Among one of the greatest, and most historic debates in the fire service is the use of smooth bore versus fog nozzles. What’s better and/or safer etc.? A byproduct of that debate is hose stream selection for fire attack. The question is, do you use a wide fog pattern, a narrow fog (a.k.a. power cone) or a straight (or solid) stream for offensive interior fire attack? Watch this video and form your own conclusions.
At a recent training burn, great video was taken of many different people making interior attacks on pretty hot room and contents fires (nice, hot, smoky and confined areas where victims like to wait for us). Jeff Kuehn, a firefighter and free-lance photographer created the video and provided great feedback on the conditions that he experienced as a “spectator” inside a room and contents fire.
Some points to ponder:
- During the video, pay particular attention to the knockdown time and visibility. In the first attack, visibility never really changes and knockdown is very quick.
- You should always check your stream shape either during charging (you have to bleed the air anyway) and/or before making entry into fire area.
- With a straight stream, cool the ceiling first, this will cool the upper atmosphere and help to limit steam production. Hitting the base first can “swirl” the thermal layering and push the heat to the floor (ask Jeff).
A special thanks to Jeff Kuehn for use of the video and for taking so many great pictures.
Check out more of Jeff’s stuff at www.jeffkuehn.com
FTM-PTB and Be Safe
Also on SAFE Firefighter …
- Tips for Advancing the Attack Line – August 5, 2010
- First Due Friday; Heavy Fire on 2 Floors (Videos) – January 27, 2012
- The What, Where & Why of the First Line – December 6, 2010
- Video- Detroit’s 9th Fire in One Hour! – October 2, 2011
Just a thought – there seems to be a recurrent topic among those who frontally oppose fog patterns, in that they generate too much steam, disturb the thermal layer etc. This is true if one applies a fog pattern the same way a straight stream is applied, which is what we see in the video. An effective fog pattern uses very short pulses, often less than one second, with pauses in between. A video of a proper application of the technique:
http://www.youtube.com/watch?v=gUSrS26vP1g
and another, this time with excellent annotations and slow-motion shots:
http://www.youtube.com/watch?v=9lspFz8J-lY
Nice one Boss. This really should not be a big deal anymore. With improved technology, the fog nozzle is better than ever. In straight stream, in the proper gallonage, it is easily the equal of the smoothbore. Sorry, it is. Good nozzle control relies on a good engine company doing thier job. Get well soon to Jeff Smith KCFD, 21 years on the Job and saves a life on his last day.
Mike, thanks a lot for the links, I added them to my YouTube favorites. There is no doubt that penciling to control the overhead, as demonstrated in both the videos, is extremely effective in controlling pre-flashover conditions in an interior, but defensive, manner.
In both linked videos, the FF are holding a position outside of the fire room, while in the demo video the attack was made from the interior. At some point, we have to go in the room to accomplish final extinguishment. Also, when attack a fire in an OCCUPIED DWELLING, the water application must be effective while also giving trapped occupants the best chance for survival.
Thanks again and please comment in the future.
Tim- fog nozzles are more than capable of producing terrific results. Like anything they are limited only by the training and experience of the user. In the video, the fire was in the same room and attacked with the same line from the same rig. YOU SEE THE DIFFERENCE. Thus making both of our points.
Thanks again and I look forward to future comments.
Jeff, I will have to disagree even though I am a smooth bore advocate. You should have showed the same camera angle (vantagepoint) to confirm your assumptions of thermal layer disruption. The second evolution the firefighter decided to wash the floor for a while in full fog, which is not the correct application method for your the combination nozzle to begin with. I agree with a few others, they are two different nozzles with two different application methods. I have seen alot of fire extinguished with the short bursts of water to create steam conversion with only 200 gallons of booster water used.
FETC also said…
Matt, the video depicts the difference between a properly used combination nozzle verse not, in a non-ventilated room and contents fire. The state in which the occupancy is, also depicts whether the application is correct or not.
The first evolution the firefighter is using a combo nozzle in the “Right to Fight” application mode. We run these on our engines and they will flow 200gpm at 75 tip pressure. The video demonstartes similiar characteristics of a smooth bore nozzle. The second evolution is a firefighter who opens the bale in the “Left for Life” mode, and decides to wash the super heated floor for a while. That improper and incorrect method alone would create un-wanted steam conversion.
I would have liked to see the same camera angle to compare the decreased vision, and thermal layer disruption.
FETC,
Thanks for the comments, they’re always appreciated.
Regarding the view, the videographer was sitting in the same position for both videos. The biggest difference was that the first Nozzle FF brought the line into the room (getting out the doorway/ chimney), while the second stayed in the doorway.
The visibility at the end of the first attack clip is how it stayed. The “blackout” at the end of the second was from the steam (no video editing or effects). The same nozzle was used for both attacks with very different results.
As a trainer, do you find that firefighters seem to only be trained at the certification level (i.e. this is a hose, this is a nozzles, wet goes on red)? There are a tremendous amount of nuances to our profession, little things that make a huge difference.
Dave Stacy said…
nice. I always thought there must be a reason why all of our attack lines are smooth-bores ; )
ok…smooth bore can create a “fog type” pattern. Bouncing the stream off the ceiling or angling the stream off the wall onto the ceiling creates “big ‘ol fat drops” of water that will cool down the “black fire” at the ceiling level. Water droplets go up and convert to steam and drop onto hot gases thus cooling them, with little to no thermal disturbance…just got out of a flashover can where this principle was applied…can’t deny the principle…by the way I have been a student of the game for nearly 20yrs
Good video but I do think that some video should be made using a fog pattern with a different application technic. I have been a training officer for over 20 years now and one of the hardest things that I have faced is good video on stream application. In a non-vented or even with some restricted ventilation I have trained firefighters to enter the room and sweep a medium fog not at the fire but strait up at the ceiling. This should be applied about as fast as you can without water hammer. Then stop, 3-4 seconds, and watch the fire. If the fire darkens down them you have control. If not then try a second application. If it does work, and most cases it will, then just sit there and watch the fire for a few seconds. Apply water in the same manner if the flames start to get brighter. Steam is as transparent as air and you should get some improved visibility at lower levels. By this time some type of ventilation should be in order and a direct attack on the remaining fire can be made. Done correctly you should have a few smoldering hot spots to extiquish and the arson investigators will praise you. Firefighters in the heat of battle tend to perceive 3-4 seconds into milliseconds, apply more water to fast, and the whole thing turns into a mess. The main idea is that steam goes around corners, into other rooms, into the attic, and continues to absorb heat and break the fire triangle. It the fire is cooled to fast then you loose the steam advantage of smothering and cooling. Now you are faced with only chasing and quenching all the way to the second floor attic!
Agreeing with Troy Scott, semi fog done right in the right application is not taught properly enough. I havent met alot of fires that behave as nicely as a training video fire especially one set up to prove a particular point. Automatic combination nozzles offer the advantage of what you need when you need it including fog protection in situations when a smooth bore will penetrate and that’s it.
Thanks for checking out the site and caring enough to give feedback.
There was NO AGENDA for the creation of this video. The video was created by a firefighter who was recording and photographing random operations during live fire training. He made an astute observation and created a “training moment” with a great soundtrack.
Though it’s title indicates “straight stream vs. fog”, the video really demonstrates someone who is mentally and physically prepared to do their job vs. someone who is not. Fire can be put out a straight stream, a fog, a water can or a sprinkler head for that matter. All applications have their time and place.
My question is, do you have the knowledge, skills and abilities to identify and evaluate the conditions and apply the correct tactic to accomplish an objective safely?
Thank you for your feedback. It’s always welcome and appreciated. Be SAFE.
Keep getting well, JEFF SMITH (KCFD).