How do you know the storm shelter is safe?

Note: The following are excerpts only, occasionally paraphrased, from documents from Texas Tech, but do not constitute an endorsement of any product.

Testing of Shelter Component by Texas Tech University Wind Engineering Research Center http://www.wind.ttu.edu

March 24, 2001
Fiberglass Creations

Re: Shelter Component Testing

On September 7, 2000 and January 22, 2001 tests were conducted on "The Refuge" cellar door and locking Mechanisms. The tests were consistent with FEMA 320 (Taking Shelter from the Storm) guidelines requiring the cellar door to resist a 15-lb. 2x4 missile traveling vertically at 67 mph. This missile relates to debris dropped by a 250 mph tornado.

Congratulations on your shelter door successfully passing the FEMA 320 tests.

Sincerely,

L.J.T. P.E.

Research Associate

INVESTIGATION OF WIND PROJECTILE RESISTANCE OF … SHELTER DOORS

Testing Performed by
The Wind Science and Engineering Research Center
Texas Tech University
March 26, 2001

Texas Tech University was contacted by Fiberglass Creations to assess the ability of their door system to resist tornado forces and debris impacts.

The missile used for the tests was a 15-lb. 2x4-in. wood board traveling along the board's longitudinal axis, striking the panel perpendicular to the panel face. The tornado test criterion uses this missile traveling at 67 mph which corresponds to debris dropped vertically by a 250-mph ground-level wind and is the criterion used in designing for occupant protection. Additional factors of safety are inherent in the criterion since there is a very small probability that a missile will be traveling along its axis and will strike perpendicular to its surface.

Conclusions

Within the bounds of reasonable engineering and technical certainty, and subject to change if additional information becomes available, the following is my professional opinion:

The door assembly for The Refuge (underground shelter), manufactured by Fiberglass Creations, is capable of resisting the 15-lb. 2x4 traveling at 67 mph, as required by FEMA 320…

L.J.T. Public Engineer