Fog Tip vs Straight Tip Nozzles on Elevated Master Stream

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Permalink Reply by Bob Franklin on June 7, 2010 at 10:58pm

Hello Moe,
When using an elevated master stream there is a tremndou amount of heat being released from the structure. We used fog streams for over twenty years and after consideratable research, we found that the smoothbore tip gave us (1) better reach (2) least effected by wind (3) little evaporation from the radiated heat. The smoothbore produces the least wind enjected into the burning building. The fog nozzle is a broken stream of water and is greatly impacted by wind and evaporation. The reach deep into the fire is non existant. I have actually seen in my 39 years water evaporating from a 1000 gpm fog nozzle several feet from the involved structure from the radiate heat. The fog creates it wind effect and will actually pread the fire further into unburned areas, saw this happen at a shopping center fire. The aerial pipes actually pushed the fire into other stores in the complex. We have changed all our master streams to smoothbore tips. Make sure that you have stream shaper on your nozzle.

Take care,
BOB

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Permalink Reply by Michael Grcich on July 29, 2010 at 11:14am

Is the manufacture of the monitor or the truck that told your department they could not use stack tips?

Have you done actual reach and impact comparison test between the fog and smooth bore nozzles?

Bryan Aube said:

We have a fog nozzle and have found very few times when it wasnt on a straight stream. We cant change ours out to a straight tip per the manufacturer but it would have a smooth tip if we could. Our deck guns and ground monitors are all equipped with smooth tips. I dont see much use for a fog pattern other than for large exposure protection or as a makeshift decon shower. If you are using an aerial for a master stream you are gonna want the reach and the penetration of a straight stream.

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Permalink Reply by J. Phillip Strickland on September 12, 2010 at 11:35am

Master streams and forced air? I would like to hear your experiences about master streams forced air effects on fires. I am not against master streams but feel that we may be over looking a very important fact that is making our jobs harder and dollar losses go up.
Before two recent experiences I was in the normal Firefighter mindset on the use of master streams. When in doubt drown it out! I am not sure enough thought and research has been done on the amount air a master stream carries into a fire. Think of it like this, would you place a PPV fan on a working fire. No, because it would make it worse. Same with a master stream device; what the water don't or can't hit gets a breath of fresh air. How often have we used a hand line (mechanical ventilation) to clear a room of smoke? If we can push that much air with a 125gpm flow, how much air are we pushing with a 750 to 1000 gpm flow?
In viewing the videos of two recent fires in my area, where master streams were put in service early in the incident, I noticed evidence of fire enhancement from the forced air. In short where the water contacted the red stuff the fire went out. Watching the areas around the point of impact I noticed the fire taking on a torch effect. This practice in turn pushed the fire further into unburned territory with a vengeance. Since there was no fire stopping point created ahead of the fire, it was pushed throughout destroying the entire structure.
In the fire service we have learned the best way to minimize fire damage is to attack the fire from a direction that will not push it further into the structure. The same effect on the fire can be applied to the use of a master stream when used in the wrong way. What are your thoughts?

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Permalink Reply by Michael Bricault (ret) on September 12, 2010 at 1:12pm

-Like you Larry I prefer to have the straight tip stack of nozzles on the master stream, after all the whole point of a master stream is to put out a lot of water. The fog is an interesting appliance for a master stream but really nothing more than just interesting. Someone once told me that fog nozzles on master streams do nothing but cool the thermal column for pigeons.
-As someone that is assigned to a ladder truck I will strongly disagree with your advice of building and attaching ANYTHING to the tip of the ladder. If you want to change out the nozzle, though I can't imagine why, that should be done while the ladder is bedded.
-Changing anything in the air is needlessly dangerous to the firefighter and reckless. Not to mention that it is almost impossible to change out a master stream nozzle in the air. But, if the intent is to change out the nozzle on the ground than just carry the nozzle in one of the many, many compartments... it's what they're there for.
-Furthermore if the "box" is to be easily accessible to a firefighter it must be mounted to the inside of the ladder which will unnecessarily reduce the access way on the ladder and create snag hazards for those attempting to use the ladder as an access device. Our policy is to no longer mount ANYTHING to an aerial ladder, especially within the ladder-way itself. The top fly section is already narrow, don't make it worse.
-If you mount such a box to the outside of the ladder you change the scrub characteristic of the aerial itself as well as adding a permanent torsional load to the aerial which will be unnecessarily detrimental and dangerous over the service life of the aerial and will change the ladder performance characteristics when water is flowing.
-Moe, I suggest to you that you mount NOTHING to the ladder. Such ideas are afterthoughts and nothing more than design or tactical "band-aids" that will alter the ladder performance characteristics. Mounting a box to carry an appliance is a band-aid for poor firefighting. Do the job properly and you won't need the band-aid.
-ANY changing of nozzles should be done safely and deliberately while the ladder is bedded. If you need the master stream it is going to be at an event that is long and drawn out, requiring lots of water and supply and therefor there is no need for such extreme expeditiousness, the urgency for speed is past. Master stream operations are not like pulling cross lays... it is more akin to haz mat; slow down, we're going to be here for a while.

Larry Lasich said:

Keep the stack tip on, and build a box or clamp for the fog stream that is at the end of the ladder.
It depends on what you do. If you like the area effect or do exposure protection, stay with the fog.

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Permalink Reply by Larry Lasich on September 12, 2010 at 1:23pm

Michael Bricault said:

-Like you Larry I prefer to have the straight tip stack of nozzles on the master stream, after all the whole point of a master stream is to put out a lot of water. The fog is an interesting appliance for a master stream but really nothing more than just interesting. Someone once told me that fog nozzles on master streams do nothing but cool the thermal column for pigeons.
-As someone that is assigned to a ladder truck I will strongly disagree with your advice of building and attaching ANYTHING to the tip of the ladder. If you want to change out the nozzle, though I can't imagine why, that should be done while the ladder is bedded. -Changing anything in the air is needlessly dangerous to the firefighter and reckless. Not to mention that it is almost impossible to change out a master stream nozzle in the air. But, if the intent is to change out the nozzle on the ground than just carry the nozzle in one of the many, many compartments... it's what they're there for. -Furthermore if the "box" is to be easily accessible to a firefighter it must be mounted to the inside of the ladder which will unnecessarily reduce the access way on the ladder and create snag hazards for those attempting to use the ladder as an access device. Our policy is to no longer mount ANYTHING to an aerial ladder, especially within the ladder-way itself. The top fly section is already narrow, don't make it worse.
-If you mount such a box to the outside of the ladder you change the scrub characteristic of the aerial itself as well as adding a permanent torsional load to the aerial which will be unnecessarily detrimental and dangerous over the service life of the aerial and will change the ladder performance characteristics when water is flowing.
-Moe, I suggest to you that you mount NOTHING to the ladder. Such ideas are afterthoughts and nothing more than design or tactical "band-aids" that will alter the ladder performance characteristics. Mounting a box to carry an appliance is a band-aid for poor firefighting. Do the job properly and you won't need the band-aid.
-ANY changing of nozzles should be done safely and deliberately while the ladder is bedded. If you need the master stream it is going to be at an event that is long and drawn out, requiring lots of water and supply and therefor there is no need for such extreme expeditiousness, the urgency for speed is past. Master stream operations are not like pulling cross lays... it is more akin to haz mat; slow down, we're going to be here for a while.

Larry Lasich said:

Keep the stack tip on, and build a box or clamp for the fog stream that is at the end of the ladder.
It depends on what you do. If you like the area effect or do exposure protection, stay with the fog.

OK We have a bucket and we have: BA connections, piercing nozzle, pony line and a coupling grip that grabs a 4 inch female. The fog tip lives there now. It's not there for a speed change, it's there so that it doesn't get lost. As a rule, I won't put anyone in the bucket during a water flow operation (unless it's small amounts during an overhaul), so changes will occure while the ladder is bedded down. However, having the change out part in the location where it will be used seems smart to me.

PS. kuddos on your response of May 18.

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Permalink Reply by Michael Bricault (ret) on September 14, 2010 at 10:11am

-Ok... seems reasonable enough for a tower ladder. When I read the postings and responded it was not clear to me that we were discussing a tower unit. I was under the impression we were still talking about a straight stick aerial device and tailored the response as such. I will read your posting much more carefully in the future.

OK We have a bucket and we have: BA connections, piercing nozzle, pony line and a coupling grip that grabs a 4 inch female. The fog tip lives there now. It's not there for a speed change, it's there so that it doesn't get lost. As a rule, I won't put anyone in the bucket during a water flow operation (unless it's small amounts during an overhaul), so changes will occure while the ladder is bedded down. However, having the change out part in the location where it will be used seems smart to me.

PS. kuddos on your response of May 18.

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Permalink Reply by Bryan Aube on September 25, 2010 at 9:01pm

It was the manufacturer. When we ordered the truck our chief wanted to have both options and they stated the ladder would not accept stacked tips. We have not done the comparison testing either.

Michael Grcich said:

Is the manufacture of the monitor or the truck that told your department they could not use stack tips?

Have you done actual reach and impact comparison test between the fog and smooth bore nozzles?

Bryan Aube said:

We have a fog nozzle and have found very few times when it wasnt on a straight stream. We cant change ours out to a straight tip per the manufacturer but it would have a smooth tip if we could. Our deck guns and ground monitors are all equipped with smooth tips. I dont see much use for a fog pattern other than for large exposure protection or as a makeshift decon shower. If you are using an aerial for a master stream you are gonna want the reach and the penetration of a straight stream.

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Permalink Reply by Shareef Abdu Nur on November 16, 2010 at 11:46am

More coverage with a fog tip? yes, but more coverage with what? air with a few droplets of water? A Smoothbore tip provides more water with less operating pressure and with significantly more "punch" when and where you need it.
In all of the pictures and videos of elevated master streams 100's of feet in the air raining down a semi fog pattern onto a fire, how much water do you think is actually reaching the seat of the fire or the structure itself for that matter?

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