By: Robert Avsec, Executive Fire Officer
First a quick review of western European history. What was the Age of Enlightenment?
The 18th Century proudly referred to itself as the “Age of Enlightenment” and rightfully so, for Europe had dwelled in the dim glow of the Middle Ages when suddenly the lights began to come on in men’s minds and humankind moved forward (Lewis, H. The European Dream of Progress and Enlightenment. 1992)
Digging into the details of that statement, Enlightenment was a wide-ranging intellectual movement of scientists, philosophers, artists, mathematicians, theologians and other “heavy duty” thinkers who sought to better understand the natural world and humankind’s place in it solely on the basis of reason and without turning to religious belief. The movement claimed the allegiance of a majority of thinkers during the 17th and 18th centuries, a period that Thomas Paine called the Age of Reason. At its heart it became a conflict between religion and the inquiring minds that wanted to know and understand through reason based on evidence and proof.
The fire service is, in my opinion, entering into a similar Age of Enlightenment as long-held truths, strategies and tactics are falling by reason based on proof and evidence. The technology available today to fire behavior researchers like those at NIST and UL gives them an unprecedented ability to measure all aspects of a fire’s behavior including temperature at various levels in a space, air flows within a space, infra-red imaging within a space, and video recording and editing capabilities that “brings all the data together”. Fire based research has given us empirical evidence that proves:
- The long-accepted—and taught—concept that fire streams “push” fire is a myth; proper application of a fire stream in the ceiling area above the fire from the exterior of the structure quickly reduces heat, prevents the ignition of unburned hydrocarbons, and reduces interior room temperatures.
- The fuel loads in residential structures have changed. Today’s homes are constructed and furnished with synthetic materials—materials that burn faster, deplete the available oxygen in a space more quickly, and generate more unburned hydrocarbons.
- The way that homes are constructed and the materials used in that construction have changed. The engineered
lumber and light-weight building construction techniques, e.g., wood trusses, used in today’s construction do not maintain their structural integrity when exposed to fire like the “old” dimensional lumber used prior to the 1970’s.
- The structural fires that we encounter today—that occur in more tightly closed spaces and involve synthetic fuels—are most likely in a ventilation-limited state rather than a fuel-limited state when we arrive.
- Ventilation does not have a cooling effect on a ventilation-limited fire, but instead can greatly enhance the fire by providing a flow path that brings oxygen to the fire.
- Exterior fire attack is not strictly a defensive tactic, especially when properly applied to cool the hostile atmosphere and improve the interior conditions for civilians and firefighters.
- Exterior fire attack will not harm victims; cooling the superheated gaseous hydrocarbons in the ceiling area near the fire dramatically reduces interior room temperatures from the floor to the ceiling and improves victim viability.
- The best tactic for combating basement fires is not using a top-down approach; if the flow path is not properly controlled, e.g., a door or window in the basement is opened, the interior basement stairs become the primary flow path and personnel in that flow path will be subjected to intense heat, smoke and fire gases.
- Venting the structure, entering and searching (VES) before suppressing the fire is not the best way to aid entrapped victims and improve their survivability; a more effective tactical approach should be IVES (Isolate the fire, ventilate so as to control the flow path, enter, and search).
Why do I characterize our current day as the Age of Enlightenment for the fire service? Because after decades of firefighting strategy and tactics that are based upon the “I think, feel or believe” method of decision-making we’ve entered into an era where technologies and applied research are yielding the information we need to truly move toward becoming a data driven decision-making profession.
For those of us with Advance Life Support medical training and certifications, we observed this change happen in earnest in EMS beginning around the turn of the century (the most recent one!). EMS agencies, hospitals, allied health organizations and federal agencies started evaluating the effectiveness of long-accepted pre-hospital treatments, e.g., IV therapy for trauma patients, administration of sodium bicarbonate during cardiac arrest resuscitation efforts, etc. With that examination, many long held “truths” about patient care and outcomes have become obsolete and discontinued.
As we continue to move into our Age of Enlightenment, we are seeing the same manner of conflict between “religion”
(That’s the way we’ve always done it!) and the inquiring minds that want to know and understand through reason based on evidence and proof (Look at what the NIST and UL videos are showing about “hitting it hard from the yard!”).