Pump Operations with hydrants on 48 inch water mains

jlab

jlab

Joined
May 10, 2019
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When a hydrant connected to a 48 inch main is available, and the fire condition demands maximum water, how does the pump operator maximize use of the available water since the hydrants (red with 48 main size) still have only the one 4 1/2 inch steamer connection and one 2 1/2 inch connection ?
 
A pumper can use a 35ft yellow on the 4.5 and a gated 2.5in or 3in length on the 2.5 connection at the same time for max volume. A single pumper is limited as to how much water it can put out- 2000 gpm. The idea is to have more than one pumper connected to that 48in main.
 
scoobyd said:
A pumper can use a 35ft yellow on the 4.5 and a gated 2.5in or 3in length on the 2.5 connection at the same time for max volume. A single pumper is limited as to how much water it can put out- 2000 gpm. The idea is to have more than one pumper connected to that 48in main.
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On a main that size with 60 psi, a 2000 GPM pumper can pump 2500 to 2700 GPM albeit without a discharge pressure of more than about 100 psi. However, putting another engine or two along side it can take the volume and pressurize it. Also, you can tandem pump, which is two engines side by side and the second engine using a hard suction to take excess water from the first engine by connecting to the steamer connection on the first engine. There are several ways to do this but that size main with a 60+ psi pressure can easily allow 5000-6000 GPM from a single hydrant utilizing several engines with 6” lines coming off all the hydrants discharge outlets. 2.5 X 4.5/5”/6” adapters. Read Paul Shapiros “ laying the big lines”. I have gotten 2200 GPM out of a single engine with a 1500 pump on a great main. Remember a pump GPM is rated from a draft not a pressurized source .
 
Capttomo said:
On a main that size with 60 psi, a 2000 GPM pumper can pump 2500 to 2700 GPM albeit without a discharge pressure of more than about 100 psi. However, putting another engine or two along side it can take the volume and pressurize it. Also, you can tandem pump, which is two engines side by side and the second engine using a hard suction to take excess water from the first engine by connecting to the steamer connection on the first engine. There are several ways to do this but that size main with a 60+ psi pressure can easily allow 5000-6000 GPM from a single hydrant utilizing several engines with 6” lines coming off all the hydrants discharge outlets. 2.5 X 4.5/5”/6” adapters. Read Paul Shapiros “ laying the big lines”. I have gotten 2200 GPM out of a single engine with a 1500 pump on a great main. Remember a pump GPM is rated from a draft not a pressurized source .
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I am familiar with everything you speak of. I remember doing all those evolutions in pump school! I will admit that it would take a lot more brainpower than I have to remember how to do it and pull it off!
 
We don't have mains that large where I am from!! Biggest main around here is 12". But I was always told that if you hook up to a hydrant with a hard suction (most engines don't carry true hard suction hose anymore) you could steal water from the next pumper using ldh, etc. Never got a chance to try it but it seems logical.
 
Spanner said:
We don't have mains that large where I am from!! Biggest main around here is 12". But I was always told that if you hook up to a hydrant with a hard suction (most engines don't carry true hard suction hose anymore) you could steal water from the next pumper using ldh, etc. Never got a chance to try it but it seems logical.
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So I was always told true hard suction for drafting would come apart on a pressure hydrant, we did it with a 60psi hydrant and it indeed came apart. It was suction hose that drafted just fine as well.
 
Sfdc111 said:
So I was always told true hard suction for drafting would come apart on a pressure hydrant, we did it with a 60psi hydrant and it indeed came apart. It was suction hose that drafted just fine as well.
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I've seen true hard suction, in the sense that it looks and functions as hard suction, that has been rated to take pressure as well. If I remember correctly, it was super expensive.
 
Capttomo said:
On a main that size with 60 psi, a 2000 GPM pumper can pump 2500 to 2700 GPM albeit without a discharge pressure of more than about 100 psi. However, putting another engine or two along side it can take the volume and pressurize it. Also, you can tandem pump, which is two engines side by side and the second engine using a hard suction to take excess water from the first engine by connecting to the steamer connection on the first engine. There are several ways to do this but that size main with a 60+ psi pressure can easily allow 5000-6000 GPM from a single hydrant utilizing several engines with 6” lines coming off all the hydrants discharge outlets. 2.5 X 4.5/5”/6” adapters. Read Paul Shapiros “ laying the big lines”. I have gotten 2200 GPM out of a single engine with a 1500 pump on a great main. Remember a pump GPM is rated from a draft not a pressurized source .
Click to expand...
Thanks for the response. I wonder why they just don't use hydrants on those large mains with 2 or 3 steamer connections to take the volume ? Would connecting the new super pumper to a hydrant on a 48 inch main wiht 60 psi would be quicker than hooking up two pumpers in parallel or tandem as you describe above ?
 
Bulldog said:
I believe that ISO still requires hard suction and engine companies. Not that all areas Req it however.
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ISO and NFPA actually give you a choice. In most cases, the verbage is identical for most specs or requirements. Last time I looked it read either 2 10 foot lengths of hard suction or 1 20 foot length of soft supply line on engines. My dept did away with the hard suction years ago, since we carry 1200 feet of 5 inch, and a 50 foot length of 5 inch under the passenger side intake, and humat valves. Only time we ever did take them off the truck was the yearly pump tests. Polk County which is the county my city is in, on the other hand, still rely on tenders (tankers) on occasion so they carry both 6 inch hard suction and ldh, and 3 inch on their tankers.
 
The 48" and 72" mains are more for DEP with distribution then it is for firefighting. In regards to the hard suction, yes, you can "steal" water, especially on a smaller main only being fed from one direction or if multiple engines are connected to the main. I have seen it happen.
Back when only the satellites had 2000 gpm pumpers, and a 48 or 72 inch hydrant was available, those where preferred for them.
 
Back when I retired from the job engine companies in Philadelphia responding on the second or greater alarm were required to use the hard suction when making their hydrant connection.
 
XPFD3 said:
Back when I retired from the job engine companies in Philadelphia responding on the second or greater alarm were required to use the hard suction when making their hydrant connection.
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The same rule applied in the FDNY ...not sure if it's still in the books today ?
 
I have operated on both ends of the water supply spectrum. hot hydrants where the engine was a glorified manifold wagon up to my current where we have so few hydrants that we seldom if never have one to hit so we must draft and or shuttle. Water does make the fire go out!
 
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