In residential design the simplest way to maximize your usable square footage while limiting your overall building footprint is to increase the number of stories, to go UP instead of OUT. This is just basic “architecture 101”. The same is true of shipping container design (even though we’re already working with a very small footprint). And, obviously, if containers can be stacked 10 or 12 high on a cargo ship that is traversing the high seas from one continent to another, they can certainly be stacked on your property and be structurally secure.
On a cargo ship, when containers are stacked they use something called a “twist lock”. This is essentially a triangular hunk of steel that is set atop the bottom container, in all four corners, and then when another container is stacked on top, these triangular pieces “twist” and “lock” in place. This creates a mechanical bond, or link, between the two containers. These same twist locks are used to stack containers being used for housing design as well. By creating this mechanical bond between our two containers we create a “seam” between them.
Mechanical bonds are great. They get the job done, but we want to take it one step further and add a chemical bond by way of welding. By welding our two containers together we effectively end up with ONE container that is now twice the size. In terms of structural stability and hurricane/tornado preparedness….well, let’s just say if Dorothy had lived in a container home, she may have still been in Kansas when all was said and done that day and the Wicked Witch would still have her ruby slippers.