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How effective is this stream?

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  • How effective is this stream?

    I've seen quite a bit of discussion here lately on the use of adjustable fog vs. solid bore nozzles. Some even quite heated at times. I just received the June issue of Firehouse magazine and I think the cover photo is very timely. I normally don't like to just look at a picture showing a split second in time and then trying to critique it but this picture got me thinking.

    Is the straight stream setting on this adjustable nozzle having any effect on this body of fire or would a solid bore nozzle be better? The hose looks to me to be a 2 1/2" and other than using a master stream, I think that is the correct line size for this volume of fire. I'm just wondering what everyone thinks about the nozzle choice.





    Please try to give your honest opinions without knocking what others say. If you can give a good argument for you choice, please do, but be open minded enough to listen to what others have to say. Thanks.

    Disclaimer: It is not the intent of this post to critisize the firefighters in this picture or the departments they represent. To the contrary, I think their operating tactics are excellant. They are fully suited up, down low, and both on the same side of the line.

  • #2
    Is the straight stream setting on this adjustable nozzle having any effect on this body of fire or would a solid bore nozzle be better?

    Doesn't look like the stream setting is the problem.

    It does not look like it is being supplied properly - flow/pressure seems way too low.

    How soon into the fire was the pic taken? Maybe they were just getting started.

    I'm just wondering what everyone thinks about the nozzle choice.

    If it is a 2" or 2.5" line, good choice.

    If it is a nozzle capable of supplying more than the needed flow it is a good choice.

    Comment


    • #3

      [This message has been edited by ntvilleff (edited 06-06-2001).]

      [This message has been edited by ntvilleff (edited 06-07-2001).]

      Comment


      • #4
        If the line is a 2 1/2", it is, in my opinion, a good choice. The nozzle, on the other hand, is not a good choice. A fog nozzle on a 2 1/2" line is much too difficult for two people to operate, let alone advance. That 100 p.s.i. nozzle pressure causes a lot of nozzle reaction. As a result, the operator of the nozzle shown in the picture may not have the nozzle open fully in order to maintain control. Or, perhapse there is not enough pressure available to develop the required 100 p.s.i. at the nozzle. If a
        1 1/8" or 1 1/4" smooth bore nozzle at 40 to 50 p.s.i. nozzle pressure were utilized here, a flow of 265 to 325 g.p.m. could have been developed, with less nozzle reaction and greater reach and penetration than the fog nozzle. This would result in a much quicker knockdown.

        [This message has been edited by DCFD1051 (edited 06-06-2001).]

        [This message has been edited by DCFD1051 (edited 06-06-2001).]

        [This message has been edited by DCFD1051 (edited 06-06-2001).]

        Comment


        • #5
          Here's what Firehouse says about the cover:

          Firefighters from Freeburg, Il, were assisted by the Smithton, Fayettville and Mascoutah fire departments in battling a fire in a rural dwelling on april 14, 2000. Firefighters had to relay water from 1 1/2 miles away. during the early-afternoon blaze, firefighters were hampered by exploding ammunition and a liquid propane tank inside the structure.
          Cover photo by Robert Schield

          From the look of the picture, I'd say he just cracked open the bale and is adjusting the stream.


          I would tend to agree he is adjusting the stream but the bail appears to be fully opened and not just cracked. His hand is also not on the bail so this would suggest at least a few seconds have elapsed since the time the nozzle was opened. Like mongofire_99 says, maybe the water supply is just not adequate. Any other thoughts?


          [This message has been edited by Plug-Ugly (edited 06-06-2001).]

          Comment


          • #6
            With all due respect and with every hope of keeping this civil I submit...

            A fog nozzle on a 2 1/2" line is much too difficult for two people to operate, let alone advance.

            A properly handled 2.5" fog is not too much for two people to handle. Using a technique different than what the guys in the pic are doing it is a piece of cake.

            Advancing the line while flowing 300+ is another story, be it fog or smooth bore - knockdown, shut down and reposition. Either way, advancing while flowing in this case is not an issue.

            As a result, the operator of the nozzle shown in the picture may not have the nozzle open fully in order to maintain control.

            I believe the nozzle gate is full open.

            I would agree the hose team is not in a position to handle the line at the needed flow.

            If a 1 1/8" or 1 1/4" smooth bore nozzle at 40 to 50 p.s.i. nozzle pressure were utilized here, a flow of 265 to 325 g.p.m....

            50 to 350gpm flows are possible with the 2.5" TFT handline nozzle that should be on the line.

            Anyway...

            I wonder if the flow is low on purpose to conserve water....

            Comment


            • #7
              I agree, I think the problem is the water supply isn't adequate for some reason.

              Depending on how much of the building out of the picture is involved, a 2" could work for this as well. 300gpm is easily handled by a couple of rookies here:

              Comment


              • #8
                2.5" is the correct size line. The TFT is not the best choice, like other people have noted the stream doesn't look quite right. Having worked with TFT's in the past I'd say that the line isn't flowing anywhere near what it could. The bail looks open to me, so the lack of flow must be due to something else.

                I would personally use a smooth bore or a Vindicator Blitz Attack, WIDE-BORE NOZZLE (as coined by firehouse's article on water flow in this months magazine p. 72)

                Comment


                • #9
                  I'd like to see TFT's BlitzFire battle that one. I bet it'd perform well.

                  Comment


                  • #10
                    I agree with the Previous Comments. I think the flow was probably low to Conserve water. I know I have had to do it In My Very Rural Area.

                    ------------------
                    Firefighter C.M. Baker

                    Comment


                    • #11
                      The bail is or almost is all the way back, so it's open.

                      So either the line is being underpumped or there's an obstruction. Most likely underpumped.

                      Why we don't know. It could be there SOP is to keep a fairly low pressure while the line is initially positioned then up it. Could also be they just ran out of water and in a moment the stream will be piddling out.

                      Let's see,
                      Obviously no firefighters are inside on this on.
                      Porch still looks structurally sound in the photo.
                      First floor isn't compatible with life, and the second floor either isn't or won't be very, very shortly if the fire isn't put out.

                      Open the pattern to a 30 degree fog -- much, much less reaction force, even than a smooth bore of the same flow. Knock down porch and fog the first floor. Once you've pushed the fire back, you can brace against the door/window/etc if needed and go to straight stream. Hopefully by then the 1.75" lines can mop up.

                      Your bigger challenge isn't reaction force, but the weight of the 2.5" hose your advancing.

                      Matt

                      Comment


                      • #12
                        This is definatly a 2 1/2" fire as a minimum. The problem I noticed when I got the magazine the other day was the inadequate stream then I looked to see what size hoseline they were using. Next I looked at the nozzle and saw the TFT. The nozzle is doing exactly what it is supposed to do, maintain a good looking stream regardless of water supply, This is the reason we sometimes get into trouble, we forget the basic principles on which the automatic nozzle operates. The salesmen will tell you that the automatic will develop an effective stream no matter what the flow. Now lets define effective, to me it is a flowthat is capable through reach and volume to overcome the BTU's being produced to extinguish the fire, without this the fire will continue to burn until it is small enough to be controlled by the water supply available. Fire flow MUST be matched to the size of the fire.

                        One other thing I also noticed was the nozzle,, it is all the way open. I know some people who gate the automatic nozzle down to help them manage the nozzle reaction better. This cuts down on the flow but again the stream still maintains a good looking profile.

                        Now my personal opinion is that the hose line waas the right choice as a minimum size but I would have used a smoothbore with an 1 1/8" or 1 1/4" tip for sure.

                        Comment


                        • #13
                          Right line, wrong nozzle I think, although the fire might have needed a shot from a deck gun first though. It looks to me, as others have noted, that this nozzle has been open for at least a few seconds from the nozzlemans hand not being on the bale. I've seen this scenario several times in my career, the smaller drops of water from a fog nozzle, despite being in a straight stream, are evaporating before they get to the building. A solid stream nozzle would indeed be more effective on this fire, at least at this point.
                          Why is it evaporating? Well, it may not be sufficiently pumped as some have said, or possibly this is a fire requiring more than 250 gpm. Looks like we've got more than 750 square feet of fire to deal with, which is what a 250 gpm stream can handle according to the NFA fire flow formula (length x width / 3).

                          Now that I've thoought this out some more. Let's turn the deck gun on this one, we're gonna be here for a while.

                          Comment


                          • #14
                            May not be a bad idea to blast the deck gun on this one. Although the concept of water conservation baffles me. If the fire needs 1000 gal a minute to be extinguished and we apply 250, won't the fire eventually burn down to the required flow? The fire needs 1000gal (ex). Put it on it and put it out!

                            Comment


                            • #15
                              Oh come on folks, the problem is an inadequate VOLUME of water being delivered, and it would still be inadequate whether it's a smoothbore coming out and dropping on the ground before reaching the porch, or an automatic making a nice looking low flow stream. Without the water behind them, neither nob would be effective.

                              Say you run a 1-1/4" smoothbore on your 2.5" line. Kick butt nob -- delivers about 325gpm @ 50psi.

                              But if your pump op is only giving you 100gpm, your nozzle pressure is only gonna be 5psi. How far is that stream gonna go?

                              Fundemental problem in this pic is inadequate volume to supply the nozzle, not which nozzle is being used.
                              ==============================

                              To expand a point of mine from last night (cut short when we got toned for a Heroin overdose...grrrrr)
                              Your bigger challenge isn't reaction force, but the weight of the 2.5" hose your advancing.

                              I don't object to a 2.5" line being pulled. Looking at the fire, a 2" or 2.5" would be appropriate for the flows.

                              But what strikes me funny is a lot of people who support smoothbores 'cause they have lower reaction force also want the big hose.

                              Say you run a 150' 2.5" line with a 1-1/4" smoothbore running 50psi and 325gpm. The reaction force on the nob is 123lbs. And the hose has 300lbs of water in it, plus it's own weight!

                              You could switch to 2" hose, still achieve those flows with very reasonable pump pressures, and cut the weight of the hose down to 195lbs -- still heavy, but still easier to humb than 300lbs!

                              Where it might make a difference is if your on a short-handed crew you may flake and charge the 2.5" to start knocking down the fire, but find your crew unable to advance the line for lack of muscle. 2" you've probably reduced your manpower by 1 or 2 guys to hump it forward.

                              150' of 1.75" by the way contains 150lbs of water, and 150' of 1.5" weighs in at 115lbs.

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