
Principles of Fire BehaviorPrinciples olJamesG.QuintiereFire BehaviorPrinciples of Fire Behavioronty its hazards but alse its bunefitsALSOAVAILABLEFROMDELMARPUBLISHERS:KlinoffIntroducttiontoFire Protectior0-8273-7252-3BuckPreparing For Terrorism: An Emergency Services Guide0-8273-8397-5DiamantesFirePrevention:InspectionandCodeEnforcement0-8273-8412-2FormoreinformationabouttheseandotherDelmarFire/Rescuebooks,call 1-800-347-7707VISITDELMARPUBLISHERSTo.accessawide-wariefyofDeron the Worid Wide Web, pointFIRE/RESCUEWEBSITEIrourbrowertohttp:/www.cengage.com/delmatccess intematonarCengagePublishingyToacthanJamesGQuintierePointyourbrowsertoand20.000productsbrowsehttp://www.firesci.comDELMAR中NGAGELearninalmareboueDelorprefemedow9307,is_ocids1estanstn
To learn more about Delmar, visit www.cengage.com/delmar Purchase any of our products at your local bookstore or at our preferred online store www.cengagebrain.com © 2011 Delmar, Cengage Learning 0827377320_hires_cvr.indd 1 01/02/11 11:44 AM CENGAGE Learning· • comprehen Ive lTeatment glvu g sp of JI fil"9 behavlor9 • cientfflc approach yields lnalght to pin from experience alone • lmple formulas empower . fl,. , asseu damage. limelne of fire events • Introduction of quanut:811'1,e COt'iC 111 . ,.,. preci Ion to the users understanding of fire beh vlor • special section on combustion products and compartment fires help readers u.nderstand prfnclpl s of re behavior in specific sttuatlon ISBN-13: 978- -8273-7732-5 ISBN-10: -8273-7732- □ 9000 9 780827 377325

DELMARCENGAGE LearningPrinciples of Fire Behavior1998Delmar, Cengage LearningJames G.QuintiereALL RIGHTS RESERVED.No part of this work covered by the copyright herein maybe reproduced, transmitted, stored or used in any form or by any means graphic,Publisher: Alar Elkenelectronic, or mechanical, including but not limited to photocopying,recording,Acquistions Editor: Mark Huthscanning, digitizing, taping, Web distribution, information networks,or informationDevelopmental Editor: Jeanne Mesickstorage and retrieval systems, except as permitted under Section 107 or 108 of the1976 United States Copyright Act, without the prior written permission ofProduction Coordinator: Toni Bologninothe publisher.Art and Design Coordinator: Michelle CanfieldEditorialAssistant:DawnDaughertyFor product information and technology assistance, contact us atMarketing Coordinator: Mona CaronCengage Learning Customer & Sales Support,1-800-354-9706For permission to use material from this text or productsubmitallrequestsonlineatwww.cengage.com/permissionsFurther permissions questions can be emailed topermissionrequest@cengage.comLibrary of Congress Control Number: 97-11199ISBN-13: 978-0-8273-7732-5ISBN-10: 0-8273-7732-0DelmarExecutive Woods5Maxwell DriveClifton Park, NY 12065USACengage Learning is a leading provider of customized learning solutions with officelocations around the globe, including Singapore, the United Kingdom, Australia,Mexico, Brazil, and Japan. Locate your local office atwww.cengage.com/globalCengage Learning products are represented in Canada by Nelson Education, Ltd.To learn more about Delmar,visit www.cengage.com/delmarPurchaseanyofourproductsatyourlocalbookstoreoratourpreferredonlinestore www.cengagebrain.comNotice to the ReaderPublisher does not warrant.or guarantee any of the products described herein or perform any independent analysis in connection with any of the product information containedherein. Publisher does not assume, and expressly disclaims,any obligation to obtain and include information other than that provided to it by the manufacturer. The readeris expressly warned to consider and adoptallsafety precautions that might be indicated by the activities described herein and to avoid allpotential hazards.By following theinstructions contained herein, the reader willingly assumes all risks in connection with such instructions. The publisher makes no representations or warranties of any kind, includingbut not timited to, the warranties of fitness for particular purpose or merchantability,nor are any suchrepresentations implied with respect to the material set forth herein,and thepublishertakes no responsibility with respect to such material., The publisher shall not be liable for any special, consequential,or exemplary damages resulting, in whole or part,fromthe readers useof,or reliance upon, this material.Printed in the United States of America15161718191514131211
© 1998 Delmar, Cengage Learning ALL RIGHTS RESERVED. No part of this work covered by the copyright herein may be reproduced, transmitted, stored or used in any form or by any means graphic, electronic, or mechanical, including but not limited to photocopying, recording, scanning, digitizing, taping, Web distribution, information networks, or information storage and retrieval systems, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without the prior written permission of the publisher. Library of Congress Control Number: 97-11199 ISBN-13: 978-0-8273-7732-5 ISBN-10: 0-8273-7732-0 Delmar Executive Woods 5 Maxwell Drive Clifton Park, NY 12065 USA Cengage Learning is a leading provider of customized learning solutions with offi ce locations around the globe, including Singapore, the United Kingdom, Australia, Mexico, Brazil, and Japan. Locate your local offi ce at www.cengage.com/global Cengage Learning products are represented in Canada by Nelson Education, Ltd. To learn more about Delmar, visit www.cengage.com/delmar Purchase any of our products at your local bookstore or at our preferred online store www.cengagebrain.com Principles of Fire Behavior James G. Quintiere Publisher: Alar Elken Acquistions Editor: Mark Huth Developmental Editor: Jeanne Mesick Production Coordinator: Toni Bolognino Art and Design Coordinator: Michelle Canfield Editorial Assistant: Dawn Daugherty Marketing Coordinator: Mona Caron Printed in the United States of America 15 16 17 18 19 15 14 13 12 11 For product information and technology assistance, contact us at Cengage Learning Customer & Sales Support, 1-800-354-9706 For permission to use material from this text or product, submit all requests online at www.cengage.com/permissions Further permissions questions can be emailed to permissionrequest@cengage.com Notice to the Reader Publisher does not warrant or guarantee any of the products described herein or perform any independent analysis in connection with any of the product information contained herein. Publisher does not assume, and expressly disclaims, any obligation to obtain and include information other than that provided to it by the manufacturer. The reader is expressly warned to consider and adopt all safety precautions that might be indicated by the activities described herein and to avoid all potential hazards. By following the instructions contained herein, the reader willingly assumes all risks in connection with such instructions. The publisher makes no representations or warranties of any kind, including but not limited to, the warranties of fi tness for particular purpose or merchantability, nor are any such representations implied with respect to the material set forth herein, and the publisher takes no responsibility with respect to such material. The publisher shall not be liable for any special, consequential, or exemplary damages resulting, in whole or part, from the readers’ use of, or reliance upon, this material. - 1~ DELMAR ~, . CENGAGE Learning·

ContentsixPrefacexiAcknowledgments1Chapter1TheEvolutionof FireScienceIntroduction/2What IsFire?/2Natural CausesofFire/3Fire intheUnitedStates/5FireResearch/12Visualizationof FirePhenomena/14ScientificNotation/15Summary/2123Chapter2Combustion in Natural FiresIntroduction/24Fireand Its Ingredients/24DiffusionFlames/25Smoldering/38SpontaneousCombustion/39品PremixedFlames/42Summary/4547Chapter3Heat TransferIntroduction/48 Definitionsand Concepts/48 FormsofHeatTransfer/49HeatFluxas anIndicationof Damage/60Summary/6365Chapter4IgnitionIntroduction/66 Piloted andAutoignition/66Ignition TimeforSolidFuels/69Summary/8083Chapter5FlameSpreadIntroduction/84Definitions/84Theory/85SpreadonSolidSurfaces/86SpreadthroughPorousSolidArrays/91Spread onLiquids/94Typical Fire SpreadRates/97StandardTestMethods/97Summary/99vii
contents Preface Acknowledgments Chapter 1 The Evolution of Fire Science Introduction/2 ■ What Is Fire?/2 ■ Natural Causes of Fire/3 ■ Fire in the United States/5 ■ Fire Research/12 ■ Visualization of Fire Phenomena/14 ■ Scientific Notation/15 ■ Summary/21 Chapter 2 combustion in Natural Fires Introduction/24 ■ Fire and Its Ingredients/24 ■ Diffusion Flames/25 ■ Smoldering/38 ■ Spontaneous Combustion/39 ■ Premixed Flames/42 ■ Summary/45 Chapter 3 Heat Transfer Introduction/48 ■ Definitions and Concepts/48 ■ Forms of Heat Transfer/49 ■ Heat Flux as an Indication ofDamage/60 ■ Summary/63 Chapter 4 Ignition Introduction/66 ■ Piloted and Autoignition/66 ■ Ignition Time for Solid Fuels/69 ■ Summary/BO Chapter 5 Flame Spread Introduction/84 ■ Definitions/84 ■ Theory/85 ■ Spread on Solid Surfaces/86 ■ Spread through Porous Solid Arrays/91 ■ Spread on Liquids/94 ■ Typical Fire Spread Rates/97 ■ Standard Test Methods/97 ■ Summary/99 vii ix Xi 1 23 47 65 83

viiiContents101Chapter6Burning RateIntroduction/102DefinitionandTheory/102MaximumBurningFlux/106EnergyReleaseRateQ/107ExperimentalResultsforSelectedItems/113FireGrowthRate/121Summary/126129Chapter7Fire PlumesIntroduction/130TurbulentFirePlumes/130FlameHeight/132FirePlumeTemperatures/139FlameHeightandTemperatureGalculations/142Summary/146149Chapter8CombustionProductsIntroduction/149ScopeofCombustionProducts/149Yields/152Concentrations/157Hazards/159Summary/167169Chapter9CompartmentFiresIntroduction/170 StagesofFireDevelopment/170Fire-InducedFlows/173CompartmentFlowDynamics/175SingleRoomFireAnalysis/185SmokeTemperature/185SmolderingFirein a ClosedSpace/190Summary/194197Chapter10FireAnalysisIntroduction/198FireSafetyDesign/198PerformanceCodes/200FireInvestigationExamples/203ComputerFireModels/221Summary/224227AppendixANumbered Equations230AppendixBReferenceTables250Acronyms251Glossary255Index
- ~-co_n_te_nts Chapter 6 Chapter 7 Chapter 8 Chapter 9 Burning Rate Introduction/102 ■ Definition and Theory/102 ■ Maximum Burning Flux/106 ■ Energy Release Rate, Q/107 ■ Experimental Results for Selected Items/113 ■ Fire Growth Rate/121 ■ Summary/126 Fire Plumes Introduction/13O ■ Turbulent Fire Plumes/13O ■ Flame Height/132 ■ Fire Plume Temperatures/139 ■ Flame Height and Temperature Calculations/142 ■ Summary/146 combustion Products Introduction/149 ■ Scope of Combustion Products/149 Yields/152 ■ Concentrations/157 ■ Hazards/159 ■ Summary/167 compartment Fires Introduction/17O ■ Stages of Fire Development/17O ■ FireInduced Flows/173 ■ Compartment Flow Dynamics/175 ■ Single Room Fire Analysis/185 ■ Smoke Temperature/185 ■ Smoldering Fire in a Closed Space/19O ■ Summary/194 Chapter 10 Fire Analysis Introduction/198 ■ Fire Safety Design/198 ■ Performance Codes/ZOO ■ Fire Investigation Examples/2O3 ■ Computer Fire Models/221 ■ Summary/224 Appendix A Numbered Equations Appendix B Reference Tables Acronyms Glossary Index 101 129 149 169 197 227 250 250 251 255

PrefaceThis book has been written for the practitioner in firethefirefighter,code official, or inves-tigator.A working knowledge of algebra is needed to effectively use the formulas presented.Acquired technical knowledge or course background in the sciences will behelpful.The textcontains material given to fire protection engineers, but not at the same depth of theory ordetail given in an engineering course. However, the conceptual explanations contained heremay benefit these more advanced students as well.The book arose from coursematerial prepared in conjunction with training sessions forthe Bureau of Alcohol, Tobacco, and Firearms (BATF) arson programs,Parts of it have alsobeen used ina BATF coursefor stateand local officials under the auspices of theFederal LawEnforcementTraining Center (FLETC).Ihave benefited greatly fromthis association byenrichingmy scope of real fire events and in appreciatingtheapplication of science to them.Rick Miller and Jackie Herndon of BATF encouraged me to meet the educational challenge ofthese programs, and Bill Petraitis (BATF) has helped to convince me of the benefits of fireanalysistoinvestigators.This book begins with a perspective on the fire problem,the background of research,and how the student needs to approach the study of fire.Visualization is important to displayconcepts, and mathematical symbols and scientific units need to be digested.Anoverviewoffireaddressesdiffusion flames,premixedflames,smoldering,andspontaneous combustion.Experiments with a candleflame are described to helpdefine someconcepts.Heat transfer,ignition,flame spread, and burning rate are discussed.Formulas are pre-sented to allow the student to examine and appreciate quantitative aspects of fire.Energyreleaserate (Q)inkilowatts (kW)is shown tobe an importantfireparameter.Later chapters explain thefire smokeplume,products of combustion,and how firebe-havesinaroom.Again,quantitativeformulasarepresented.The book closes with a discussion of the use of fire analysis to fire safety design and fireinvestigation.Examples are given, including a description of the Branch Davidian fire nearWaco,Texas (April, 19, 1993).Hopefullyby the final chapter the student will see how toapplythebookmaterialto his orherproblemscedreader.FirecanbeunexpectedlyinjuriousandAcautionarynotetotheinexdeadly.Asmallflanconds,andafireinahomecanbecomeCan.causdeadlyandinescapableinminutes.ussedandsuggestedforeducationHsosal purposes,ifconducted,need tobeinmentwhere attentionhasbeengiven toproper ventilation and control of combustibles.Extreme care should begiven in the use andhandlingof liquidfuelsix
P•et:ace This book has been written for the practitioner in fire-the firefighter, code official, or investigator. A working knowledge of algebra is needed to effectively use the formulas presented. Acquired technical knowledge or course background in the sciences will be helpful. The text contains material given to fire protection engineers, but not at the same depth of theory or detail given in an engineering course. However, the conceptual explanations contained here may benefit these more advanced students as well. The book arose from course material prepared in conjunction with training sessions for the Bureau of Alcohol, Tobacco, and Firearms (BATF) arson programs. Parts of it have also been used in a BA TF course for state and local officials under the auspices of the Federal Law Enforcement Training Center (FLETC). I have benefited greatly from this association by enriching my scope of real fire events and in appreciating the application of science to them. Rick Miller and Jackie Herndon of BATF encouraged me to meet the educational challenge of these programs, and Bill Petraitis (BATF) has helped to convince me of the benefits of fire analysis to investigators. This book begins with a perspective on the fire problem, the background of research, and how the student needs to approach the study of fire. Visualization is important to display concepts, and mathematical symbols and scientific units need to be digested. An overview of fire addresses diffusion flames, premixed flames, smoldering, and spontaneous combustion. Experiments with a candle flame are described to help define some concepts. Heat transfer, ignition, flame spread, and burning rate are discussed. Formulas are presented to allow the student to examine and appreciate quantitative aspects of fire. Energy release rate (Q) in kilowatts (kW) is shown to be an important fire parameter. Later chapters explain the fire smoke plume, products of combustion, and how fire behaves in a room. Again, quantitative formulas are presented. The book closes with a discussion of the use of fire analysis to fire safety design and fire investigation. Examples are given, including a description of the Branch Davidian fire near Waco, Texas (April, 19, 1993). Hopefully by the final chapter the student will see how to apply the book material to his or her problems. A cautionary note to the inexperienced reader. Fire can be unexpectedly injurious and deadly. A small flame can cause a burn injury in seconds, and a fire in a home can become deadly and inescapable in minutes. The experiments discussed and suggested for education - al purposes, if conducted, need to be in an environment where attention has been given to proper ventilation and control of combustibles. Extreme care should be given in the use and handling of liquid fuels. ix

AcknowledgmentsThe author and Delmar Publishers would like to thank the following reviewers for the com-ments and suggestions they offered during the development of this project. Our gratitude isextended to:Edward M.Garrison, CFIClint SmokeATFNorthern Virginia Community CollegeRaleigh, NCAnnandale,VAChris HawleyRobert LafordBaltimore CountyFire DepartmentMassachusettsFirefightingAcademyTowson,MDOrangeFireDepartmentOrange,MADavid L.FultzLSUFiremanTraining ProgramMichael McKennaBaton Rouge, LAMissionCollegeSanta Clara,CATom HarmerTitusvilleFire&EmergencyServicesTimothy G.PittsTitusville,FLGuilfordTechnical CommunityCollegeGreensboroFireDepartmentJackFennerUniversity of CincinnatiGreensboro,NCCincinnati,OHRodWesterfieldTraining HorizonsJohnMirochaSouthernStoneCountyFireProtectionSenior Special AgentDistrictBureau of Alcohol,Tobacco,andKimberling City,MOFirearmsChicago, ILTheodoreK.CashelFire MarshalPrinceton TownshipPrinceton,NJxi
Acknowledg1nents The author and Delmar Publishers would like to thank the following reviewers for the comments and suggestions they offered during the development of this project. Our gratitude is extended to: Edward M. Garrison, CFI ATF Raleigh, NC Robert Laford Massachusetts Firefighting Academy Orange Fire Department Orange, MA Michael McKenna Mission College Santa Clara, CA Timothy G. Pitts Guilford Technical Community College Greensboro Fire Department Greensboro, NC Rod Westerfield Training Horizons Southern Stone County Fire Protection District Kimberling City, MO Theodore K. Cashel Fire Marshal Princeton Township Princeton, NJ xi Clint Smoke Northern Virginia Community College Annandale, VA Chris Hawley Baltimore County Fire Department Towson .MD David L. Fultz LSU Fireman Training Program Baton Rouge, LA Tom Harmer Titusville Fire & Emergency Services Titusville, FL Jack Fenner University of Cincinnati Cincinnati, OH John Mirocha Senior Special Agent Bureau of Alcohol, Tobacco, and Firearms Chicago, IL

ChapterThe Evolution ofFire ScienceLearning ObjectivesUpon completionofthischapter,youshouldbeableto:Definefire.Develop an awareness of fire in history.Understand thefactorsmotivatingfireresearch.Recognize the role of visualization and scale models in fire researchExplainS.I.unitsandscientificsymbols
The Evolution ot= ll=ire Science Upon completion of this chapter, you should be able to: ■ Define fire. ■ Develop an awareness of fire in history. ■ Understand the factors motivating fire research. ■ Recognize the role of visualization and scale models in fire research. ■ Explain S. I. units and scientific symbols. 1

Chapter1TheEvolution of FireScienceINTRODUCTIONTo understand fire, we must have a scientific definition of fire consistent with ourperceptions. We must understand the role fire has played in history-its benefitsand its costs to society in terms of people and property damage.Controlled fire,or combustion,for useful power is studied in conjunction with the market forcesthat drive our economy.The study of uncontrolled fire appears tobe motivated byclear risks to society and by societies having the means to invest in such study.Thedevelopment of the science of fire has accelerated over the last 150 years.It is acomplex area involvingmanydisciplines,and it is relativelyprimitive comparedtoothertechnological fields.WHATIS FIRE?fireBefore there was life there was fire. It has left its imprint on history in many ways.anuncontrolledIn scientificterms,fireor combustion is a chemicalreaction involving fuel and anchemical reactionoxidizertypically the oxygen (O,) in the air. Rusting and the yellowing of oldproducing light andnewsprintdofit this definition; however,thoseprocesses are neither combustionenergysufficienttonorfirefor energy mustbe released forthereto be either.Can we distinguish com-damage the skinbustionfromfire?In scientific terms,combustionand fireare synonymous.In con-ventionalterms,wegenerallytreatfireasdistinctfrom combustion,inthatfireiscombustioncombustion that is not intended to be controlled.Firefighters attempt to control itfire,orcontrolledfireby adding water or other agents, but the process of fire is not"designed" com-bustion,asinafurnaceoran engine.Combustionexpertswhostudysuch systemsmayknow very little about fire,and those who deal with fire mayknow very lit-tle about combustion.Fire is a chemical reaction that involves the evolution of light and energy insufficient amounts to be perceptible. Will there always be light in a flame (fire)?No.For instance,theburning of hydrogen (H2)with air or oxygen produces onlywater vaporfrom its chemical reaction.Although significant energy is produced,we would notsee flame.But in most other fire classificationswe would see thecombustion process and a fire or a flame would be energetic enough to be sensed,particularly with sufficient energy to damage our skin.It may notbe very big, butits energyreleaserate per unit volume of the chemical reaction zone would be sufficient to give us a local burn injury.This is fire.It is the result of striking a match,the glow of the charcoal briquette, the conflagration of theforest,and the spon-taneityofasmokinghaystack.One last word on this chemical reaction called fire:On Earth it typicallyinvolveshydrocarbon-based fuels,those composed ofatoms of carbon (C).hydro-gen (H), and perhaps some oxygen (O) and nitrogen (N). Man-made substanceshave been added to this array of materials (molecules), such as chlorine (Cl)bromine (Br),fluorine (F)and other atoms.For example,wood molecules consist
-~-c_h_ap_t_er_1_Th_e_Ev_o_1u_ti_on_o_f_F_ir_e_sc_ie_nc_e fire an uncontrolled chemical reaction producing light and energy sufficient to damage the skin combustion fire, or controlled fire INTR0DUOI0N To understand fire, we must have a scientific definition of fire consistent with our perceptions. We must understand the role fire has played in history-its benefits and its costs to society in terms of people and property damage. Controlled fire, or combustion, for useful power is studied in conjunction with the market forces that drive our economy. The study of uncontrolled fire appears to be motivated by clear risks to society and by societies having the means to invest in such study. The development of the science of fire has accelerated over the last 150 years. It is a complex area involving many disciplines, and it is relatively primitive compared to other technological fields. WHAT IS FIRE? Before there was life there was fire. It has left its imprint on history in many ways. In scientific terms, fire or combustion is a chemical reaction involving fuel and an oxidizer-typically the oxygen (0 2) in the air. Rusting and the yellowing of old newsprint do fit this definition; however, those processes are neither combustion nor fire for energy must be released for there to be either. Can we distinguish combustion from fire? In scientific terms, combustion and fire are synonymous. In conventional terms, we generally treat fire as distinct from combustion, in that fire is combustion that is not intended to be controlled. Firefighters attempt to control it by adding water or other agents, but the process of fire is not "designed" combustion, as in a furnace or an engine. Combustion experts who study such systems may know very little about fire, and those who deal with fire may know very little about combustion. Fire is a chemical reaction that involves the evolution of light and energy in sufficient amounts to be perceptible. Will there always be light in a flame (fire)? No. For instance, the burning of hydrogen (H2) with air or oxygen produces only water vapor from its chemical reaction. Although significant energy is produced, we would not see flame. But in most other fire classifications we would see the combustion process and a fire or a flame would be energetic enough to be sensed, particularly with sufficient energy to damage our skin. It may not be very big, but its energy release rate per unit volume of the chemical reaction zone would be sufficient to give us a local burn injury. This is fire. It is the result of striking a match, the glow of the charcoal briquette, the conflagration of the forest, and the spontaneity of a smoking haystack. One last word on this chemical reaction called fire: On Earth it typically involves hydrocarbon-based fuels, those composed of atoms of carbon (C), hydrogen (H), and perhaps some oxygen (0) and nitrogen (N). Man-made substances have been added to this array of materials (molecules), such as chlorine (Cl), bromine (Br), fluorine (F) and other atoms. For example, wood molecules consist

Chapter1TheEvolution of FireScienceoftheatoms involvingH,C,and;polyvinyl chloride(plastic)containsH,C,andNOTEO plus Cl atoms; and polyurethane (plastic) contains H,C,and Oplus Natoms.A chemical reactionThese additions to the H-C-Obase complicate the nature of combustion productsdestroys molecules butand their potential threatto the environment.notatoms.All chemical reactions conservemass,which means all the atoms survive,incontrast toa nuclear reaction in which some atoms are converted into new atomswith some matter transformed to energy.In a chemical reaction,however, mole-cules are not conserved.Their destruction is the essence of a chemical reaction inwhich they are converted to new molecules.For combustion or a fire, the forma-tionofnewmoleculesfromthefuelandoxygenmoleculesgivesoffanetamountof energy.This energy comes from releasing the binding forces that hold the mol-ecules together.This is as close as we get to molecular physics.From here on,our discussionoffireprincipallyconcernswhat we canseeand feel.Ofcoursewerelyon somemeasurements, but these are at the macroscopic level in contrast to the micro-scopicormolecularlevel.NATURALCAUSESOFFIRENatural phenomena that can cause fire because of their high temperatures arelightning and molten rock from volcanic activity.Thesephenomena datebackto theformation of the Earth.As organicmatter developed,we could expect tohave fire.Even today,these phenomena are a leading cause of accidental fire.Lightning strikes are recorded by the workers keeping watch over our forests.These strikes can cause smoldering underbrush on theforest floor, and a day ortwo after a storm, flames can erupt.The forest crews track these strikes andattempt tofollow upwith needed extinguishment.Of more concern tomodernsociety is the effect of an earthquake,rather than direct volcanic activity.Anearthquake can play havoc with fire and fuel sources used for heating and cook-ing.More damage was done by the conflagrations resulting from the San Francisco earthquake of 1906 and the Great Kanto earthquake of 1923 in Tokyo andYokohama than from the actual quakes.During the fire following the Kantoearthquake,38,o00 people werekilled by a fire whirl-a flaming tornado-thatspun off the mainfire column.Thesepeoplehad taken refuge in a park adjacentto the Sumida river in the Hitukuso-Ato district of Tokyo.This horror is depict-ed intheJapaneseprintinFigure1-1a andinthegruesomephotographofcorpses resulting from the fire whirl in Figure 1-ib.It is surprising thatmorestudy is not done on the effects of fire due to earthquake as opposed to the struc-tural impactofthe jolt.There is one more natural cause of fire that humankind has not experienced,but unfortunately,the dinosaurs did.It has been generally established that inabout65millionB.C.alargemeteoritesmashedintotheEarth,Themeteorite'spas
Chapter 1 The Evolution of Fire Science ■ NOTE A chemical reaction destroys molecules but not atoms. of the atoms involving H, C, and O; polyvinyl chloride (plastic) contains H, C, and 0 plus Cl atoms; and polyurethane (plastic) contains H, C, and O plus N atoms. These additions to the H-C-O base complicate the nature of combustion products and their potential threat to the environment. All chemical reactions conserve mass, which means all the atoms survive, in contrast to a nuclear reaction in which some atoms are converted into new atoms with some matter transformed to energy. In a chemical reaction, however, molecules are not conserved. Their destruction is the essence of a chemical reaction in which they are converted to new molecules. For combustion or a fire, the formation of new molecules from the fuel and oxygen molecules gives off a net amount of energy. This energy comes from releasing the binding forces that hold the molecules together. This is as close as we get to molecular physics. From here on, our discussion of fire principally concerns what we can see and feel. Of course we rely on some measurements, but these are at the macroscopic level in contrast to the microscopic or molecular level. NATURAL CAUSES OF FIRE Natural phenomena that can cause fire because of their high temperatures are lightning and molten rock from volcanic activity. These phenomena date back to the formation of the Earth. As organic matter developed, we could expect to have fire. Even today, these phenomena are a leading cause of accidental fire. Lightning strikes are recorded by the workers keeping watch over our forests. These strikes can cause smoldering underbrush on the forest floor, and a day or two after a storm, flames can erupt. The forest crews track these strikes and attempt to follow up with needed extinguishment. Of more concern to modern society is the effect of an earthquake, rather than direct volcanic activity. An earthquake can play havoc with fire and fuel sources used for heating and cooking. More damage was done by the conflagrations resulting from the San Francisco earthquake of 1906 and the Great Kanto earthquake of 1923 in Tokyo and Yokohama than from the actual quakes. During the fire following the Kanto earthquake, 38,000 people were killed by a fire whirl-a flaming tornado-that spun off the main fire column. These people had taken refuge in a park adjacent to the Sumida river in the Hitukuso-Ato district of Tokyo. This horror is depicted in the Japanese print in Figure 1-la and in the gruesome photograph of corpses resulting from the fire whirl in Figure 1-lb. It is surprising that more study is not done on the effects of fire due to earthquake as opposed to the structural impact of the jolt. There is one more natural cause of fire that humankind has not experienced, but unfortunately, the dinosaurs did. It has been generally established that in about 65 million B.C. a large meteorite smashed into the Earth. The meteorite's pas-

Chapter1The Evolution of Fire ScienceFigure1-1aJapanesepaintingofthefirewhirl during thegreatKantoearthquakeinTokyo,1923.Photocourtesy of Y.Hasemi.Figure1-1bPhotograph ofcorpsesfromtheeffectof the firewhirl intheHitukuso-Atodistrict of Tokyo,1923.PhotocourtesyofK.Saito
Figure 1-1a Japanese painting of the fire whirl during the great Kanta earthquake in Tokyo, 1923.Photo courtesy of Y. Hasemi. Figure Mb Photograph of corpses from the effect of the fire whirl in the Hitukuso-Ato district of Tokyo, 1923. Photo courtesy of K. Saito. Chapter 1 The Evolution of Fire Science