After all of the conversations we’ve had about this topic, I’m still amazed that I see that “dreaded dragon” of ISBU construction popping up over and over again. We’ve spent years debunking this myth.
Of course, I’m talking about the act of playing “ISBU Peek-A-Boo.” Yes, I’m referring to burying shipping containers in the ground.
People… you cannot bury ISBU containers in the ground… unless you’re trying to build a coffin. I’ve (along with many other trade professionals) done the calculations and the element analysis over and over again.
Simply digging a hole in the ground and then burying a container to create a “low budget bunker” or storage room won’t work. I don’t care who tells you this works or how many idiotic photographs you saw on Facebook describing/documenting this “feat”.
The act of burying (or concealing) a container means that you’re talking about applying several feet of earth or cover to the top and sides of a hollow steel box that wasn’t designed to handle it. No matter where you live on the rock, earth is heavy. For a good reference about material weights per cubic foot you can download this handy reference sheet;
Once you do that (and do the math) you’ll see exactly what I’m talking about.
Sadly, some naysayers will still forge ahead into “steel stupidity”. I’m sad to admit that I’ve personally been involved in the investigations of failed “buried” structures using ISBUs, including digging out and then removing the bodies.
Not only do the containers collapse if you bury them but burying the container will make the steel rust out eventually.
ALL ISBU containers are constructed in a similar fashion. A pair of massive steel end frames are connected together using steel rails and then closed in using corrugated Corten steel sheeting and pesticide ridden plywood laminates.
While Corten Steel (weathering steel) is known for it’s oxidation properties that inhibit rust, an ISBU will still rust (corrode) through over time if not maintained or protected properly.
Where we live there are oil and gas fields all around us. A quick survey of some of these tankage guys will reveal that any steel tank or structure buried underground will eventually fail due to rust failures. You can slow down the rust process using cathodic protection, but you’re still chasing a dragon’s tail.
Also note that the corrugated steel sheeting used to construct ISBUs (shipping containers) is NOT structural.
The corrugation simply closes in the box to allow freight to be placed within the box created. The framing within the container itself isn’t designed to support exterior loads, either. It’s not a “roll cage”. It’s simply there to allow an attachment point for the corrugation.
A cubic foot of dry earth weighs approximately 75 pounds. Get that same cubic foot of earth wet or turn it onto mud and you’re talking about 115 pounds a foot plus.Most people suggesting the burial of containers target a depth of about 3 feet or more. Do some math. A cubic yard of wet earth weighs over 3,000 pounds. How much surface area does your container have? The first time it rains, your “low budget bunker” is going to look something like this:
I’ve said it before (and I’ll probably be forced to repeat it until I’m out of breath – I’ve even written a book about it!), but the ONLY way to bury a container underground safely is to surround it with concrete and then add corrosion control processes. Please note that this “vaulting and corrosion control process” will actually eliminate the need for the container in the first place.