OK folks....I just completed a pump-ops class....and got drilled that smooth bores are the way to go....less nozzle reaction for the same or greater amount of water....So, what is everyone using...? and why...? I know we have task force/Fog nozzles but are currently going to smooth bores...thanks...look forward to your responses.....Paul
"less nozzle reaction for the same or greater amount of water" - hate to say it but it can be obtained by other combination fog nozzles, but many pump-op classes are lacking on the latest nozzle technology offered today.
We got away from TFT fog nozzles a long time ago. We have smooth bores as an option but we went to fixed gpm low psi combo nozzles, Akron's called the Chief's Nozzle. The combination is great for a manageable, low (NF) nozzle force tip and offers a great adjustable stream (straight-full fog) The tip only requires 75 PSI and our tip flows 175gpm. The internals are different than a automatic gallonage nozzle. They even have a 50 PSI / 250 GPM fog nozzle for the 2.5 attack line. There are many other nozzles on the market, like the vindicator is another great one.
Our pumpers have (5) preconnected 1.75 lines with 3 Chief Nozzles and 2 smooth bores, so the end user has a choice of tips (preconnected) Our pumps are spec'd with 5 preconnects for choice.
Smooth bore does offer great gpm for the low 50 PSI, but it does limit the end user to just a solid stream.
I'm happy to stick with our issued combination branches (nozzles to North America) thanks. I want the water, I leave the flow on maximum; I wan't less water when the fire has been knocked down, I wind the flow back; I need fog because everything is going pear-shaped, I go from jet to fog and get myself and my partner out.
Smooth bores are way "old school", that kinda got lost over the years but are being revived. Everything has it's pro's and con's. Smooth bores do have less nozzle reaction, and can deploy more water than a combination nozzle. Combination nozzles offer more versatility for changing conditions. But as Newton observed, the opposite reaction of a smooth bore is that, by increasing the volume of water output, means a decrease in pumping time unless you have an adequate water supply. Smooth bore nozzles do not upset the thermal balance in a room as a combination nozzle can resulting in less heat being brought down on the firefighters.
My department uses adjustable combination on our short (150') pre-connects, and automatic combination on the longer (250') pre-connects. The smooth bore is reserved for the 2 1/2'. The small size of our response district means we can usually catch the fire earlier and are able to make a quick stop with the combination nozzles. We also make a lot of trash and grass fires. Smooth bore nozzles are not the choice to use on grass fires.
So I would venture to say, it depends on your service area and the type of fires you make that should dictate which nozzle to use.
I hear you Brothers...As I said, looking for input...Who said "Too old to learn..?" I was doing a search and guess what....? FDNY is now running smoothbores on all their attack lines...they carry 1 Fog nozzle on each truck for "special purposes" is how they word it...We all learn from one another so I thought I would see what is out there...and hey, maybe give it a try....Thanks all for the input....Hope more is coming.....Paul
OOPS,,,excuse my misstatement....On their "Engines" or if you prefer on the "Pumper"...it was my mistake you see us country folks cannot afford the expense (in mampower or money) of having "truckies" we have to do it all with what we have....Sorry..........Paul
Smoothbores and the FDNY is not something new to them. But as it has been pointed out by some others about using a nozzle that fits your response district. I would like to add that due to the height and construction of the many, many structures in the city, the engine company does have an increased chance of operating in a very under ventilated environment. Hence the "pipeman" has one tool for the job, smooth bore, and it offers great extinguishment capabilities without the worries of thermal balance interuption or steaming multiple companies while operating in an under ventilated fire like a high rise.
Be cautious to completely removing fog or combo nozzles from your inventory. Every type of nozzle has its place.
You use FDNY as an example. Smooth bore nozzles are not a bad idea there due to the abundance of older construction methods. Type I, II, III and IV construction probably outweighs the Type V construction. Smooth bore nozzles are prided on their penetration capabilities. This is great if you are in a concrete floor and wall apartment building or a plaster and lathe row house. Not the brightest choice while operating in a newer constructed town home with lightweight construction and drywall. The pinpoint force of the stream a smooth bore produces can easily punch holes through this lightweight setup and push fires into unaffected areas. This will definitely have you playing catch up.
We have a mix of all types and configurations of construction in my area. From the one story rancher to the large multi occupancy warehouse and everything in between. We have combination nozzles and they have performed flawlessy for years. However, I do like using a small smooth bore tip for overhaul. does a good god tearing down drywall when you are kinda winded.
Not trying to preach, but the way to determine their effectiveness is to take a close look at the types of construction in your area. That's the best I can offer on this topic.
How is that a smooth bore will push holes through newly constructed properties??? "Pinpoint"? If that's a concern I would worry about the higher operating pressure required of an automatic or adjustible nozzle's 75-100psi doing that rather thana 50psi smooth bore stream.
This is an-going debate that will NEVER end. I guess it's not what you have, but how you use it? Personally I prefer options of both. Smooth bore certainly for larger sized handlines, such as the 2.5". Smooth bore nozzles are far less likely to malfunction or 'choke" from debris, which could be catasrophic. There is absolutely NO reason to use anything BUT a smooth bore for standpipe/high rise loads. That SHOULD be self-explanatary.
The real concern for modern construction should be the GPM's. Staffing is also a concern. Lower operating nozzle pressures are great for reduced staffing, but then you must consider the kinking problem as well. Adjustible nozzles are important for vapor dispersing. A one or two room fire with an agressive crew will be extinguished by either nozzle with relatively the same results. More important is how the hose is loaded, and how well the company is drilled in stretching and placing the line. But given my choice, anything beyond that one or two rooms involved, I personally will order the smooth bore 1.75", or the 2.5" with regards to certain situations. A 100psi operating pressure adjustible nozzle iserves no purpose on a 2.5" handline. Use of these nozzles on 2.5" s have resulted in the failure to pull the big line when clearly indicated in many cases.
However, obviously when making an interior attack, the nozzle will be on straight stream (at least here in the US). And there is clearly a difference in a straight stream vs. a smooth bore stream. Many departments have conducted their own research and experiements using both nozzles. I have found the best performance to come from a smooth bore nozzle, overall. 175gpm is 175gpm. But how it flows that 175gpm IS different, if even just marginal. In many cases, it's just almost immeasurable...and the fire goes out.
my dept uses fog nozzles and we have a combi-nozzle on each engine.the combi has proven itself effectice on multiple calls but not enough of our members fully understand their capabilities.when choosing between fog or smooth bore ill take the fog.fire attack and overhaul can both be handled by each nozzle but have you ever tried to hydraulically ventilate a smoke filled room with a smooth bore?
Probably the best answer is a break-apart nozzle like the Akron Assault series nozzles. We have standardized with two different types. The 1-3/4 nozzle is a 15/16 smooth bore with a pistol grip designed to flow 185 GPM. The fixed-gallonage combination tip is designed to flow 150 GPM. The operating pressure in both modes is 50 PSI.
The 2-1/2 version is a 1-1/8 smoothbore with a designed flow of 265 GPM. The thread-on combination tip is designed to flow at 250 GPM. The operating pressure is also 50 PSI.
Since we also have dual-agent foam (Class A, and alcohol-resistant Class B) we've found that the Class A gets much better fuel coverage in a 30-degree fog pattern. A slightly narrower pattern works best for Class B liquids. The nice thing is that the pump operator doesn't have to calculate different operating pressures and flows depending upon a choice between fog and solid streams.
And...solid streams can indeed punch holes in drywall ceilings, walls, etc. if the nozzle is close to the surface and the pressure is jacked up.