How to Build an Underground Tornado Shelter

Make an underground tornado shelter that will withstand intense winds in a secure underground location that is simple to construct.

This shelter will have the steel walls of a shipping container and the security of being underground. An extension cord or batteries will supply the power, and the metal can be used as part of a radio antenna for reception during the storm.

Order a shipping container. Use the grinder to cut a 4-inch hole in roof of the shipping container for ventilation. Sandblast the shipping container. Repaint it using a polyurea coating over the entire structure for a little insulation, rust prevention, a non-slip surface and durability.

Dig a hole that is deep enough for the shipping container to fit in on top of a 6-inch layer of sand (for drainage). Place the container in the hole with the doors in the open position at both ends. Place the one open door at a 135-degree angle from the side of the container at each end so that the door can help to shore up the soil and create two emergency exits. Use stakes of rebar driven into the ground to hold the doors open and weld them in place. Place the displaced soil from digging the hole in a heap on top of the shelter. Place a 4-inch pipe in the hole and weld it in place. Give the pipe a candy cane bend with a pipe bender so that the rain does not flood your shelter.

Pour a concrete pad at each end that allows the other (non-staked) doors to swing freely. Dig out the dirt wall around the concrete door pad. Make a terrace around the entrance that serves as stairs and shores up the wall with railroad ties. Make sure that the concrete pad is set below the level of the door for drainage.

Cut those ties into 2-foot sections. Drill a hole that pierces the tie near one end. Repeat this at the other end and again in the middle. Stack the tie sections so that one hole overlaps between ties. Drive rebar through the hole 2 feet into the ground. This should form a wall of checkerboard pattern railroad ties holding back the dirt that are themselves held in place by rebar. Drive three sections of rebar through each section of railroad tie. Grow plants in the spaces around the ties to slow erosion. Use the ties as ladders to get in and out of the shelter.

Drill holes every 3 inches into the metal around where the door that has been staked back that are the same diameter as the shaft of your rivets. At intervals of 3 inches in acrylic glass, drill holes that correspond to the ones drilled into the into the shipping container.

Glue the two pieces of acrylic glass (Plexiglas, for example) together around the edges with super glue to seal the space between the two sheets together.

Use a rivet gun to rivet the double layer of acrylic glass onto the frame of the shipping container. Use a layer of insulation (sold in auto supply shops to be used around the edges of car doors) on the edges of the door on the shipping container and the edge of the acrylic glass.

Make sure that the acrylic glass does not have any stress on it when the door is closed so that it does not shatter. Make these windows at both ends of the container so that the doors can close and reinforce them.

Things You Will Need

  • Shipping container that opens at both ends
  • Sand blaster
  • Grinder
  • 4-inch pipe and pipe bender
  • Welding equipment
  • 6 inches of sand
  • Crane or other means to lower the container into the hole
  • Polyurea coating
  • 4 bags of concrete
  • 13 railroad ties
  • 18 sections of rebar
  • 2 sheets of acrylic glass (used in shower doors)
  • Rivet gun and rivets
  • Car door weather stripping (insulation)

Tip

  • Run an extension cord to the container for electricity. Use battery-powered appliances in case the electricity goes out. Wiring the storage container is not necessary unless it will be used often.

Warning

  • A stove may be installed for heat if desired, but make sure that you have adequate ventilation. Consult a general contractor and engineer to make sure that you comply with all safety requirements. Read and follow all instructions that came with the equipment that you are going to use. Always wear safety glasses. Make sure that the shelter has adequate ventilation. Add any necessary ventilation by adding vents to the door.