Learning to Recognize Flashover
by: Lou Angeli
Flashover! Even though firefighters are beginning to understand it, this fatal phenomenon is still shrouded in a veil of mystery. Experts in the fire training arena have differing opinions and descriptions of Flashover, but they all seem to agree on one thing. It's a nasty thing!
Simply put, room and contents begin to burn at a very rapid rate during the growth stage of the blaze. Heat is radiated from burning combustibles, then reradiated by the walls and other structural elements. This "thermal feedback" causes an even greater acceleration of heat. Finally, the entire room and its contents ignite with violent and explosive force.Our culture and its technology have served as a major contributor to the problem of flashover.
Up until the 1960's, the average residence contained natural products made up of woods, cottons and other fabrics. Back then it often took a blaze from 8 to 10 minutes to grow from inception to the fully-involved stage. But in our present day world of synthetics, plastics and hydrocarbons, the same room takes only 2 to 3 minutes to reach the peak of fire growth. This accelerated rate of burn has become a major concern for firefighting teams and the officers who command them.
Oddly enough, it was a prevention tool designed to save lives that first brought Flashover to our attention - the home smoke detector. In days gone by, fires were typically unreported until they vented from a window, sending the fastest civilian running for the Gamewell Box.
Today, because of the effectiveness of early warning systems, departments are now notified of fires much, much earlier.Companies now arrive on the scene during the growth stage, entering the structure at the worst possible time, just prior to flashover. Combine this with the standing practice of aggressive interior attack, and one can quickly understand why firefighters have become more aware, and much more concerned, of the phenomenon.
The simple fact is - we're seeing Flashover conditions much more often.
Low Tech System - High Tech Results
In Europe, where line of duty deaths, and interior attack, are quite rare, the multi-national fire community was shocked, when in 1987, two Swedish firefighters lost their lives to a flashover incident.
In response, training officers in Stockholm saw the need to create an awareness program for the brigade's firefighters. They developed a rudimentary simulator that allows attack teams to identify potentially dangerous environments during the early stages of the firefight. Their primary goal: to demonstrate to suppression teams how to escape a flashover and exit safely.
On the fire training grounds near Stockholm, I prepare to videotape the special fire training simulator designed by the Swedes. I was expecting a high-tech block structure, with thermal sensors, gas jets, and emergency sprinklers. Instead, I'm led to a series of overseas shipping containers, that have been laid out in random fashion to represent various firefighting scenarios.
According to Roland Lindquist, Director of the Raddnings Verket, (The Swedish Fire Rescue Services Board) the system was adopted by all departments in Sweden by 1990. Instructors there further refined both classroom and hands-on curriculum, and today every Swedish firefighter is required to take this special training course. It's dubbed the Swede Survival System, and it's taken Europe, and this nation, by storm.
6,000 miles away from Stockholm, in America's heartland, Indianapolis firefighters carry on a tradition that's been passed down from generation to generation -- mounting an aggressive interior attack. Like so many departments nationwide, Indy fire administration have armed all front-line personnel with the very best in protective equipment. A secure envelope, that guards firefighters from intense heat and vicious flames.
But some say that this very same envelope denies firefighters the use of an important God-given safety regulator – the sense of feel. In short, present day protective gear is so damned good, it's difficult to determine when to bail out.
A 3-alarm blaze in Indy's downtown section, found three firefighters deep inside the bowels of the beast. A huge structure, the Athletic Club blaze was stubborn, and difficult to ventilate. According to other interior personnel, the trio entered a smoky room in search of the seat of the fire, but within moments the room erupted in an explosion of flame, instantly snuffing out their lives.
IFD was determined to prevent similar horrible accidents from ever happening again. They imported the Swede Survival System, and since its installation, EVERY IFD firefighter and officer has received extensive flashover training. Many, more than once.
In other departments throughout the USA, training officers have adapted the system to meet the needs of America's aggressive firefighters. Their goal, to show an uncontrolled blaze in a SAFE, controlled atmosphere. And to date, nearly fifty departments and agencies have answered the call.
(1) Swede Survival Systems (Drager Safety)
Copyright 2011, Lou Angeli, All Rights Reserved