Thread: smooth bore vs. fog nozzles
11-07-1999, 09:53 AM #1Ronald KayFirehouse.com Guest
smooth bore vs. fog nozzles
Our engine house has quite a debate on the use of smooth bore vs. fog nozzles on our attack lines. All 3 shifts keep going back and forth on what nozzle to place on the engine for there shift. One shift puts on smooth bore for the day and another puts on fog. My question to all of you is What type nozzles do you use on your engines attack lines smooth or fog. And what are your pro's and con's in regards to the use of either type. I look forward to reading your reply's
Lt. R. Kay
Toledo, Ohio FD
11-07-1999, 10:22 AM #2Halligan84Firehouse.com Guest
This is bound to get ugly as usual! I'd put the nozzle with the highest flow and lowest nozzle reaction. That could be either depending on what you have.
11-07-1999, 10:32 AM #3FyredUpFirehouse.com Guest
Here we go again. The great nozzle debate.
I will try to just state a few points and hopefully not **** off everyone from either side.
My FD uses a break a part nozzle. It has a low pressure combination tip, 200GPM at 75PSI backed with a 1 1/4" slug tip. We use 2 inch hose, but the concept is still valid with 1 3/4" hose. The choice of whether to use fog or smooth bore is entirely up to the nozzle operator. They can spin off the fog tip and flow 325GPM with the smoothbore, or use the combo tip on either straight stream or fog at 200GPM.
I think you can make valid arguments for either nozzle. It is nice to have fog capability for some types of fires and for venting. I like the thought of the 50 PSI or less smoothbore for standpipe operations, as well as for interior attacks on large open type warehouse or barn type structures.
So for me, I say get break a part nozzles. With the combo tip and the smoothbore slug flowing whatever your standard GPM flow is and then everyone is happy.
Now I am ducking behind my computer desk because the battle has just begun!!!!!
Good Luck. On the bright side, your guys care enough about water flow to have an opinion and not just go whatever is there I'll use.
11-07-1999, 12:08 PM #4JimDWFDFirehouse.com Guest
My dept. uses smooth bore nozzles on our attack lines. A 7/8" tip on our 1 3/4" lines and a 1 1/4" tip on our 2 1/2" lines. This gives us 150 GPM and 300+ GPM for attack. The smooth bore gives us good volume and reach and it's easy for the nozzleman to control the tip because of low nozzle reaction. The biggest problem i've seen using a smooth bore is the hose can kink easily because of the lower pressure.
We do carry combination nozzles on our crosslays. We use crosslays for car and rubbish fires. We don't use them for structure fires.
My personal opinion, i'd take a smooth bore over a combination nozzle anytime when going in at a structure fire. Can't beat the flow, reach, or easy control of the tip.
The debate continues. Stay Safe
11-07-1999, 04:37 PM #5Dalmation90Firehouse.com Guest
Whatever works for you as long as everyone's on the same tactical playbook!
If you run all smoothbore, or use straight fog streams, and aggressive move to the seat of the fire, that works just fine.
If you run a direct fog attack to push the steam, smoke, and fire out a vent hole, fine!
If you go with an indirect fog to just hit the room, steam it up to displace remaining Oxygen, and close it up to stew in it's on steam a few minutes, then repeat, fine!
All three have their advantages and disadvantages, and all work well in different situations.
Go with what works well for you and your situation...just make sure the truckies and the hosers are all on the same game plan so ventilation and search tactics are compatible with how the fire is being attacked!
11-08-1999, 11:44 AM #6EPFD-ALFirehouse.com Guest
Lt. Ronald Kay, I had the same situation in my fire station back in the mid 70s when I was a professional firefighter at the Picatinny Arsenal (IAFF - Local F169) in Dover, NJ.
Platoon A liked Akron Brass Navy nozzles. Platoon B would switch to the Akron 60-95-125 gpm fog, and then Platoon C would go with a stacked tip smooth bore using 15/16 and 1/2 inch tips.
The only problems occurred when firefighters were recalled for major alarms, when we swapped shifts for one another, or covered someone's emergency sick leave. Firefighters use to using THEIR nozzle didn't like OURS and blah blah blah.
Someone asked the Chief to intervene; but he refused saying we had to work it out.
But, to answer your question about what kind of nozzle my department uses, why, and the pros and cons; all I can say is we have the break-a-part type. I love them, and FINALLY everybody's happy.
11-08-1999, 02:46 PM #7K AFirehouse.com Guest
All types, styles and brands of nozzles are successfully putting fire out fire somewhere.
It's the water, not the nozzle. Steam is a function of the nozzleman not the nozzle.
Funny thing our fathers and grand fathers brought us 1 3/4" and 2" hose and got away from smooth bores during the heavy fire 70's and 80's and went to automatic nozzles to solve a variety of water supply issues now the fire service in the non-fire 90's is moving to smooth bores.
Those water supply and pump operator issues have not gone away. Gramps and dad didn't have a problem holding a 1 3/4" line with a 100 psi TFT on a 150 feet long line at 200 to 220 psi edp. Why can't today's guys do it? All we hear is, "it is too hard to hold." Low pressure nozzles are just another way to say non-NFPA compliant. Explain to the jury when you get someone killed or injured using a non-approved nozzle.
Did it ever to occur to anyone the new nozzles are not new? They are simply a ploy by today's salesmen to replace perfectly good nozzles to a rather dumb (hydraulicly) fire service.
Fix flow fixed pressure were the original nozzles. A fix 200 gpm nozzle at 100 psi will flow 175 gpm at 75 psi or 140 gpm at 50 psi just like it always had. The stream won't look much different and the fire won't know you're using an old or new nozzle.
Don't throw out perfectly good nozzles and go to the new thing sold by the salesman. Your Turbo Jets, or Select o Flows will do everything and a lot more than the new fixed flow low pressure jobs on the market.
Your automatic nozzles will still do everything ever claimed of them...as long as your engineer knows what he is doing and will even do well if he doesn't, you can't say that about a fixed flow nozzle or smooth bore.
The ff's of the past also had preconnected hard suction that we've all gotten away from and are now going back to.
I bet there is not an engineer in the country who can pump three smooth bores with different tips on different lengths and diameters i\of line properly and safely at the same time.
11-08-1999, 02:48 PM #8K AFirehouse.com Guest
...All three have their advantages and disadvantages, and all work well in different situations. ...
A smooth bore will not do all three but a combination nozzle will.
11-08-1999, 04:21 PM #9InfernoFirehouse.com Guest
Reply is Below
[This message has been edited by Inferno (edited November 08, 1999).]
11-08-1999, 04:28 PM #10InfernoFirehouse.com Guest
I would go with a smooth bore any day! However, that would be for a structural situation only. They are great to put in a high rise pack (Automatic nozzles are the worst thing that you can put in a high rise pack. Low PSI loss due to increase in elevation = Low GPM) No matter what your PSI is with a smooth bore, you will always be flowing however much water is coming through that hose. In a structural fire, the smooth bore often cuts through the thermal balance, not disturbing it, thus increasing visibility for you and making a more livable breathing environment for any victims. With an indirect attack, the smooth bore uninterrupted the thermal balance and once it hits the ceiling, the water falls down on to the fire like rain, making less steam than a mist from a fog nozzle does. Or, if you want to make a mist with the smooth bore, open it slightly, and it makes a choppy pattern.
On the other hand, fog nozzles are better for most other situations. Maybe, if there are two preconnects in your hose bed, make one a fog nozzle, and one a smooth bore.
When In Doubt, Blitz It Out!
[This message has been edited by Inferno (edited November 08, 1999).]
11-08-1999, 06:47 PM #11SBrooksFirehouse.com Guest
Well here's my one main beef with smoothbores...stacked tips.
Never seen the point of these, they either never get used, or they mess up the pump calcuations. If you're going to hump a 2 1/2" line around, why bother with anything smaller than a 1 1/4" nozzle? I say if you're going to use a smoothbore, use ONE tip size per line size. That way you always know what pressure to pump per length. (or use preconnects with the proper pressure marked at the panel) something like this might work for you:
1" nozzle on 1 3/4" line, 50 pounds per 100';
1 1/8" nozzle on 2" line, 50 pounds per 100';
1 1/4" nozzle on 2 1/2" line, 20 pounds per 100';
So 250' 1 3/4" = 175 psi;
350' 1 3/4" = 225 psi;
300' 2" = 200 psi;
400' 2 1/2" = 130 psi.
easy math for made up lines, no math for preconnects. You could double check yourself with a flowmeter if you had one.
I believe Iowa-American (and probably others) makes smoothbore tips with female threads inside the outlet for you to screw a 1/2" overhaul tip into.
The company down the street from me has been using smoothbores pumped to 35psi tip pressure for years with no problems.
11-08-1999, 10:10 PM #12FyredUpFirehouse.com Guest
Our low pressure nozzles flow 230 Gpm at 100 psi how does this make them non-compliant?
Also, how do you make an automatic nozzle flow in a standpipe situation when the standpipe is pressure regulated to 45-65 psi? The whiz bang TFT that switches to low pressure still needs almost 75 psi to work. I was involved in a demo where a 100 foot section of 1 3/4" hose was hooked to a flow meter. A pressure switchable TFT was placed on the end. The pressure at the gated wye was 45 psi. In normal mode the TFT flowed 13 GPM, in low pressure mode the TFT flowed an incredible 14 GPM!! That's right switching to low pressure gained 1 GPM. A 15/16" smooth bore was then placed on the line, same hose, same pressure, it flowed 118 GPM and had about 30 feet of reach. What would I rather have? 14 GPM and about 70 feet of reach or 118 GPM and 30 feet of reach? Gee, I think that is a complete no brainer.
TFT makes a fine product, in fact the best automatic nozzle on the market, but it is not the answer for every situation.
By the way, Dad and Gramps fought fire with no SCBA, in rubber coats, and rode in open cabs. Should we do that too?
HEY KA, THANKS FOR THE HELP WITH MY ISO QUESTIONS. I believe that we kicked some serious butt. At least from the FD side. Now the waiting game begins.
[This message has been edited by FyredUp (edited November 08, 1999).]
11-08-1999, 11:01 PM #13DDFirehouse.com Guest
I like the idea of the solid bore slug with a removable combi tip. I hope to try it and the heavy attack "Vindicator" this winter.
11-09-1999, 01:08 AM #14RomaniaFirehouse.com Guest
I like break aparts! Best of both, each have applications.
Alan Romania, CEP
IAFF Local 3449
My Opinions do not reflect the opnions of the IAFF or Local 3449.
11-09-1999, 11:02 AM #15Scene25Firehouse.com Guest
I see the need for all of the above. But prefer a fog noz over the bore (TFT Pistol grip). And to really fire things up, why not use foam for structural firefighting. My station is in that debate now, and its getting ugly. But I will say all of the above.
11-09-1999, 12:57 PM #16e33Firehouse.com Guest
WE SHOULDNT BE TRYING TO COMPARE APPLES TO ORANGES. THERE IS NO ARGUMENT...EACH HAS ITS MERITS.(UNFORTUNATELY, THIS WILL BECOME ANOTHER BATTLEGROUND SOON...WAIT AND SEE).........CARRY ON
[This message has been edited by e33 (edited November 09, 1999).]
11-26-1999, 09:20 AM #17KEAFirehouse.com Guest
'Explain to the jury when you get someone killed or injured using a non-approved nozzle."
I would suggest that you read the current NFPA 1964 standard - 1998 edition. Nozzles are NOT required to be operated at 100psi.
The new standard now recognizes low pressure nozzles!
Also note that NFPA does not "approve" any products. They simply provide a standard which Manufactures may comply with.
[This message has been edited by KEA (edited November 26, 1999).]
12-05-1999, 11:40 AM #18Capt108Firehouse.com Guest
My department has a smoothbore on 1 preconnect on each vehicle. Each vehicle has 4 preconnects. The smoothbore is usually going to be the thirdline pulled. In my district it is mostly residential, with light commercial. The option is there for penetration, and visibility. I have been training with both. They both have there pro's and con's. It all comes back to training. Train your department to use them. Let them know when the right time to pull them is. They have to feel comfortable going in with them. Myself, feel smoothbore nozzles are not made for all fires, but when they go in make a world of difference if used correctly. Alot less steam, less heat and alot more visibility.
12-15-1999, 11:11 PM #19pvtcfd22Firehouse.com Guest
I am not convinced that the reach of a smooth-bore tip is greater; have read about tests that show the higher pressure will go farther. Having said that, I feel that they certainly have a place in the arsenal. I wish to have a selection to use at the proper time. The break-aparts seem to be the best of all worlds, although I have not had the oporunity to use one. The problem I do have is a training issue. If a firefighter sees a good looking stream from a TFT he may feel he is getting adequate flow. This may not be the case! And they may 'throttle-back' the handle to make it easier to handle, reducing necessary flows again. Also, interior ops in occupied buildings (including occupied by the ffs operating!) should be conducted with straight streams only until fire is knocked down, unless we want to punish ourselves and kill trapped occupants. What I would like to see is flow meters on all discharges as well as pressure gauges. This would improve fireground ops and for some reason is not the norm.
For a stand-pipe or high-rise op, I would certainly want the smooth bore option.
Bottom line is, like any other tool in the fire service, no one item fits all circumstances.
12-19-1999, 12:56 AM #20FletchFirehouse.com Guest
It seems to me that we have lost sight of why we deploy handlines and nozzles to begin with. That reason, quite simply put, is to extinguish the fire. Unfourtnately, we often forget the basic principles of fire attack. The length of the building multiplied by the width of the building divided by three equals the total required GPM of water for 100% involvement of the structure. A lesser degree of involvement requires the appropriate GPM percentage.
The second principle is to apply the water to the BASE OF THE FIRE. To date, I have been unable to find a recognized fire service publication that recommends applying water in a combination and/or indirect manner with a fog nozzle to extinguish the BASE OF THE FIRE.(If anyone is aware of such a publication, please let me know).
What line do we employ to deliver 250 gallons of water per minute to the base of the fire, which happens to be located on the second floor of the fire building about 300 feet from the engine? Keeping in mind that the fire has increased in size from the time that the determination of the required GPM took place and the time that the nozzle actually makes it to the fire floor.
How do we move this handline(2" or 2.5")to the second floor, search the building, throw up ground ladders and ventilate the structure; all with a four person engine company? I ask this question because since we insist on using a nozzle requiring a higher pressure, thereby making the mobility of the hoseline poor at best and the subsequent nozzle reaction more than two personnel can efficiently handle, we certainly won't be able to address some of the other kinda important tasks described above.
The answer, or at least my answer, is we deploy a handline and NOZZLE that allows two members of our company to arrive at the second floor flowing 250 gpm. A handline and nozzle that provides our personnel a higher degree of mobility which greatly increases their ability to move the handline and apply the water to the BASE OF THE FIRE. Therefore, effectively eliminating the primary problem that required our response in the first place. Extinguishing the fire certainly makes other fireground priorities much easier to handle.
My answer is a 2.5" handline with a 1 1/8" solid bore nozzle delivering 250 gpm with 39 psi friction loss, a additional 5 psi for the elevation change, a nozzle pressure of 50 psi, all adding up to a pump discharge pressure of 94 psi and a nozzle reaction of 100 psi. (As opposed to a 2.5 inch handline with a fog nozzle which requires 100 psi to operate AS DESIGNED. Add to that the 39 psi of friction loss for 300' of 2.5 inch hose, 5 psi for the elevation change, resulting in a pump discharge pressure of 144 psi and a nozzle reaction of 127 psi?) More work, effort and difficulty for the same flow? How are we doing?
Fog nozzles certainly have a place within the fire service. But, with very few exceptions, initial fire attack isn't one of them.
I have another question for the group. Why do the nozzle manufacturers insist on engineering an automatic nozzle that requires 100 psi to properly operate? Have you ever asked a nozzle company representative that question? The next time you have the opportunity, ask, you will be very surprised by the answer.
Of course, all of the following rambling diatribe is my opinion, I could be wrong.
12-19-1999, 10:26 AM #21FyredUpFirehouse.com Guest
All valid points, except for one thing. Low pressure combo nozzles, particularly the 250gpm at 50psi will do everything your smooth bore will and still give a fog pattern if needed.
Having said that, I like the smooth bore attack also. Even with our combos we use a straight stream attack at the base of the fire.
12-19-1999, 03:42 PM #22FletchFirehouse.com Guest
Ok, help me out here. There is a combination nozzle manufactured today that operates efficiently at 50 psi? I have practiced "underpumping" a combination nozzle (not automatic) to achieve a desired flow. (i.e pumping a 2.5 combo nozzle at 75 psi to acheive 185 gpm, thereby flowing at a lower pump discharge pressure and decreasing nozzle reaction.) Example: 300' of 2.5 inch hose flowing 185 gpm = a friction loss of 24 psi, add 75 for the nozzle pressure (flat terrain with no FL) = 99 psi for pump discharge pressure with a nozzle reaction of 70 psi. Not bad for a fog nozzle.
However, maybe I need to do more research and study if there is a combination nozzle on the market today that operates at maximum GPM at a lower psi.(less than 100 psi).
I guess I should have prefaced my first post by saying that I was one of those firefighters that used to grab a line and run in without doing the math. Unfourtunately, no one in the department (not my current department) was doing the math either. We were simply using the standard 5 & 10 method for determining friction loss and starting the PDP at 100 psi.(Automatic nozzles) The result was brought in clear focus one day when an outside instructor arrived to do an hydraulics class. We were flowing 47 gpm (established by a flow meter at the nozzle) on a 300', 1.75 preconnect. How were we doing?
This same instructor turned me onto
solid bore nozzles and doing the math. The result was a much better understanding of hydraulics and "bombings" of subsequent structure fires. We were making huge stops and extinguishing the fire. Go figure.
As I said before, fog nozzles certainly have their place in the service, but give me a solid bore nozzle and a competent AO and we will certainly go take care of business.
12-19-1999, 07:59 PM #23FyredUpFirehouse.com Guest
Yes there are low pressure combination nozzles. We use them. The ones we use are 200gpm at 75psi and 250gpm at 50psi.
If you want more info e-mail me, I am happy to share what I know with you.
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