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It’s only a matter of time until a tornado hits a major city, according to Fred Haan ’92, associate professor of mechanical engineering at Rose-Hulman University.

In the meantime, Haan, a tornado and wind storm expert, is working to reduce the damage and death toll of such an occurrence.

“We need to know tornado velocities near the ground,” he said. “If we knew the wind speed, we could prevent deaths by building stronger hospitals, schools and homes, but tornadoes rarely run over existing wind-speed instrumentation.”

Currently, most tornado wind-speed estimates come from damage assessment rather than wind-speed instrumentation. Haan’s research seeks to obtain more exact wind-speed data from vehicle motion. “Vehicles are plentiful in tornado damage zones,” he said.

Using his tornado simulator, Haan is researching the peak wind speed necessary to cause vehicle sliding, flipping and lifting. 

These data will help in the development of better building designs that will keep roofs on structures and structures attached to their foundations, even during powerful winds and upward suction created by tornadoes. Haan said stronger connections between building components—often in the form of relatively inexpensive clips and brackets—make a significant difference in keeping structures intact during wind storms. He said 90 percent of tornadoes are rated EF2 or lower and that wind speeds in those tornadoes are comparable to what engineers already design for in hurricane regions. 

“The more tools that we have to estimate wind speeds near the ground,” he said, “the better our ability to design safer structures.”