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Interior firefighting

Our service uses combination branches on our hose lines, and has done for many years. I have been interested in the discussions about smooth bore v combination and have read a number of articles and viewed a number of training videos about the differences. It seems apparent that there are a number of advantages with solid streams, especially for a direct fire attack. Having had no practical experience with this type of nozzle (other than putting the combination onto a straight stream now and then), I have one nagging question regarding their suitability for interior firefighting. As a fire moves from the room of origin via overhead gases (convection) and travels to other areas within the structure, firefighters are often met having to deal with these superheated gases. Frequently a "roll over" condition exists, making advancing to the fire room hazardous, and flashover imminent. With our combination branches we have the spray pattern set on about 30 degrees and cool the overhead gases with controlled application (not too much water so as to overly disturb the thermal layers causing excessive steam) above and in front of us. The droplets of the spray absorb large amounts of heat as they covert to steam (the point at which water aborbs most heat). Water does not generally come into contact with the structure itself, and is just dealing with the gases. I have done this often in live fire training and at working jobs, and it has the effect of chasing the flames back into the room. Advancement can then be made to the fire room, where a direct attack with narrow spray can be made to extinguish the fire. This scenario most often occurs in hallways while moving down to the fire room in a house or apartment block. I can not imagine the smooth bore nozzle effectively achieving dealing with overhead rollover, although I'm sure it does. I'm interested to know how those of you with smooth bores deal with this situation. Are there any videos that demonstrate this, and do you think that the solid stream is as effective on overhead gas cooling? I'm not for one second doubting their effectiveness in these situations, but just have no experience with them and am very interested in finding out.

Regards

Michael D

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Permalink Reply by Jerry Calabrese on September 10, 2009 at 2:54pm

I don't think the deabate over a smooth bore versus a combination nozzle will ever end. There a lot of different opinions. We personnally like the combination nozzle because it let us be more flexible. Straight stream for direct fire attack, a fog pattern for hydraulic ventilation or when applying water into a closed space - such as an attic.

The smooth bore does operate at a lower nozzle pressure which make it a little easier to manuver but the down side is that hose lines will kink easier then with higher pressure comination nozzles.

My best suggestion to you is to go out and try both to see what works best for your department. What may work very well for us may not be practical for your application.

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Permalink Reply by Greg Wyant on September 10, 2009 at 11:51pm

Brother read what ever you can find written by The Late Great Lt Andrew A Fredericks FDNY 9/11/01 he also made some good videos you will find these on this site and firenuggets.com STAY SAFE

Jerry Calabrese said:

I don't think the deabate over a smooth bore versus a combination nozzle will ever end. There a lot of different opinions. We personnally like the combination nozzle because it let us be more flexible. Straight stream for direct fire attack, a fog pattern for hydraulic ventilation or when applying water into a closed space - such as an attic.

The smooth bore does operate at a lower nozzle pressure which make it a little easier to manuver but the down side is that hose lines will kink easier then with higher pressure comination nozzles.

My best suggestion to you is to go out and try both to see what works best for your department. What may work very well for us may not be practical for your application.

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