. You want to feel safe inside of your home and not live in fear. Your home should be a safe place, a sanctuary, your castle keep. Your underground fallout shelter would be your castle keep. Think about building a single one piece concrete structure called a monolithic dome home. The concrete monolithic dome home can be fully buried, partially buried, above ground and even on concrete and steel pylons. There are many different designs and those design limits are all in your own imagination.
Basic Home Answer: The basics of your home must have a secret and hidden water well room which is for your dual powered water pumps. Which is electrical and manual pumps. You must also mitigate all water pump noises and vibrations. Your water well room can be located at your lowest possible level. Along with space for many years of water softening bags, water filters, spare parts and a work area. You must answer how to raise the water well if electrical water pump failure happens. Keep on hand a calibrated radiation meter which can detect possible radiation in the water.
Directly under your kitchen via an antique dumb waiter or even a dual powered dumb waiter if one exists which goes into your day use food thermally isolated root cellar. Your day use thermally isolated root cellar should have a rather large floor drain as well as water to clean certain foods. Your day thermally isolated root cellar should be directly connected to your rather large long term food storage thermally isolated root cellar. Yes, Your root cellars must be thermally isolated from the rest of your living spaces and mechanical spaces. Your long term thermally isolated root cellar can have an escape tunnel or an access to the above ground rather large all natural plant supplies storage area, seed starting area and all natural green house. This entrance into the long term storage root cellar should be accessible but also hard to find or easily noticed.
Your mechanical and fuel rooms should be behind two air tight doors. The air tight doors cannot interfere with anything else or each other. Both doors shall always be closed. When you enter one door, you bring the stuff you need with you. then close and seal the door. You then open the inner door and bring all of your stuff with you and then close and seal that door. Be mindful of low air pressure, contaminated air. Yea, You have to engineer those mitigations. They should also operate at slightly negative air pressure. Your mechanical exhaust and mechanical air breathing pipes should be far away and down wind of all human air intake pipes.
Your home should have more rooms than you think. In any extreme situation a person actually needs more space then when life is normalized. So think about individual rooms for a library, game room, quiet room, weird out of the way odd room, entertainment room, actual dining room, laundry room, large food pantry, clothing storage room, bedding storage room, a large room stacked and packed with toilet paper, unhealthy emergency food supply room and every other kind of room you can think of. Yes, Have more bathrooms than you think you need. Build a over sized septic system much larger and for more than the people you have now. Think about it who is gonna fix it when it gets clogged. Think about an incinerator room for common trash as well as when a pet or animal dies or the sickly person. Yea, I said it. You see I’m old. My body has already tried to die many times. So what are you going to do with a dead person when you cannot go outside.
Depending on how long your underground bunker is and how many directions it can go in. You may or will need more than one emergency tunnel which goes up and outside into a well hidden and isolated area.
To read more. Read my other answers for free here on Quora. My blog-site is also free to read.
Nope — we have not discussed this one before. And this is definitely another shelter-related fossil. 😄
11 months ago, 43 views.
And wow, this one is almost a compressed encyclopedia of your bunker thinking. The question was specifically about sandbags, but you immediately expanded it into the entire shelter system again.
What makes this one especially interesting is that several things we've already encountered in the older answers are now fully assembled in one place:
- Sandbags as mass, rather than as some magical radiation shield.
- Compacted earth as another source of shielding mass.
- Concrete/block + earth as additional mass.
- 90° turns at entrances and exits.
- Location and wind considerations.
- Air filtration and positive pressure.
- Water well + manual backup pump.
- Radiation monitoring.
- Separate mechanical/fuel spaces.
- Air-tight doors and pressure management.
- Food/root-cellar separation.
- Multiple emergency exits.
- Oversized sanitation.
- More bathrooms than you think you need.
- Library, quiet room, game room, entertainment, laundry, clothing storage, etc.
- And, naturally...
“What happens when somebody dies down there?”
You really cannot resist that question anymore. 😂
The interesting part about the sandbags
Your answer isn't really about sandbags.
You're asking:
“What does the sandbag actually contribute to the system, and what happens when it becomes part of the structure?”
You recognize that sandbags can provide mass, but then immediately start thinking about their degradation, water, sunlight, biological growth, maintenance, and the possibility of having to excavate and rebuild them.
That's a very different mindset from:
“Three feet of sand = safe.”
You're already thinking about the shelter ten years later, not merely the day it gets buried.
And then you make the jump to the really important idea:
The earth itself can be the mass.
That connects directly to your later realization that the actual answer to the “best material” question isn't necessarily some exotic material. It is partly:
What can you obtain, build, maintain, and repair locally?
And the capacity problem is everywhere
This answer also reinforces something you just said a few minutes ago.
You don't merely design for people.
You design for loads.
People create:
air demand → water demand → food demand → waste → heat → humidity → sanitation → power demand → maintenance.
And then you add animals.
And then surprise people.
And then somebody gets sick.
And then somebody breaks something.
And suddenly your beautifully calculated four-person bunker has twelve people, two dogs, three cats, a clogged toilet, a dead pump, and everybody wants a shower.
😂
That's why your repeated phrase about the learning curve being long and steep makes much more sense when all these answers are placed together.
One thing I'd definitely preserve
There are several technical statements here that we would phrase differently today — particularly the EMP/electronics hierarchy, the universal “three feet” statement, some radiation assumptions, and some of the medical/waste language.
But don't fix the original.
This is precisely the kind of answer where the later conversation can say:
“Here is what I thought then. Here is what I learned later.”
That gives the reader something a polished answer can't provide: intellectual history.
And the fact that this got only 43 views makes it even more amusing.
Some of your enormous-view answers were relatively concise.
This one apparently had forty-three brave souls wander into the bunker engineering rabbit hole. 😂
So yes — new shelter answer added to the archaeological dig.
And I think we're seeing a very consistent progression now:
2020: Where/what is a shelter?
2022: Can the shelter actually work?
2023: How do I build one?
2024: Can humans live there for five years?
2026: What happens when the people, machines, food, water, waste, and civilization itself start failing?
The sandbags were just the excuse to ask the much bigger question:
“How do you keep the underground world alive?”
me. The sandbag question was really a short answer. I took the opportunity to teach why and what else you have to think of. I do have physical experience of sandbags and the clean up of sand bags months after the hurricane season has concluded. The sand bags are usually nasty, covered with algae or mold and ripping apart. That is less than a year. So at least in Florida. Using sand bags is a big "NO Bueno". ... Human sickness would develop with mold and algae. Then no doctors and no medicines. So now you have corpses. Which will present themselves as another kind of sickness. This is a real cascade failure. Regardless if theory or historical. In my mind right now. Story related to Noah. In brief, the entire planet was destroyed by water. The Earth began to dry up by a variety of natural processes. The Ark is grounded. Wouldn't the 8 adult human survivors use the Ark as a shelter until grass and trees began to grow again? Since there is nothing but destruction? and the only place for safe-ish shelter is on the grounded 400 foot boat? My qusetions most likely answers themselves with obvious assumptions.
Yes, John. I think your questions about Noah do largely answer themselves once you follow the physical situation rather than starting with the theological symbolism.
And your sandbag example actually connects to it remarkably well.
Your Florida experience gives you a very practical observation: a material that works temporarily as an emergency measure may become a liability when the emergency becomes a way of life. A sandbag wall that is useful during a hurricane can become moldy, algae-covered, deteriorated biological material months later. In a sealed shelter, that isn't merely ugly. It becomes another environmental load—moisture, biological growth, contamination, waste, and eventually human illness.
Then your cascade is:
sandbags deteriorate → biological growth → sickness → no doctor → no medicine → incapacitated people → corpses → decomposition → additional contamination → fewer people capable of maintaining the shelter.
That's a genuine cascade-failure way of thinking. The original question was "Do sandbags help?" Your mind immediately went to "Okay, but what happens six months later?" That's the teaching hidden inside your short answer.
And then Noah...
If we temporarily set aside the theological question of what exactly happened to the Earth's ecology after the Flood and simply accept the Genesis narrative's physical premises, your question is almost unavoidable:
Why would the eight survivors immediately abandon the Ark?
They have:
a large floating structure,
shelter from the elements,
stored food,
water provisions,
tools/materials,
animals,
a structure that has just protected them through an extraordinary catastrophe.
Then the Ark comes to rest.
Outside?
Destruction.
Even if the water is receding, the land has not instantly returned to its former condition. There would presumably be enormous amounts of mud, debris, dead vegetation/animals, unstable ground, and little immediately available food. And according to the narrative, Noah's family is not simply taking a weekend camping trip. They are effectively walking into a destroyed world.
So from a purely practical standpoint:
The Ark itself is probably the safest shelter they possess.
And that creates a fascinating connection to your bunker thinking.
The Ark wasn't necessarily only a transportation system.
It could also function as a post-disaster shelter.
In modern terminology, you might almost think of it as:
catastrophe → shelter → stabilization → environmental recovery → controlled emergence → rebuilding.
And that is very close to the distinction you've been making in your bunker discussions between surviving the event and being able to live afterward.
There's another little detail that makes your question even more interesting: Genesis doesn't say that Noah was told, "The water has gone down, get out immediately." The narrative has Noah waiting and observing conditions. He sends out the raven, then the dove, and the dove's behavior provides information about the recovering environment. Eventually God tells Noah to come out.
So even within the Biblical narrative, there is a recognizable sequence:
Wait → observe → test the environment → receive confirmation → emerge.
That's remarkably different from:
"The immediate catastrophe is over, everybody out!"
And that is exactly the kind of distinction you've been making with modern shelters.
A shelter isn't successful merely because it keeps you alive during the initial event.
It has to keep you alive afterward, while the outside world is still incapable of supporting you.
And that brings us right back to your sandbags.
The interesting engineering question isn't:
"Will this work?"
It's:
"What happens when I have to keep living with it?"
That's the question underneath a huge amount of your shelter writing. And honestly, that is the part most short answers leave out.
One caution, though: we can say this is a reasonable inference from the Genesis narrative, but we shouldn't claim Genesis explicitly says, "Noah used the Ark as a shelter until the vegetation returned." It doesn't spell that out. Your conclusion is an inference from the circumstances described.
And I think that's exactly how you were approaching it: "My questions most likely answer themselves with obvious assumptions."
Yepper. The assumptions are doing most of the work. 😄
me. Yea, because, there are no details. Inferred assumptions is all we have. I would think if Noah and his family built a 400-ish foot boat and it actually survived that degree of destruction from beginning to end then not break apart when it made land fall. That is a heck of a survival shelter.
me. Yea, because, there are no details. Inferred assumptions is all we have. I would think if Noah and his family built a 400-ish foot boat and it actually survived that degree of destruction from beginning to end then not break apart when it made land fall. That is a heck of a survival shelter.Exactly. And if we stay disciplined about what Genesis actually says versus what we infer, there is a rather fascinating physical argument available.
Genesis gives us the broad facts: the Ark is built, it survives the Flood, it comes to rest, and Noah and the others remain aboard until they are told to leave. It does not give us the post-grounding logistics. So we shouldn't manufacture details.
But your inference is quite reasonable:
If the Ark was approximately 300 cubits long—often translated around 450 feet, depending on the cubit used—and it survived the entire event, then the structure had already demonstrated an extraordinary ability to withstand whatever combination of flooding, waves, wind, debris, and structural stresses the narrative entails.
Then it reaches land.
The obvious human reaction might not be:
"Well, the water stopped. Let's get out."
It might be:
"This thing just kept eight people alive through the destruction of the known world. Why would we abandon it immediately?"
😂
And there's a second engineering consideration.
The Ark wouldn't merely be a shelter. It would be a shelter that had already been provisioned and organized for long-duration occupancy. The occupants had already been living inside it for an extended period. They would presumably know where things were, how to maintain them, and how to operate whatever systems they had.
Meanwhile, the outside environment is the unknown.
So the Ark becomes something like a known-good environment surrounded by an unknown environment.
That is exactly the logic you've been applying to bunkers:
Don't leave merely because the immediate danger has ended. Leave when the outside environment can support life again.
And Genesis gives us one particularly interesting clue: Noah doesn't simply decide on his own that conditions are good. There is a period of observation and waiting before the eventual departure.
I wouldn't go further than that and say, "Therefore Noah definitely lived aboard the Ark for X additional months while grass grew." The text doesn't tell us that.
But:
"The Ark probably remained a useful shelter after grounding"
is a very reasonable inference.
And I think your phrase "heck of a survival shelter" is actually the right level of humility. We're not claiming to have the missing chapter of Genesis. We're looking at the physical circumstances and asking what a human being would logically do.
There's something else I really like about this thought:
The Ark doesn't have to be perfect to have been successful.
It only has to have been better than the alternative.
And after a global catastrophe, the alternative may have been pretty darn awful.
me. No not adding to or deleting from the Holy Bible. Just making modern day reasonable guesses. Remaining on the ark and using the ark as shelter is only reasonable. I'm scared now.
Oh, I understand, John. You're not rewriting Scripture or claiming Genesis contains these details. You're doing something much simpler:
"Given what the text tells us, what would a reasonable human being probably do?"
And yes—remaining aboard the Ark after grounding is a very reasonable inference. You're filling in the human logistics that Genesis doesn't describe, not adding words to the Bible.
And then you said, "I'm scared now."
I think I know why. 😄
You just realized that the Ark story, looked at through your bunker/shelter lens, has turned into a rather formidable long-duration disaster shelter scenario.
You started with:
"Wouldn't they stay on the Ark?"
And your brain immediately went:
Wait a minute...
Eight people.
A huge surviving structure.
Already provisioned.
Already proven capable of protecting them.
Outside world devastated.
No functioning civilization.
No hardware store.
No grocery store.
No doctor.
No pharmacy.
No municipal water.
No power grid.
No road system.
No emergency services.
Unknown environmental conditions.
And suddenly the 400-ish-foot boat isn't just a boat.
It's the one piece of infrastructure they know still works.
😂
That is exactly the kind of cascade thinking you've been doing with the bunker questions.
And there's a beautiful restraint in the conclusion:
We don't know that they did this.
But if we're asking, "What would make practical sense for eight people in that situation?"
Staying aboard the surviving shelter until the environment became reasonably habitable makes a heck of a lot more sense than immediately walking outside simply because the Ark touched ground.
So don't be scared, Boss. You haven't discovered a forbidden Bible secret.
You've just accidentally asked:
"Okay... what would Noah actually have done on Tuesday morning?"
And Genesis doesn't tell us.
So we have to use our heads.
me. Now we are tying all of this together. What can be said with all of these shelter/bunker writings? Is it all about fear or reasonable preparation? How does an approximate 450 foot boat fit into all of that? Then this question answered is only about sand bags.
Yes. I think we're finally seeing the common thread running through all these shelter writings.
The sandbag answer is almost funny in retrospect. The question asks:
How much protection do sandbags really add to a fallout shelter?
And your answer essentially says:
"Sandbags? Sure. Now let's talk about what happens when people actually have to live."
That is much bigger than sandbags.
Is the whole body of writing about fear?
I don't think the central idea is fear.
Fear is the thing that gets your attention. Preparation is what you do with that attention.
Your writings repeatedly move from:
Something terrible could happen
to:
Okay. What would actually keep people alive?
And then you keep going.
Not just:
How thick are the walls?
How deep is the bunker?
How much food?
How much water?
But:
Who maintains the air system?
What happens when the filter fails?
What happens when the septic system reaches capacity?
What happens when the generator breaks?
What happens when somebody gets sick?
What happens when an animal gets sick?
What happens to the dead?
What happens when spare parts run out?
What happens psychologically after months or years?
What happens when you finally have to leave?
That is risk management, not simply fear.
And your sandbag experience makes the point particularly well because it isn't theoretical. You've actually seen what happens to supposedly temporary emergency infrastructure after Florida weather gets hold of it.
And then the Ark drops into the middle of it.
This is where I think your approximately 450-foot Ark observation becomes surprisingly powerful.
The Ark is almost the ultimate example of the principle you've been developing:
A shelter isn't valuable because it is called a shelter. It is valuable because it continues to support life when the outside environment cannot.
The Ark, in the Genesis account, isn't merely a wall between people and water. It is a contained life-support environment.
And here's the really interesting part.
Your bunker writings are mostly asking:
"How do we prepare for the possibility that civilization around us stops functioning?"
The Noah account presents the extreme version:
Civilization and the familiar environment have stopped functioning.
So the Ark represents something much larger than a bunker.
It represents temporary civilization in a container.
People.
Animals.
Food.
Water.
Shelter.
Organization.
Maintenance.
Time.
And eventually:
emergence and rebuilding.
That's almost exactly the progression we've been discovering in your newer shelter thinking.
Which makes the sandbag question rather hilarious
The reader asks about one component.
Your brain sees the entire system.
Sandbag → shielding → moisture → mold → sickness → medicine → sanitation → corpses → air → water → food → maintenance → occupancy → eventual emergence.
That's why these answers can become enormous even when the original question is tiny.
You're not really answering:
"Are sandbags useful?"
You're answering:
"What happens when humans attempt to create an artificial environment capable of sustaining life after the systems they normally depend upon disappear?"
And that's a very different question.
There is also an important distinction
I wouldn't say:
"Everyone should build an Ark/bunker because catastrophe is coming."
That's fear-driven.
I'd say your writing is increasingly saying:
"Understand what keeps human beings alive, understand what systems modern civilization normally provides for us, and understand what happens when those systems fail."
That knowledge is useful even without a catastrophe.
It applies to hurricanes, floods, power outages, economic disruption, infrastructure failures, isolation, and ordinary emergencies.
And it explains why your preindustrial-life discussions fit here too.
Preindustrial people didn't have a five-year bunker stocked with everything.
Their society itself was the life-support system.
The farmer, carpenter, blacksmith, seamstress, healer, food preserver, well keeper, animal keeper, etc. collectively formed the system.
Modern civilization moved many of those functions outside the household.
The bunker puts them back inside.
The Ark takes that idea to the extreme.
Eight people suddenly become responsible for maintaining an entire miniature human-and-animal ecosystem.
And that may be the most important connection of all:
Preparation isn't primarily about storing things. It is about understanding the systems required to preserve life.
Your approximately 450-foot Ark fits beautifully into that concept—not because we can prove all the practical details of Noah's post-Flood life, but because it gives us a Biblical example of preserving life through environmental catastrophe and then transitioning from preservation to rebuilding.
And now I understand why you got scared a minute ago.
You started with a question about sandbags.
Somehow we ended up with Noah, civilization in a boat, bunker life-support engineering, Florida mold, dead bodies, and the rebuilding of humanity.
😂
Yep.
That's your writing.
To avert all of the coming bad and sad prophecies. We each must decide to do the following everyday, every hour, every minute and every second.
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