Inspecting a restaurant
This is in reference to Glenn P. Corbett’s excellent article “So You Have to Inspect ellipse A Restaurant” (Fire Prevention Bureau, Fire Engineering, April 2000).
One of the items in the article intrigued me because I was not aware of it until I read the article. Corbett stated, “Fusible links must be replaced annually; no cleaning is permitted.” I was not clear if he was quoting from NFPA 96 or speaking from his knowledge and experience. My question is, Why is it necessary to replace fusible links annually? Is it a combination of factors such as contamination of heat, grease, and so on, creating a problem for the fusible links’ effectiveness, or is it a limited life cycle that reduces the links’ effectiveness or stability?
I would really appreciate as much information as possible on this subject, since our California Automatic Alarm Association sponsors and provides training for AHJs on a regular basis, and this kind of information would be helpful as a part of that training.
H. Wayne Boyd
President
U.S. Safety & Engineering Corp.
Sacramento, CA
Glenn Corbett responds: A look at most model codes and standards shows the “link replacement” requirement has been in place for several years. This requirement was apparently put in place because of the great difficulty in properly cleaning grease from the link; it also is an assurance that a clean link will be put in place at least annually. One such code, however, allows for links to be “maintained to ensure proper operation of the system”-whatever that means! My suggestion: If the code is not clear, replace the link. They’re cheap enough!
Glenn Corbett’s article reminded me of a story from long ago, probably circa 1954, when I was employed by the former New York Fire Insurance Rating Organization, now ISO. One of my fellow inspectors told me of a diner he had inspected several times, over a period of as many years. At his then most recent visit, he had taken a quick look around the outside and then went in to talk to the owner. A conversation somewhat as follows ensued:
Inspector: “How many times have I told you to change the stove and oven vent where it exits the building just barely beyond the outside wall?”
Owner: “Yeah, yeah, yeah, you’re always bugging me about that. I’ve never had any problem with it, and maybe sometime I’ll do something about it.”
Inspector: “Well, may I suggest that you call your fire department, because the outside wall and the eaves above that vent are on fire right now!”
By the way, I have enjoyed and learned much from Fire Engineering since I first subscribed around January 1947. I do remember that the first issue I received after subscribing featured the Winecoff Hotel Fire of December 7, 1946. Keep up the good work!
I am 76 years old and still an active member of my present department, although restricted to outside work as a Class “C” firefighter and “unofficial” safety officer.
Stuart M. Dean, P.E.
Altamont, NY
Smoke detectors and life safety
William F. Crapo’s article “Smoke Detectors and Life Safety” (May 2000) was quite interesting, and I appreciate the thought and sophistication that went into his analysis. I’d like to comment on a few of his points.
First, you really can’t tell the impact of smoke detectors-or any other fire safety program-from trends in total home fires and associated deaths. That’s because those numbers reflect the net effect of many different developments in fire hazard and fire safety, some favorable and some not so favorable.
Second, Crapo is right that households without smoke detectors tend to have a higher preexisting risk than those with smoke detectors and that not incorporating those differences will tend to overstate the estimated impact of detectors. However, a case can be made that the difference in preexisting risk is not that large. Not only is the overall share of households with detectors very high, but so is the share for every group we know to be a high-risk group for fatal home fires-e.g., the poor, older adults, people with less education, rural households, and minorities.
More importantly, there is another condition that our analysis at the NFPA also does not directly factor in but that will tend to understate the impact of detectors. Detectors cause not only a reduction in fire deaths but also a reduction in reported fires, because people with smoke detectors are able to catch many fires early enough to control them without needing to call the fire department, as they would have had to do if discovery had occurred later. A one-time special analysis, described in an appendix to the NFPA’s annual report on detectors (Marty Ahrens, U.S. Experience with Smoke Alarms, NFPA Fire Analysis & Research Division, Quincy, MA, January 2000), suggests that the diversion of real fires from reported to unreported status is huge and possibly a much bigger factor than the differences in preexisting risk between households with and without detectors.
We use side analyses only on the two factors of differences in preexisting risk and detector impact on reporting of home fires, rather than trying to adjust our primary measures of detector effectiveness directly, because the data on those two factors isn’t robust enough to make us confident that our primary estimates would be more accurate if we did. Our unadjusted analysis is as good a main estimate as one can get and, if it’s off, it’s as likely to be too low as too high.
Crapo’s analysis of fires where detectors were present but did not operate vs. fires where detectors were not present is interesting and essentially consistent with the NFPA’s own analysis. I would cast his conclusion a bit differently to make that consistency more evident: If you know that your smoke detectors are operational, you can expect much more than a 40 to 50 percent reduction in your risk of dying if fire occurs, but because many detectors aren’t working, the overall reduction is about 40 to 50 percent.
My conclusions aren’t that different from Crapo’s, except that he’s put more emphasis on some of the second-order factors and less on others that we’ve done in our analysis at the NFPA. Certainly, his summary conclusion-that detectors are effective but it’s hard to know just how effective-is one I can endorse, and I hope Fire Engineering readers receive the front part of that message clearly despite the second part.
I would say that referring to national estimates as only “best guesses” is too harsh and sets an implied standard that no statistical system in the United States could hope to meet. Even the national census gets more accurate results when it accepts the fact that counts are never complete and statistics are always estimates and uses valid statistical methods to produce the best estimates possible. The combination of NFIRS data and NFPA survey data gives us a national data base that is more detailed and validly comprehensive than any other in the world. That’s why when analysts like Crapo and ours at the NFPA say smoke detectors are effective, you can be sure it’s true.
John R. Hall, Jr., Ph.D.
Assistant Vice President
Fire Analysis & Research
National Fire Protection Association
Quincy, Massachusetts
William Crapo’s subject matter is very worthwhile. However, his compilation of data seems convoluted and confusing.
Everyone in the fire service should concentrate on spreading the word in straightforward terms. Fire detectors are proving to be the most positive, direct tool in home fire safety. Every residential bedroom should have one, as required in hotels/motels.
The ongoing problem is proper maintenance of those smoke detectors presently installed. Homeowners, tenants, and innkeepers need constant reminding. We in the fire service are the logical ones to make others fire safety conscious.
Crapo’s numbers seem to mislead in some respects. In my view, many fire incidents of a very minor nature are detected and eliminated before they become dangerous. We can never know how many smoking appliances and wastebaskets were discovered before a fire developed. Those unknown numbers are the key to the remarkable drop in the 1977 to 1997 “home” fire incidents reported by the NFPA, in my opinion. There is a positive correlation between those numbers and the advent of the home smoke detector.
Robert E. Lowe
Lowe Fire Investigations
San Juan Capistrano, CA
Little drops of water
I read with interest the articles “Little Drops of Water: 50 Years Later, Parts 1 and 2” by Andrew A. Fredericks (February and March 2000) and the recent Letters to the Editor in the June 2000 issue, in particular the letter from William F. Crapo.
I totally agree with Fredericks! As a young firefighter enrolled in a fire science degree program, I was introduced to the fog concept. At that time, the Detroit Fire Department primarily used the “Rockwood” nozzle, which was basically the nozzle used by the Navy and Coast Guard to provide a solid stream application of water. Adjustable stream nozzles were also available. I decided to experiment.
It didn’t take too many steam burns to figure out I was safer using a straight or solid steam. Many of Detroit’s busier companies still prefer the open bore nozzle.
Crapo’s letter took me back nearly 30 years when fog steam application was being pushed. When you think about it, wasn’t it the insurance and fire equipment companies who were endorsing fog?
One of the best books on fire stream application is, interestingly enough, the National Fire Protection Association’s Fire Behavior and Sprinklers by Norman J. Thompson. Thompson provides a great analysis of fire behavior in relation to water application.
In Chapter 7, Thompson states: “The most important effect on a fire in ordinary combustibles is that of direct wetting and cooling of the burning combustibles themselves so as to extinguish the fire.” Sprinkler systems are designed to wet burning and surrounding combustibles to prevent ignition. Shouldn’t we try to achieve the same with a fire stream?
Based on my experience, the straight or (preferably) solid stream tends to accomplish this. A good stream directed at the ceiling breaks into smaller droplets that absorb upper level heat, but not to the point that they scald the firefighter. Additionally, the now broken stream produces larger droplets, which are capable of penetrating the heat plume developed by the fire to actually wet the materials burning. Water droplets will also wet surrounding combustibles to prevent ignition. And, the thermal balance will not be greatly disrupted.
Crapo’s assertion that fires today are “no worse than they have been since at least 1988” based on water usage is interesting but not complete. The very concept of using larger size hoselines is a consideration, using less water to darken down the fire. Class A foams have reduced water supply needs.
His assertion ignores the fact that lightweight wood construction has contributed to a greater and faster fire spread and plastics that produce greater Btu release than natural materials. If fires have not changed, why are we experiencing so many flash-overs?
Many synthetic materials have relatively low decomposition temperature. Most do not start decomposing below 2127F, which means if they are wet, the amount of toxic and flammable gases released should be minimal. However, if we use indirect fog attack and invert the thermal balance, bringing superheated steam to floor levels, we could actually heat synthetic materials to decomposition temperatures and cause the release of toxic gases-just when many firefighters shed their face piece.
Regarding water damage, regardless of the stream used, whether a fog or a straight stream, I can incur excessive and unnecessary water damage if I don’t shut the nozzle down after knockdown. This is where training and experience become important.
Many synthetic materials start to decompose at relatively low temperatures. We may, using a steam smothering method produced by the indirect fog attack, be heating these materials to decomposition temperatures where they produce extremely toxic gases. This is often the time that firefighters start taking their masks off.
Nearly 30 years ago, I was introduced to and experimented with fog stream application. Water damage concerns seemed to be the theme of the day. Sprinkler systems, pipes, and hardware did not appear to be subjected to the same criteria that firefighters (humans) were expected to perform. Sprinkler systems are designed to wet the combustible materials burning as well as surrounding combustible materials. Why shouldn’t the nozzle person try to accomplish the same?
Instead, firefighters are expected to fog the ceiling to absorb upper level heat and induce steam to floor levels to smother the fire. It means close approach by humans, who are then subjected to scalding.
Using a straight or solid stream, firefighters can basically achieve a similar effect that sprinklers are designed to do. Where the thermal and smoke levels allow approach, directly attack the materials burning. Where this approach is not possible, indirectly attack the fire by placing a straight stream on the ceiling, breaking the stream into small droplets for absorbing upper-level heat in a gradual and controlled fashion and producing larger droplets, which can penetrate the thermal plume to actually wet the combustibles burning, wetting surrounding combustibles to prevent ignition and synthetic materials to prevent decomposition and degradation into toxic gases.
We need to use care that when we study theory we still add some good old common sense.
Andrew Fredericks should be commended on a well-written series of articles.
John A. Reardon
Commerce Township, MI
I have been reading with great interest the age-old debate of fog vs. straight stream that Andrew Fredericks has rekindled as a result of his “Little Drops of Water” articles. I especially took interest in William Crapo’s Letter to the Editor. As a captain in an active engine company, I can assure you that Crapo’s opinions do not reflect those of many of the current members of the District of Columbia Fire Department (DCFD).
Just as Fredericks does, I also disagree with the entire content of Crapo’s response. I especially disagree with his contention that the fires of today are no different than they were 20 years ago. My department’s as well as national statistics show that thermal injuries are on the rise. In addition, scientific studies and test burns have shown that the heat energy output from the fires of today are causing flashovers to occur faster and more frequently than ever before. At a recent basement fire we fought in a private dwelling, temperatures above the fire on the first floor reached a staggering 5007F at only 1.6 feet above floor level, with temperatures exceeding 1,5007F at ceiling level. (These temperatures were calculated in a computerized fire model conducted by the National Institute of Standards and Technology.) The heat alone from this fire resulted in severe burn injuries to three of our members who were operating above the fire on the first floor. Sadly, two of these outstanding and courageous firefighters succumbed to their injuries.
I also disagree with Crapo’s comments on the use of fog streams for interior fire attack. The use of fog streams in an atmosphere such as described above without adequate ventilation (which is often a problem in my department because of limited staffing on ladder companies) is suicide. The water will convert to steam as soon as it leaves the nozzle and does very little to extinguish the fire. A straight stream is the only way to deliver water to the seat of a fire under these conditions without excessive steam production.
As an adjunct instructor at the DCFD Fire Academy, I can attest to the statement related in Fredericks’ response that current recruits in the DCFD are taught to use a straight stream pattern for interior fire attack. They are also taught to check the nozzle settings on assuming duty and on bleeding the line before attacking a fire to ensure that the pattern is set on straight stream (we have found that the nozzle settings are often accidentally changed during the process of pulling and advancing a hoseline). In addition, our current fog nozzles used with 13/4-inch hoselines are of a two-piece construction, with a removable fog tip and a 15/16-inch smooth bore tip (slug) built into the cutoff. It is my opinion that the smooth bore nozzle is the simplest, most efficient and effective nozzle for interior fire attack. It is “firemanproof,” in that you don’t have to worry about what pattern or flow it is set on. You open it up and, at the correct nozzle pressure, water comes out at the same flow and pattern every time! It is just that simple. Oh, and you get the added benefits of reach, penetration, increased flow, and decreased nozzle reaction to boot! What’s not to like?
Daniel M. Troxell
Captain, Engine Company 15
District of Columbia Fire Department
Washington, D.C.
Forcible entry challenge
This letter is in response to “A New Forcible Entry Challenge” by Matt Stewart (Training Notebook, February 2000) where he describes the Phoenix Defender locking device. Stewart went into great detail on the forcible entry problems this device creates. He omitted one thing from the article: Are these devices legal?
NFPA 101, the Life Safety CodeT, states, “Doors shall be arranged to be opened readily from the egress side whenever the building is occupied. Locks, if provided, shall not require the use of a key, tool, special knowledge, or effort for operation from inside the building.”
NFPA 101 further states, “A latch or other fastening device on a door shall be provided with a lever, knob, handle, panic bar, or other simple type of releasing device having an obvious method of operation under all lighting conditions. The releasing mechanism for any latch shall be located not more than 48 inches (122 cm) above the finished floor. Doors shall be openable with no more than one (1) releasing operation.”
Inspectors and preplanners should look into their local laws and ordinances to verify that these regulations cite the Life Safety CodeT and enforce it to ensure that no person-civilian or firefighter-can be trapped inside a building by a device as insidious as the Phoenix Defender.
M. J. Mitchell
Fire Inspector
General Inspection Division
Herman WiegandDivision Supervisor
Nassau County Fire Commission
Office of Fire Marshal
Uniondale, NY
Matt Stewart responds: First, I would like to address the issue of the NFPA in Indiana. Indiana is not an NFPA state and has not adopted NFPA documents into Indiana State code, meaning NFPA 101 is not applicable in Indiana. However, Indiana has adopted the 1997 Uniform Fire CodeT published by the International Conference of Building Officials, with Indiana amendments, as the 1998 Indiana fire code. Section 1207 of the Indiana Fire Code states, “Exit doors shall be openable from the inside without the use of key or any special knowledge or effort. Exit doors shall not be locked, chained, bolted, barred, latched, or otherwise rendered unusable.” The fire code further states that panic hardware shall be mounted at a height of not less than 30 inches, nor more than 44 inches from the floor. “The unlatching force shall not exceed 15 lbs. when applied in the direction of travel.” The Phoenix Defender is a legal device in Indiana but may not be in place while the occupancy is open. Our fire marshal’s office aggressively inspects for egress violations and is very knowledgeable of state and local laws. Unfortunately for firefighters, most business owners are only worried about the security of their facility and not the lives of firefighters. Fire companies must take every chance to inspect, get in, and walk through every structure they may have the possibility of operating within.
Now is not the time to roll over
You have probably read or heard about how well the fire service has done in Washington this year. How we almost got the Fire Bill passed. How we might still get $100 million from the Supplemental Appropriation Bill ($80 million from this bill would be devoted to a 50/50 grant program that most fire departments cannot afford to match). Now, we are hearing the all too familiar “wait till next year.”
First, the year is not over. The Fire Bill can be passed this year. Second, this is a presidential election year. What better time than now for the fire service to speak out? Third, every congressional representative and one-third of the senators are up for reelection.
Now is not the time to roll over. Now is the time to act.
Now is the time for the fire service leadership (IAFC, IAFF, NVFC, and so on) in Washington, D.C., to tell each and every one of its members exactly what to do to get the Fire Bill passed this year. We cannot wait until next year. We cannot wait for another Worcester. Now is the time to get every union local, every fire district, every fire council, every firefighter, every fire officer, and every fire chief involved.
Now is not the time to roll over. Now is the time to act.
It is time for the fire service leadership to ensure that, when the Democratic Party and the Republican Party hold their national conventions this summer, one of the planks of their party platform is support for the fire service. The Democratic Party and the Republican Party leadership must support the fire service. They must support the people who do the job, the American firefighters. They must support the Fire Bill.
Now is not the time to roll over. Now is the time to act.
It is time for President Clinton to come out and strongly support the fire service and the Fire Bill. It is time for the presidential candidates to take a stand with a show of support for the fire service and the Fire Bill.
Now is not the time to roll over. Now is the time to act.
We must contact every congressional representative [270 are cosponsors of the Fire Bill (H.R. 1168)] and ask them to speak out for the fire service and the Fire Bill at their national convention.
We must contact every senator [22 are cosponsors of the Senate version of the Fire Bill (S. 1941)] and ask them to speak out for the fire service and the Fire Bill at their national convention.
We must reach out to the county and state Democratic and Republican Parties and ask for their support for the Fire Bill and the fire service.
We must find out where every new candidate for Congress and the Senate stands. Will they support the fire service?
Finally, with unfunded mandates such as two in/two out and cities such as Baltimore closing fire stations, now is the time for the fire service leadership to act-not roll over.
Tom Kennedy
Committee Member
Northeastern States Fire Consortium
Thermal imaging cameras
The Calumet Park (IL) Fire Department is requesting information on how departments have developed advertising campaigns to generate political and public support for the purchase of thermal imaging cameras. Please direct responses to Firefighter Christopher Brennan, Calumet Park Fire Department, 12457 South Ashland Avenue, Calumet Park, IL 60827.
