In reference to “Building a Case for Implementing Smooth Bore Nozzles” by Todd Connors (Fire Engineering, February 2006), I can attest to the reluctance of many to change to solid bore nozzles. My department is a composite department with 23 career and 120 paid call firefighters. We cover 100 square miles and serve approximately 85,000 people. It has taken us about a year of testing various nozzles and hose configurations to get to the stage we are at nowwe have just ordered our first solid bore nozzles and lightweight hose for apartment packs. I firmly believe that as our crews use and get more familiar with the solid bore nozzles and their knockdown ability, they will choose solid bore each time for the aggressive interior attack.
We chose the 15/16-inch size tip. We found the 50-pounds per square inch (psi) operating pressure more realistic for inside buildings using standpipe operations, and we agree with the author’s findings that we could flow 180 gallons per minute at 50 psi. To flow 200 gallons per minute with our midrange turbo jets, we would need pump pressures higher than 200 psi, which is not practical in an apartment building fire. We have ordered lightweight hose, since we typically have small crews and deploying 2½-inch hoses is not practical if you don’t have the personnel. So, to get our flow rates up, for the exact reasons stated in the article, we decided on solid bore nozzles.
We have also chosen the option to add a fog tip to our solid bore nozzles. It gives us the ability to use hydraulic ventilation; also, we can use the adjustable gallonage feature of the fog nozzle to conserve water and prevent water damage, since we have a young keen core of paid call firefighters with limited experience. By switching to a 75-psi operating-pressure fog nozzle, the pump operator does not need to adjust pump pressures. I intend to have everyone in our department read Connors’ article; it is a comprehensive and detailed account of the value of having a solid bore nozzle vs. a “traditional” fog nozzle.
Mark Collins
Captain, Chilliwack Fire Department
British Columbia, Canada
Observations on chimney fires
In reference to “Extinguishing Chimney Fires” by Jonathan Riffe and Larry Patin (March 2008), I had several problems with the information. The first is that at no time in my 38 years in the fire service did I ever attack a chimney fire from the top down. The word “draft” was used several times in the article; this needs to be expounded on further. The natural draft of a chimney is from the inside of the house up the chimney and out the top; that is why it is called an “updraft.” With that in mind, it makes more sense to me if you take an ABC extinguisher into the house and fire it up the chimney. Let the natural vent process work and carry the extinguishing material up the chimney and extinguish the fire.
The other thing is the use of the chain to clean out the chimney. Since there was a fire in the chimney and the tile liner has been heated, the use of the chain inside banging around can break the tiles and add to the homeowner’s expense. Just letting the tile cool down normally, making sure that no fire spread has occurred, should be a sufficient safeguard for the fire department. Once the chimney has cooled and no fire spread has occurred, you can tell the homeowner not to use the fireplace until a certified chimney sweep has inspected the inside of the chimney, firebox, and venting system.
The same things hold true for a hood and duct system. Remember that if you operate the hood and duct extinguishing system, the entire system will fire. Not only will the duct heads go, but so will the surface protection. The first and last time I did that, I messed up a Chinese restaurant. The owner was standing next to me when I turned on the system. The only thing he said was, “Aw, shoot.” I was a young officer at the time and really messed up the poor fellow’s place. If you operate the hood and duct extinguishing system, make sure you need to.
Lawrence Taggart
Shift Commander (Ret.)
LaGrange (IL) Fire Department
Jonathan Riffe and Larry Patin respond:Lawrence Taggart’s comments have some merit. The term “draft” probably did deserve more explanation. A typical chimney works on the principle of hot air rising. As the hot air (such as the by-product of burning wood) rises in the chimney, it creates a pressure difference and draws cooler air at the bottom. Simply put, cool air is pulled into the chimney, is heated, and expands. The heated air occupies more space than the cool air. So as it moves upward, it does so at a higher pressure than air outside the chimney, which is what causes the cooler air to be drawn into the chimney.
Taggart’s comments illustrate another point. Although we generally adhere to the same basic principles of firefighting, there are a vast number of regional differences in operations. The departments in our area for the most part fight chimney fires the way we detailed in the article. We generally do not discharge fire extinguishers in the bottom opening of the chimney, and we do not wait until the chimney is cool to examine for damage. We do fight them from the top and bottom and use the chimney “bombs” as described. These bombs do not “explode” until they hit bottom. When they do explode, the contents draft upward, extinguishing the fire in the process. I think we agree on the use of extinguishing agents. How we use them is probably more regional.
The writer also commented on the use of chains and damaging the liner. In the 28 years I have been on a number of chimney fires, I do not recall an operation where the liner was damaged by the chain. The chain and attached weight are not used like a wrecking ball, and an officer should supervise the operation. Additionally, as we know, the extinguishing powder is not always 100 percent effective in extinguishing a chimney fire. The chain and attached weight support the chimney bombs by knocking the burning creosote off the liner. Many times, the creosote is so thick that the firefighter has to use the chain and attached weight to ensure that the fire has been effectively extinguished. More importantly, if the lining is cracked behind the creosote, it is mandatory to remove the creosote to prevent fire spread into the walls or attic.
In our department, we do not have time to sit around and wait for the chimney to cool. Additionally, how can we be so sure that the chimney is cool? I wouldn’t want to give that opinion to the homeowner. It may appear that the outside of the creosote is cool; however, that may not be the case throughout the several inches of creosote attached to the lining.
We did not mention a hood and duct system in our article; that is a completely different type of response.
More emphasis on prevention
I read both the print and Web versions of Fire Engineering. I also attended FDIC this past year. One thing that continues to be a systemic problem in the fire service is how much lip service is paid to prevention. I often have great difficulty in finding prevention topics in Fire Engineering. If the magazine is for the department leadership, shouldn’t more emphasis be placed on prevention? To paraphrase Chief (Ret.) Alan Brunacini, Phoenix (AZ) Fire Department, “Suppression means we have already lost.”
Ronald Campbell
Deputy Fire Marshal/
Fire Prevention Coordinator
Raleigh, North Carolina
Technical Editor Glenn P. Corbett responds:As our former editor, the late Tom Brennan, pointed out many years ago, Fire Engineering has expended a large amount of ink on the topic of fire prevention. Your point is well taken; however, we can’t print what we don’t have. We encourage our readers to submit timely and thought-provoking fire prevention articles for consideration.
