I am glad to see more departments at least giving their guys a choice (break-aparts with SB option) other than just "straight or fog patterns." While it is true that hydraulic ventilation can push up to 30,000 c.f.m. out the window, it is still a POST fire control concern. I like Steve's (Gillespie) point that the Nozzleman should only be concerned with putting the fire out. Do riflemen in the military worry about what caliber to set their M-4s to? So why are we still concerned about being able to change stream patterns. Smoothbore or straight stream should be the nationally accepted pattern (wonder if the NFPA would put a standard number to this!). Although break-aparts are a step in the right direction, why can't departments just switch to smoothbore and call it a day (cheaper and safer alternative). If "ventilation capability" is still a PRE control concern for you, realize that you can still push over 5000 c.f.m. (same as a smoke ejector) by "cracking"
open the bail with the tip removed on a smoothbore shut-off with a 180 gpm flow rate at the pump. You'll have flows in excess of 150 gpm and enough c.f.m. to put and push, respectively, the fire out. Unfortunately, NIST is rumored to be reheating the debate ("scientifically") on smoothbore vs. combination nozzles. I'll bet this is at the behest of nozzle manufacturers who are losing money because departments aren't buying their sales gimmicks anymore. Smoothbores are cheaper, have greater reach, and flow more g.p.m. What further research do we need?
Andy Fredericks (FDNY Squad 18, RIP) wrote a great series of articles in Fire Engineering some time ago that I believe was entitled "Little Drops of Water," which I found to be very enlightening on the debate between smooth bore and fog nozzles. I know it had a great deal to do with both increasing my knowledge on the subject, and converting me to an advocate of smooth bore nozzles.
We use 2" attack lines with low pressure automatic / break apart with 1" tip. We work in an industrial setting so we have to keep a fog handy and on straight stream unless the situation calls for something else. The 2" line gives us an upper hand on most situations . First line off flows 210gpm provides the knock down power of a small cannon. If more departments would flow test their attack lines ,most still using the fog would be suprised on what they are NOT getting.
We use a breakpart nozzle & low pressure design. The combination tip is 150gpm@50 psi, the slug tip is 15/16". We have no department policy on which is to be used, that is left to the company officer. My choice is simple. For vehicle fires and brush fires I use the combination tip anything to do with a structure fire the combination tip comes off and stays at the engine. All of our 2 1/2" lines use only 1 1/14" SB.
My career department uses adjustable gallonage fog nozzles and my volly department is going to all low pressure fog and smoothbore. The adjustable gallonage fogs are supposed to be set at 125gpm with no specification on the pattern. My engine sets them to 200gpm, straight stream and the chauffer pumps the same as he would for the 125 setting. In our testing we found this gives us 160gpm. We still have the issue of a complicated nozzle with potential for it being turned to another setting or on some of our break apart nozzles twisting the bumper to the right for straight stream and cutting off the flow, or at least reducing below an adequate amount for the fire.
My volly department is looking at the 15/16" SB for attack lines and keeping a couple of low pressure fogs around just in case. We are already running 1 1/8" SB on our 2 1/2" hoselines. Anyway, if any of you fog guys would like to purchase some fairly new fog nozzles, let me know.
I was taught the same thing about right to fight , but left for lobster. Protection from what? Yea, if you are on a LPG fire attacking the tank valve, i understand. If you commit your crew to the interior, your pattern should be of a straight stream pattern, no matter what type nozzle you are using. I have even heard of people teaching in flashover conditions, selecting the fog ppattern for survival. Where are the superheated gases, what temp. does water turn to steam? Okay 2'-3' out of the end of the nozzle all your water just vaporized as a fully developed fire is still progressing your way. I feel a straight stream, heavy hitting flow should be worked agressively over the fire area for the best chance of survival. TFT does have a good design until the end of the nozzle is melted, or drug across the street, or some other cause damages the formed teeth. This causes the replacement of the entire bumper instead of the small plastic ring. Oh yea, what are we talking about, do we even need these teeth?
In Wichita, the officer has a choice between a combination fog nozzle or a 15/16" smooth bore tip on the 1 3/4's . The 2 1/2 is equipped with a stacked 1 1/8 - 1 1/4 tip. Only about a quarter of the bosses in the city opt for the smooth bore for interior firefighting. The smooth bore is slowly gaining popularity as the SB nozzles are a still relatively new (6 years) addition to our engines.
In my company the standing order for the first line is the smooth bore nozzle.
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