The cold war era shaped the thinking on underground bunkers, and shortly after World War II, fallout shelters became somewhat popular in the United States. Underground has always been a way of escaping bombs, invading armies, civil conflicts, and even from marauders and in particular since the 1950’s protecting oneself from a nuclear war.
Basements below ground level were, and still are, an alternative to certain underground bunkers as long as all the walls are all below ground, surrounded by soil in other words. Doing World War II in Great Britain the government issued corrugated metal shields called Anderson Shelters that homeowners could install over their outside stairwells that lead down to the basements. The arched shaped shelters could hold up to six adults.
The shelters were issued free to residents making under a certain amount of household income. The metal was galvanized, corrugated steel and came in sheets that were bolted together. The shelters could also be buried up to four feet deep and the top covered with up to 15 inches of soil. The residents would huddle underneath the metal shield covering the stairwell, and even if the house received a direct hit, the occupants had protection (andersonshelters.org, n.d.).
Basements not below the ground would be basements created by split-level homes, and the bottom story is often times called a “walk out” basement. One or two walls of the bottom story would likely be considered “outside” walls and would not be surrounded by soil typically, thus rendering them ineffective as shelters.
The reality show Doomsday Preppers has had families on the show that were in the process of putting in underground bunkers and in some cases, the bunkers depicted were shipping containers.
Shipping containers while inexpensive compared to bunkers designed especially for underground living are not ideal, and in most cases, they are extremely dangerous if buried without being reinforced.
Shipping containers are not manufactured to withstand being buried. One cubic yard of dry topsoil weighs approximately one ton, 2,000 pounds per cubic yard, and when wet of course, it is even heavier. The containers are designed for stacking, so while the four corners are sturdy enough nothing else in between is.
The containers would have to be made moisture proof as well. While they are waterproof when used as intended once buried and surrounded by moist soil for an extended period they would allow moisture to seep inside in all likelihood.
Soil on top of the container will crush it unless you reinforce the top and sides, and this of course defeats the entire purpose. You would essentially have to build a bunker to house your bunker, which makes no sense at all.
You can build your own underground shelter by excavating a large hole and then build forms for the walls and pour concrete yourself that is reinforced with rebar, or build block walls. If you are going to that expense you might as well make sure, it can protect you from a nuclear blast, so have at least five feet of soil between your bunker and the surface. The deeper the better, but the more expensive it gets.
Then there are companies that build bunkers to your specifications, haul it out to your site or build it on site, bury it, hook up the utilities and then hand over the keys, at a considerable expense of course.
Before Drawing up Plans and Writing Any Checks Decide Why You Need a Bunker
Underground is probably one of the safest places to be during a tornado, so if you live in an area prone to tornadoes an underground shelter could save your life. Typically, a shelter for this type of disaster is only designed for short periods of occupancy, several hours usually. There would be a single entrance/exit, seating and possibly room for a small amount of emergency supplies. In some cases, the shelters can be built on concrete foundations above ground.
Fallout shelters if built properly would be able to sustain a certain number of people for extended periods, weeks and even months in some cases, and could be designed to protect against nuclear, chemical or biological contaminates.
The shelter would need an independent air supply with intake filtering devices as well as filtering devices to remove carbon dioxide from the air. Waste management is another consideration, as well as, a reliable water and energy source independent of any public power grids.
Shipping containers buried and used as survival caches would still need to be reinforced and measures taken to protect items inside it from moisture damage. Burying a shipping container just to cache/stockpile supplies would be a major undertaking and not likely to be beneficial in the end.
Unless you have multiple exits, an underground bunker can be a trap. Even if you had multiple escape exits, coming to the surface while someone or some group is hunting for your bunker or knows the bunker is there and essentially has you under siege puts you in harms way unless the exits are several hundred yards away from the bunker itself so you can exit undetected.
You cannot launch attacks from an underground bunker unless you do have multiples exits and even if so, it would be difficult, and just how many armed personnel would be in the bunker to launch any type of attack to begin with.
Avoiding detection is your best defense, and that may be difficult because of the infrastructure that may be evident above ground. If someone or a group suspected there was a bunker on the property, they would be able to find and possibly disrupt/destroy your energy and water source if given enough time.
You can of course purchase a piece of property in a remote area of the country and construct a bunker or convert certain underground facilities into a bunker that could sustain a group of people for an extended period. The biggest problem is getting there during a crisis. Another problem is secrecy, so unless you did all the work yourself by moonlight, multiple people will know there is a survival bunker there.
Some have purchased space (community shelters) in converted missile silos or other underground facilities, but it is extremely expensive, and you have essentially given over your life to someone else in the event of a crisis. The facility will only be as good as the people selling you the space, for millions of dollars in some cases.
An underground bunker can be beneficial if done properly. You have to decide however, what its intended use is. Is it for protection against natural disasters, or manmade ones or is it a supply depot essentially?
How long you would have to stay in one is a major consideration, and you would not know that until after the crisis has struck. You would however, have to assume and prepare for the worst-case scenario, which would be a nuclear attack, and that would mean radioactive fallout.
Given the state of the world today if you were to build a bunker it would be prudent to make sure it could protect you from a nuclear, chemical or biological attack.