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June-July 2003 |
Engine Company Operations: Back to the Basics
Part 1
By Matt Rush
I would like to dedicate this article to my close friend, the late Andy Fredericks. I was honored to teach beside him, humbled to be his student, and honored to be his friend. Not a day goes by that I don’t think of him. God Bless Andy.
For the purposes of our discussion here, I will focus on advancing a 1¾-inch handline with a three-person nozzle team. The tactics discussed here can easily be applied to attack lines of smaller and larger diameters. Obviously, the 2½-inch “big guns” may require more personnel.
As we all know, the 1¾- inch handline has a very practical application in today’s fire service. It is lightweight, often used as a preconnect for quick attack, can be handled quite easily with smaller crews, and is used primarily as a residential line. It is critical that we get water on the fire, and to do this we must get the proper length of hose to the seat of the fire. With the widespread use of preconnects in today’s fire service, this can often times become tricky. Three simple stretch techniques can be used at every fire, no matter what type or set up of hose the engine company chooses to use. First, assess what type of situation the engine company has on arrival. Is the structure residential or commercial? Is it small or large, single-story or multi-story? Are there standpipes? You understand the picture. Choose a correct handline that will supply enough water and the proper length for the situation. Second, size up how much hose is needed from the engine to the front door (or entrance of choice) of the structure. Third, size up how much hose is needed from the front door to the seat of the fire. This obviously gets tougher as you add floors into the equation. A good rule of thumb when estimating hose on the interior is to use one length per floor plus a length on the fire floor (perhaps two in large commercial buildings). For example, a fire on the fourth floor would require four lengths of hose. One length between the first and second floors, one length between the second and third floors, one length between the third and fourth floors, and a length for the fire floor. Do not forget to add the hose needed from the engine company to the entrance point of the structure. Will your department’s preconnect reach the fire? If not, be prepared to add on to your attack line or choose a different hose load. Another good rule of thumb is to have at least 50 feet of hose when advancing into the fire area.[i] Hose stretches must be as precise as possible. If the nozzle team pulls too little hose, they will fall short; while if they pull too much hose, they will end up with a “spaghetti bowl” in their lap. Make sure you have a contingency plan should your current hose loads fall short. Train until stretching becomes second nature to the nozzle team; do not wait until entering the fireground to learn.
Due to the fire-load characteristics we face today, the recommended minimum flow for fire attack is 150 GPM in a residential setting. When firefighters from around the country were asked what their department was flowing on a 1¾- inch handline, the unanimous answer was 100 GPM with a fog nozzle. Many firefighters may say (and have actually done so) that you can easily extinguish a residential fire with 80-95 GPM with a properly placed stream. Although true, what about having enough water in “reserve” should Murphy’s Law take effect and conditions deteriorate? What about a contingency plan for firefighter safety? Therefore 150 GPM is the minimum recommended flow for interior fire attack (more is better, but keep property conservation in mind). With a target flow of 150 GPM, we can now compare the fog nozzle with the smooth-bore nozzle. With 200 feet of 1¾- inch handline (simulating a typical preconnect) and a flow of 150 GPM, the Pump Discharge Pressure (PDP) for both 75 psi and 100 psi fog nozzles is roughly 147 psi and 172 psi, respectively. The PDP for the 7/8-inch smooth bore nozzle is 122 psi while flowing 160 GPM (a 15/16- inch smooth bore nozzle has a flow of 182 GPM at 50 psi nozzle pressure). While flowing the same GPM the obvious difference here is the PDP which correlates into a substantial difference in nozzle reaction force.
Have a three-person nozzle team advance the 200-foot, 1¾- inch handline around four corners into the back bedroom of an “apartment” with water flowing the entire time. The reason to have water flowing all of the time is to simulate a large body of fire and to negate the tactic of “spotting” as the nozzle team advances. As stated previously, the majority of firefighters are accustomed to advancing a 1¾- inch handline with a fog nozzle flowing approximately 100 GPM, which is a PDP of only 107 psi (low pressure fog) to 132 psi. The nozzle teams will encounter a much higher nozzle reaction force when advancing the fog nozzle with 150 GPM flowing. Repeat the scenario with the smooth bore nozzle and ask your crews which nozzle they prefer.
To combat the higher nozzle reaction force, lower pressures with the smooth bore, and to review basic tactics, stress nozzle team positions: the nozzle firefighter, the backup firefighter, and the door firefighter.
The Nozzle Firefighter
The nozzle firefighter will be taking the brunt of the heat and must be able to read fire conditions. For this reason, some will say that this position should be for the veteran firefighter on the team (not to include the officer). The nozzle firefighter must use good nozzle technique. This includes proper hand position and technique when putting water on the fire. With the invention of the pistol grip nozzle and higher nozzle reaction forces with the fog nozzle, proper hand position has dwindled. The ideal hand position should be to have the nozzle out in front with the nozzle firefighter’s hand away and off of the bail.
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Notice the hand positioning. The nozzle firefighter’s first hand is at the coupling between the nozzle and handline. It is free of the bail to allow thorough nozzle movement and to eliminate the risk of gating down the nozzle. |
Place your first hand behind the coupling that separates the nozzle and the handline. Place your second hand in a comfortable position behind the other. The bail will still be in arms reach should it need to be used. This is done for two reasons. First, it gives the nozzle firefighter more control, speed, and safety when bending the nozzle up, down, or sideways. Second, it keeps the nozzle firefighter from gating down the nozzle when his hand is not on the bail. This seems to be a natural choice when the nozzle reaction forces are high. Since we are flowing 150 GPM and predominantly used to 100 GPM, the natural reaction is to gate down because it feels as though the nozzle is getting away. Gating down the nozzle only reduces GPM, which contradicts our purpose.
To address proper nozzle technique with an aggressive interior fire attack, I advocate the use of straight streams and solid streams ONLY. Why? First, the inventors of the fog nozzle never intended the fog pattern to be used for an aggressive interior fire attack, but for ship fires and an attack made from outside the structure (what we now refer to as an indirect attack).[ii] Second, straight and solid streams are much less dynamic when they disrupt the thermal balance. Therefore, they provide better visibility and longer reach, prevent the rapid conversion to steam close to the nozzle team, and reduce the risk of pushing fire into unwanted areas. Keeping all this is mind, proper nozzle technique dictates a straight or solid stream in a vigorous clockwise motion, often thought of as “whipping,” directed to the main body of fire. Vigorously “whip” the nozzle at the seat of the fire, walls, ceiling, and floors as you advance. The floor should be swept clear of hot water and debris, primarily sharps (sweeping the floor is also an effective way to sound for holes and walls as you advance). As my good friend Andy Fredericks used to say, “Make the room look like an August Thunderstorm.”
In the next issue we will look at the “backup firefighter” and the “door firefighter.”
[i] Fredericks, Andrew A., “Stretching and Advancing Handlines, Part 1,” Fire Engineering, March 1997, 56-71.
[ii] Fredericks, Andrew A.,“Little Drops of Water: 50 Years Later,” Fire Engineering, March 2000, 113-135.
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