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  • #61
    I think we need to look at this from a slightly different angle. We should be looking at lines with the same flow, and then look at nozzle reaction and ease of handling the line.
    Prior posts are correct. How often are you fighting a fire in a 130' room?
    If you have a SB flowing 180 GPM and a 100psi fog flowing 180 which one will be easier to move? The Smooth Bore. We have already identified that the fog will be used on straight stream, so why do we want to beat ourselves up fighting the line?
    If you want to make life harder than it has to be go back to steel bottles on your scba, they are less expensive and more durable.

    When it comes to exterior attacks use whatever will flow the most water onto the seat of the fire. Again the SB would win out. How many pictures have you seen of ladders surrounding a building with nozzles flowing good looking streams out of their fog tips, but with the stream being broken up or turned to steam by thermal updrafts prior to any water hitting the seat of the fire. You need the cohesiveness of the solid stream to hit what is burning. The only other way around this is to flow so much water that the fire can't defeat the stream, but that would certainly lead to a discussion on the Vindicator and our dance card is pretty full to add this to the current post.

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    • #62
      KEA: What I believe from those numbers of most nozzles reaching 120' to 150' range, arguements over reach of one nozzle style to another is irrelevant for interior firefighting.

      Rarely will you be trying to apply a stream to a fire more than 40' away from you.

      ADSN: You need the cohesiveness of the solid stream to hit what is burning. The only other way around this is to flow so much water that the fire can't defeat the stream

      Vividly been there on a barn fire I was assigned to the ladder pipe. If I tried to hit the center of the fire, stream broke up -- and I was taking enough heat I actually got the equivelant of a bad sunburn on my legs from radiant through the 3/4 boots I was wearing (Didn't have bunkers with me that day, so I *thought* the tip of the ladder would be the safe place!)

      But that didn't mean I only had one choice, to switch to SB to penetrate it. I simply moved the stream to the front edge of the building where it was cooler, and worked the stream slowly into the middle. Since I started cooling the fire from the coolest part at the edge, I was able to defeat the thermal current and knock down the fire. After a couple passes, I'd signal the turntable operator and he'd rotate the ladder over so I could repeat a yard or so over. Fire went out. Just used some good judgement with situation presented me, and used an appropriate tactic.

      I really don't like seeing a ladder pipe operated without someone at the tip most of the time -- you don't know where the stream is going, if it's being effective, if it's even hitting what's burning or should instead be moved, or if some other team working the fire just came into the line of fire of your stream. Those eyes up there are important.

      Also, being in a predominantly rural area having to use SB on our aerial would be a major crimp on operations.

      Often we'll start flowing water through the aerial once the first round of tankers are in. Then we'll increase the flow as long hose lines are established or a larger tanker shuttle gets going. Say we start at 500gpm for 5 or 10 minutes before having the water to bump up to 1000gpm. That initial stream can often cut off the spread of the fire. The larger flow once we have it kills the fire and accomplishes "hydraulic overhaul."

      Let's see, 80psi @ the nozzle, 500gpm we'd have to start off with a 1-3/8" tip. Want to flow 1000gpm through that tip? Gotta shutdown the ladder pipe, unscrew the tips down to the 2", start flowing again. Uh-oh, we don't have the water supply we thought we did. Shut down the aerial, screw the 1-3/8" tip back on, charge it. Hey, OK, we figured out what was wrong, we got the water now. Shut down, unscrew the 1-3/8"...

      Put an Automatic Combination tip on there.

      Got all the water you need? Pump Operator doesn't need to do anything. Even if you have a 250gpm handline you need 200psi to supply, 200psi sent up to the auto on the tip will still just deliver 1000gpm.

      Short on water? You pull out a flow chart you've made up and tested previously on your truck so it's accurate for your plumbing, etc and it says:
      100' Extension, 70' Elevation:
      Tip Flow = Pump Discharge Pressure
      500gpm = 135psi
      750gpm = 145psi
      1000gpm = 155psi

      Only have the water supply established to supply it with 500gpm? Keep the main pump discharge pressure down at 135psi.

      Ok Pump Op, we now got 700gpm of water, but we want to run a 200gpm handline over their to cut off fire under the eaves. Ok Chief. Pump Op knows his 150' 1.75" line needs 200psi to deliver 200gpm through it's Auto Combo. Crank up pump to 200psi PDP, and gate back the Ladder Pipe feed to only 135psi when flowing.

      Got more water? Crank open the discharge. Running shy on water? Crank it back. No need to change tips or shut down to do so.

      I suppose if you run in an area with good, consistent water supplies you can select the right tip from the start and us SB on your aerials.

      If you run in an area like mine where we work heavily off of tanker shuttles and/or long laid lines, using SB master streams can be an incredible headache for the Officers, Pump Operators, and Water Supply Officer as the only way to effectively control their flow is changing tips.

      Yep, we run SB on our 1st in Engine-Tank. For one special tactical use -- it's rigged to deliver 600gpm fro 2 minutes off our 1200 gallon tank if the ET happens to be in the right place at the right time. All our other master streams are kept with combo fog tips, including the bomb line on the ET (300' 3" with 350gpm-1000gpm master stream).

      ---------
      Actually, Fixed-Gallonage combination nozzles are almost as bad as SB for operations when water supply is or may be limited. You don't have to shut down to change flow, but if the nozzle crew sets it to a certain flow the nozzle will try it darndest to make that flow.

      Automatics allow the crew to select the flow up to a limit of either the nozzle, or what the pump operator will allow. I don't like limiting flow to interior teams, but when operating multiple handlines and master streams on the outside, an officer and pump operator can set the discharge pressures so the crews can not flow more than a certain GPM from a central location.

      Comment


      • #63
        I personally don't like automatics on a ladder pipe because of the chance that the engine pumping your gun isn't pumping what you should have.
        Sure, we can talk about an engineer needing to know his job, but with the infrequent use of ladder pipes plus all of the elements involved it is easy to have the incorrect NP.
        With anything but an automatic it is obvious that the pressure is low.
        Depending on your setup Prepiped VS ladder pipe I also prefer the lower pressure of the SB. (Less nozzle reaction going against the ladder)

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        • #64
          Dalmation90: Please help me out on this one.

          500gpm = 135psi

          100-psi for the tip
          35-psi for elevation

          That totals 135-psi. Does your rig have some new magical plumbing that eliminated FL?

          Sorry for my confusion but the numbers dont make any sense to me.

          Just looking for clarification.

          Thanks



          ------------------
          Kirk Allen
          First Strike Technologies, Inc

          Comment


          • #65
            ADSN/WNFLD: It would appear that gating discharges can be done during a fire based on Dalmations explanation. Go figure, they are even able to operate multiple lines by opening and gating them.....and they are using automatics.

            Just thought that was interesting considering the last debate you and LHS had on that subject.



            ------------------
            Kirk Allen
            First Strike Technologies, Inc

            Comment


            • #66
              This post temporarily taken down till I can fix the physics

              (For those of you who read, most of it is correct, but I had a problem with some of the math 'cause I had a brain fart and combined benfits of constant flow and constant gallonage nozzles together on one!)

              Matt

              [This message has been edited by Dalmatian90 (edited 05-25-2001).]

              Comment


              • #67
                Dalmation90:
                /The design of the nozzle limits the volume to 1000gpm, and the design of the nozzle limits the discharge pressure to 100psi. Nozzle reaction doesn't increase on bit./

                Please beware if you think this is true. The nozzle does not limit the volume nor does it limit discharge pressure. If you are flowing 1000-gpm with a 100-psi pressure at the nozzle, you can very easily go over the 100-psi NP by simply pumping more. Its called overpressureizing the nozzle and you will be suprised how easy it is to do it.

                Dont take my word for it, call the manufacture and ask them if the nozzle limits flow or discharge pressure.

                The only way it could limit flow was if it had a relief valve that dumped the excess pressure to it.

                Since the automatic works very similar to a relief valve, we know that when it is at its peak flow (1000-gpm) the stem is pushed out all the way. Now that the stem is out all the way the orifice becomes a fixed size. Send to much flow for that size orifice and your NP goes way up while flow only increases marginally.

                Try it some time using an inline pressure gauge at the nozzle and a flowmeter. You will see that the nozzle can flow more than 1000-gpm and your NP can go well above 100-psi.

                Still curious about your lack of friction loss for your 500-gpm flow.






                ------------------
                Kirk Allen
                First Strike Technologies, Inc

                Comment


                • #68
                  Kirk, I do believe your right about the over pressurization But I'm finally going to dinner so I'll have to redo my math later.

                  Here's the calc I'm using for the estimate on FL to the tip of the aerial.

                  30' of 4" piping from midship pump to rearmount turntable. 100' 4" piping up the aerial. 130' 4" using the rubber lined fire hose calculation 'cause I didn't feel like looking up aluminum or stainless steel is 5 psi/100' or 1.3*5=6.5

                  It's probably close to the actual numbers when you consider new metal pipe will have a lower FL per foot, but I'm not adding in elbows, possibly undersized valves, etc.

                  70' in elevation gain will cost you 70*0.434psi or 30.4psi.

                  30.4psi + 6.5psi = 37psi which I rounded off to 35psi.

                  Because of all the variabilities in materials and design, your best running an actual flow test to build the chart. That also gives you a baseline in case you have a future problem and have to go looking from a clog somewhere in the pipes

                  Comment


                  • #69
                    Fireboy,

                    You getting all of this?

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                    • #70
                      I don't know about the rest of you but my brain hurts from all of this math I am reading!

                      Comment


                      • #71
                        Originally posted by E229lt:
                        Larry,
                        Your comments about the FDNY,

                        //"And they knock off more guys too! They just started to provide EMS, wear bunker pants, buy imagers, etc, so they a few decades behind the rest of fire service, let's not hold that against them.

                        Fire activity isn't something to brag about it is a living example of a failure to perform the whole task of the fire service. Try a few codes and sprinklers. //"

                        How can you put your foot in your mouth when your head is up your ***?

                        ---------------------------------------------
                        LHS (Larry)
                        The fact that you would knock any department based on the loss of brother firefighters has brought you below any and all of the bean counters, administrators and budget makers of every municipality in the nation.

                        The very men we choose to never forget for their sacrifices, you have chosen to use in an attempt to place a black mark on one of the finest departments on the planet.

                        I ask anyone on this forum to support your statement in regards to the FDNY, and I quote "And they knock off more guys too! "

                        You have shamed our fallen, their families and yourself. I once read your posts with an open mind, I was foolish. You are a hack and have no place in the fire community.

                        If you want to knock a department, begin with your own. They have placed you among their ranks and for that they should be ashamed.
                        Lieu:
                        Thank you! You get two nominations for Best Post in Topic.


                        [This message has been edited by NozzleHog (edited 05-25-2001).]

                        Comment


                        • #72
                          Dalmation90:
                          /Here's the calc I'm using for the estimate on FL to the tip of the aerial./

                          Thanks for the update. I was under the impression your numbers were from actual tests and not estimates.

                          I agree, doing the actual flow test lays a foundation to work from in the future.

                          Thanks

                          Comment


                          • #73
                            //I personally don't like automatics on a ladder pipe because of the chance that the engine pumping your gun isn't pumping what you should have

                            Hmm, NFPA does state a flow meter shall be plumbed to the water way? That a pressure gauge shall be plumbed to the water way? Doesn’t state a pressure relief shall be installed? There are three ways to insure proper flow and pressure.
                            .
                            //it is easy to have the incorrect NP.

                            Especially when you use a smooth bore tip on a ladder pipe. Hmmm, 100 foot ladder flow 1000 gpm at 80 psi tip pressure to a SB tip. What level do you pump to? 33’ high, 66’, 75’, 100’? If you pump for 33 feet and end up supplying the tip at 66 feet 14.3 psi too little. If you pump for 66 feet and have the ladder at 33 you pump 14.3 psi too much. If you pump for 100 and have the ladder at 33 you’ve got 30 psi too much. If you pump for 75 and have the ladder at 100 you end up with 11 pounds too little. If you pump for 100 and use the ladder at zero degrees you’re 44 psi too high.

                            //With anything but an automatic it is obvious that the pressure is low.

                            What no smoke at your fires?? With an automatic the pressure isn’t ever low. It is always 100 psi.

                            //Depending on your setup Prepiped VS ladder pipe I also prefer the lower pressure of the SB. (Less nozzle reaction going against the ladder)

                            Oh really? No on makes low pressure automatics? How do you get this lower reaction when you are over pumping the ladder by as much as 44 psi? Your 65 to 144 pounds more reaction than the 100 psi automatic and 292 pounds higher compared to a low pressure automatic! That is enough to damage a portable ladder pipe or dump the ladder. Are your hydraulics so good you can be dead on 80 psi?????

                            Does an automatic limit flow and reaction better than a smooth bore?

                            A smooth bore tip 2 inch at 1000 gpm 81 psi. Reaction is 486 pounds.

                            A 1000 gpm automatic 100 psi nozzle 505 lbs.

                            A low pressure automatic 80 psi at 1000 gpm only 452 lbs reaction.

                            Now let's increase the nozzle pressure by 44 psi.

                            2" tip flows 1328 gpm and has reaction of 750 lbs.

                            1000 automatic 1200 flows gpm and has 727 lbs reaction.

                            Low pressure auto 1114 gpm and 624 lbs.

                            Seems to me the automatic always wins and does a much better job of limiting flow than a smoothbore. The calculations above do not take into acount one make of Auto master stream that has a stream straightner built in that costs 100 gpm worth of loss at 1000 gpm. So in reality on that nozzle you'd be looking at 667 and 568 lbs reaction respectively. Gee, evem lower.

                            Dalmation depending upon the make, or by simply adding a short stream straightener you can pretty much insure you won't exceed 1100 gpm no matter what you do.

                            //It would appear that gating discharges can be done during a fire based on Dalmations explanation. Go figure, they are even able to operate multiple lines by opening and gating them.....and they are using automatics.

                            KEA

                            Are you referring to this post? Or Something else? When you said the above?

                            //Automatics allow the crew to select the flow up to a limit of either the nozzle, or what the pump operator will allow. I don't like limiting flow to interior teams, but when operating multiple handlines and master streams on the outside, an officer and pump operator can set the discharge pressures so the crews can not flow more than a certain GPM from a central location.


                            [This message has been edited by LHS* (edited 05-25-2001).]

                            Comment


                            • #74
                              Larry, I was referencing another post where there was quite a debate over feathering the discharges.

                              To everyone: I have read these posts with great interest. I wonder out of all those who like the automatic nozzles how many have ever tested them with a pressure gauge and flowmeter year after year.

                              A recent visit to the Dallas area reflected 9 out of 12 automatics would not regulate pressure properly. Dont take my word for it, ask Big Paulie, he was with us.

                              Another trip to the LA area offered 5 out of 5 would not regulate pressure properly. 3 out of those 5 would not change flow or pressure even though they were tried in both normal and emergency modes.

                              Whats my point? No its not to pick on the nozzle type. The automatic nozzle works fine.....when the proper maintenance is done.

                              What bothered me the most was that in every case everyone was willing to bet their life on the nozzle operating properly.

                              In some cases we found that when the flows were good (150-200-gpm) the nozzle pressure was 60-75-psi and not the 100-psi it was designed for. Or when the flows sucked (40-90-gpm, the nozzle pressure was 115-125-psi.

                              I have tested well over a thousand nozzles and just about every configuration you can imagine. The one thing that continues to come to the surface when flows and pressures are not what they think is that none of them are doing the proper maintenance. If they are doing the maintenance the fail to test them with flowmeters and pressure guages to ensure they are working properly.

                              If you use automatic nozzles, PLEASE test them with pressure gauges and flowmeters and ensure they are working the way they are supposed to. If you live in an area that has hard water, you may find that your maintenance requirements will be much more frequent than those who have softer water.

                              Again, this is not an attack on the type of nozzle. If anything, its an attack on those who have failed to ensure their equipment is functioning properly.

                              I have said it before and Ill say it again,
                              TEST, TEST, TEST!

                              Im done

                              ------------------
                              Kirk Allen
                              First Strike Technologies, Inc

                              Comment


                              • #75
                                Enough with all of this math!!!!!!!!!!! The best thing we can all do is go out and find which nozzle works best with our department and which will set up for the property that you will be protecting in your district.

                                The next thing everyone should do is go out on the next live burn they can have the chance to and experiment with both nozzles. Do all your math there, use only the water in your booster tank and see how many gallons of water it takes you to successfully knock down the fire. Then take the following readings:
                                1. Temp at or around helmet level. Record before the water flow begins and then after water flow has ceased.
                                2. Visibility...how is it? Which can you see. Set up a marker point to use. See how far you can be away from it before you can see it.
                                3. Set your lines for equal gpm flow and see which line gets deployed faster and how much strain is placed on the crew. How do you do this...baseline vitals. measure baseline and then check the vitals after each attack, (this is supposed to be done anyway in accordance with nfpa)

                                Let your crews experiment with the attacks and patterns they use. Do this with a one room contents fire and allow the fire to reach the rollover stage just before calling for the crew. I have worked about 50 live burns during my career and have many more planned. Before we began using smoothbore on the initial attack, many of us (instructors) as well as students was receiving steam burns, suffering from heat exhaustion must faster than normal due to the heat caused from the thermal inversion, and $1000's of dollars of equipment being destroyed. This is all in a "controlled" enviroment. Since we have switched over to using SB, the only way a helmet is melted is if a student stands up. Also our helmets have been lasting much longer throughout the training year.

                                The biggest thing to remember is that if we cant stop getting firefighers burned in a "controlled" enviroment, then how can we keep them from getting burned at the actual fire scene.

                                My final thought i will make on this post is about LHS's comments about FDNY. How could you stoop so low so make the comments that you made. There is no reason to down grade a department for their methods they do. Yes many die in their organization, but look at the fires they see. Can you say that you have ever seen a 10 alarmer? Most cant. Look at there run totals. 1.5 million last year, with Chicago under 1 million being the closest. When a brother firefighter is lost we should not attack their ways nor their department, but see if there is something we could do to change it. But to attack the FDNY like you have, i think its a horrible act of class on your part. If i had to give you an ISO rating, you would be an 11, because a 10 is even to low for you. If you want to attack a person in the forum with something they said about a procedure or disagree with a comment, be my guest....but if you want to attack a department and try to make them sound like they are nothing but careless, inexperienced, and down right stupid in their ways of fighting fire, do us all a favor, go **** up a tree in somebody else's world, because i wont speak for anyone but myself, but i think you are low life trash for doing such.



                                ------------------
                                Captain James Collier
                                McMahan Fire Rescue
                                KCTCS Area 6 Instructor

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