Video Proof of the differences of 1 3/4", 2 1/2" , fog nozzle vs. Smoothbore. This should settle any arguement!

Replies to This Discussion

Permalink Reply by Ben Fleagle on July 10, 2009 at 10:15pm

Brother Roark,

I seem to remember a slight incident with you involved and a runaway gated wye. Anyway, in order not to digress, I will say that my interest is more along the avenue of large box fires. I do agree with you though, the math is needed to get the pressure to the floor and you cannot rely on a radio to make those pressures adequate.
As for the nozzles, I think TFT makes by far and away one of the highest quality combo tips, but I just don't like being trapped into one option. I started out in my career using Elkhart break away's, (don't remember the technical name), but we had a "bale" with replaceable tips. Gave you some choices. Here we have TFT's smootbore play pipes, but I'd like a selection for the smaller lines as well. Our real issue though, is trying to make the case for using 2 1/2" lines as attack lines vs. 1 3/4" with the TFT's at high pressure. That is where I'm trying to make headway.

IndianaFireNews-Brandon Roark said:

Brother Fleagle,

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.

Permalink Reply by Esteban Andrés Cabrera Rebolledo on September 8, 2009 at 9:35am

What is that????

Eric Myers said:

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?

Permalink Reply by Jeff Schwering on May 8, 2010 at 4:00pm

Mike and Brian, thanks, but, even with proof, some in our job will swear it was staged, fixed or the like.

Stay safe guys!
Jeff

Permalink Reply by Michael Bricault (ret) on September 23, 2010 at 1:02pm

-Something many firefighters forget/overlook or just plan do not understand is that the stand pipe is designed and engineered by fire protection experts to be used with and pumped/suppled for a 2 1/2" hose and a play pipe.
-Stand pipe systems are most often not designed for nor will they properly facilitate the PDP associated with an 1 3/4" and/or a fog nozzle. Coupled with stand pipe systems equipped with pressure reducers, the excessive pressures needed to properly operate an 1 3/4 and/or fog nozzles will many times damage the stand pipe system itself.
-Obviously the system engineer had something in mind when the fire protection system was designed and the responders need to understand this in order to utilize the system properly and safely.
-Lastly, hydraulics aside, those that still advocate employing an 1 3/4" with a fog nozzle have not taken into account the flex time in this operation.
-Flex time being the amount of time that is measured beginning when the company arrives on scene and stopping when the company has accomplished a definitive task; i.e. water flowing or a rescue is under way.
-The average flex time in a high rise operation is on the order of 8-10 minutes for an engine to get water flowing on the fire from the time of arrival. With that amount of time ticking off just to get water flowing... you'll want the extra punch that the 2 1/2" will deliver because many people just seem to overlook that the fire is getting bigger until you do something about it. Just arriving doesn't stop the forward progress or growth of the fire.

Permalink Reply by Pierre-Louis LAMBALLAIS on April 9, 2011 at 10:38am

Hi,

 

These videos proove absolutly nothing. Or, in fact they don't proove what you think they proove!

The difference you see between the fog nozzle and the solide bore, don't came from the fact you have a solide bore in one side and a fog nozzle on the other.

It came from the fact that the fog is an automatic one, which is the worst kind of nozzle you can find. But, it's not becausen it's a TFT. If you try with a POK automatic, you'll have the same result.

What' happening? Inside the automatic, there is a system trying to change the "out" pressure of the nozzle. If you lower the "in" pressure, this system try to increase the "out" pressure, by closing the flow rate system inside the nozzle.

So these nozzle can be used only if you are sure of the "in" pressure.

 

If you use a non-automatic nozzle (eg a TFT Quadrafod or and Akron or a POK and so...) you don't have this effect.

This bad effect is NOT linked the the fact it's a solide bore or a fog but due to the way the flow rate is set. We've tried by comparing TFT Quadrafog (selectable galonnage nozzle) vs a TFT Ultimatic and the Ultimatic sucks a lot. The worst think you can get, is when you connect an automatic nozzle and a selectable galonnage (or a fixed gallonage) nozzle, together, using a single hose line and a divisor: while having the automatic opened, wait a little, they open the "manual nozzle": you will see immediatly the automatic loosing it's flow rate.

 

For structural firefighting, NEVER use automatic nozzle.

 

After that, if you want, we can speak of slide bore vs fog nozzle.But this can't be with such a video.

 

Best regards

Piertre-Louis

 

Permalink Reply by Mike Walker on April 23, 2011 at 7:06am

I agree that automatic nozzles are problematic. In fact, I personnaly wish they were outlawed for the fact they are deceptive. It is difficult for the nozzleman to actually know the GPM of line because of the spring compensating for the pressure. Though to know the actual gpm is impossible with any nozzle selection, the nozzleman can tell if the stream is generally adequate with a smoothbore or constant gallonage fog. Unfortunately, too many departments have been lured by elequent salesmanship and slick presentations.

 

The main piont attempting to be communicated is to NEVER use an 1 3/4" or 2 1/2" with a fog nozzle from a standpipe when an active fire is brewing. A smoothbore will give a decent stream with as low as 45 psi. Even the best fog nozzles cannot achieve that. Also, the importance of using a 2 1/2" line, in case a very low pressure situation is encountered. If the 45 psi situation is encountered, the 2 1/2" with a smoothbore is more likely to achieve a positive result. As Michael brought up in a previous post, by NFPA the standpipes are specifically designed for the larger line with a smoothbore.

 

Remeber this is the HIGH RISE GROUP; meaning the tactics and tools discussed is that a HIGH-RISE fire is the basis for the discussions.

Damn my lying eyes! 

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