Thread: PRO'S & CON'S LDH NEED HELP
01-16-2001, 07:44 AM #1esemans55Firehouse.com Guest
PRO'S & CON'S LDH NEED HELP
HELLO I'M FIRE CHIEF FROM A SMALL CO. LOOKING TO GO TO LDH. CAN SOMEONE HELP ME WITH PROS AND CONS OF 5" HOSE. RIGHT NOW WE HAVE 3" AND WORK WITH TANKERS,ARE DISTRICT IS GROWING AND GETTING HYDRANTS WITH OVER 1000 GPM. I"I'M LOOKING FOR AS MUCH INFO THAT I CAN GET TO SELL THIS PROGRAM TO OUR OLDER MEMBERS THAT DON'T SEE CHANGE IN FUTURE. THANKS IN ADVANCE. PLEASE BE SAFE OUT THERE!
01-16-2001, 12:36 PM #2M GFirehouse.com Guest
Its simple, more water, farther distances, more efficiently. Now trying to draw it as a picture for all to see is the challenge. People on here can give you some numbers and I think your chances of seeing some helpful replies are good. But dollars to donuts says you have buildings that have fire flows in the hundreds and thousands and your 3 inch wont do that unless you lay MULTIPLE lines.
The information presented herin is simply my opinion and does not represent the opinion or view of my employer(s) or any department/agency to which I belong.
01-16-2001, 10:20 PM #3RADFIREFirehouse.com Guest
I'm interested if the usage of the area growing. If it's commercial they should be sprinklered (residential would be nice also, but expensive).
5" is big water for a big fire and a long stay, because once down it's staying there.
It also can't be driven over once charged.
I like 5" as an option is very valuable, but first due on everything isn't a good strategy(in my opinion).
The more options you have, the better prepared you are, the safer you are.
Could you elaborate on your district?
01-17-2001, 12:11 AM #4FyredUpFirehouse.com Guest
If smoke and / or flames are showing why not lay the big line first in? Would you rather wait until it overwhelms you and then have second or third due companies bring in the big water and go right over you?
For flow comparisons:
3" with 2 1/2" couplings, 500gpm 500 feet is 100 psi of friction loss
Dual 3" lines 500gpm 500 feet 25 psi friction loss
Dual 3" lines 1000gpm 500 feet 100 psi friction loss
5" 500gpm 500 feet 10 psi of friction loss
5" 1000gpm 500 feet 40 psi of friction loss
5" 1500gpm 500 feet 90 psi of friction loss
5" 500gpm 1000 feet 20 psi friction loss
5" 1000gpm 1000 feet 80 psi friction loss
These are calculations and actual friction loss may be more or less depending on the hose brand.
If you are laying 3" hose and not supporting it with a pumper you are wasting your hydrants by not getting the max flow capable of your hose.
5" hose can eliminate the hydrant pumper and still move more water farther.
LDH and particularly 5 inch is the way to go to maximize water flow.
Take care and stay safe,
01-18-2001, 12:14 AM #5LFD2203Firehouse.com Guest
first, contact either a vendor or a neighboring dept. that will let you borrow 500 - 600 feet of 5". lay off your 3" (same length as however much 5" you have borrowed)as a supply line and flow all you can. next, put a pumper on the hydrant, push all you can to the pumper at the end of the line. lay out the 5", see how much you flow. you will more than likely see that you will get as much water out of the 5" supply line as you got out of the 3" pumped relay line. this translates into the capability to move as much, or more, water with one pumper and 5" hose as 2 pumpers and the 3" hose. now, compare the cost of the second pumper to the 5" hose, and call the hose vendor.......
01-24-2001, 10:40 PM #6tony pericFirehouse.com Guest
The only problem that I can see you having when you go with 5", is finding a spot in your station to store all your 3"!!No really though, we had a fire this A.M. laid 300' of 5". The intake gauge read 150 psi with two 13/4 lines flowing. Great stuff, the only real problem is this hose is the weight. It seems to weigh twice as much when its time to put back on the truck!! Good luck in your decision
01-27-2001, 09:24 PM #7JohnMFirehouse.com Guest
Greetings from Dover. I really didn't think LDH was such a great idea until I got a chance to use it and see how great it was. It was the biggest increase in firefighting capability that I have seen in my career. And what it did for us was to allow the first engine to just about max out the hydrant, by its self, with no engine pumping to you. Then the next engine can do the same from another source. It doubled our flow with the same amount of engines. And if really necessary, it can be driven over. We have done it many times, just stay away from the couplings! Of course we try not to make a habit of it. I think it is easier to rack. Once the hose is drained, drive the engine over or beside the LDH. Let the truck do the work, you just make the connections and hand it up to the hose bed. The low friction loss makes for real easy work for drivers also. And if you can get a gun in the future with a single 5" inlet, you get big water with almost no friction math for your driver. We do have a fair amount of spare 5" in the station, and I know we have loaned it out in the past for people to evaluate. I would imagine our Chief would loan you guys whatever you wanted if that would be of help. As far a cons, I don't have any! Good luck and hope you guys can get some big yellow!
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