Fire hose nozzles: How to choose and use the right fit
Anyone can try to make all situations fit only a single nozzle's parameters, but this is a false supposition that could create safety issues for your crews as they advance into a structure
We have covered a handful of tactical impacts in this series so far while completing the REC-REVOS acronym. In this next installment of the Coordinated Fire Attack series, we move to the Extinguishment part.
In an earlier article, "Fire Attack: Advancing Hose Lines," I went into great detail of how to select the proper hose line based on a number of fireground impacts.
This article will deal more with the art of extinguishment as it applies to the team process that an attack line crew should utilize when applying water on a fire.
The art of extinguishment has many different opinions when it comes to nozzle selection and application of water streams.
Having 25 years of experience, I know that I will not convert the zealous opinions held by noboperators worldwide. When selecting the nozzle to utilize, they are generally the ones at hand that are already on your department's pre-connects.
Whether or not you agree with that choice, the bottom line is to know what a solid stream or fog nozzle is capable of and when they should be utilized.
Anyone can make a decision to use only a single nozzle and try to make all situations fit that nozzle's parameters. This is a false supposition and could create safety issues for your crews as they advance into a structure.
It is a better approach to know what each nozzle brings to the party so that you can choose the right tool for the job. Doing things "the way we have always done it" is no basis for a professional decision.
Effective stream operation
We will begin by covering the rules of effective stream operation. The first item for consideration is choosing the most effective nozzle based on the possibility that people may be near the seat of the fire.
How much steam production will your nozzle produce when water hits fire? Using a solid stream or fog nozzle (on solid stream position) should aid in the rescue of victims and reduce steam production.
After the attack line has been selected, deployed and charged, open the nozzle to bleed the air and check the nozzle pattern. It might be a good idea to flow the nozzle long enough for the engineer to set his pump pressure at this time.
Once interior, it might be more difficult to find your nozzle pressure is woefully inadequate because you did not ensure both you and your engineer are on the same page.
- All personnel on the attack line should be on the same side of the hose.
- Check exterior doors for heat prior to opening. If the door opens inward, stay to the side of it to prevent fire blowing out of the door and exposing the firefighter to dangerous levels of heat or smoke.
- Some departments require their initial attack crews to utilize a short piece of rope or webbing to close the door if it appears they will need to do it quickly.
- For doors that open outward, stay behind the door and use it for cover until you are comfortable that the environment will allow for keeping it open.
Once the door is open, make a quick sweep of the threshold to look for victims. Prior to entering the structure, sound the floor strongly to ensure the existing structure can support the weight of the team.
Stay low when smoke is to the floor; otherwise use your best judgment to gauge the required speed the team must advance the hose line versus the ability of the team to visualize the area ahead for safety.
Feel walls and floors and check the ceiling periodically for fire above, below or beside your crews as they move through the structure.
Utilize thermal imaging cameras to direct interior crews and continue sizing up the structure for fire spread or victim locations.
Also, continually monitor the hose line to ensure a sufficient amount of hose to reach the fire. This may require some personnel to drop back to assist with moving the hose line through doors and around corners.
Exterior back-up teams may be considered to assist with moving the attack line through the front door.
If possible, try to vent heat and gases from the area of the fire before accessing the fire room. The positive pressure attack tactic works well for this objective, but like all tools in the toolbox, it is not always the proper tool for the job.
Staying low to the ground accomplishes a few things: It increases visibility, reduces the environmental heat abuse the attack team takes and helps to keep the attack crew from operating in the fuel-rich gases generated by the breakdown of the contents of the fire.
While we have to work in the smoke and heat, it makes more sense to stay out of the ignitable gases that stratify above our heads.
In addition, utilize doors, dressers or beds as cover when opening the pre-connect to reduce the blowback of steam as it expands upon hitting the fire. I have seen firefighters who feel this is not tough enough or brave enough, but it does reduce the overall punishment your body will absorb over a 20-year career.
If fire is exiting the top of the doorway when opened, hit with your steam to cool and control the fire gases. Sweep the floor if necessary to cool burning debris and hot surfaces.
Test the integrity of the floor inside every door prior to committing the team's move forward and take the time to ensure there is not fire burning overhead before entering and placing a fire behind your crew.
Many departments teach that opening the water line should only be done when fire can be seen. The thought is that water on smoke doesn't put out the fire but only causes water damage.
However, using water overhead can cool down fire gases that may be pre-flashover and cool the environment. A combination attack is a good selection when the fire area has high heat levels.
This method consists of applying water to the fire and area above it, utilizing a narrow fog or straight stream in a T, Z or O pattern.
This can also be called "penciling the ceiling," bringing its temperature down to prevent a flashover until the fire can be extinguished. It is critical to use a narrow stream at this time to prevent significant steam generation.
This pre-flashover prevention is one of the times when the survival of the interior attack crews overrides the creation of a tenable environment for a victim.
If the room the crew is accessing is hot enough to be considered pre-flashover, the likelihood of a survivable victim is extremely low. Once the seat of the fire is found, open the nozzle and hit the main body of fire.
When the fire is knocked down, shut your nozzle down and let the area vent. Open the nozzle again if necessary to finalize the extinguishment of the fire.
Basement fire considerations
When advancing hose lines into a structure, it is not guaranteed that you will rapidly find the seat of the fire. This may be as a result of a fire below the attack crews instead of on the floor they used to advance into the structure.
If you find that the area into which your crew is advancing is very hot and you have found no fire, consider a basement fire.
Note: Attack line selection for a basement fire should consider the nozzle that will cause the least amount of steam generation (i.e., solid bore).
While a large number of fire departments are moving toward the consistent use of a solid bore nozzle, the use of a fog nozzle can be an effective tool if you keep a few safety thoughts in mind:
- Use of a fog nozzle should be restricted to unoccupied/confined spaces.
- Area opposite the direction of the nozzle should be adequately ventilated to allow for steam movement.
- No more than a 30-degree angle should be used in an initial fire attack.
- Only use a fog nozzle when reach of stream is not a problem.
Transitional attacks are those types of fires when an exterior attack is used to assist with getting an initial volume of fire knocked down and then having interior attack lines finish the extinguishment.
This may be required if on-scene resources are insufficient to advance the number of large hose lines required to attack from the interior, or it may be the initial method of controlling the fire during the time it will take to stretch the lines into the interior.
It is critical that all crews on the fireground are aware that an exterior line is being used to make an initial knock. Communicate to attack crews when to initiate their interior attack once the exterior suppression is complete.
In addition, crews who utilize this attack should be more aware of the supporting structure if they are sending crews interior during a transitional attack. It is critical that they test the structural integrity of the floor and watch the ceilings constantly to keep from being caught in a collapse.
Another concept that cannot be reinforced strongly enough is the need for and consistent application of a back-up line.
This line is necessary when initial attack lines are not quickly controlling the fire. It should be the same size or larger than the initial attack line.
I recommend a 2 1/2" back-up line for all fires. Yes, it is bulky and difficult to move, but if the initial 1 3/4" pre-connect is ineffective, larger volumes of water are the next best answer.
Some departments recommend the advancing of the back-up line into the structure immediately following the placement of initial lines, but I will leave that to the IC to decide.
When using a back-up line, position it close to initial attack lines, and it must be charged and ready to be effective. Once fire is out, back-up lines may be shut down and smaller lines used for overhauls.
Extinguishment is the tactic for which all firefighters joined the fire service. As this is the "meat and potatoes" of our profession, we should be smooth, practiced and competent with this skill if nothing else. Keep up the good work and practice to stay safe!