Mobile home? Ideally, not Air-mobile...

James McDonald, professor of civil engineering at Texas Tech University in Lubbock. "There's not a whole lot you can do because of the way they are constructed," says Texas Tech University Professor James McDonald. McDonald is the director of the Institute for Disaster Research.

A mobile home is, 'a very lightweight structure with a large, exposed surface area, says McDonald, "that's built with very little margin for error."

Getting Stronger
Mobile homes are getting stronger. The federal government passed a new regulation after Hurricane Andrew devastated part of Florida in 1992.

The regulation strengthened building standards for mobile homes, so new models should be able to withstand 30 to 40 percent stronger winds. (McDonald says earlier homes had been built to withstand barely 60 mph.) The standards will improve fastenings within the home, with particular emphasis on exterior corners where wind stresses are particularly severe.

Don't Fly Away!
A second, equally severe challenge is to prevent the home from flying away. The standard anchoring technique, McDonald says, is to screw steel rods with plates on the end into the ground.

But the bolts have some problems. "There's a catch-22," McDonald says. "If the ground is soft enough for the anchor to penetrate, the soil is too soft to prevent it from pulling out. If the ground is stronger, the stake won't go in deeply enough."

So McDonald, suggests going a step further. He notes that "95 percent of mobile homes are never moved after they are placed." Thus he advocates anchoring mobile homes to concrete foundations, an expensive measure that can be done to existing homes.

Still, the basic drawbacks of lightweight construction, and the lack of a basement, remain. Would McDonald feel comfortable riding out a tornado warning in a new-standard mobile home bolted to a concrete foundation? "No."

Last Stop: Tornadoes effect nature, too.

There are 1 2 3 4 5 6 7 8 9 10 11 12 13 14 documents. (Credits | Glossary | Bibliography) 

 Home Page 

This lesson created by "The Why Files," a NISE project funded by the NSF. Lesson used by permission. Original lesson and graphics copyright NISE. Modifications copyright BPNM.
 Mobile home photos courtesy James McDonald., Texas Tech University. .