Category Archives: S2 Tornado Shelter Blog

Tornado Shelter Walls versus Kinetic Energy and Deformation

Growing up, my Dad had sitting on his office desk a little device called Newton’s Cradle.  It had 5 suspended steel balls hung from a frame.  You raised one of the end balls, let it go and when it hit the others, the one on the opposite end would fly up.  This device represents Kinetic Energy.  I didn’t understand it at the time but for a kid, it was fun to play with!

Now, using that same principal, think about one’s head leaning up against the exterior wall of a concrete or masonry tornado shelter.  On the opposite side of the wall, a 15 pound 2×4 traveling at 100 mph strikes right where one’s head is against the wall.  Get the picture?

Along those same lines, the ICC-500 states that a maximum of 3” of permanent deformation of an interior surface is allowed.  3”!  So, you are sitting in one of these steel shelters where the only thing between you and the tornado debris is a sheet of steel that can deflect up to 3” and the shelter manufacturer has so conveniently put a built-in bench for you, on the exterior wall of the shelter with the interior surface of the shelter as you back rest.  A backrest that can have a permanent deformation of 3”!  How do you think one’s skull, spine, and/or shoulder blades are going to react to that potential 3” deformation?

The long and short of this is regardless of the shelter or the shelter material, during a tornadic event, shelter occupants should stay at least 3” away from the exterior walls of the shelter.

Be careful out there!

Post by Corey Schultz, AIA, LEED AP BD+C

Tornado Shelters – Are They Worth the Cost?

There is no doubt that a tornado shelter costs more than normal construction, both in design fees as well as the cost of the construction.  Many say that tornadoes occur so infrequently they it is hard to justify the cost.  Typically, those are people that have not been affected by one of the wind events, regardless of the intensity.  There are eight sets of parents in Enterprise, Alabama, and seven sets in Moore, Oklahoma that lost children to one of the events while the kids were as school.  Would they say that the cost of a tornado shelter would have been worth it?  You bet they would and they have.

So let’s put the shelter cost into perspective.  Currently, the FAA has established that when you step on an airplane, your life is worth $6.9 million.  When we design a school shelter for 600 occupants, per the FAA, the total amount of lives would be worth $4.14 Billion (with a “B”).  If this shelter has a premium cost of $500,000 – $1 million to protect $4.14 Billion, isn’t that a no brainer?

The need for tornado shelters is a proactive issue.  If one waits to support the construction of a shelter until they are affected by an event,…..well, it’s too late just as it was too late for those 15 students in Enterprise and Moore.  For some, the cost of a shelter is not worth it as long as it is affecting someone else.  Forget what the FAA says, look at it this way; what is YOUR life worth?  What is YOUR spouse’s or YOUR child’s life worth?  Isn’t that a no brainer?

Post by Corey Schultz, AIA, LEED AP BD+C

Tornado Shelter Revisions in the IBC 2015

It is my understanding that the IBC 2015 will begin printing in June, 2014.  There are some changes in that code relative to tornado shelters.  A colleague that I have worked with for the past 10 years on the ICC-500 committee was kind enough to provide me with the exact language from the upcoming code.  It shall read as follows:

423.3 Critical emergency operations.  In areas where the shelter design wind speed for tornadoes per Figure 304.2(1) of ICC 500 is 250 MPH, 911 call stations, emergency operation centers and fire, rescue, ambulance and police stations shall have a storm shelter constructed in accordance with ICC 500.

Exception: Buildings meeting the requirements for shelter design in ICC 500.

423.4 Group E occupancies.  In areas where the shelter design wind speed for tornadoes is 250 MPH per Figure 304.2(1) of ICC 500, all Group E Occupancies with an aggregate occupant load of 50 or more shall have a storm shelter constructed in accordance with ICC 500.  The shelter shall be capable of housing the total occupant load of the Group E occupancy. 

Exceptions:

  1. Group E day care facilities.
  2. Group E occupancies accessory to places of religious worship.
  3. Buildings meeting the requirements for shelter design in ICC 500.

Now with that said, it does in fact have to be adopted by local jurisdiction which here in Kansas can take several years.  Other jurisdictions may adopt much sooner.  For my designer colleagues out there, pay heed to this revision, especially if you are dealing with projects that are being budgeted today but not designed until later, i.e. school bond issues.  You could find yourself caught between a rock and a hard place.

Post by Corey Schultz, AIA, LEED AP BD+C

Public Tornado Shelters/Safe Room Management-Part I

During the week of April 28, 2014, there were a rash of tornado’s that cut swathes of destruction through several communities and took the lives of some 35 individuals. We continue to see more and more tornado shelters/safe rooms being constructed throughout the US. Many of those are private residential shelters/safe rooms but many are also community shelters, some are open to the public and some are not.

This latest round of tornadoes exposed many “chinks in the armor” regarding the operation plan and management of shelters/safe rooms that are open to the public. There are stories out there where shelters/safe rooms were supposed to be opened and were not, or members of the community could not find the shelter/safe room or did not know where the
entry to the shelter/safe room was located. These problems expose a lack of planning and a complete lack of understanding the extreme importance of managing public shelters/safe rooms regardless of the intent.

It is truly fortunate that none of the individuals that were unable to access or locate the shelter/safe room were killed. Tornadic events are NOT the time to work out the kinks in a shelter/safe room operations plan. These are peoples’ lives that were are dealing with and the general public does not want to be a guinea pig when it comes to the use of public shelters.

Opening a tornado shelter/safe room is to the public is admirable and at the same time a huge responsibility. In subsequent blogs, we will explore some of the issues to consider in a shelter/safe room operations plan.

Post by Corey Schultz, AIA, LEED AP BD+C

Public Tornado Shelters/Safe Room Management-Part 2