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  1. #1
    Firehouse.com Guest

    Post Solid vs. Strait

    The debate continues over solid or strait/fog. I do not understand how this debate can still continue? You are always told to use the best tool for the job. You would not use an ax over a K-12. Why, because the K-12 is the better tool.
    So why do we strait streams for interior attacks when the better choice is the solid stream.
    A solid stream is the better tool. It will not convert to steam as fast as a strait stream will. (a strait stream is a narrow fog pattern not a solid stream.) The nozzle reaction is lower, the GPM's are higher, the line is eaiser to advance, it will protect you from a flashover, you will not ruin your visability with the production of steam, faster fire knock down due to more GPM's reaching the fire before converting to steam, the reach and penetration are greater, you do not have to worry about low pressures in standpipes, you can hydrolicly ventilate by placing your thumb over the end, I could go on forever.
    So after all thoes facts why do people still want to use the strait stream/ automatic nozzles?

    I would like to hear your responses?

  2. #2
    Firehouse.com Guest


    Debates which get solved on the internet:

    vollie v. paid
    red fire trucks v. green fire trucks
    Stihl v. Husqvarna
    leather v. plastic
    blue lights v. red lights v. no lights on POV
    solid bore v. straight stream

    I support automatic nozzles because they are the best option for my department. Might not be for yours...but I would say a fog nozzle is much more like a K-12 -- more versatile and can do more jobs more effectively and efficiently than a solid bore which is the old reliable axe of the fire service.

    And dare I say if you're in a position to cause yourself steam burns other than in a basement attack, your department better start thinking about something called ventilation again and stop worrying about whether smooth bores are better than straight streams or red fire trucks are more recognizable than green ones -- they both get the job done well.

    By the way, the "effective reach" on both straight and solid bores according to the Akron Brass catalogs are both over in the 140' range for 200gpm flows -- I doubt you see very many structure fires that you're shooting water from 100+ feet away from the base of the fire!

    The more and more I've read these debates, frankly the less and less a supporter of smoothbores for interior operations I've become. Fog nozzles seem to have become a scapegoat for other changes in the conditions the fire service faces.

  3. #3
    FF McDonald
    Firehouse.com Guest


    Well, here's my two cents.....

    1. It's 'straight' not 'strait' (Sorry- I had to )

    Ok - now that that is out of the way--

    I feel that both nozzles have their place on the fireground. There are time when you will want a smoothbore nozzle (solid stream) for its penetrating power. And it's ability to do "hydraulic overhaul".

    There are also times that I prefer to have an automatic nozzle (straight stream) as my friend Mr. Dalmation ( ) has already mentioned, todays automatic nozzles rival smoothbore's for reach, as for gallonage - I hope the Engineer is doing his stuff at the pump panel-- cause yer too busy at the knob. I feel that an automatic nozzle has it's advantages; for example, you can hit the seat of the fire with the straight stream, and then break out a window and perform hydraulic ventilation- you just made the conditions in the fire room more tenable for a possible victim, and lessened the amount of smoke you have to deal with. On the other hand, if things go to crap-- you can turn that puppy to the 'FOG' setting, and beat a hasty retreat. Can't do that with a smoothbore.

    There's probably a bunch of stuff that I have missed - but it's late at night.


    The opinions presented here are my own, and not those of any organization that I belong to, or work for.

    "In Omnia Paratus"

  4. #4
    Paul Grimwood
    Firehouse.com Guest


    I'll answer your post ENGR43 if you'll answer mine below - about smooth-bore streams...why all the hype?

    I have seen many posts in support of smooth-bore streams but they are all based upon instinct.

    I have seen as many posts supporting the combination type of straight stream but most of these were based on the results of tests carried out by scientists, engineers and noted authors who support theory with evidence.

    The debate here evolves further into a discussion between the merits of water-fog versus SS......let's keep to the topic as posted!!!

    If it's simply SS versus SB then - I don't see the difference when, at equal flows, the same amount of water hits the target from either! So the studies say....


  5. #5
    Firehouse.com Guest


    ENGR 43, try taking out a window and clearing the glass and sash with a K-12. I like the ax for that job.

    Every job is different, use the best tool for the job.

  6. #6
    Firehouse.com Guest


    <<A solid stream is the better tool.>>

    Where isyur proof? Wil it out reach a fog tp at standard nozzle pressures? No. Will it penetrate better? No. Will it impact harder? No. Can you vent a room with it better than a fog? No.

    <<It will not convert to steam as fast as a strait stream will.>>

    You have some proof to support that? How much faster?

    The SB guys say bonce the stream off the ceiling. Won't a straght stream make less
    steam than a broken smooth bore?

    <<The nozzle reaction is lower,>>

    Only when comparing aples to oranges. If you use a SB and a SS with the same tip pressure there won't be any difference. How much lower? 7 to 12 pounds for the same flow 50 compared to 100 psi. Big deal.

    <<the GPM's are higher>>,

    Not if you use the same NP's and flow ratings. And how much higher? Can't the pumper throttle up an make things a tie?

    <<the line is eaiser to advance,>>

    Not if the same NPs and flows are compared. Even apples to oranges comparison either can be moved the same. Low EPs equal kinks, lots of kinks, whatever advantage you had in flow and pressure is lost in kinks.

    <<it will protect you from a flashover,>>

    Not better than a fog. How does it prevent flashover better?

    << you will not ruin your visability with the production of steam>>

    If you bounce the ceiling it will, if you over apply it will. How much faster will you lose it?

    <<faster fire knock down due to more GPM's reaching the fire before converting to steam,>>

    Really, how much faster? Thermal imaging tests with measured results of the water flow before and after show no steam production with a SS stream. More gpm is a function of comparing apples to oranges, if the flow the same then the same amount reaches the fire. Exterior attack would always favor a combo nozzle by 10 to 20 to 1.

    <<the reach and penetration are greater,>>

    Really, how much further? Point a 50 psi SB straight up and a 100 psi combo. The SB always loses. It has to d with Issac Newton. A SS will almost always out reach a SB if it doesn't out reach it it will go as far. Penetration is a function of NP 100 psi always beats 50 psi, reac is also a function of NP 100 beats 50 or 80 every time.

    <you do not have to worry about low pressures in standpipes>>

    Really, NFPA 65 psi standard, if you use 200 feet of 2 1/2" hose and a 1 1/4 inch tip you are going to be short 35 psi and have lots of kinks. Once again apples to oranges, same tip pressure same flow range same results...always.

    <you can hydrolicly ventilate by placing your thumb over the end,>>

    Really, how many cu ft of air will the SB hydraulically nozzle move? A 1 3/4" tip will move 10,000 cu ft, that is twice what most blowers ca move. U of MD testing shows a 10 to 1 advantage for the fog combo tip over a SB gated or thumbed.

    <<So after all thoes facts why do people still want to use the strait stream/ automatic nozzles?>>

    I'm not sure they are all facts.

    If the competion is apples to apples you'll get the same results. If the comp is apples to ranges then eithr can win, whatever has the advantage of NP and flow setting will win. For example, a 35 ps combo tip could out flow, have lower NR, be easier to hold than a 50 ps SB.

    But let's talk what you've ignored. How do you operate two streams from two different length lines flowing difering volumes at the same time with SB's? Say 150 feet of 2 1/2" with a 1" SB and a 250 foot 1 3/4" line with a 15/16" tip. The auto tipped line would pump one pressure and the SB rig would do what???????............

    Remember the fire service was 100% SB, they chose to go to combo tips. Most fires today are fought with combo tips, two builders will tell you they sell 100 to 200 to 1 combo to SB. So I'll ask you, are 1.2 million firefighers wrong in their nozzle selection? Aren't the fires going out in their towns? How do you take on an LPG or flammable liquid fire with a SB tip? How do you push fire with a SB?

  7. #7
    Firehouse.com Guest


    First off I would like to say this. "The fire truck is a big tool box and it contains many tools that have to be selected for the job at hand. You do not have one wrench for all tasks do you?" The author of the book "Fire Stream MAnagement", Dave Fornell said these words (or some to that effect on one of his videos if memory serves me correctly. This quote is what we all need to remember when doing our difficult job.

    Second just to throw out something that I feel is a false sense of security that was mentioned by FF McDonald; He said that you can trun the fog nozzle to a fog position for "protection" if you need to beat a hasty retreat. I like all of you were taught just that, if the fire flashes you can turn it to fog and get out. My food for thought is this: Who has reflexes that quick so that they can realize what is happening, reach the nozzle, open it up on fog, in the split second it takes for the fire to flash..Just wanted to see what people think about that and I am not saying the others are arong in what they teach just let's not get a false sense of security.

  8. #8
    Paul Grimwood
    Firehouse.com Guest



    Ffr Mac gives good advice but I see your point. It all depends on -

    a) If the 'flashover' is in the compartment (room) you occupy or an adjacent compartment.

    b) The size of the 'flashover' - related to the size of the fire-load.

    c) If the 'flashover' is wind assisted.

    d) The speed of the 'flashover' - some ignitions of the fire gases are slow (rolling) whilst some move at a sprinters speed - 30 feet per second - others detonate!

    I use the term 'flashover' in a generic form here.

    If all turns to 'crap' you MAY get the time to use a fog pattern to your advantage....you may not. At least the option is there....

    But the topic is SS versus SB right?


  9. #9
    FF McDonald
    Firehouse.com Guest


    Gentlemen -

    I did not intend my posting to provide anyone with a false sense of security, as I hope that most people are educated with the tools that they are using.

    In MY opinion -- both nozzles have their advantages, and their own applications. If you were going to attack a LPG fire (say a BBQ grill w/ a small tank) -- would you use a smoothbore for thermal protection from the radiant heat. NO - you would use a fog nozzle.

    In MY OWN HUMBLE OPINION- I would rather be interior with an automatic (read straight stream / fog / whatever you call it) nozzle. I feel that it presents you with more options.


    The opinions presented here are my own, and not those of any organization that I belong to, or work for.

    "In Omnia Paratus"

  10. #10
    Firehouse.com Guest



    should I throw myself into this debate????

  11. #11
    Paul Grimwood
    Firehouse.com Guest


    'Hurl' yerself in here Capt!!!

    In 1985 the Fairfax County Fire Dept (USA) completed some pretty interesting tests....comparing the attributes of:

    Smooth-bore versus Straight Stream (From a combination nozzle) versus Fog-pattern!!

    Their findings were based on data recorded scientifically using protected thermocouples.

    They concluded that a fog pattern was nearly three times more effective in cooling the overhead than the smooth-bore!

    They also demonstrated that the straight stream from a combination was TWICE as effective in cooling the overhead as the smooth-bore.

    The firefighters who took part in the tests stated conclusively that they all preferred the nozzles that provided the fog/straight stream options, commenting -

    "When you get to the fire and get set to start the initial attack, only then do you know what the best tactic is. What is needed is the FLEXIBILITY to choose on the spot - fog, straight stream, a little water or high GPM's to get the fast knockdown. We use the aggressive attack strategy here. Move in...hit it....move in again to get the water directly on the seat of the fire"....


  12. #12
    Firehouse.com Guest


    Paul is right about Fairfax County Virginia. Except in the Early 90's they did some studies using aquired structures and further tested the smoothe bore vs straight and or combination. Assistant Chief Jeff Coffman and Lt. Stanley Earl give quite an effective presentation of this sb concept. Admittedly so, its intention was to be used for running attic fires with limited access and large fire volume as well as garage or basement fires. But...the solid bore was most effective in these cases and then the straight stream. Use of the SB and aggressive hook work provided a quick knock down as the stream reached the seat of the fire easily. Made a beleiver out of this old school hard core fog stream dude!

    [This message has been edited by Captstanm (edited April 27, 2000).]

  13. #13
    Firehouse.com Guest


    I must agree with the spotted one because we will never ever solve these probing questions...but here's my thoughts on it anyway.

    Smooth bore nozzles are a good tool. In a dept where the truck is doing it's job and removing the heated gases from the building, it's a good way to fly. Can put out fire with it.

    Variable stream nozzles are also a good tool. Can vent out window with them....can use the Grimwood Pulse method (which I've used and it works guys). Can put out fire with it.

    HMMMMMMM....can put out fire with both...why? GPM BTU Absorption > BTU's END OF STORY!

  14. #14
    Firehouse.com Guest


    I think either nozzle works in every day building fires. I do see an area where the smooth bore nozzle is the best tool. That is in a high rise operation. It will give a useable stream with almost any nozzle pressure. Yes an automatic will do this also. However when the debris, rust, pipe tape, mice, and who knows what else comes through the line, the s/b has a much better chance to pass that junk out the tip. I would guess most stand pipe systems have not had any water flow in 20, 30, or 40 years. I don't care about a pretty pattern, just want to get wet stuff on the red stuff. A smooth bore with a leader tip has 1 1/2" threads on the outside of the tip. Run short on hose? The next in company connects to your nozzle with their hose pack, open your bale, and press on. Don't have to shut the line down to do any of this, just close your nozzle. I think time is important as a high rise evolution takes longer to put a line in service, and any advantage a big help. I also like a s/b because it is cheap, simple, reliable, and lighter to lug around in the high rise pack. Only 1 moving part (bale) and it is almost firefighter proof.

  15. #15
    Firehouse.com Guest


    This post is not intended to claim the SB is better than a fog or vise-versa. It is intended to encourage all readers to see through the smoke! Let me make my point, challenge it if you may but know this, its all based on factual physics with no play on words. Read carefully and think! When you understand it you will not be fooled by the slick talkers again

    Fact: Exit velocity from any nozzle is what determines its speed, not inlet pressure at the base.

    Fact: Exit velocity from any nozzle is what determines its reaction, not inlet pressure at the base.

    These two points are laws of physics that cannot be disputed.

    What’s my point?

    It has been insinuated on other posts that my teaching or demonstrations are less than honorable and even deceitful. For those who have ever sat through one of my presentations you know this is simply false. The more I read this thread and certain posts I felt that its time to expose some more truth.

    Have you been led to believe that your combination nozzle has a harder hitting stream because of a 100-psi nozzle pressure? If so beware. The fact is no 100-psi combination nozzle to my knowledge ever has an exit pressure of 100-psi as they would have you believe. In fact you will find that as much as 34-psi of pressure is lost within some automatic nozzles thus providing an exit velocity of only 66-psi. This is a far cry from the 100-psi they use to make their case against Smooth Bore nozzles and in reality much closer to a standard 50-psi SB exit velocity. (I know Larry…66-psi is going to hit harder than 50-psi at the same flow)

    I attended a class where the speaker claims that the 100-psi nozzle is going 83 MPH during one part of the presentation using the theoretical exit pressure of 100-psi while that same person knows without question the very nozzle he speaks of did not have 100-psi of exit pressure. This is called speaking in half-truths. The statement is correct as long as the term Theoretical is used, however I believe it is deception when the one making the statement KNOWS that the exit pressure is not 100-psi and is actually 66-psi. That’s 34% less than what we were lead to believe. (Key phrase- “led to believe”) If you do the math based on measured exit velocity the actual speed is 67 mph and not 83. A smooth bore at 50-psi goes 58.5 mph.

    I may be wrong, but I think that if you going to compare apples to apples like has been suggested by certain people, then do so across the board. Exit pressure for exit pressure, flow for flow! Realize that if you do this there wont be any more to argue about because the laws of physics win.

    Amazingly the 100-psi argument is used in one breath to support the position that the stream always hits harder because of the theoretical 100-psi pressure yet when explaining the reaction force they insist on using the measured exit pressure to show how low the reaction is.

    I must ask, why not use the 100-psi in the reaction argument that was used in the hard-hitting stream argument? The answer is because it would show the reaction to be much higher and that doesn’t sell nozzles.

    Why not use the exit velocity to show how fast the stream goes? The answer is because it would show that the stream does not go nearly as fast as they want you to believe and that also doesn’t sell nozzles.

    Fact: You can have a lower exit velocity from a nozzle and have it hit harder and go farther than a nozzle with a higher exit velocity. HOW? By having the lower velocity stream simply flow more water than the higher velocity stream. The extra mass is what offers more punch.

    Which nozzle is better? As certain people have said at the defeat of numerous valid arguments against their position…all nozzles are putting out fires everyday somewhere in the world

    This post is not intended to attack or degrade any type of nozzle. It is only intended to help people understand the REAL truth about the theoretical 100-psi fire stream and how the facts are being manipulated to support half-truths.
    I feel that there is no gain in pointing fingers or naming names of those that do this. They know who they are and all I can say is be prepared the next time you try to promote your half-truths to sell your goods, someone might just call your bluff!

    Kirk Allen
    First Strike Technologies, Inc

  16. #16
    Firehouse.com Guest


    Hey guys--Food for Thought
    Havn't seen discussed yet on this topic, but combine the straight bore with a combo tip. The two depts I work with (1 Career 1 voli),
    we use the Elkhart B-275-GATF. The Combo tips flows (205-BA) 125 gpm/75 psi with a straight bore flows at 75 psi (7/8" Waterway)
    approx 195 gpms. We would not trade them for anything.

    Just another 2 cents.
    Till next time "They light'em, we Fight'em".

  17. #17
    Firehouse.com Guest


    P.S. This a break-a-part nozzle if had not figure out with a pistol grip. Only thing you have to do shutdown the nozzle and remove the combo tip to become a straight bore and still have the shutoff in your hand.
    No since of leaving the fire area and lose ground to change nozzle.

  18. #18
    Paul Grimwood
    Firehouse.com Guest


    Capt Stan - thanks for that info....!

    (Can you mail me a copy of the report if you have access to it - I would be very interested to see it). I am wondering about the 'running attic' fires with limited access - was this an exterior attack??? You also talk of basement fires....I would like to see the test results. Its interesting that a fire department would reverse its initial test findings some five years later!

    KEA - WOW!!! Thinking on this post.........!!
    Doing lots of it!!!!

    Capt 3211 - 'Go with the break-aparts - allllllright'!!


  19. #19
    Paul Grimwood
    Firehouse.com Guest


    OK - more food for thought.......

    United States Navy approves 3D water-fog applications!!

    The Naval Research Laboratory (NRL) initiated some full-scale tests in 1994 that compared smooth-bore streams against 'pulsing' fog tactics based on information in my book FOG ATTACK (1992).

    The fire compartment of 2,600 cubic feet housed fires of wood cribs; particle boards and paper/cardboard that reached 'flashover'.

    Everything was monitored scientifically and recorded test data concluded that 3D water-fog applications clearly cooled the overhead areas more effectively than the smooth-bore streams. Firefighters on the nozzle confirmed this fact and several suffered steam burns from the smooth-bore applications....which did not occur with the pulsing fog tactics.

    The thermo-couples demonstrated clear thermal layering disruption with the smooth-bore streams that did NOT occur with the 'pulsed' fog!


  20. #20
    Paul Grimwood
    Firehouse.com Guest


    KEA -

    Much deliberation in trying to come to terms with what you are saying!

    Does an automatic nozzle have 100 psi exit pressure? I am uncertain as to the exact (true) settings of various automatics but in the UK we run some of our TFTs on high-pressure systems - in certain situations the exit pressures from these nozzles are in excess of 175 psi! Beyond certain parameters the exit pressure of this type of automatic nozzle increases directly as the pump pressure increases.

    I have also looked at the TFT handbook on automatic nozzles - they clearly show calculations based on 100 psi in the 'reaction argument'.

    I note you have not directed these claims at any one particular manufacturer but your statements seem to discredit all types of 'automatic'.

    Can you provide greater detail on these claims - I do not fully understand your calculations (maybe I'm missing something!)and - clarify how your post either supports or opposes either style of branch in relation to the topic - 'Solid .v. Straight'?


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