Thursday, August 13, 2009

Structural Stability of Engineered Systems: What do you really know?

I recently posed some questions related to Engineered Structural Assemblies & Systems (ESS) and asked if you knew what they represent and how these components, assemblies and systems may affect or influence incident operations. In addition, I asked you to do some research and check the terms that were presented for starters. OK, its examination day…Did anyone do any basis research yet? Did you ID the terms? (…I can hear those crickets chirping).

In preparation for a program presentation at IAFC FRI in Dallas the end of this month on Building Construction, specifically aimed for Command and Company Officers, it occurred to me that many personnel have not taken advantage of an exceptional resource tool available to them (FREE) thru the Underwriters Laboratory (UL) Online University (HERE), where they offer over 1500 courses, many of which have direct interest to the Fire Service.

One program of note is the Structural Stability of Engineered Lumber in Fire Conditions, online CBT. This two-hour presentation summarizes a research study on the hazards posed to firefighters by the use of lightweight construction and engineered lumber in floor and roof designs. The program provides comparative test results related to legacy (conventional) versus modern engineered construction systems. The operative insights that I want to draw your attention to are the opportunities to gain mission critical insights on time to collapse timelines, as well as operational limitations and readings related to thermal imaging devices while working above fire involved floor or roof areas.

Pay particular attention to the time-to-collapse sequences and times; consider these in you IAP and tactical deployment. The tests also provides indicators that floor or roof assembly deflection (give or bounce), which has been a universal tactic as an possible indication of imminent collapse, may actually not be a reliable indicator, with some floor assembly tests having a deflection of less than 3/4” immediately before structural failure. Add to this carpeting or lightweight concrete coatings, top-side surface temperature (TIC readings) may change little even as the structural integrity of the support system is rapidly diminished below.

You do not have the buffer of allotted operational time that you might have presumed. These faulted assumptions may have catastrophic consequences. In my lecture series Buildingsonfire: Engineered Structural Systems & Fireground Operations, as I've traveled around the country presenting these programs, common themes prevail from coast to coast; the fire service assumes it has more operational time than is actually present before a collapse will occur, that the collapse will be isolated and survivable, that RIT will prevail in a successful outcome and that there is an inadequate knowledge base of understanding of ESS, legacy/conventional construction and the relationships of command risk managment and tactical operations by commanding officers.

I would encourage you to invest some time in taking this program and gaining a fresh view of Engineered Structural Assemblies & Systems (ESS) and how these emerging test results and data may influence your field operations the next time you’re in the street confronted with fire suppression operations in an occupancy with suspected or known ESS.

For those of you attending the IAFC FRI in Dallas, here are a couple of programs worth looking at (there are many more..), HERE, HERE, HERE, HERE and HERE.

Remember, Building Knowledge = Firefighter Safety.
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1 comment:

  1. Really appreciate this information, I am excited to start up being a firefighter myself.

    ReplyDelete

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