Prepare for SHTF - or just everyday life

Underground bunkers shouldn’t be made from shipping containers!

Damn I’m bored!

Why is it so dangerous for underground bunkers to be made from shipping containers?

I bet you were thinking that I was about to give you plans about how you should dig a hole for a cheap underground bunker with a door to be used for a simple SHTF/TEOTWAWKI survival bunker. Well, you’re wrong. What I’m here to tell you is that if you listen to pretty much all of the bullshit advice on the web, that you’ll be wrong. Not like I haven’t said that before.


Shipping containers were built to be stacked. They’re called Intermodal Freight Containers because they can be moved on trains, boats, helicopters, whatever. They are meant to be large portable closets. They were not to be buried or cut into, and certainly weren’t designed to be used as underground bunkers. Once you do that, you start changing their effectiveness. They are not built for lateral pressure and not designed for long-term wetness or acidic/caustic soil. I spent quite a lot of time in Iraq and saw some of the buried shelters that were only underground partway, and they were all buckling under the pressure. Guarantee they aren’t still safe even today.

Just for reference, a cubic yard of dirt weighs somewhere between a ton and 2700 pounds or so. Imagine how much pressure a buried container bunker must have to withstand and then realize that the whole thing is surrounded by metal that’s only about as thick as a saw blade.

If you’ve never studied mechanical engineering, you need to understand that something that can withstand a LOT of pressure on one angle won’t necessarily withstand even close to that pressure at another. Think about an egg. If you push down from the top of an egg, it’ll hold up to a lot more pressure than you’d think. Press it on the sides though and it crushes before you even start pushing. Same thing for a beer can. You can stand on one with no problem but then push your finger into one of the sides and the whole thing crushes. That’s because the force pushes down on itself, which is why shipping containers can hold a lot of weight if they’re stacked.

These containers are designed to hold a LOT of weight as long as it’s held in the right spots, but anywhere else and you might as well just bury an enclosed car trailer. Take a look at what happened with this container that ended up being sent to auction.

This is why you don’t bury shipping containers

Why? It’s physics, baby! Go to college and learn why. I’m just here to tell you that it happens, even though you may not have heard about it. Start vetting your sources before you listen to them and you’ll start seeing a pattern, and then you’ll start seeing which stories are true and which are just fluff to get you to click on their links. If you want a decent beginning to the design and capabilities of shipping container structures, check out this book.

The biggest lesson you need to learn is that if you’re gonna build an underground shelter, you need to have a building inspector come in and take it all into consideration. If you have electricity running through it, have an electrician check it all out. Why on Earth would you try to save a few hundred bucks to risk it caving in on your family or electrocuting your kid to death during the first rainstorm? Are you a really a prepper?

Other reasons why you may want to rethink burying a shipping container – or underground shelters altogether

WTF are you trying to accomplish? Sure, you can get a shipping container for a few thousand dollars. Those few thousand dollars buy you a very small room. A room that I’ve lived in for many, many, many months overseas in different combat zones. They’re called Containerized Living Units (CLU’s) or Containerized Housing Units (CHU’s). I used them just to sleep in, along with anywhere from one to three roommates and I gotta tell you, it’s not fun. I couldn’t imagine being stuck in one of them with other people for months at a time.

A shipping container is pretty much a rectangular metal tent. Imagine living in an underground bunker for months before coming up. If you’ve never spent weeks living out of a tent at night, you have no idea what it’d be like living in a bunker for months, both day and night. That’s not even counting the actual logistics of not leaving the container, including human waste, trash, emotional pressure and the actual tactics involved. I’ll be visiting the tactical idiocy of almost all underground bunkers I’ve seen in a later post but if you just think about things from the enemy’s viewpoint and how they’d attack you, you’ll either quickly see how stupid it is or you really need to just go ahead and do it now so you’re out of the gene pool before you procreate.

If you’ve ever been in combat in an urban environment, you know just how shitty of a decision it is to hole up in a room with only one entrance. One entrance means one exit. If they control the entrance, they control the exit, and they have a lot more room and supplies outside than you could have in a bunker. No matter how fortified your structure is, unless you spend a CRAPLOAD of money, all they have to do is wait you out and can easily speed up your schedule to come out.

Now I’m not saying that you shouldn’t consider a fortified underground bunker at all, but if you do, just realize that you’ve shut out a lot of your capabilities such as escape, resupply and support if you don’t make a pretty extensive plan.

Not to mention the fact that shipping containers are prone to have toxic paint and chemicals in the wood, including fumigation sprays that will likely require you to replace all the wood and strip all the paint to be safe.

Enough of that for now though because there are ways to plan around these problems but I wanted to mention them because people who are drawn to burying shipping container bunkers are the same idiots who’ll not consider what I’ve mentioned already, let alone the tactical disadvantage of being buried in a box a few feet below the surface with limited air supply and exits. I may go into the tactical ways to design and protect an underground bunker in a later thing but at the moment, I just want you to realize that if you’re going by what you’ve most likely been reading in some pretty popular articles about burying shipping containers, that you’re probably wrong.

The plain and simple truth is that a shipping container is designed to be stacked and have pretty much zero horizontal external pressure. Burying it will add a LOT of side pressure, especially if you’re in a rain-prone environment or have certain soils. They’re just not built for that. Might as well just build a frame and fill it with cement in the walls for a lot cheaper.

If you’re gonna use a shipping container bunker as an underground shelter, realize that it’s most likely made out of Corten Steel. Pretty decent stuff as long as it doesn’t get scratched and dented. If it does, it’ll start rusting through. Not a good thing if you’re 10 feet underground. They are pretty cheap and have their place in your plans if you’re smart. Here’s an example of one I found on Amazon for $2500:

As long as it’s sealed, you can make it useable if you spend some time reinforcing the walls, depending on the soil and rainfall in the area. Just make sure that you don’t bury a 9-ish foot container under 6 feet of earth in an area that has a water table 12 feet under the ground. If you want to see some common specifications of shipping containers, check out this wikipedia article.

Basically, a shipping container is pretty good for above-ground fortification as long as you fix any chemical problem. You can decide to bury one (or more) but to do it properly (not even counting the tactics and other considerations), you’ll have to spend a lot more money to make it right than just buying and delivering the containers. Remember though, just because it’s metal doesn’t make it bullet-proof (one big advantage to an underground bunker) Don’t take my word for it, do some research specifically looking at the limitations and dangers of burying shipping containers for yourself instead of just looking at the cost savings.

Structurally, pipes are MUCH better at withstanding pressure, from any direction. The problem is that they’re round and we like our stuff to be on flat floors with flat walls. If, however, you could put a rectangular shipping container into a cylindrical pipe underground, you’d be set structurally. You’d still have to deal with the fact that you’re buried underground though. Here’s a video of an example of one made out of metal:

So what should you do if you really want an underground bunker using these metal boxes?

Think it through. Have someone come take a look at your plans before you commit. Don’t be an idiot. A shipping container is a great starting point for an above-ground shelter or if you’re planning on adding a supporting structure to it (provided you’ve figured out all the tactics of being stuck in a hole in the ground with people who might want to get you out). It just might not be the cheapest way to go if you’re planning on burying it.

The biggest thing though is that if you’re trying to use it, or anything else, as a buried defensive bunker, you’d better have a hidden exit somewhere to get out if you’re found, and should be thinking about some serious camouflage around it for your entrance and vents. It would suck to spend all that money, planning, and time just to make yourself a ridiculously overly-complicated coffin.

Underground shipping container bunkers are possible; just don’t think that all you have to do is dig a deep hole, drop a shipping container into it, bury it and decorate.

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About Scott Kelley

I am a military veteran who has deployed to combat theaters in Africa, Iraq and Afghanistan and have almost three decades of military and military contracting experience.

My goal is to help preppers and others understand how to intelligently protect their family and their way of life.

  • 1_no_political_lemmings_1

    Thank you Graywolf for sharing your wisdom. Have a good one…………… (former B 1/75 ‘old scroll’ Rangers)

  • Rumfitt Booya

    Hi graywolf, firstly id like to say excellent advice, I have seen many “preppers” online recommend shipping containers and until reading this was along the same line of thought myself.

    Can I ask, where in the UK would you recommend to go in a SHTF situation? I was thinking wilderness like scotland would be a good idea but wanted an experts advice? THanks

    • graywolfsurvival

      I haven’t been to the UK since I was in RAF Mildenhall in the 80′s. It would all depend on what the situation is really. A group solution is best though. At least you have a lot of land that you can live off all around there. If it were up to me, I’d head to St James’ Gate in Ireland and hole up in the Guinness brewery.

  • Inkognito Jones

    Reinforce the container, properly prep the exterior and interior for corrosion resistance, and then bury it. I’ve had mine in the ground under 3′ of dirt for almost 6 years now. During a recent ‘remodel’ of some of my plumbing, I dug up one side of the container and not a spot of rust – looked as good as the day I covered it up. Don’t be stupid, and you’ll be fine.

    • Katherine Lee James

      Can I ask you a question? what made you only have your container 3 ft under dirt? I am thinking of using shipping containers (several of them) and reinforce them but going 20 ft under dirt.

  • Katherine Lee James

    I am very new to prepping & was thinking of using containers under ground for my family but also thought I would certainly need to have them reinforced & was told its best to bury at least 20ft under ground,is that correct.. Im concerned now as what to do, I am not in a position to purchase the bunkers that are sold specifically for this purpose.I live in Australia and there isnt anyone selling them on the market over here.Maybe someone should start up a business of sorts as there are plenty of people wanting them. I have a large family and want to do whatever it takes to keep them all alive but in saying that want to do it right. I would appreciate any ideas or suggestions,thanks, Kat James.

    • graywolfsurvival

      Hi Katherine

      The deeper you go, the less likely you are to be discovered and the more protection you’d have from radiation, blast, attack etc. the problem is that your engineering requirements go up due to increased pressure, more difficulty in cycling air, danger of hitting the water table – especially during rainy season, etc.

      You also have to consider that your entrance and escape avenues have to be just as deep. Remember that if there’s only one way in then there’s only one way out.

      I’ll have to write a post some time on how to properly bury and defend a shipping container because there’s a lot to discuss, especially when it comes to tactics.

      • Katherine Lee James

        Hello Graywolfsurvival,
        Thank you for your reply, most appreciated. I’m looking into proper air filtration which is the same used in the bunkers sold by Atlas Survival Shelters which suggest you bury your bunker 20 feet down so I’m thinking I’m on the right track. I am also interested in canning meat if you have any ideas on this.. From what I’ve seen Americans use glass jars & call this canning, we call it preserving. I would certainly have a few escape tunnels & security camera’s with night vision. Wow there is so much to consider & take into account & to organise. I am doing this solely on my own which is going to take some time, thank
        you for any suggestions.

        • graywolfsurvival

          In a lot of cases, a buried bunker is so expensive and complicated that it isn’t the best choice. By the time you get it all safe, secure and working, you could have paid for a fantastic above-ground facility that has its own benefits. You get a LOT more room and flexibility for the same price.

          Burying a couple of long escape tunnels and camouflaging their exits can be pretty damn expensive to do it right, but you might want to consider putting one or two of them in even if you don’t go underground. All depends on your layout and what exactly you’re planning for. Just remember that if your escape hatch is within view of the place you’re escaping, it’s shit.

          For most people, using a fraction of that money for tactical and medical training is much better spent. What would you do if you spent everything on your bunker and had to leave it or couldn’t make it there when the time came? Learning is much preferable to buying.

          I don’t know jack about preserving. I have started to at least buy canning jars and freeze food when I make too much though lol.

          • Katherine Lee James

            We don’t have access to guns unless you obtain a licence which I might add is not easy to get, actually almost impossible so to live above ground frightens me especially when Ill have small grandchildren & no protection & nothing in the way of protection against nuclear disaster..We are buying acreage early next year so we will have the space and the bunkers will be placed on our property. To buy one of Atlas Survival shelters or any of the other one’s its going to cost about $60,000 + just for one and that’s only big enough for 6 people, so I’d need at least 4 of them, then its something like $70,000 to ship one over here, so my thinking is shipping containers is going to be the cheaper option. The tunnels or escape routes will be hidden to the human eye, I have too many lives at stake not to take great care on these crucial parts elements..I have been a mum for 37 years & ten kids later so I have more medical knowledge then most & have done some medical training as well. You are very informative & I take your suggestions seriously. Thank you again. I will have to google how to preserve meat, I do however know how to make jerky.

          • blueeagle

            you might think of building ur own bunker , made out of cinder blockes, u can get more space for ur money.and will last a lot longer than a Shipping container and its a lot safer/

  • Renaissance Ronin

    Amen, brother, A-freakin-MEN. I wish people would STOP asking me about this. Just because you see idiots doing it on “sensationalista TV” doesn’t discount the “I R a Moron” factor. Listen to Graywolf. PLEASE listen to Graywolf. You CANNOT bury a Corten Steel Shipping Container in the ground and achieve anything but failure.I don’t want to be tasked with digging out your sorry butt and then burying you in a proper grave. (I’ve actually had to do this.) You can throw a ton of money at this “dig a big hole and drop the box – solution” but in the end, it’ll make that container unnecessary. I KNOW what I’m talking about. I’m one of the TOP rated ISBU guys on the planet. ;)

    • graywolfsurvival

      I kept seeing people suggesting that others should bury these things but they didn’t actually do any digging into how exactly you’d do it. I was originally gonna just write the post about the tactical mistake of doing this (which will come at some point now) but I found so many problems with the logistics of doing this that I completely changed the article. Thanks for your input RR!

  • arguendo

    I do indeed have plans along this line. I was planning to use a smaller 20ft container, paint it with paint that prevents hydrolisis, and add concrete around the lateral walls and rear. Hadn’t really hammered out what sort of concealment to use at the entrance, yet.

    • graywolfsurvival

      Adding concrete is the key but you may find that you can use just the concrete and have a little more flexibility.

      The concealment is the hard part, no matter how you build an underground shelter. To do it properly, you need an entrance that is not only hidden from people passing by but also gives you a plausible reason that they lost you if they followed you there so they don’t start digging around. If that’s not possible, you need to at least be able to verify if you’re being followed before you turn off to it without them knowing there was a turnoff in the first place.

      A big thing though is that if you only have one entrance, you only have one exit. A small, buried shelter is a bitch tactically.

      • arguendo

        Agreed. The area is out in the middle of nowhere. More of a “last resort standby and hunker down till (whatever) passes” than a plan A option. I like the ideas of a fairly secure fallback option though.

  • http://www.risingsbunkers.com/ Chad Robinson

    A: WALLS –

    RSC Steel bunkers are constructed from 1/4″ plate steel and 1/4″
    C-Channel. Shipping containers offer no structural reinforcement and
    the walls are made from thin 14-gauge steel. This means that the ENTIRE
    Rising S unit is a load-bearing structure capable of supporting weights
    in excess of 300,000lbs. Shipping containers are only load-bearing at
    it’s 4 corners.

    B: CEILING & FLOORS –

    Constructed from 1/4″ plate steel and 1/4″ 2′x4′ Square Tubing.
    Shipping containers offer no structural reinforcement and the walls are
    made from thin 14-gauge steel. There are wood floors in most shipping
    containers only further weakening the over all strength of the
    structure.

    C: DOORS AND EXPANDABLE UNITS –

    Shipping containers are not easily expandable. Aside from the main
    challenge of cutting away the door and fabricating a connector piece
    between two shelters; removing any part of a shipping container’s wall
    will only further weaken the already flimsy structure.

    In contrast; Rising S bunkers are easily expandable. Using flanges;
    we are able to offer our clients the ability to expand their floor-plans
    and virtually enlarge the bunker to endless possibilities. Between
    each unit; there are also security doors offering redundant layers of
    protection against intruders. RSC floor plans are limited only by budget
    and imagination. If you can dream it – we can build it.

    D: STAIRCASE ENTRY AND HATCH DOOR –

    Every underground bunker that Rising S Company builds comes with a
    steel staircase and entry hatch. This hatch is lockable from the inside
    and acts as your first line of defense in times of trouble. A security
    door lies at the foot of the staircase giving occupants a second layer
    of security and protection against assailants or looters. Shipping
    containers offer no such convenient entry methods nor do they offer the
    added security that a RSC staircase and security doors can provide.

    E: SHIPPING CONTAINERS: Not a load bearing structure!

    WARNING! If you bury a shipping container without re-supporting the
    walls, ceiling and floor; IT WILL COLLAPSE! The thin steel used in the
    walls and ceiling isn’t strong enough to support the weight of the dirt.
    Every shipping container is built to be strongest at the corners. If
    you place significant weight & pressure anywhere other than the
    corner posts; the container will collapse. The only way to reinforce
    the structure is to line it in concrete blocks or in wood… both of which
    are inferior methods compared to the strength of the heavy steel used
    in RSC units. Not to mention that regardless of the re-stabilizing
    method used; it all subtracts from the available floor space.

    F: THIN & POOR CONSTRUCTION.

    The standard shipping container’s walls are very thin (16 gauge steel). These walls are problematic for several reasons. A:
    They are weaker than the steel used in RSC units and without
    significant re-stabilization of the walls and roof; they will collapse
    under the weight of being buried. B: They have no corrosion protection so deterioration is quickened. C.
    The walls are corrugated so installing a sealed floor is near
    impossible …short of adding more steel to the unit, Ideally; occupants
    need to be able to seal the unit off from moisture and potentially
    toxic air. Air filtration is only possible in units that are air-tight.

  • Timothy Cogdill

    Totally agree. I’ve looked into the whole shipping container thing and the only viable option I found was to pour a footing/slab, build a block box with sump and then put the shipping container inside of it. Sounds kind of stupid at that point doesn’t it. You can actually build an underground concrete block room for what you would pay for a shipping container. Concrete, and block is cheap. If you don’t mind doing the work yourself it’s cost effective, and a Much better option. Along with an emergency exit.

  • XBrody Charles Garth II

    Do you really know what you are talking about? First thing that lead me to think you do not was “they are only about as think as a saw blade”. A standard steel shipping container can withstand a blast from a .357 at 10 foot range,I am pretty sure a saw blade can not do that.

    • graywolfsurvival

      Here’s a video of your .357 going through a shipping container at 30 feet – http://vimeo.com/38596700

      … And the same shipping container being penetrated by a 9mm at the same 30 feet – http://vimeo.com/38592222

      Still think a shipping container can withstand a .357 at 10 feet?

      Now to the pertinent facts as related to the article…

      The thickness of ISO shipping container walls is about 2mm (14 gage) – http://www.elitebuildings.com/userfiles/ISO_Container_Specifications.pdf

      Here’s just one example picked at random of a selection of saw blades available, showing them to be available from 1.8mm-4.4mm, meaning that 2mm falls within the definition of “about as thick as a saw blade” – http://www.guhdo.com/sawblades/documents/2011SawBlade_004.pdf

      Plus, no where in the article did I mention a single sentence about being bulletproof as a deciding factor in burying a shipping container, only that the walls can’t take the side pressure from dirt when buried.

      Not sure where you’re getting your facts but you should really find more reputable sources.

  • Sean Donnelly

    Heyya Wolf, I hadn’t really thought about the directional vectors involved nor the corrosion factor. I would have thought that the metal would have lasted ‘long enough’ for what it would be needed for. I would have figured something like a shipping container would only be useful for the primary die-off hence corrosion not factoring for me. As far as tactical considerations go, however, I am in 100% agreement with you. Anything with only one way in is known to thinking people as a “trap.” I have the same problem with people building, what is essentially, a panic room. It’s fine when the police will be showing up in fifteen minutes to half an hour. When you don’t have police, or someone else, coming to flank the people waiting you out … it becomes a death trap.

  • Joseph Taylor

    Good information to know before spending tons of money on something that won’t last and could be dangerous also.

  • TurkeyMan

    Great article, Great advice.
    Thank you for putting it out there the way it really is.

  • ibelievein3

    Can you bury a mobile home (not motor home/rv) AKA prefab home or “trailer” as in “trailer park”? I am curious if anyone knows the specs.

    • graywolfsurvival

      I’m gonna go out on a limb here and say no. Trailers are much weaker structurally than a shipping container.

  • Corey Michael Naughton

    That Atlas shelter video was stupid. The only 3/8ths steel which will stop “pretty much every bullet but a .50 cal) would be AR500 steel. The door would weigh over 200 lbs and it still wouldn’t stop any sub-50. cal round that is AP (like readily available 30-06 AP). Also, why would you demo your product when it’s unfinished and there’s potential customers inside???
    Anyways, the problem with burying a shipping container is that most people just plain do it wrong. The thing isn’t designed to support lateral load ONLY compression load. If you want a shelter just build an above ground earth bag building. It’s bulletproof and fireproof by design.

    • graywolfsurvival

      Spot on Corey

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