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2 1/2 Inch attack line used for IA what do you think
Just getting some input the ups and downs of using a 2 1/2 inch line as a IA attack line would like all input. thanks
AZFIREFIGHTER
AZFIREFIGHTER
Replies to This Discussion
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Permalink Reply by Ben Waller on
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There you go again...please show us where I - or anyone else - declaired (sic) our opinions to be the word of God.
When you keep shouting "NEVER" and "USELESS, DANGEROUS, RIDICULOUS", that doesn't limit the context to your mental gymnastics about how WestPhilly or the FDNY does it.
When I cut-and-paste something you said verbatim, that's not misquoting you, no matter what mental gymnastics you attempt to apply.
And...in internet terms, when you post in UPPER CASE, you're shouting.
When you state that you will "NEVER" use 2.5 inch as an interior attack line, the underlying message is that it's OK to go to certain fights while intentionally undergunned. That attitude, not interior attacks with 2.5 inch lines, is the real "USELESS, DANGEROUS, RIDICULOUS" idea here.
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...and most of us understand that. Michael apparently does not.
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WestPhilly,
I agree completely, but I think we're spitting into the wind here...kind of like using a 1.5 inch attack line instead of a 2.5 inch line for an interior attack on a big box fire.
And, trust me, you have no problem communicating a coherent thought. There's only one person with communications difficulties here, and it's not the any member of the group that like having more than one tool in the tool box.
Ben
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Michael,
You are arguing two mutually exclusive thing here...
On one hand, you state that you see no reason to stick a nozzle on a 2.5, and elsewhere in the same conversation you state that 2.5 inch lines equal a master stream. Given that you can't use a 2.5 for a defensive (exterior) attack without a nozzle, that doesn't make sense.
Which is it?
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Michael,
A 400-foot 1.5 inch line creates friction loss as follows:
Using the C(Q squared)L formula, for 1.5 inch line C=24.
Let's be generous and say that you have a 120 GPM nozzle, so your Q is 1.2 squared.
That results in the friction loss being 24(1.44)4.
Working the math gives you 138.4 pounds of friction loss in a 400-foot 1.5 inch line. Add a typical 100 PSI nozzle, and you are pumping 238.4 PSI as the PDP just to get an adequate stream to the nozzle for a single line.
Compare that to a 2.5 inch line, where C=2.
Doing the math for a 400 foot line with a 250 GPM nozzle, you get 2(2.5 squared)4.
That works out to 2(6.25)4, which equals 50 PSI of friction loss for a 400-foot line. Add a 100 PSI for the nozzle, and you get 150 PSI for the PDP.
Given the science, moving an additional 100 GPM per company at almost 100 PSI less is a pretty good idea. Please explain how increasing the extinguishing power of a single line by nearly 50% is "USELESS, DANGEROUS, RIDICULOUS"?
Overpumping a 400-foot 1.5 inch line is a lot closer to "USELESS, DANGEROUS, RIDICULOUS" than is using 2.5 inch with a nozzle for the same hose stretch.
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My department generally uses 1.75 inch for interior attack, but for strip malls, big box fires, and other large, open structures we have the option to use 2.5 inch situationally.
"NEVER" is dogmatic, and we use risk-benefit assessments for our interior attacks, not dogma.
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Telling you that we think you're wrong isn't denying your right to have an opinion or to post it. It's just that we believe you are wrong.
You're absolutely right about one thing...you can indeed "...learn alot about people by just seeing how they respond to things on here." When you respond with statements like "NEVER" and "USELESS, DANGEROUS, RIDICULOUS", it's pretty easy to figure out what kind of responses you're going to get from people that can easily demonstrate that those statements simply are not accurate.
You can also learn a lot about FFN members by their efforts to persuade with logic, rationale, science, or practical examples. All you have is your opinion. The rest of us have provided logic, rationale, science, and practical examples in a variety of ways. You refuse to listen or consider that a non-dogmatic approach might be better than the "NEVER" dogma that you shout here. That does indeed tell the rest of us a lot.
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Permalink Reply by Larry Taggart on
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You know, you are all missing the point. 2 1/2" hose should be considered only another tool in the fire fighting arsenal, like 1 3/4", 1 1/2" and booster line. If you don't train with all the weapons at least once per month then you should adjust your schedule accordingly. With the advent of high volumn low pressure nozzles the job should be a little easier. You all do enough medical training I would hope the fire fighting has just as much of a proirty(sp). The fire service today seams to have trouble with heart attacks and poor driving. I see a lot of roll overs. That really should not happen, if the drivers are taught that straight line drivering is the only way to get to the scene, it may help.
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Permalink Reply by Robert Owens on
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Well if you were standing there and if you watched the videos I provided as proof then you would know just how valuable the 2 1/2 is as an interior line when an installer messed up the installation of the PRD's.
If you watched the videos you would see that even at 40 PSI the 2 1/2 still had a firefighting stream that was useful and your precious 1 3/4 or 1 1/2 hose did not even register on the flow meter. If thats not enough to convince you that the 2 1/2 has a place as an interior line in certain situations then you will never get it.
As for living with "absolutes" I know there is no such thing....thats why you have to be able to use all the tools in the box and pick the best one for the situation based on size up, occupancy type, and fire conditions...not based on what you feel more comfotable with or your own personal bias. Doing any thing other than this will only have a Teddy Bear affect on the fire.....sure youll feel good flowing that 1 1/2 in a big box store but the fire wont be impressed at all.
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Permalink Reply by Michael C. Harrison on
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Pay close attention to the words I am about to type, and maybe JUST MAYBE you will be able to understand this time.
1) I am NOT advocating (in other words I am NOT recommending) that any/all depts. use 1.5 inch line and not use 2.5 inch line as interior lines.....that would be even more asanine than the conversation you and I are having (if that is even humanly possible) because MOST depts. in the USA have a severe lack of manpower, along with a lack of water supply, and usually a long response area.....and therefore have very advanced fire conditions by the time they arrive with enough people and water to do anything.
I am stating that I won't use a 2.5 as an interior line, because if there is a need for that in the areas that I operate in, the fire will be a defensive operation,,,,,,and THAT is my input in this discussion.
There is a big difference between stating what YOU/I/WE do......and recommending/advising/advocating to others what THEY should do.........maybe you will now understand, maybe not.
2) I may be "just talking to myself in a public place" from the way it seems here sometimes........but then "myself" has made alot (oops...WestPhilly there it is again) of comments back to "myself".
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Ben, I stand by the way I/my depts. operate, we operate that way on a daily basis and have not had any major problems since the day I joined (and long before that) I can state examples (even though I have been branded a liar) I have no reason to set up scientific studys, and I have stated many times before......my rationale is that , the way we operate in this area is.....if a 2.5 is needed, then so are masterstreams......that works here.....has for a looong while, and will continue well into the forseeable future.
The only thing I have said about the ways others operate, their opinions ect. is that IF they operate differently ONLY because "So And So Dept. " operates that way....and thats why we do......I think (just my opinion) is sad.
If those same people/depts operate the same way as FDNY/Chicago/LA because it works for them.....I say more power to you/them......thats the smart way to do things (just my opinion again)....try them out, see if they work....modify them to suit your needs.
Just as there is equiptment that is carried on most engines/pumpers in the US that one of my depts. does not carry.....it works just fine for us......most other depts. would be BEYOND foolish to not carry it........IF asked my opinion on the subject, I would offer it....but would NEVER advocate or recommend to othrs to operate that way.
Just because I/we/my depts. operate one way , does not make the way others operate inferior (nor have I ever stated that)......I have stated what I will and or won't do......but if my location changed to where YOU (not meaning JUST you....meaning to other places/areas) are, many things would change.
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A lot of what you previously posted didn't make the distinctions you're making now.
If you were only discussing what you would personally do in the very limited circumstances you describe, and that these circumstances are so limited that you're not advocating that anyone else should use them, then why did you post anything on the topic at all?
How could a master communicator such as yourself miss such an obvious point?
Further, you haven't answered the question the TLP posed, nor did you describe anything about the structure types, response times, manpower, number of apparatus assigned on the first alarm, or any other variable that is pertinent to the discussion yet. Are you such a great communicator that we're supposed to read your mind and determine those variables?
The big perception mismatch here is that you continue to insist that you are not advocating for or against anything...while continuing to make absolutist statements without any kind of qualifier or description of the variables involved. Given the vast differences in the audience members here, if you don't include those qualifiers or the differences in variables, then the audience is understandably going to interpret what you say as advocacy for the things you always do and against the things you say you woud "NEVER" do.
In other words, your denials ring very, very hollow, given the content of many of your posts, especially the initial ones. Denial won't change the fact, and it won't likely change the perceptions of the audience, particularly given your continued insistance that your broad statements were intended very narrowly.
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