Those videos are great but I would like to see what the GPM is with a 1 3/4" line and a smooth bore nozzle with the 65 PSI and 40 PSI standpipe pressures only because our high rise packs are currently 1 3/4" with smooth bore nozzles. I am trying to convince our dept. to switch to 2 1/2" for high rise applications so it would be nice to be able to show proof that the 1 3/4" line is not overly effective even with a smooth bore nozzle in a high rise stand pipe application.
We use 1.75" and 2.50" high rise bundles 100' feet in length. Smooth bore nozzles are preferable to minimize pump pressures above ground. We recently began experimenting with the "Corona Role" configuration. I have to admit I love it. It deploys great with the 1.75 and just OK with the 2.50. What do you guys do?
I don't argue the value of 2 1/2 line or straight bore nozzels. I would like to see the GPM for the hose lines not the hydrant refilling the tank, that meter was inline with the hydrant. I don't question the outcome that you can flow more water out of a bigger hose with less restriction, but as it is set up there, you have compromised the integrity of the test. The videos make their point, the lower pressure of standpipes deserve a lower friction loss hose and nozzle combination. All our hi-rise packs are for long lays inside the local mall, or the one hospital that has 6 stories. Every department that services the area uses 13/4 with smooth bore nozzles. I have always said that we should be bringing 2 1/2 to the mall but no one wants to carry it. The first big fire inside that mall ought to change some minds.
Chris, I might be able to help you out with this.
Whenever you are doing flow tests it's common to put a GPM gauge on the intake side; instead of the discharge. Whatever is going out of the nozzle has to come in first. The tank valve is kept closed and when operating as such low pressures, many times the pump is not even engaged since even at idle it would create too high of a discharge pressure. The engine is used as a giant gate valve, depending on the pressures of your local water system. If you have the benefit of two flowmeters you could even go as far as placing one on the intake and one on the discharge and you would still get the same results. Usually there is a 3-5gpm margin of error between the two. There is no compromise to the tests.
Big fires or fires with big potential should have an ADULT line brought to the party. Try to keep convincing them about the benefits of large volumes of water so that first big fire inside isn't some firefighters last one. You'll get there eventually.
Great videos Mike! Our FD is still using 1 and 3/4 hose with 75 psi fog nozzles for hi-rise firefighting, and obviously this worries me. We've had some near misses in the past with hi-rise fires. I believe our fire chief is considering changing our hi-rise operations, and John Norman is giving a hi-rise firefighting seminar here in September. I would love to see us change over to 2 and 1/2 hose with smooth-bore nozzles for hi-rises. I've had this conviction for several years now, but these videos have convinced me even more.
Simple and to the point. What are some other useful articles on this subject? I'm building a case on this for our Battalions, they were raised on combo's and love the TFT! They are beginning to listen to us after a few significant fires in our first due that have been too much for our 1 3/4" lines. But I haven't swung too hard yet, I'm trying to get all the ducks lined up first. Your videos will help a lot!
We're using strictly TFT tips both the older 50 - 350 gpm and the smaller version in your video. We have some large buildings in our area, more all the time. Big boxes, a lot of 1 story high large area warehouse and multiple occupancies with vehicle bays. So my question isn't necessarily about high risess as much as it is about other sources on the nozzle debate. The videos provided an excellent clear cut, easy to see advantage for the smoothbore. Are there any other works that cover use in other applications like those mentioned above?
I'm advocating a more flexible approach on our rigs, with a combo tip and straight tip available for the company to choose per the size up vs. the set nozzle - choice already made. I'm also advocating the use of the 2 1/2" line on initial attack in such structures. I'm sold already. I'm looking for material to fortify my position.
Mike Walker said:
I'm not sure what you have and what you don't have but Dave McGrail's book on High Rises gives a fantastic explanation.
I am a strong advocate for smoothbore in box box scenarios. An odd approach may be to take the building construction path. Brannigan's Building Construction could be of help. More then once in the book he refers to instances where the larger water droplets provided by the SB can reach farther and help cool the steel trusses better.
You know my situation and my TFT connection, with that said we recently conducted a similar test after a fire pushed us down a hallway (due to department guideline we use the Elkhart Brass SM30 on our 1.75" cross lays, and the SM20 on our high-rise packs).
Common in our city are 3-5 story walk-up apartment complexes. Our high-rise packs are 100 ft of 2.0" line. We found that to operate on a 3rd floor fire - stretching 3.0" inch line to the landing and connecting the wye we were losing all of our water before it even reached us (we fixed only the major kinks in the line in an effort to maintain real world application).
We found some interesting facts regarding this scenario: 1st: Everyone of the engine drivers on the day of the test were all called in their firehouses and ask what they would pump this simulated fire at, utilizing a sm20 nozzle and then a 1.125" smoothbore. Sadly, and I don’t have the exact numbers in front of me, was that most drivers were just guessing, many of them stating they would just pump it at normal pressure and then let the nozzleman radio down if he needed more water. Lesson, our drivers need more and recurrent training.
2nd Lesson learned: was just how much friction loss we encountered before the water ever left the rear 3" discharge (up to 35psi loss) on our 2006 pierce dash. It is so easy to forget to account for the friction loss within the rig itself.
3rd lesson learned, and this day it was the most important...ALWAYS CAP THE UNUSED SIDE OF THE WYE! ....by the time the radio traffic was received by the engineer we had dumped between 200-300 gallons of water in the part of the building that, as the training chief's direct order spelled out, we were not to do any damage to. Opps, 3rd , 2nd, 1st floors, the basement, and elevator shafts all soaked...and with the exception of the elevators/basement, all were carpet. In addition guess who showed up less then 10 min after...
Without coming right and advocating one nozzle or the other, we must select the best tool for the job. Often Chiefs and city managers want the best bang for their buck and while that is not always a bad practice it isnt always the best practice either. I can force a door, vent a window, pull ceiling and vent a roof with a halligan but that doesn't make it the best tool for each one of those task.
As Rob said "the proof is in the puddin", sounds like its time to have a puddin' party at the U.
I have the data, videos and photos from our testing in my locker at the firehouse. I will post again when I get back to work with that information.
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