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Tuesday, March 10, 2009

Burying a Shipping Container or CONEX, by Danny Papa

Back during the first Gulf War we used excess shipping containers for underground storage and protection. Out first few attempts to make use of these containers met with disaster. Although they will support a huge amount of weight, in the range of 400,000 pounds directly on top, It must be place directly over the load-bearing corners. The sides and top are vulnerable to flexing, if they flex they can and will collapse. With all of this in mind let’s go through how to bury one the right way, so that it will be ready and usable when the time comes.

First let us start with container preparation. Most of these containers have spent years at sea covered with salt water. This means rust. Very simply the rust needs to be removed as best as possible. A drill with a wire brush does this well.

This is a time consuming job but it will add years of life to your container. Grind off all of the rust and then paint everything [with specially-formulated rust-resistant paint], and I mean everything. Don’t forget underneath. For safety, I have rolled these containers over on their sides to do this step, it would creep me out to jack it up and crawl underneath one. A little grinding and paint will help protect your investment. Once the container is ready be sure to let the paint dry for a couple of days before burial.

The hole needs to be 16 feet wide 55 feet long and 8 feet deep.
Think about this if you dig a hole it will eventually fill up with water.
So we either need to build a sump in the bottom or trench it out to day light. I prefer the latter, since it requires no electricity or manual labor to pump it dry.
Let’s presume we have trenched it to daylight and go from there.
Line the bottom of the hole with foundation plastic, heavy duty black plastic. At least two feet up the sides. Place French drain pipe with silt shield in bottom of hole and out to daylight. Stake it in place where it will not be directly under the edges or corners of the container. Drive a t-post every 8 feet around the edge of the hole through the plastics within 6 inches of the sides. Place 6 inches of gravel in bottom of hole.

Now comes the hard part, getting the container in the hole. .
You want the container centered to the back of the hole within 42 inches of the back wall. A big track hoe can move these containers but make sure with the owner when renting one that it can pick up at least 8,000 pounds if not you may need a small crane. I could go into many different ways to get it into the hole but the key is to get it onto the gravel with out it digging in, where it needs to be and level.

Next, we will discuss Gabions or HESCO baskets. This is basically a wire basket with a liner to hold rocks and sand that will bear the load for the sides of the container. This wire basket wall will be built completely around the containers to support the sides from both lateral pressure and water. To save time and explanation, see the Wikipedia pages on gabions and HESCO bastions.

Here is a shopping list for "do it yourself" basket materials. Please realize that this is that this is the Army way which means expensive. I will go over alternatives later.

24 - Hog panels. These are welded wire 34 inches tall by 16 feet long.
34 - Cattle panels these are welded wire 52 inches tall by 16 feet long
20 - 8 foot long T-posts which are used in the bottom of the hole
Hog ring pliers and a large sack of heavy gauge hog rings (these are to hold the baskets together).
2,240 square feet of chicken wire with 1/2" size mesh
56 - 3 ft. pieces of 3/8 rebar, with one inch bent down on each end.
28 - 3 ft. pieces of 3/8 rebar, with one end bent into hooks

The hog panels are the bottom middle and top support for the baskets the cattle panels. Place hog panels over t-post and let them to ground where panel is flat on the ground. Line them up end to end with one across the back of the hole.

Place the cattle panels in between the T-post and the wall of the hole. Use the hog rings to tie the bottom together at least one every 6 inches. Take the hooked rebar and drive into the ground every four foot between t post. Now place a cattle panel on the other side of the hog panel and tie them together along the bottom.

Do this all the way around the container. Here is where a little experience is helpful. Build the one in the back first. Put the bottom and the sides and cut a hog panel to the right length for the ends of the basket. Nest do the long side this will be 48 feet long. Now do the other side but we will do it a little different. Once you are four feet past the end of the container cut off the cattle panels and hog panels and build end for the basket. Then build another small basket that goes at a 90 degree angle to the middle of the hole forming an "L" for the doorway.

Now you have the baskets. Cover the outside cattle panel with landscape fabric to keep silt from filling between the rocks then line the entire inside of the basket with chicken wire--use the 1/2" inch mesh variety. Make sure the basket walls are straight up and down. Use the rebar with the bent ends to tie the sides together. Now fill the baskets with rocks any rocks will do as long as they are packed in and do not leave a bunch of gaps I like rocks about the size of a baseball, the key is that they have to be big enough to not go though the wire mesh. Now put the top on the basket which will be the bottom of the next row. And then build the next layer of baskets. Once the wall of baskets is built then use what ever you have to reach from one wall of baskets to the other. In Saudi we use these wood floor pieces that they made for our tents which were a sheet of 1/2 inch plywood on a 2x4 frame it took two of them to get across but once we put them in place and covered them with plastic we would pile a layer of sand bags on top of them at least three sand bags deep. Then cover the whole thing with another sheet of plastic and top it off with a layer of sand.

On the end where the door is I had you build an L shape this is a basic entrance for any bunker over this end you need to use heavy timbers to support the sand bag covering we used old cross ties from one basket to the other not sure if this is a good idea considering the creosote on the ties.

Now this would take a squad about two days to build but once completed right they will last for decades. Before rotating out of the country, we had a bull dozer drive across one, just to see what would happen. Other than crushing the wooden panels supporting the sand bags there was no damage to the container. Now, to do this the way a civilian could do it...

For the Gabion/HESCO baskets there are many alternatives, such as:

  • 55 gallon drums filled with sand and anchored together with metal strips.
  • Old tires stacked and filled with sand but keep these at least 8 inches away from the side of the container.
  • Sandbags

Sandbags are very labor intensive and again need to make sure there is a gap between them and the container they have a "slide" effect that is hard to overcome without experience. You can even just use packed sand in the basket if you line it completely with landscape material or fabric that will keep the sand in the basket.

Another point of experience: I have had people ask why not use bailing wire or concrete ties to hold the baskets together the simple answer is that rust will eventually destroy this light-gauge wire. You can use this but I would advise that paint the wire after it was twisted it together and don’t expect it to last as long as the hog rings.

Also remember that many things can happen when you are underground, so always keep equipment in the container that can be used to break your way out. Ax, saws, a pick ax, and a hydraulic jack.

To sum it all up you just have to remember three key things. Rust removal and prevention, keep it dry, and alleviate any lateral pressure.


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