LETTERS TO THE EDITOR

LETTERS TO THE EDITOR

Attila the Chief

I must tell you how much I enjoyed reading “Attila the Chief” by Steve Meyer in the September issue. His analogies were right on target. Until recently, I had been of the opinion that Peters and Waterman had discovered (or at least were the first to write about) participative management in the early 1980s.

This past summer I read the book The March of To/ly, by Barbara Tuchman, who quoted Machiavelli (14691527) as saying, “A prince ought always to be a great asker and a patient hearer of truth about those things of which he has inquired, and he should be angry if he finds that anyone has scruples about telling him the truth.” It appears that the theory has been around for a long time. It has just taken a while to catch on.

For the student of participative management, I also would like to recommend About Face, by Colonel David II Hackworth. Although this is certainly not a management text, his descriptions of leadership problems in the military closely parallel those of the tire service.

Gary R. Long, EFO

Fire Marshal

Fast While la i ul Township

Frazer. Fen nsyh an in

Penny wise, pound foolish

It is truly tragic that Bill Manning’s editorial in the October issue, “Life Sentence.” needed to be written — and, as is often the case, with a repeat of words spoken or written before some of us were born that could have been written to fit a recent tragedy

Money has two “faces”: that which is saved and that which is lost. It is indeed unfortunate to be burned out of a job and a business, but is it worth being sued out of business?

Could you, in time, prove your point in light of our litigious end to the 20th century by a follow-up of the cost to the company of its “costeffective” measure? 1 agree with you; it indeed is sorrowful to have the finality come down to “a life was worth X dollars,” but maybe that’s the value to which some persons assign life.

Donald C. Freyer

Rural Fire Defense

Program Coordinator

Georgia Forestry’ Commission

Macon, Georgia

Tandem pumping

In my 37 years in the fire service, with 18 years of teaching pumper operation at Texas A&M Fire School. 1 have never heard the operation described by David P. Fornell in the sidebar to “High-Rise Flows with PRVs: The Boston Tests” in the October issue as tandem pumping. The operation described is the exact procedure used for what is known as “relay” or “scries” pumping. The pumper attached to the hydrant pumps water to the next unit in series/relay, and this pumper can feed the next pumper. The operation can be used to supply water for long distances or to boost pressures.

The operation known as “tandem pumping” is used when a pumper fed from a hydrant sends water to the fire scene and a second pumper is attached to an inlet steamer of the pumper attached to the hydrant on the opposite side from the steamer attached to the hydrant. Thus the two pumpers are fed from the same hydrant, and the second pumper sends its water to the scene under pressure. The pump of the first pumper does not supply water under pressure to the second pumper; the second pumper is supplied by the hydrant through the first pumper at hydrant pressure and not with a boosted pressure.

Tandem operations can be done only if the hydrant can supply the necessary quantity of water.

Frank Janoch III

Retired Chief

Kemah (TX) Fire Department

A word of caution

1 would like to congratulate Frank M. Panek, author of “Firefighting in the Pine Barrens” (November 1991). It was a very informative article and demonstrates that there is yet one more of many dangerously fire-prone areas located in the United States that has the problem of structural/wildland urban interface. This is a subject that I have been very involved with for nearly 25 years. Panek may be aware of the identical fire problem that exists in southeastern Massachusetts and in the Boston area.

1 offer one constructive criticism. The photo on page 51 shows two brushfire units and crews working a major forest fire. The safety violation is that the units are directly below high-voltage transmission wires. The brushfire units have long whip antennas and fire personnel are standing on top of the units. One person wore absolutely no protective clothing. The crowning fire appears to be very close to both the fire crews and the high-voltage lines.

I developed and teach an interface firefighting course to fire departments, and one safety item that is stressed is to stay away from wires— especially high-voltage transmission types. These wires can droop downward from radiant and convective heat and direct flame impingment from a wildland fire. Smoke also can act like a transmitter of high energy that completes a circuit. Driving a brushfire unit up a hill that is under wires can bring the unit and its crew much closer to the wires than if on flat ground. Any one of these scenarios could produce an electrical arc with obviously devastating results. So stay clear of all wires.

Robert M. Winston

District Fire Chief

Boston (MA) Fire Department

High-rise columns: a strong point

In reference to Frank Branningan’s article “Can High-rise Columns Fail?” in the November issue, I am concerned about one major point. It is important to note that our actual experience with columns in modern high-rise fires has been remarkably good. Of all the structural components in several recent high-rise fires, the columns have been the best performers.

Branningan’s concerns are wellstated—that there are several reasons to be concerned with the fire-resistant protection that is provided on structural elements in any type of construction. Unprotected or inadequately protected columns have failed in many different types of buildings under a variety of fire conditions. Experience is showing, however, that in most modern high-rise buildings, the columns are the least likely element to fail, and their failure should be preceded by major problems with beams, girders, floor sections, connectors, and other structural components.

Columns have several major advantages over other structural elements that should provide additional confidence. Since the columns have to support the entire weight of the floors above, they have to be much stronger than elements that support the load of only a single floor. That strength comes with additional mass, so a typical column has a lot more mass than most beams. It takes much longer for the fire to heat up the columns than the beams because of the additional mass to absorb the heat. In addition, most building codes require more fire-resistive protection on columns than on beams that support only a single floor. Even if both are unprotected, most steel beams will react like heated butter before the columns are ready to soften.

The higher you go in the building, the less weight is supported by the columns, so they become more slender. The top-floor columns are usually about the same relative mass as the horizontal members and are likely to fail at about the same time. This is equivalent to the steel in a singlestory’ unprotected structure, where the beams and columns often collapse simultaneously.

The load on the columns is all compressive load, so their natural tendency is to buckle when they lose strength. The resistance to buckling is inversely proportional to the square of the unsupported distance. Since the columns are effectively braced at every floor, the unsupported distance for most column sections in a high-rise building is relatively short—around 10 to 14 feet. Interior columns are braced in all four directions, and most exterior columns are braced in three directions. In simple terms, the configuration naturally resists buckling.

Floor beams are often as long as 30 feet and are restrained only at the ends. The long span is relatively slender (less mass) and is subjected to both shear and bending stresses. Heating a beam will cause rapid elongation, which exerts force against the columns at each end. The columns resist the elongation force with their mass and because they have other beams resisting the force in two or three directions. Since the beams cannot elongate against the columns, they bend, warp, and twist. They may create enough force to tear themselves away from a column, resulting in a partial floor collapse.

In steel construction, separation of the beams from the columns may most likely occur during cooling, particularly when hose streams are applied to unprotected horizontal members. Rapid contraction may rip the connectors loose and cause a pancake collapse. This occurs infrequently, but it is potentially very dangerous. Experience does not suggest that rapid cooling is a problem with columns.

Connectors are often the critical factor in both steel and concrete construction. When elements are heated they will try to expand. The question is which way they will try to expand and which part of the assembly will fail first. The force will go in the path of least resistance, and in concrete construction this may depend on the order of pouring different sections and the manner that is used to connect the rebars between elements. A continuous column is very resistant to failure, but a column section that sits on the floor below and is weakly connected to the floor abovemay be easily dislodged.

This should not be taken as absolute assurance that high-rise columns will not fail. There are numerous situations that need to be considered, particularly in old construction with cast iron columns or where modifications have been made to the original structural frame. A steel column that is tall and slender is much more vulnerable than one that is short and fat, so be aware of construction designs that cause a column to extend two or more stories without lateral support. Look out for missing or compromised fire-resistive protection on all types of steel members. Also, be aware of exterior architectural elements, such as curtain wall panels, that could be pried loose by elongation of the steel members.

It is important, however, to appreciate that fire experience with modern high-rise structural assemblies has been very good. The horizontal members have warped and twisted and there have been some localized failures of floor sections, but there have been no catastrophic collapses, even where fires have consumed all of the available fuel. The evidence does not suggest that one of these buildings is going to fall over or collapse into a heap of tangled rubble, at least based on what we have experienced so far.

J. Gordon Routley

Phoenix, Arizona

Just the facts

The fire service must continue to seek advances in fire suppression to combat the new dangers of toxic and highly inflammable fire hazards, and I believe that today there is new openness to modern methods.

This creates the need for a forum for practical firefighters to debate new technology rationally as opposed to emotionally. This need can be met by adopting the publication method used by the scientific community to build up a credible body of substantiated knowledge through referencing experimental work and previously published material.

The scientific method reduces inadvertent publication of claims that cannot be backed by fact. Firefighters reading such claims can be misled to the point of endangering life.

Fire Engineering, with its long-established reputation—“Training the Fire Service for 115 years” —is in an excellent position to meet this need by adding a scientific publications feature on new technology such as Class A foam and compressed-air foam systems, which promise to revolutionize firefighting.

I sincerely hope that Eire Engineering will take advantage of this opportunity to improve this already excellent magazine.

C. Bruce Edwards

Eire Suppression Consultant

North Vancouver, B.C., Canada

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Hutchinson Kansas fire

Man Arrested After KS Fire That Killed Two

A man was arrested on Monday in connection with a deadly Hutchinson house fire on Saturday where a woman and girl died.