BY MARTIN HAMRICK
Much has been written and discussed about which combination of handline and nozzle is the best for initial attack. To answer this question, ask yourself, How soon do I want to put out the fire? It’s common sense, really; you have to have enough gallons per minute (gpm) to overwhelm the British thermal units (Btus). If you were on safari in Africa hunting Cape buffalo, one of the most dangerous animals on earth, would you take a BB gun or opt for something more powerful? It is no different when choosing a weapon for fire attack. Too often, our firefighters are battling the beast with inadequate water power. How many times have you made an interior attack thinking you had everything you needed, only to have the heat push you to the floor and eventually out the door you came in? What happened? Doesn’t the fire know that you are the fire department and it’s supposed to die when you spray water on it?
One thing we have to understand is that these are not the fires that our elders fought. Despite what the crusty old veteran may tell you, because of contemporary construction methods and materials and the increased use of plastic in furnishings, fires now are hotter, burn more quickly, and reach the flashover point more quickly than you realize. The “books” will say that flashover should occur from 10 to 15 minutes after the fire starts, but the National Institute of Standards and Technology research clearly shows that flashover can and will happen in less than four minutes. In many cases, this is around the time the first-due companies are arriving on-scene. The initial stretch and weapon selection are among the most important jobs on the scene, if not the most important. “How the first line goes, so does the rest of the fire.”
HANDLINE SELECTION
The correct hose size to pull depends on several factors. Is it a room-and-contents fire or a large commercial building fire? Let’s begin with the booster line, which is easy to remove from and replace on the engine. I have seen it used for anything from trash fires to house fires. It is a very dangerous piece of equipment, capable of only around 60 gpm. Take my advice: Don’t use it. But it is good for washing off dirty tools after the fire.
Now let’s look at the “line of choice” for most firefighters, the preconnect, usually a 1½-inch or 1¾-inch line. I hope everyone is using 1¾-inch; its benefits are huge. It is lightweight, is easy to maneuver, and can provide up to 200 gpm and possibly more. That’s 50 gpm more than the 1½-inch line, which can flow 150 gpm at best. Most of us should have a good understanding of this line, since we have had our hands on it since the beginning of our career.
What about the 2½-inch? Is it good for anything besides “surround-and-drown” operations? The “big line” will easily achieve 300 gpm or more. Remember back to the early days of your fire service career, back when you were “taught” how to use the “big line.” I remember it well: “Hey, probie, hang on to this.” Next thing I know, the pump operator increases the pressure until I am literally off the ground, only to be slammed back to earth while everyone gets a good laugh. Did your first experience with the 2½-inch go like this? It burns a distinct memory into your mind. I have seen company officers who will not pull it for just that reason. “It’s too hard to advance” and “I don’t have enough personnel” are just two of the excuses I have heard. I have even heard it called the “give-up line,” something to be pulled only when the 1¾-inch can’t put the fire out from the interior. This was my opinion also, until I had a class on engine company operations at the Fire Department Instructors Conference with District Chief Dave McGrail of the Denver (CO) Fire Department. Although the 2½-inch is intimidating, you can use it as an attack weapon. All it takes is good training and practice. Get it out and practice advancing it through the station or the apparatus bay. Learn how to advance it before you try to do it at a working fire. This is the proper line to slay a large dragon.
In addition to McGrail’s instruction, the late Lieutenant Andy Fredericks from the Fire Department of New York did excellent work on initial attack, making the first stretch, and smooth bore nozzles. Google these names, and you will find a wealth of information on these subjects. It is up to us to keep up the work that they and others have started.
Fredericks gave us the acronym ADULTS as a guideline on when to use the “big line”:
- Advanced fire on arrival.
- Defensive operations.
- Unable to determine the extent (size) or location of the fire.
- Large, uncompartmented areas.
- Tons of water (it’s easy to get one ton of water per minute with a 11⁄8-inch smooth bore tip).
- Standpipe operations.
Now that you have the proper handline, you must determine what to put on the end of it. Depending on what you choose, you may not get all the gpm out of that handline that it’s capable of providing. You have to make good decisions on which size line to pull for initial attack. It’s up to you really; you can take enough gpm through the front door and kill the beast or get out the lawn chairs and have a picnic. Regardless of which size line you pull, you have to get to the seat of the fire to be effective at extinguishment.
NOZZLE SELECTION
Now it’s time for the great debate—smooth bore vs. fog. No, I am not going to try to win hearts and minds here, but do some research and you may find, like I did, that there is a place for each one. What I hope to do is open some eyes to the fact that there is a better and safer way. Let’s go back to what I stated earlier—it takes sufficient gpm to overwhelm Btus—and build on that.
Automatic fog nozzle. The automatic fog nozzle is designed to break apart a solid stream of water into millions of tiny droplets using pistons, springs, and spinning teeth. These droplets, when heated to 212°F, then become steam, which is used for extinguishment. Most fog nozzles must have at lease 100 pounds per square inch (psi) at the nozzle for proper operation to overcome interference of the mechanism inside them.
I did some flow testing recently on my department’s automatics that was eye-opening. Our standard preconnect is a 200-foot, 1¾-inch handline with an automatic fog nozzle. I verified the results using the engine’s onboard flowmeter and a flowmeter at the nozzle. Our pumps are 2006 models (our department is very lucky) with the computerized pressure regulator preset at 130 psi, which yielded a 110-gpm flow. According to the manufacturer, we should get around 150 gpm at that pump discharge pressure. I, among others, consider 150 gpm the critical flow for initial fire attack. To achieve this, I had to increase the pressure at the pump, but this made advancing the line difficult because of the nozzle reaction. How many times have you been in this same situation?
Also, remember that the stream will look the same regardless of the flow. This is what an automatic does best. It gathers whatever it is supplied and makes a nice pretty stream out of it, regardless of whether it is flowing 50 or 150 gpm. Do some research, and you will find numerous incidents in which firefighters were injured or killed as a result. Also, these nozzles can jam easily if any rust or debris makes it past the pump, which is common in standpipe operations.
This nozzle works by converting steam: One part water creates 1,700 parts steam. What happens to a viable victim? Although you may have the latest and greatest personal protective equipment, do they? What happens during the steam conversion? If not done correctly, you will disrupt the thermal balance, and you will lose any visibility you had. This slows down the search team and could harm an otherwise unharmed victim. The great thing about this nozzle is that anyone can fight fire with it. You just let steam do the work, and your job is done. If this is your weapon of choice, please test it to confirm that it actually flows what you think it does.
Smooth bore nozzle. The smooth bore has tradition written all over it. When we got rid of the buckets, this was the only weapon. In Denver, this is “the people’s choice” nozzle. There was a reason it worked then and a reason it works now: It’s basic, it has nothing to jam it up, and it provides a lot of gpm.
According to the late Tom Brennan, longtime Fire Engineering editor in chief and technical editor, “No nozzle, pattern, distribution, or shape of drops of water ever made a great engine poor or a poor engine great. With that said, remember that the purpose of water for extinguishment is to cool the fuel source sufficiently so that it’s no longer at its ignition temperature and the gases given to the fuel supply are shut down (are no longer produced) …. Having the cooling water change to steam at the hottest part of the flaming is ideal cooling. Having the cooling water vaporize on the way to the target is less effective, to say the least. The larger the ‘slug’ of water, the more it will get through the heat to the target.”
Okay, so fires are hotter now, but we have better gear. What’s the problem? We get in a lot deeper now; it’s hotter, and I don’t want those “little droplets” vaporizing before they can do their job. Remember that with a fog stream, the little droplets of water turn to steam very easily.
A smooth bore nozzle provides a laminar flow—that is, a solid stream of water, which doesn’t vaporize as quickly. This allows us the reach needed to hit the seat of the fire and extinguish it effectively. This is where I step on some toes. Remember when I said that anyone could be good with the fog nozzle, but the smooth bore will prove how good a firefighter you really are? This nozzle has to be out in front and worked effectively; you can’t just “spray and pray.”
“But you can’t do hydraulic ventilation with it,” some object. Well, you can, but why let the nozzle choice dictate ventilation tactics? Look, I’m a truckie at heart, and if I can’t vent or search, I’ll just take the nozzle from you engine guys. Benefits include less nozzle reaction, better reach and penetration, more gpm, and cost effectiveness. We use 15⁄16-inch-tipped smooth bores on one of our preconnects. It will flow 165 gpm with 50 psi at the nozzle.
“But you can’t flow foam with it,” is another objection. Why waste the foam before overhaul?
Breakapart nozzle. I have recently tested a breakapart nozzle; this seems to be the best of both worlds. You have a fog tip that screws onto a smooth bore shutoff. The model we tested had a constant-gallonage fog tip (not an automatic) that is rated for 175 gpm at 75 psi nozzle pressure. This can be either underpumped or overpumped and is much less likely to jam up. We also tested this on a 200-foot, 1¾-inch handline at 130 psi pump pressure. It yielded a flow of 140 gpm with 60 psi nozzle pressure. Increasing the pump to 180 psi gained a flow of 175 gpm at 75 psi nozzle pressure. Also, the nozzle reaction was less than what was felt with the automatic. If that’s not enough water, unscrew the tip to expose the one-inch smooth bore, which managed 170 gpm at 35 psi nozzle pressure (130 psi at the pump) and 210 gpm at 50 psi nozzle pressure (180 at the pump). All of the models we tested are adjustable; the fog tip can be changed to a variety of flow/nozzle pressure combinations to achieve whatever flow you desire. Likewise, the smooth bore orifice can be whatever size you choose.
Regardless of which size line or nozzle you use, the gpm must overwhelm the Btus. It’s just that simple. Water has to reach the seat of the fire for effective extinguishment. When you knock down the fire quickly, all the other problems go away. These are just tools in the toolbox; there is no one size fits all. Remember, when you are hunting that Cape buffalo, don’t take a BB gun. Be sure you have the firepower to stop it in its tracks. Drill on advancing all of your handlines. Do these same flow tests on your nozzles; you may be surprised at the results. Most importantly, do your job. Water is our weapon; learn to use it effectively. Don’t be afraid to try something new (or old). Firefighting is a dynamic activity; it’s always changing. Train for the fire you will fight tomorrow, not the one you had yesterday.
MARTIN HAMRICK, a 14-year veteran of the fire service, is a battalion chief with the Jonesboro (AR) Fire Department and an adjunct instructor for the Arkansas Fire Academy and the Arkansas Department of Emergency Management Hazardous Materials Division. Hamrick is the president of the NEAR chapter of FOOLS International.