Deadly Storms Inspire Indiana Shelter Inventors

When tornadoes tore through southern Indiana and other Midwest states in March, killing at least 13 people and nearly demolishing Henryville, Bob Gray and Steve Clingaman knew they were working on a project worth investing in.

The Frankfort duo’s creation is the Tornado Cave – a storm shelter made of steel mesh, high-density foam and other composite materials. Six adults can fit inside the small domed structure, which was made to be bolted into a garage floor.

Gray and Clingaman, who already have started to sell and install a handful of the white igloo-looking caves, head up a Frankfort insulation and roof coating company, Hoosier Square Inc.

They said they have been inspired for years to put their insulation knowledge to use for people’s safety, but when the Joplin, Mo., tornado hit last May, and Gray and Clingaman heard stories about survivors who had hid out in a freezer to weather the storm, they got excited.

“We took that idea and put it on steroids,” Clingaman said.

Now, the Tornado Cave is just about ready for FEMA’s stamp of approval. It has a provisional patent, Clingaman said.

FEMA has high standards for shelters and safe rooms, Gray said.

The organization’s website states rooms must meet certain requirements to “withstand high winds and flying debris, even if the residence is severely damaged or destroyed.”

The Tornado Cave was designed to withstand up to level five tornadoes on the Enhanced Fujita scale, Gray said, like the one in Joplin, Mo. But the product also can be customized to withstand less serious winds.

How can Gray and Clingaman be sure the Tornado Cave is strong enough to protect people from the natural disasters?

The team frequently tests the product by catapulting two-by-four pieces of wood out of a cannon going more than 100 miles per hour at the cave’s weakest point to see the damage.

During a test of the cave’s strength that the team showed the Journal & Courier, the wood bounced right off the Tornado Cave after shooting out of a cannon at 114 miles per hour, with the force of 135 pounds per square inch.

When the same test was repeated, this time with the target a makeshift side of a house instead, the wood easily shot through it after coming out of the cannon at just a quarter of the speed.

Gray said his team is constantly working to refine the Tornado Cave. The group of 12 works on perfecting it between other projects in the company’s Frankfort studio.

The product was designed for homes that don’t have adequate refuge, Gray said, such as homes without basements or cellars.

Slab homes have become increasingly popular because they cost less, Gray said.

It costs about $20 more per square foot to build a home with a basement instead of on slab, according to the Chicago-area based Portland Cement Association, which conducts market development, engineering and education research while representing U.S. and Canadian cement companies.

Marketing the Tornado Cave, which costs up to about $6,500, is in its initial phases, Gray said.

“It’s worse than life insurance,” Gray said. “Unless you’re experiencing the fear of a tornado, you might not invest in it.”

There is an average of 1.4 strong to violent tornadoes each year in Indiana, according to the National Climatic Data Center.

So, as they wage a battle on the Tornado Cave sales front, the developers have come up with another product. It has a similar look.

People are usually more willing to spend money on entertainment than safety, Gray said.

This product’s use? It’s a man cave for ice fishers.

The team said there has been a lot of interest in the ice fishing product.

Topics Catastrophe Windstorm