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A Testament to the Dome Shape

Freda Parker July 05, 2011, 11:29 a.m. Monolithic Dome Benefits: Survivability

Image: Dome Shape Survives Direct Tornado Hit – ...Dome Shape Survives Direct Tornado Hit – On May 24, 2011 in Blanchard, OK, this house, which is a thin shell concrete dome but not a Monolithic Dome, was hit by an EF4 or EF5 tornado. Although badly damaged by heavy, flying debris, the dome shell survived. That, we think, is a testament to the dome shape. Conventional homes hit by this tornado were flattened and swept off their foundations. (Josh South)

Image: Gapping Holes – Debris smashing against this ...Image: Serious Cracks – Because this thin shell ...Image: Survivor – This Blanchard, OK dome was ...

A horrific tornado

At about 5:38 pm on a hot, humid afternoon, an EF4 tornado – possibly an EF5 – with winds of about 200 mph hit little Blanchard, Oklahoma and its 3225 residents. Fortunately, unlike some of its neighbors hit by the same spate of tornadoes, Blanchard suffered no fatalities. But some people were hurt seriously and had to be hospitalized; vehicles were overturned and flung about; giant trees and shrubs were twisted and uprooted; heavy debris was blown hither and tither; and 200 homes were either destroyed or damaged.

Dome takes direct hit

One of those homes – a thin shell concrete dome – constructed in 1981 by an independent builder took a direct hit.

When the tornado alert sounded, the owners, Jane and George Cox, both in their 80s, were in their dome home, feeling perfectly safe. According to Debbie Leonard, their daughter, they felt so safe they remained near the windows hoping to watch the tornado.

Debbie said, „My parents were inside and they were injured because they didn’t take cover. I was taking it (the tornado alert) very seriously. They kept saying, ‘These houses are tornado-proof.’ And I kept telling them the windows were not tornado-proof.

“If they had been in their closet, they would not have been injured,” Debbie added. “But they kept looking out the windows. When they saw it coming, they started toward the back of the house, and that’s when it hit. They were knocked down and bombarded with all sorts of stuff. They’re lucky to be alive.”

The debris that came flying through the window included a 300-gallon diesel tank and a full roll of barbed wire fencing, and the dome was hit by cars and all kinds of heavy debris.

Debbie said, “My parents had to go to the hospital and get stitches. Mom’s ankle and foot were seriously hurt but should heal without surgery. It was bad. I mean, they wouldn’t be alive if they had been in a regular house.”

Not a Monolithic Dome

A few days after the tornado, Josh South of South Industries, Inc., who was in Oklahoma working on Monolithic Domes being built for a school in nearby Dale, visited Blanchard, talked with Debbie, inspected and photographed the Cox dome.

Josh said that he could see that although the Cox home was a thin shell concrete dome, it was not a Monolithic Dome. Josh sent the photographs and reported his findings to Mike South, vice-president/operations director at Monolithic.

Mike said, „Even in those early days (1981) of this technology, that dome was not properly reinforced. It was built primarily with steel fibers, had only a few steel reinforcing bars (rebar) running vertically but none running horizontally. Monolithic Domes are reinforced with rebar running in both directions. Its Airform had been removed so the urethane really got battered.

“If it was a Monolithic Dome, it wouldn’t have had any cracks in the shell whatsoever,” Mike added. “But it’s still a testament to the dome shape! What other shape could have survived that kind of destructive force?”

Debbie’s home

Debbie also lives in a 30-year-old dome that is near her parents’ dome and constructed by the same builder.

“My home did not get a direct hit, and I stayed in my bathroom that doesn’t have windows,” she said. „I didn’t catch as much debris. But that tornado did a lot of damage around my dome. I have a metal building and it lost its windows. It blew the windows and door in and shattered the skylight on my dome. But it’s all just glass damage.

“People all around us lost their homes,” Debbie said. “Regular houses were just flattened and swept off their foundations.”