Original post: https://community.fireengineering.com/profiles/blog/show?id=1219672%3ABlogPost%3A690818
A frequent criticism of Modern Fire Attack (MFA) methods, often phrased as a warning against their adoption, is that the actual number of experimental fires upon which they are based totals only a few hundred, while Traditional (TFA?) tactics have been “proven” effective many thousands of times. To be exact, I counted just 106 test fires performed by the National Institute of Standards and Technology (NIST) and Underwriters Laboratories (UL) in the most widely-discussed studies published over the past 7 years (see list below), confirming at least the numerical basis of that argument. That is, if the relative number of occurrences of a particular activity corresponds to the relative effectiveness of that activity, then what we have been doing would win, hands down. Except, this is not a popularity contest, nor an argument that can be decided by a “vote”.
There are certainly many inherent problems when attempting to compare the results of a limited number of controlled burns with frequent and ongoing real-world experiences. First, though, it must be pointed out that fire dynamics researchers have not recommended the abandonment of any tactics, much less entire approaches. In fact, none of the studies even analyzed complete methods; nor could they. The infinite variability in incidents, and potential responses thereto, even when considering the same type of fires in the same community, would render this futile. Instead, researchers have necessarily focused on the analysis of one factor at a time in a setting with consistent parameters, such as ventilation location, size, or timing; or nozzle flow, pattern, or direction, all in order to be able to detect differences or similarities in effects that were consistent and reproducible. The resulting “tactical considerations” that have been inspired by the experimental findings, therefore, have been focused and specific, and regard particular interventions in particular situations. Although these recommendations are nonetheless revolutionary, contradicting as they do established teachings, the wholesale abandonment of our usual methods has never been promoted, nor even suggested, at least by the scientists themselves.
Acknowledging the narrow scope of the various fire dynamics enlightenments provided by researchers, we might now proceed with a discussion of their validity. Recall, if you will, that we in the North American fire service had been taught for decades that flowing water from the exterior of a structure fire was not only minimally effective, but also harmful for any living victims or firefighters indoors; and that ventilation provided cooling and clearing when performed on a still-burning interior fire. How many experiments should it take to refute these or other long-held concepts?
Disproving something that had been promoted as an absolute fact is easy: just identify an exception. In the case of these doctrinal beliefs, they actually had difficulty even demonstrating anything close to what we had been lead to expect. For exterior streams, the use of a narrow, immobile hose stream was found to rapidly and extensively cool the interior of a burning structure, without spreading heat, smoke, or steam to other areas. Regarding ventilation, increasing it to a still-burning compartment consistently caused the creation of more heat and smoke than was released. The phenomena upon which we had based many of our tactics, and which had lead us to delay water application until interior hoselines could be placed, and to ventilate fires before entry, were not present, even in some instances where the experiments were specifically designed to create them.
Any analysis of the effects of even a limited change must be well-designed, ensuring that what is being measured is the proper parameter. And, repeated experiments must be performed in order to confirm that the results were accurate and reproducible. A review of the study reports of any of the experiments listed below would provide assurance that the processes employed by researchers met these standards. Through these carefully-designed experiments, they not only demonstrated many instances of inconsistencies between our prior beliefs and their results, but were able to explain in detail the fundamental scientific basis of the actual observations. Admittedly, it was also shown that it was quite possible to cause a deterioration of interior conditions if a wide-pattern stream was directed from the exterior, and the ill effects of ventilation were delayed, depending upon the distance of the opening created to the seat of the fire, often sufficiently long enough to allow a hoseline to be stretched for extinguishment. Of course, using a wide stream even while inside a burning structure can cause a blow-back of products of combustion and steam onto hose teams, and the time lag of hazards of ventilation were matched by a similar lag in its benefits, so that these were not surprises so much as confirmations of underlying principles. The real value of the research results, though, was to provide more information upon which to base fire control efforts, not to refute or promote change. (Those efforts apparently follow naturally, as the intensity and duration of the debates within the fire service regarding implementation of these tactical suggestions indicates.)
Despite the narrow targets of the fire researchers, the effects of the changes they have inspired are still far-reaching, given that they affect the very foundations of our tactics: water application and ventilation. So, even though it may never have been suggested that we stop what we have been doing, it was certainly made clear that the beliefs on which those approaches were based were erroneous, thereby requiring us to reconsider our entire plans. Some things were confirmed, like the need to quickly apply water; while others were dismissed, like the need to first enter the structure to do so. Also, though only the recommended timing of ventilation was addressed, that shift in sequence is significant in its modification of the priority assigned to that activity, effectively changing it from an extinguishment aid to an overhaul process.
So, while the relative amount of fire dynamics research to date is quite small compared to our collective, and often even individual, experiences, the information and insights they have generated are not only valid, but logical and repeatable, so that we can be confident in basing necessary changes on these newly-illuminated facts. While many have criticized the research as calling for an unjustified leap of faith, I would counter that refusing to modify tactics based on now-disproven principles represents an even more egregious obstinance in the face of evidence. In short, we have been provided with alternative, sound, and logical models of fire behavior with which to plan fire attacks. With our doctrine having been revised, changes to our practices must necessarily follow.
The author can be reached at [email protected]