Containers make excellent above-ground storage containers. With some minor modifications they can even be made livable to some extent. But below ground is touch and go depending on the acidity of the ground and the degree of oxidation of the container. Rust will eat through such containers in about the same time as it would, say, an automobile. You would suffer moisture leakage, and probable contamination depending upon the water table contamination and the age or lack of positive seals on the doors. In most all cases, your first enemy underground is moisture.
Offered by Brian.
Electrical charges pass through the earth constantly and the soil has a resistance to these charges. Any metal object placed in the ground can act as a short-cut for electrons to get where they are trying to go, thus any buried metal experiences much more corrosive force underground than on the surface. Something along the lines of ten times as much! Corrosion is dependent not only on the shipping container itself and how well it is covered but also on the type of soil and amount of moisture in the soil. The corrosiveness of the soil can be tested ahead of time. For a full bury the container might be additionally protected by coating with a hot asphalt tar emulsion which you can get locally. Check with your highway dept., as they use it to coat and patch cracks in the road. There are other more high tech coatings which might be tried, but for cost effectiveness I like this one. In the partial bury solution the container is kept out of the ground and dry enough to not need any additional corrosion protection other than a good industrial coating.
Offered by Steve.
Transportation is an issue to consider if planning on using containers at your survival location. 40' containers require a semi-trailer (18+ wheeler) and a crane to transport and unload, which adds to the cost substantially and limits your distance from "civilization". 20' containers require a tilt truck and can get to any location accessible by road, including well maintained or sturdy dirt roads. A maneuvering area of 16 or 20 square metres, reasonably flat, was mentioned to me also. I've been thinking about partially burying a 20' shipping container (or two) into the a hill side with the doors opening outward, away from the hill. Yesterday I went to visit a secondhand container refurbishment business and learned that steel containers will rust badly if buried within the ground with the dirt piled against them. To counter this, though, I was informed to use fully galvinised containers or stainless steel containers. However, they are not as readily available and cost from $2500 (Australian Dollars), as opposed to $1800 for the standard steel ones. When buried in the ground with the dirt in contact with the steel, the standard steel shipping containers will rust to the point where they become unusable within 1-2 years. Or so I was informed.
Offered by Gino.
Pick up some Zinc bars and place them in the ground with a heavy wire running to the container. This will minimize rusting. Marine supplies have these sort of items. They use them in salt water and with boats to minimize corrosion and rust.
Offered by Mike.