Kriss Garcia
Battalion Chief
Salt Lake City (UT) Fire Department
From the responses relating to PPV in the August Roundtable, it is apparent that those who use PPV extensively tout its benefits and those who do minimal training with PPV are uncomfortable with it and skeptical. In Salt Lake City, we have been using PPV for the past 10 years. Our confidence in it has grown to the point that we use the term “positive pressure attack” (PPA) to emphasize the need for coordinating ventilation with attack. To support this, our department has developed standard PPA evolutions that have a single engine company deploying an attack line while at the same time providing initial ventilation. After minimal practice, the evolutions can be accomplished without adding time to the fire attack. In more than 10 years of fireground application, we have seen predictable acceptance patterns among company officers and their crews.
Firefighters pass through three distinct stages of understanding when it comes to PPV: skepticism, experimentation, and acceptance.
Skepticism. All firefighters seem to start here as they begin learning and training with PPV. No matter how hard we try, this phase has to be realized and allowed. Only through harnessing firefighters` passion for caring can we then train and educate them beyond skepticism into the next stage.
Experimentation. This stage comes after firefighters experience obvious measurable successes with PPV. During this stage, firefighters cautiously use PPV and witness its tremendous benefits, which include rapid fire extinguishment, rapid rescue of viable victims, and more effective use of crews. Incident commanders realize that the small amounts of CO that may be introduced with the gasoline-powered fans are acceptable, since overall CO levels can be reduced from 800 ppm to levels as low as 30 ppm. Also during this phase, training and experimenting demonstrate that the only “pushing” or actual movement of fire occurs in areas where velocity is created by the blowers. The only air movement is generally several feet from the opening where the fan is working and several feet from where the fire and products of combustion are exiting the structure. Besides these areas, there is no more air movement than in your local supermarket, which has a pressurized interior to keep insects and dirt from entering.
A tremendous amount of learning can take place during the experimentation stage, depending on the department`s commitment to training and effective operations. For this reason, it may take several years to fully complete this phase. Only after firefighters answer these questions for themselves can they move forward to accepting PPV as innovative science and to selling others on the benefits. In fact, the urge to convince others is part of the third and final stage of PPA/PPV understanding.
Acceptance. Here, firefighters and incident commanders recognize that unnecessarily placing a third of the on-scene personnel in grave danger above a fire for vertical ventilation with no guarantee that they can accomplish their objective may be irresponsible, especially when there is a better option. Incident commanders and crews realize that ventilation that is truly going to be coordinated with interior attack can only be accomplished if ventilation starts with the initial attack. PPA is the only option that keeps our firefighters out of explosive atmospheres while at the same time allowing them to effect rapid fire control and viable rescues.
Currently, the Salt Lake City Fire Department has 18- to 21-inch blowers on all engines and larger, high-volume blowers on all truck companies. We use PPA coordinated with vertical ventilation when necessary on almost all types and sizes of fires. When considering large commercial building and high-rise fires, the benefits are even greater because of the limited ventilation options these types of construction allow.
During our department`s second phase of development, we came up with more than 20 questions that had to be answered so our members could feel comfortable with the early application of PPA/PPV. It took us nearly two years of experimenting with PPA/PPV to answer those questions.
During our decade of experience with PPA/PPV, I have found only one major cause for concern–the situation in which the fire seems to be completely out and overhaul is skipped over or done minimally. Because the PPV blowers will overcome drift smoke and residual heat from hidden fires, overhaul crews can miss these hot spots. I believe this is what is misrepresented as “pushing” fire in voids. I think it is more likely that because the area does not show the signs of hidden fire to which we are accustomed, we allow these voids to go uninspected until the fire grows big enough so we recognize its development.
Crews can prevent the possibility of overlooking hot spots by aggressively overhauling the fire area and the vertical and horizontal areas exposed to the venting fire. They must keep in mind that these hot spots can be present anytime PPV has been used. Also, overhaul crews must turn off the blowers before they make the last assessment of the structure for hidden fires.
I cannot imagine why an operation that provides firefighters with a safer operating environment while at the same time making them many times more effective in preserving life and property would not eventually gain wide spectrum support from all facets of the fire service. Some are not comfortable using PPV until the fire is under control. However, proper, dedicated training in PPA/PPV will allow you to take early control of the situation while at the same time placing firefighters in less danger and allowing them to do a much more effective job.
One small letter in response to several opinions based on varying levels of experience will not answer all questions regarding PPV. I would be willing to expand on this issue, covering the most powerful questions our department had to answer before we moved PPV into our initial attack operation.
I encourage those who do not use PPV routinely as a means of assisting fire operations to remain open-minded and to search for its benefits instead of allowing uncertainty to limit their use of this effective and innovative technique. Proper, dedicated training in PPA/PPV will allow firefighters to take early control of the situation while at the same time placing them in less danger and allowing them to do a much more effective job.
