Thread: Cafs sysytem

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    Question Cafs sysytem

    I'm looking for some techniques on how to train personel on a cafs system. Anyone got some....

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    What training have you had with a CAFS system? or did they just dump the truck on you and say have at it. Best practice for CAFS is practice everything. If you are using it as a first line of attack the only way to practice is at a live fire training centre or by doing NFPA compliant live fire training.

    Cafs when used in interior attack is diiferent in the fact that it does not remove heat. To prevent flame spread simply coating the walls will prevent further combustion. Again the bad thing is - heat is not removed and roll over can still occur - somewhat reduces the chance but it can still occur. Finding the fire quickly is key, get a quick knockdown and ventilate, or ventilate and then knockdown!

    Excellent for exposure protection, just foam what you want to protect. Your cafs dealer should have some training tapes on how the cafs operates. As I said interior work is slightly dfferent with the CAFS.
    One thing - If you are using it for interior attack make sure the hose is rigid as regular hose will kink going around corners, and that really sucks!

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    I agree with Dave, at least I agree with his first statement. The best way to really train with CAFS is in a live fire scenarios. Almost anyone can make foam with a CAFS system, but to get the ratios correct and to see how different ratios affect a fire takes an acutal fire.

    I disagree with Dave in that CAFS WILL absorb heat quite effectively. Dave, if you are having this problem I suggest that you reevaluate the ratios used on your truck. It could be that your operators are creating a "dry" foam. In that instance, you will have difficulty with heat absorbtion.

    Secondly I disagree with the statement about kinked hoses being a problem with a CAFS system. We have, in training and with the CAFS mfg. rep, kinked the hose back on itself with little or no noticeable decrease in the flow from the nozzle.
    Lt. John Kaltenbach
    Mifflin Fire - Rescue 133
    Gahanna, OH

    "Vermögen bevorzugt das tapfere!"

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    Coupla suggestions.
    Kinking the hose is more of a problem near the discharge end of the hose, the kink will shear the bubbles and may not have a chance to reform before exiting the valve and this makes the foam very wet, which isn't all that bad if you want to use this as a technique to adjust the wetness at the nozzle. The regular attack hose with foam in it may be too flexible near the nozzle. A solution to this is to use a short sectiong of hard hose like the reel-teck or piece of rubber hose then the valve. This gives the nozzleman much more control when shurting and opening the valve quickly, oh! yeah, just a reminder, ther is no water hammer action with slamming a CAFS valve shut.

    One other tip that might help with interior attack, with the discharge valve full open, lay your gloved fingers gently into the stream to create a great fan stream that will paint a wall or cieling in a New York Minute, also partially closing the discharge valve will strip some of the air from the bubbles to change the foam from dry to wet for different conditions. Momentarily shut the valve to build up the surge pressure and pop the valve open to blast the stream through both blackened sheet rock walls to extinguish a fire in the other room. Same technique works for hidden fires in the ceiling. Use the .3% concentrate setting to create a fast water draining foam and use .5 to 1% for long lasting tuff vapor and smoke sealing blankets but please use a wet setting to soak into the class A materials before you apply a long lasting blanket.

    Hope this helps.
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    My apologies, I didnt explain myself well enough. Foam does have heat reducing tendancies just not as efficient as water. After a class A fire we moved the remnants and the radiant heat in the ground was substantial, with water you dont have the same affect as the water drips through and cools everyhting, we found the foam blankets and retains the heat longer than with water. Good for a thermal barrier.

    The kinked hose prevention was a recommendation from our MFG. They recommended that the first section of hose be rigid to prevent kinks close to the nozzle and limitting the foams capabilities. This is precationary only and we dont want to take the chance of being the ones to find out that in the right circumstances a kinked hose will deminish your effectivness. This is a recomendation only!

    cfire3 has some good points - cafs is excellent for powering through drywall. Excellent for penetrating!

    Hope this clarifies
    Dave

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    Dave, thanks for the compliment.

    Have you tried the CAFS on slick ice, or used it in sub-freezing weather? I wish the guys up in the frozen eastern US knew how the foam freezes into a snow-like condition to improve traction and see how things that are covered with the frozen foam do not become icebound.

    The CAFS makes tank water a better choice than frozen hydrants for initial attack and the foam that freezes in the structures is much safer than the heavey and slick ice from water applications.
    Mark Cummins

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    Hey cfire3,

    Yeah we have used it in sub zero weather, it can actually get pretty dangerous. The foam freezes, but then the water freezes underneath the foam - can be a slip hazard especially with snow and ice on the ground. The foam itself becomes crusty - almost like styrofoam, retty intresting when it freezes. The main use for our cafs is rural fires so our main water source is tanker. Running at the proper mix our 300 gallon tank can last a long time. The CAFS system is very resource friendly.

    Im a little confused about your improved traction comment, do you have a secret for turning the foam into traction?
    Dave

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    Dave, no secret to the foam traction except we sometimes use the old lignin soap from the paper mills as the foaming agent, it has some resin in it that makes a squeeky non-slip foam. But the frozen foam you mentioned is the same as I was refering to, particularly when we apply the foam to the black ice or glazed ice that is nearly impossible to even stand up on. This type of ice forms from water applications and is supper slick.

    We increase the concentrate ratio up to 1% and back the water volume down to create a really dry foam that does not drain any water before it freezes, this foam has a texture, like you said, crusty or heavy snow, for a demonstration; find an area of ice formed with water and cover half of it with foam to see which side is easier to walk on. The foamed side is like walking in snow but if you aren't careful you can bust your, But it's a great improvement over the untreated side.
    Mark Cummins

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    lol, I honestly have never even thought of using it for traction. I geuss we are used to the slippery ground aound here! None the less we will give it a try - just need it to freeze again! Do you guys use this often for traction for rigs or personell?

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    Originally posted by Dave404
    lol, I honestly have never even thought of using it for traction. I geuss we are used to the slippery ground aound here! None the less we will give it a try - just need it to freeze again!

    Do you guys use this often for traction for rigs or personell?

    Hahaha, the good news is, down here in Texas, we don't get a lot of super cold weather but the bad news is the dozen or two times it does get really cold, nobody knows how to behave in it. So yes, we do actually use the foam to allow us to move around a little better.

    I have heard of some snowland brothers that have added a colored food dye to the foam to mark the snow covered roadways and other buried things like hydrants, entrances and covered cars.

    I guess if we added some sugar to the stuff?????? well, maybe better not go there,,,
    Mark Cummins

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    Never heard of the coloring of snow either - then again we only get a couple of big dumps of snow a year - never had a problem finding a hydrant. Intresting solutions - thats thinking outside the box for you.
    What type of CAFS are you guys running? Ours is a dedicated CAFS truck. 3cyl diesel engine runs the pump and compressor. 300 gal water and 2 - 5gallon pails of foam, with 2 spares in other compartments. Truck is also equiped with rescue tools air/hydraulic cutter spreader combo, medical equipment, ventilation and a cascade bottle. Mounted on an F-550 4x4 chasis. Only a two seater and because its classed as a mini pump, it is backed up with a pump and tanker.
    Ill try to add a picture!

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    Try this!
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    Hello all,

    My experiences with CAFS as an interior attack have been good. Both for fire knockdown and heat absorption capabilities. The key to any interior attack is to meet or exceed the critical application rate for extinguishment of the fire. CAFS is a delivery system. The extinguishment and cooling happens as a result of the water that is applied. For those who say cooling is poor with CAFS attack, I can only conclude that you are not flowing enough water (GPM). Our 1 3/4" attack lines flow approximately 100 GPM with 30-35 CFM of air, using a straight bore 15/16” tip. This is around the 3:1 ratio. Water is the prime ingredient. The class "A" foam makes the water more efficient and the application of the water and class "A" foam with CAFS makes it "SUPER" efficient. Whether you are using plain water or CAFS the basic principles of firefighter are still applicable, "Big Fire, Big Water" and "Put the Wet Stuff on the Red Stuff". For those who are having cooling issues with their CAFS, try a "wetter" mixture. Less air, more water.

    As far a kinking goes, no problems. We run our main pump discharge pressure at 80 to 100PSI for 1 3/4" handlines. If you run at a lower PSI, Yes, it will kink. Also I have experienced more kinking issues with rubber jacketed fire hose. The cloth jacketed fire hose lines have not given us any kinking problems.

    As far as freezing and safety goes, CAFS when it freezes to the ground is safer to walk on the plain water. It sounds like frozen snow when you walk on it and traction is improved. “CRUNCH, CRUNCH, CRUNCH……”

    I say this all the time, training is the key to successful CAFS operations. Also using a good quality class "A", UL listed, environmentally friendly foam works the best.

    Hope this helps.

    Be safe,

    Captain Lou
    "GOT FAOM?"

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    Like Captlou stated

    You can't absorb heat without water. Our attack setting is 2:1 and we are still usting the 2 1/2" attack line on well off structures. The only problems that we have had are people changing over the that wonderful, shaving cream thick "tree flock" that is drier then Thanksgiving stuffing. We had guys apply this to a collapsed garage fire shortly after we took delivery while just starting the overhaul process. They couldn't figure out why they couldn't put the remaining fire and hotspots out as they had coated the *%$# out of this pile. Only after running out of concentrate and reverting back to plain water were they able to get the fire out. A great assest became useless when combined with the human error. When you use it right, the results are beyond impressive. Long story short, you have still got have lots of water and as always, wet(foamy stuff) on the red stuff!!!

    Ryan

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    [QUOTE]Originally posted by Tallyho74
    [B]Like Captlou stated

    You can't absorb heat without water. Our attack setting is 2:1 and we are still usting the 2 1/2" attack line on well off structures.


    Ryan, great comments. I'm interested in your use of the 2 1/2 hose for structure fires, please tell me what type and size nozzle you use for the discharge? And can you descibe the 2:1 setting? Is that 2 cf of air(14.96 gallons) to 1 gpm? Which would be approx. an expansion of 15 gallons of foam per gallon of water.

    What CFM volume compressor does your CAFS have? and What pressure do you operate the 2 1/2?
    Mark Cummins

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    No problem. We are using a Hale CAFSpro system. We have a 220cfm compressor mated to a 1750gpm Q-max pump. We are using 1 3/8" TFT pistol grip smooth bores for 1 3/4" and 2 1/2" lines. They told us 2:1 in user training was most effective. Our air control is set at "0.5" as the preset. The setting should provide us 2 gallons water per CFM air i.e. 200gpm water/100cfm through 2 1/2" attack line. We usually run the pump at around 105-115psi. We found that there is very little friction loss. Compensating for that was causing a tremendous amount of nozzle reaction. The following (hopefully)is a pic of our Rescue Engine.

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    second attempt
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    Now that's a beautiful ride. Not to mention a kick-ss capability. Thanks for the post.

    Would it be possible for you to post any pictures of your CAFS throwing the foam and describe the setings?

    I will try to do the same with a 1.5 hose using the pistol grip 1 3/8 smoothbore with no tip, Water- flowing 50 gpm @ 110 psi, Air- flowing 125 cfm @ 110 psi, concentrate set at .5%


    The Tolar creosote lumber mill fire called on every fire department in Hood County, there were 4 portable tank shuttle operations set up in the middle of the main highway and six engine crews fighting the fire for more than 4 hours. Then the call went out to Johnson County to send a CAFS unit from Joshua VFD.
    It took 30 minutes for the two CAFS hoses to completely extinguish the fire and stop the toxic smoke and polluted water run-off into the nearby creek. And the State paid $2,500 for the foam application because it was claimed to be a pollution reduction response.
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    Hi all,

    I have a question for Tallyho74.

    Based on your nozzle seletion. If you had 250' of 1 3/4" hose stretched, charged and flowing CAFS on an interior attack. Now, that guy "MURPHY" shows up and for whatever reasons your air compressor stops and/or your foam pump stops working. All you are left with is plain water. My question is, What is your game plan for this situation to protect the firefighters on the line and to continue the operation? Aagin I base this question on your statement that you are flowing straight out of the 1 3/8" open bale of the nozzle with no tip.

    Thanks for the help.

    Captain Lou
    "Got Foam?"

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    Originally posted by CaptLou
    Hi all,

    I have a question for Tallyho74.

    Based on your nozzle seletion. If you had 250' of 1 3/4" hose stretched, charged and flowing CAFS on an interior attack. Now, that guy "MURPHY" shows up and for whatever reasons your air compressor stops and/or your foam pump stops working. All you are left with is plain water. My question is, What is your game plan for this situation to protect the firefighters on the line and to continue the operation? Aagin I base this question on your statement that you are flowing straight out of the 1 3/8" open bale of the nozzle with no tip.

    Thanks for the help.

    Captain Lou
    "Got Foam?"


    I appologize for jumping in here but I get asked this question a lot too. It's a good question, and obviously the manufactures try their best to design a dependable unit, but "Murphy" does have his ways. Here's my solution, it's pretty simple, just partially close the full flow valve and the restriction creates a wide agle high velocity water spray pattern similar to a combo tip. The hose becomes twenty times heavier and the excess water starts runing out the front door just like the regular water applications do. Call for another tanker and look for a good hydrant.

    Mark Cummins

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    Cfire3 has it exactly right. Our First worker with the new system went everyway but smooth. Engineer forgot about the pressure issues with running an LDH into the pump and not through the tank fill valve. Pressure goes haywire causing lines to jump and sag. They put the air compressor into standby mode, lines charged with water and they began flowing over 185gpm through the smoothbore 1 3/4" attack line. We are using a TFT smoothbore pistol grip nozzle currently with 1 3/8" nozzle opening. This goes for 1 3/4 and 2 1/2" nozzles. They do a great job of breaking up the stream if you pull the bale 1/4-1/2 way closed. Now it's not a fog pattern persay, however it breaks the stream up and still projects out a tremendous amount of water. I guess I'm not sure what you meen by a tip? If we wanted, we could always screw an automatic nozzle onto the end of the smoothbore nozzle as it is threaded. I guess that could work, however I am not sure you would need it. The nozzles themselves came with reducer tips as well such as 1 1/8,15/16,3/4" and another I can't recall.

    Nozzle selection doesn't replace the need for knowledge about fire conditions and ultimately your surroundings. Many big city departments are still using smoothbore handlines with plain water. Do they work with murphys law as an SOG? Probably not, as they put out more fire in the case of some departments in a month then we might see in 5 years. It's just most of us, my department included were very hesitant to stray from the nice automatic nozzles that make fog-straight streams.

    Ryan
    Last edited by Tallyho74; 01-31-2005 at 09:25 AM.

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    Hi all,

    Tallyho74, I raised the question because CAFS as you know works best when flowed from a straight bore nozzle. My concern is when it is flowed as you do from a wide-open bale for interior fire attack. I understand that you can gate down to create a "fog" like pattern when forced to go back to plain water, however in the heat of battle this isn't always the case. I have found that simply using a little bit smaller straight bore tip instead of the wide "open bale" for attack you will still be able to maintain a good gpm CAFS flow rate without compromising safety. The thing that doesn't sit well with me is the wide-open 1 3/8" as the nozzle. The only time my department uses the wide-open bale is for exposure protection when we want a dry "shaving" cream type foam.

    Think about this, if you were to put a 15/16" or 1” tip on the 1 3/8” open bale nozzle, what exactly is happening at the nozzle? As the CAF flows down through the 15/16" tip from the 1 3/8" open bale the "bubbles" on the perimeter of the CAFS stream "POP". This then gives you a CAF stream of bubbles with a "wet" solution around the perimeter being carried to the target by that high energy CAFS line. It has worked very well for my department. On our 2 1/5” line we flow out of the open 1 3/8” bale. It is a “bear” to handle but the fire extinguishing power is incredible.

    Now when "MURPHY" shows up, and have to go back to plain water, you have a straight stream nozzle that only needs to operate at 50psi nozzle pressure. With 250' of 1 3/4" hose line the pump operator would have to increase pressure a little to compensate for friction loss, but the nozzle person would not have to do anything except still fight the fire.

    As far as the fog nozzle goes, automatic or adjustable fog nozzles work the WORST with CAFS. It strips or "POPS" all the bubbles that have been made. It does remove all the energy associated with a CAFS line however it reduces the firefighting effectiveness compared to the straight bore nozzle application. We do use a fog nozzle for overhaul. Since it pops the bubble and makes a "milk" like product, it runs into all the nooks and crannies to extinguish the fire. As you stated earlier a "dry" foam doesn't work very well for overhaul, as there is not enough water to drop out of the dry bubbles to extinguish a fire. And I will also add that during overhaul we are opening walls and ceilings in conjunction with the wet CAFS application.

    What I am trying to say with all of this is for safety sake I think a fire attack with just the 1 3/8" open bale doesn't put me into the comfort zone I would like to be in. Simply using a 15/16"or 1" tip will increase safety without compromising your fire attack capabilities. I would suggest trying it on the training grounds and see what you think. My department used to do fire attack from the 1 3/8" open bale and switched to a 15/16" tip many years ago. It has worked very well for us.

    Training and safety is the key to fireground success.

    Be Safe,

    Capt. Lou
    "Got Foam?"

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    Originally posted by CaptLou
    Hi all,

    My department used to do fire attack from the 1 3/8" open bale and switched to a 15/16" tip many years ago. It has worked very well for us.

    Training and safety is the key to fireground success.

    Be Safe,

    Capt. Lou
    "Got Foam?"

    Capt. Lou, Good post and it's good to know the 15/16 tip works well for your applications.

    The first CAFS units used by the wildland agencies used very small inexpensive compressors that gave great discharges with the 15/16 and 1 inch tips, it seems counter productive to throttle down the big units ability to provide a much wider range of foam applications. If you have an elephant gun why use the pea shooter?

    I like the fact that you use the tip to strip some of the air out of the foam to make a wetter discharge but the full flow valve will do the same by simply closing the bale a little or touching the foam stream with your gloved hand to creat a wide spread pattern.

    Have you tried to adjust the chemical ratio to make the foam release the water faster? Set at the minimum concentrate for the hardness of your water the foam will drain fast, so filling wall cavities with fluffy stuff breaks down at about the same rate the class A materials will absorb it. If you push too much foam into the hole in the wall it will pull the wall for you and also squirt out the light fixtures. Saves a lot of hard work and gets everything wet. Too much concentrate and the foam stays dry too long unless that's what you want it to do.
    Mark Cummins

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    Without getting into a entire discussion on the principles of CAFS, I thought the performance comes from the bubble structure. The more bubbles, the more surface area creating more fire knockdown power. We made the decision that if the product coming out of the 1 3/8" outlet - 1 3/4" attack line was ideal, why mess with it? When using the 2 1/2 nozzle with the 1 3/8" outlet, you are already creating quite a bit of breakdown on the stream from reducing it down. If breaking down the bubble structure reduces the effectiveness, my thought is why do it? It also goes back to the statement of water still puts out the fire, even in a CAFS stream. Adding the reducer or reducing your outlet only reduces the amount of water/CAFS/Foam solution you are discharging. As far as concentrate settings, we converted from 0.5 down to 0.3% after testing and not noticing much of a change in performance other then a slight reduction in costs.

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    Originally posted by Tallyho74
    If breaking down the bubble structure reduces the effectiveness, my thought is why do it?

    I think it's not reducing the effectiveness if you need to quickly change the FORM of the foam to a wetter condition to soak rather than blanket. You need both at different times.



    It also goes back to the statement of water still puts out the fire, even in a CAFS stream.

    You might think about water puts out flames and CAFS foam puts out the hot FUEL, that is underneath the charcoal, where the hot gases are coming from, that cause the flames. You waste a lot of water and a lot of time fighting the flames trying to absorb the heat faster than it's being made.



    Adding the reducer or reducing your outlet only reduces the amount of water/CAFS/Foam solution you are discharging.

    Actually the reducer doesn't reduce the amount of water or air, it only reduces the amout of expanded foam by stripping and accelerates the velocity of the discharge. An increase of concentrate can make the foam tuffer and better able to withstand the increased velocity, reducing the concentrate makes more of the foam break down.



    As far as concentrate settings, we converted from 0.5 down to 0.3% after testing and not noticing much of a change in performance other then a slight reduction in costs.

    The amount of concentrat can be a very important part of the behavior of the foam when applied to different surfaces. Minimum concentrate = fastests drain time, maximum concentrate = most durable and slowest drain time. There's need for the full range of adjustment.

    Guage your needs, a tuff long lasting blanket or a fragile fast draining foam? Do you want to cap it or soak it? or BOTH?


    Mark Cummins

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