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4" vs 5" supply hose, which would you put on your truck?
I recently came in contact with a department that was looking to change from 5" LDH to 4" LDH, I Know that I work for a department that made the change in the opposite direction, saying that the one inch differece, was big to the extent of close to double the friction loss when moving big water. I would like to hear any other feed back from you all, so that when I debate with this desk commander, I can present a good case. I think they main objective is the weight and size of the hose when it is charged, which is in my opinion, most of the time when your needing a supply line its because you have a big enough fire that you need water, why not have alot of water.
Replies to This Discussion
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Permalink Reply by Jack/dt on
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I can't think of a better way to spend money than on something that ensures that you get the maximum water supply for your specific needs.
From here -
100ft 4" - $589 78lbs
100ft 5" - $679 97lbs.
Not sure either the weight or cost difference is 'significant'
We are decently hydranted and each engine carries 1200 ft. of 5" LDH. Once laid in, I have never seen a situation arise where the (charged) supply had to be moved. I only work on the smaller, 2" discharge side of water supply but I do trust that those in the position to decide what our operational needs are make their decisions with all due considerations.
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Permalink Reply by 55 TRUCK on
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The tragic out come of the Super sofa fire had nothing to do with there choice in supply lines.
Lack of communication,poor stratigy and tactics were what caused that outcome.
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Permalink Reply by Ben Waller on
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Read the Routley Commission and NIOSH reports. They do not agree with your opinion.
In fact, one of the first things that CFD changed in the aftermath of 6/18/07 was to upgrade their supply hose from 2.5 inch to 5 inch LDH.
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The larger the hose diameter, the lower the required pressure to move the same amount of water and the less chance there will be of unseating gaskets.
LDH spanner wrenches take care of most problems when breaking down Storz couplings.
With water supply being one of the most important things a FD does, on what higher priority would you spend the money?
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Virtually the same experience on my FD - we carry 1050 ft. of 5" LDH per engine and quint, plus additional 50ft and 25 ft sections in a compartment.
We rarely move a charged line, and generally only if it was laid where it blocks critical access for an aerial or ambulance egress. We train our drivers to lay the LDH in specific ways that maintain access for other vehicles, and we train everyone in getting major kinks out of the line prior to charging the hydrant.
As one of our previous Deputy Chiefs put it "No Anaconda Wrestling".
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The problem with that way of thinking is that when you are prepared only for small fires, those are the only fires you can extinguish.
When you are prepared for large fires, extinguishing the little ones is no problem.
If you have problems with the coupling locks, just get LDH spanner wrenches and use them.
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Permalink Reply by Don Catenacci on
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If water supply isn't part of strategy and tactics what is it?
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Permalink Reply by Mark W on
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I cant agree more with many of you, that the money can be spent on better things that might help the fire department be more effective. Im thinking putting a nice peice of gym equipment that those who bitch that the hose is too heavy can maybe put down the big mac and workout. Had to say it. cause it is getting bad when we cater to the bitchin...
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Permalink Reply by Ricky D. Weber on
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My F.P.D. uses 5" supply line as does some of the others around us.
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Here are links to the Routley Commission 1, Routley Commission 2, and NIOSH reports from the Charleston 9 incidents:
NIOSH report - http://www.cdc.gov/niosh/fire/reports/face200718.html
Routley Phase 1 Report - http://firechief.com/charlestonfirereport_1017073.pdf
Routley Phase 2 Report – http://downloads.pennnet.com/fe/misc/20080515charlestonreport.pdf
There are three bullets regarding water supply in the NIOSH report.
The Routley 1 report calls for an immediate upgrade to LDH.
The Routley 2 report has an entire appendix dedicated to showing that the 2.5 inch supply lines in use couldn't possibly supply the attack lines that were flowing.
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Permalink Reply by Scott Taylor on
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There are a few questions to be asked.
What's wrong with what you are using now? If you have a 1250 pump or larger, why restrict yourself to 1000 gal per min with 4"? A new pump rated at 1500 gpm may get you 1750 to 2000 gpm at draft and more on a plug.
Is there a general need in your area for big water?
Is there a hydrant system that can support 1250 to 2000 gal per min.
I hear most FFs complain about it"s harder to rack because it's too heavy. ( I say Suck it up!) Depending on who makes the ldh hose... 100' of 5" is only about 25 to 30 lbs heaver than 100' of 4". To move four or five inch after it's charged? you are still going to need a bunch of help.
Friction loss? In 4" your good up to 700 feet, then it increases quickly. Five inch allows for twice as much gpm than 4". With 5 inch I was able to supply 3 attack lines and a ladder pipe at the same time. (the ladder pipe was focused two towne houses down from where the handlines were being used and I had a new 1500gpm pump)
You would have to look at the pros and cons, but it sounds like it's gonna cost you money to switch and that may be a waiste of funds that could be used for TICs or other cool tools.
I suggest making a list of pros and cons for your presentation.
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Permalink Reply by Marc Hansen on
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Whats the water supply like? If their hydrants are only capable of flowing 1000gpm then why worry about larger flows. You can hit 1000 gpm with either LDH.
What does their mutual aid use? If they dont request or answer a lot of mutual aid calls this also becomes a moot point. However if they are frequent users and contributors of mutual aid then the affect on neighboring departments should be taken into account. If you switch to smaller LDH are you going to also buy all the adapters for your equipment to work with your neighbors or are you going to expect them to buy the adapters in order to come play with you? If you cant match up equipment with the neighbors, I'll bet the neighbors stop calling you for help. Budgets being what they are I bet the city fathers will wonder why they are paying the same money for fewer calls and will want to address that.
If you are funding this from a grant and just switching LDH to be able to use the grant may I suggest the next grant being for SCBA, TOG or RIT equipment. SCBA bottles go out of date and if all your bottles were bought from a previous grant at one one time all of your bottles will expire at the same time. Do all of your firefighters have 2 sets of TOG, does your department have a procedure for replacing or repairing damaged gear? Do your firefighters have personal bailout bags or does your department train and have the equipment for a RIT team?
If you have the extra money in your budget to just replace LDH supply hose because you can, I think the investment in personnel safety equipment or accountability would be a much better use of those funds.
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