ISBN 0-87814-856-6www.pennwellbooks.com

THE MOST COMPLETE GUIDE AVAILABLEON FOG NOZZLE RESEARCH & USE!

Finally, a book that describes the research, both historical and recent,which leads to the proper use of fog nozzles. The Safe & Effective Use ofFog Nozzles: Research and Practice suggests the most appropriate typesof fires, situations, tactics, and strategies that lead to the greater andbetter utilization of this often misused tool. Authors John E. Bertrand andJohn D. Wiseman examine a number of myths connected with fire-fighting that have contributed to tactics and tools that may producegreater risk to the firefighter and less efficient knock-down.

ABOUT THE AUTHORSJohn E. Bertrand, Ph.D., is an associate professor of aerospace at Middle Tennessee State University.Bertrand also serves as a firefighter, training officer, and safety officer for the Kittrell Volunteer FireDepartment in Murfreesboro,Tenn. In addition, he has also co-authored several books, published articles,and edited chapters for various academic titles.

John D. Wiseman has served as a volunteer firefighter for more than 40 years in New Jersey andTennessee. He is the author of The Iowa State Story (Fire Protection Publications, 1998) as well as numer-ous articles about the fire service. Contact the author at jdwiseman@mindspring.com.

FEATURES & BENEFITS

• Definitive • Text offers answers thatare credible and sound

• Empirical • Content is based onrecent research inNorth America and

Europe

• Practical • Research findings aretranslated to a field

orientation in a practical manner

• Approachable • Written in easy-to-

understand languagerather than technical

jargon

®

Fognozzzles cvr 3/5/03 1:28 PM Page 1

Research and Practice

Fog a FM i-xvi 1/16/03 10:43 AM Page i

Fog a FM i-xvi 1/16/03 10:43 AM Page ii

Research and Practice

John D. WisemanJohn E. Bertrand

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Copyright© 2003 byPennWell Corporation1421 South SheridanTulsa, Oklahoma 74112 USA

800.752.9764+1.918.831.9421sales@pennwell.comwww.pennwell-store.comwww.pennwell.com

Cover and book design by Clark BellJared Wicklund, Supervising Editor

ISBN: 0-87814-856-6

All rights reserved. No part of this book may be reproduced, storedin a retrieval system, or transcribed in any form or by any means,electronic or mechanical, including photocopying and recording,without the prior written permission of the publisher.

Printed in the United States of America

1 2 3 4 5 07 06 05 04 03

Fog a FM i-xvi 1/16/03 11:37 AM Page iv

Dedication v

Dedication

This book is dedicated to Floyd W. (Bill) Nelson and Keith Royer.These two men, through their research at Iowa State University,were the first to learn how to use fog nozzles safely and effectively.

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The Safe and Effective Use of Fog Nozzlesvi

Fog a FM i-xvi 1/16/03 10:43 AM Page vi

Table of Contents vii

Table of Contents

Dedication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

List of Tables and Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii

Chapter One – The Beginning . . . . . . . . . . . . . . . . . . . . . . . 1The Indirect Method of Attack . . . . . . . . . . . . . . . . . . . . . . . . . 2Parkersburg Experiments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Case Histories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91950: “Little Drops of Water” . . . . . . . . . . . . . . . . . . . . . . . . . 15The Exploratory Committee on the Application of Water . . . . 16Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Chapter Two: Success and Failure . . . . . . . . . . . . . . . . . . . 23Fire Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23The Fundamental Principle . . . . . . . . . . . . . . . . . . . . . . . . . . . 26Metric Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28The Iowa Rate-of-Flow Formula . . . . . . . . . . . . . . . . . . . . . . . 30Thermal Balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Key Test Fire. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36The Combination Attack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39Iowa State Research Summary . . . . . . . . . . . . . . . . . . . . . . . . 41The Identity Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42The Shut-off Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44Pushing a Fire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46Turnaround Tactics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48Misinformation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

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The Safe and Effective Use of Fog Nozzlesviii

Chapter Three: U.S. Naval Research Laboratory . . . . . . . 59First Test Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62Second Test Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64Third Test Series. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Chapter Four: European Research . . . . . . . . . . . . . . . . . . . 733-D Fog Attack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76Scandinavian Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84Flow Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Chapter Five: The Scientific Foundation for Fire Fighting 89Heat Energy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89Combustion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91Free Radicals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95Combustion Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95Incomplete Combustion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96Fire Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97The Fire Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99Plastics Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100Plastics Combustion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102Fighting Plastics Fires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103Scientific Uncertainty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103Thornton’s Rule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105Window Glass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Chapter Six: Strategic Principles for Fog Attack . . . . . . 113The Fifteen Strategic Principles . . . . . . . . . . . . . . . . . . . . . . . 113Fire Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115The Right Amount of Water . . . . . . . . . . . . . . . . . . . . . . . . . 118The Right Place . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

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Table of Contents ix

Needed Fire Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123No Magic Pill. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124The Fundamental Tactical Principle . . . . . . . . . . . . . . . . . . . . 126Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Chapter Seven: Tactics. . . . . . . . . . . . . . . . . . . . . . . . . . . . 129Constraint One . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130Constraint Two . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131Constraint Three . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132NFF Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133The Art of Firefighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139Fog Tactics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143Purposes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143Methods of Attack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144Methods to Avoid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151

Chapter Eight: The Mechanics of Fog Nozzles . . . . . . . . 153What is a Nozzle? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154Fog Nozzles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155Smooth-Bore vs. Fog Nozzles . . . . . . . . . . . . . . . . . . . . . . . . 158Nozzle Reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160Two Nozzle Myths. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163Fog Nozzle Teeth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165Shut-off Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167Hydraulics, Conventional Nozzles . . . . . . . . . . . . . . . . . . . . . 168Hydraulics, Automatic Nozzles . . . . . . . . . . . . . . . . . . . . . . . 169Hydraulics Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171Variable Flows. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173Blitz Attack Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

Chapter Nine: Research Highlights. . . . . . . . . . . . . . . . . 181The General Rate-of-Flow and Grimwood Formulas. . . . . . . 181Chief Lloyd Layman’s Research . . . . . . . . . . . . . . . . . . . . . . . 184

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The Safe and Effective Use of Fog Nozzlesx

Iowa State University Research:Keith Royer and Floyd W. (Bill) Nelson . . . . . . . . . . . . . . 185

US Naval Research Laboratory . . . . . . . . . . . . . . . . . . . . . . . 185European Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186Research Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188

Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

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List of Tables and Figures xi

List of Tables and Figures

1–1 Low Velocity Fog Nozzle . . . . . . . . . . . . . . . . . . . . . . . . . 21–2 Elkhart Mystery Nozzle . . . . . . . . . . . . . . . . . . . . . . . . . . 71–3 Elkhart Jumbo Mystery Nozzle . . . . . . . . . . . . . . . . . . . . 71–4 Rockwood Booster Nozzle . . . . . . . . . . . . . . . . . . . . . . . 81–5 2000 16th St. (front and rear view) . . . . . . . . . . . . . . . . 9

2–1 Nelson’s Fire Stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252–2 Too Little Water. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342–3 Too Much Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352–4 Ideal Rate-of-flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

3–1 Thomas Curve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 623–2 FOG 12 & FOG 15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

5–1 The Fire Triangle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 915–2 The Fire Tetrahedron . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

7–1 NFF Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1337–2 NFF Table Metric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1347–3 TFT Automatic Nozzle Data (English) . . . . . . . . . . . . . 1407–4 TFT Automatic Nozzle Data (Metric) . . . . . . . . . . . . . . 1407–5 Elkhart Brass Select-o-Flow Nozzle . . . . . . . . . . . . . . . 1417–6 Akron Brass Turbojet Nozzle . . . . . . . . . . . . . . . . . . . . 142

8–1 Smooth Bore Nozzle . . . . . . . . . . . . . . . . . . . . . . . . . . . 1548–2 Pattern Contro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1568–3 Automatic Fog Nozzle . . . . . . . . . . . . . . . . . . . . . . . . . 1578–4 Varying Flows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1578–5 Nozzle Teeth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1668–6 Water Triangle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1698–7 Hose Friction Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1728–8 TA Fog Fighter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1768–9 TA Fogfighter Cut-away . . . . . . . . . . . . . . . . . . . . . . . . 1778–10 TFT Automatic Cut-away . . . . . . . . . . . . . . . . . . . . . . 179

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The Safe and Effective Use of Fog Nozzlesxii

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Preface xiii

PrefaceThis introduction is being written at the beginning of the

21st century, 50 years after almost all fire departments in theUnited States switched from using smooth-bore nozzles to fognozzles. Yet arguments are being made today to return tosmooth-bore nozzles. Andrew Fredericks, in his article “LittleDrops of Water, 50 Years Later”, concludes with the followingstatement: “Fifty years after Layman’s ‘Little Drops of Water’, it’stime to admit that fog nozzles are not the answer.”1 In a recentbook published by the NFPA, authors Bernard J. Kleene andRussell J. Sanders conclude, “The reality is that there is little needfor fog streams during offensive structural fire fighting.”2

On the other side of the debate, Paul Grimwood notes howEuropean fire departments have created and used a “new-wave”3-D water fog attack. He says this is “…a new approach that hasbeen evaluated, developed, and proven scientifically.”3 Thus,European fire departments have integrated the 3-D fog attackinto their strategy and tactics so that fog nozzles play a crucialrole in initial fire attack on almost all structure fires. Grimwood’sargument is backed by Commander John P. Farley’s (US Navy)report on a series of tests conducted at the US Naval ResearchLaboratory. These tests compared the effectiveness of the tradi-tional straight-stream direct attack with the 3-D fog attack. Farleyconcluded the following: “… the offensive fog attack strategy isthe best method to safely maintain a rapid, continuous, andaggressive response to a fire when entry to the fire can be madebut direct access to the fire seat cannot be gained.”4

The US Navy in 1994 officially approved and adopted thenew 3-D fog attack for shipboard fire fighting.

This book explains the proper use of fog nozzles to providethe safest and most effective means of attack for certain types offires. It also explains how fog nozzles have been misused, leadingto the call by some for abandoning fog nozzles altogether. In ourwork we analyze the fire environment to determine the scientificfacts and principles that govern fire behavior and water behav-ior. We also analyze more than 50 years of experience in usingfog nozzles. However, neither experience nor trial-and-errormethods alone necessarily lead to the correct conclusions.Research is needed—research that involves very careful observa-

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The Safe and Effective Use of Fog Nozzlesxiv

tions and systematic analysis, all of which is based upon a thor-ough knowledge of scientific facts and principles.

Thus, the heart of this book is the presentation of researchprojects dealing with the use of fog nozzles. Though most of theresearch was conducted in the United States, this work is not wellknown nor recognized. This lack of knowledge leads to the mis-use of fog nozzles, and the calls to abandon fog nozzles com-pletely. However, research tells us that fog nozzles can be usedsafely and effectively. Our book presents the strategy and tacticsneeded to use fog nozzles safely and effectively.

We acknowledge Paul Grimwood’s help in writing the sec-tion on 3–D gas–cooling pulse tactics that are widely used inEurope. Grimwood, retired from the London Fire Brigade(England), is an author and authority on the use of fog nozzles,and he provided most of the information for the section onEuropean research. A wealth of information is available on hisWeb site: www.firetactics.com. He can also be reached by e–mailat firetactics@aol.com.

We also acknowledge the cooperation of StewartMacMillan, president of Task Force Tips. He freely made avail-able the booklet published by Task Force Tips, “A Firefighter’sGuide to Nozzles”. Much of the information in chapter 8 isobtained from this booklet.

Fog a FM i-xvi 1/16/03 10:43 AM Page xiv

Notes1Andrew Fredericks, “Little Drops of Water, 50 Years Later”, Fire Engineering

(Vol 153, No. 2, 3, Mar. 2000), p. 130.

2Bernard J. Kleene and Russell J. Sanders, Structural Fire Fighting, (Quincy,Mass., NFPA, 2000), p. 277.

3Paul Grimwood, “New Wave 3–D Water Fog Tactics”, Fire Engineering (Vol153 No. 10, Oct. 2000), p. 99.

4John P. Farley,“Fog Attack for Ship Fires”, Fire Engineering (Vol 147 No. 3, Mar.1996), p. 48.

Notes xv

Fog a FM i-xvi 1/16/03 10:43 AM Page xv

Copyright© 2003 byPennWell Corporation1421 South SheridanTulsa, Oklahoma 74112 USA

800.752.9764+1.918.831.9421sales@pennwell.comwww.pennwell-store.comwww.pennwell.com

Cover and book design by Clark BellJared Wicklund, Supervising Editor

ISBN: 0-87814-856-6

All rights reserved. No part of this book may be reproduced, storedin a retrieval system, or transcribed in any form or by any means,electronic or mechanical, including photocopying and recording,without the prior written permission of the publisher.

Printed in the United States of America

1 2 3 4 5 07 06 05 04 03

Fog a FM i-xvi 1/16/03 11:37 AM Page iv

Dedication v

Dedication

This book is dedicated to Floyd W. (Bill) Nelson and Keith Royer.These two men, through their research at Iowa State University,were the first to learn how to use fog nozzles safely and effectively.

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The Safe and Effective Use of Fog Nozzlesvi

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Table of Contents vii

Table of Contents

Dedication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

List of Tables and Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii

Chapter One – The Beginning . . . . . . . . . . . . . . . . . . . . . . . 1The Indirect Method of Attack . . . . . . . . . . . . . . . . . . . . . . . . . 2Parkersburg Experiments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Case Histories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91950: “Little Drops of Water” . . . . . . . . . . . . . . . . . . . . . . . . . 15The Exploratory Committee on the Application of Water . . . . 16Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Chapter Two: Success and Failure . . . . . . . . . . . . . . . . . . . 23Fire Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23The Fundamental Principle . . . . . . . . . . . . . . . . . . . . . . . . . . . 26Metric Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28The Iowa Rate-of-Flow Formula . . . . . . . . . . . . . . . . . . . . . . . 30Thermal Balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Key Test Fire. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36The Combination Attack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39Iowa State Research Summary . . . . . . . . . . . . . . . . . . . . . . . . 41The Identity Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42The Shut-off Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44Pushing a Fire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46Turnaround Tactics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48Misinformation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

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Chapter Three: U.S. Naval Research Laboratory . . . . . . . 59First Test Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62Second Test Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64Third Test Series. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Chapter Four: European Research . . . . . . . . . . . . . . . . . . . 733-D Fog Attack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76Scandinavian Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84Flow Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Chapter Five: The Scientific Foundation for Fire Fighting 89Heat Energy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89Combustion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91Free Radicals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95Combustion Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95Incomplete Combustion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96Fire Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97The Fire Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99Plastics Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100Plastics Combustion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102Fighting Plastics Fires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103Scientific Uncertainty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103Thornton’s Rule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105Window Glass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Chapter Six: Strategic Principles for Fog Attack . . . . . . 113The Fifteen Strategic Principles . . . . . . . . . . . . . . . . . . . . . . . 113Fire Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115The Right Amount of Water . . . . . . . . . . . . . . . . . . . . . . . . . 118The Right Place . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

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Needed Fire Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123No Magic Pill. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124The Fundamental Tactical Principle . . . . . . . . . . . . . . . . . . . . 126Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Chapter Seven: Tactics. . . . . . . . . . . . . . . . . . . . . . . . . . . . 129Constraint One . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130Constraint Two . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131Constraint Three . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132NFF Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133The Art of Firefighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139Fog Tactics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143Purposes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143Methods of Attack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144Methods to Avoid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151

Chapter Eight: The Mechanics of Fog Nozzles . . . . . . . . 153What is a Nozzle? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154Fog Nozzles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155Smooth-Bore vs. Fog Nozzles . . . . . . . . . . . . . . . . . . . . . . . . 158Nozzle Reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160Two Nozzle Myths. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163Fog Nozzle Teeth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165Shut-off Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167Hydraulics, Conventional Nozzles . . . . . . . . . . . . . . . . . . . . . 168Hydraulics, Automatic Nozzles . . . . . . . . . . . . . . . . . . . . . . . 169Hydraulics Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171Variable Flows. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173Blitz Attack Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

Chapter Nine: Research Highlights. . . . . . . . . . . . . . . . . 181The General Rate-of-Flow and Grimwood Formulas. . . . . . . 181Chief Lloyd Layman’s Research . . . . . . . . . . . . . . . . . . . . . . . 184

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Iowa State University Research:Keith Royer and Floyd W. (Bill) Nelson . . . . . . . . . . . . . . 185

US Naval Research Laboratory . . . . . . . . . . . . . . . . . . . . . . . 185European Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186Research Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188

Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

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List of Tables and Figures xi

List of Tables and Figures

1–1 Low Velocity Fog Nozzle . . . . . . . . . . . . . . . . . . . . . . . . . 21–2 Elkhart Mystery Nozzle . . . . . . . . . . . . . . . . . . . . . . . . . . 71–3 Elkhart Jumbo Mystery Nozzle . . . . . . . . . . . . . . . . . . . . 71–4 Rockwood Booster Nozzle . . . . . . . . . . . . . . . . . . . . . . . 81–5 2000 16th St. (front and rear view) . . . . . . . . . . . . . . . . 9

2–1 Nelson’s Fire Stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252–2 Too Little Water. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342–3 Too Much Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352–4 Ideal Rate-of-flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

3–1 Thomas Curve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 623–2 FOG 12 & FOG 15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

5–1 The Fire Triangle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 915–2 The Fire Tetrahedron . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

7–1 NFF Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1337–2 NFF Table Metric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1347–3 TFT Automatic Nozzle Data (English) . . . . . . . . . . . . . 1407–4 TFT Automatic Nozzle Data (Metric) . . . . . . . . . . . . . . 1407–5 Elkhart Brass Select-o-Flow Nozzle . . . . . . . . . . . . . . . 1417–6 Akron Brass Turbojet Nozzle . . . . . . . . . . . . . . . . . . . . 142

8–1 Smooth Bore Nozzle . . . . . . . . . . . . . . . . . . . . . . . . . . . 1548–2 Pattern Contro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1568–3 Automatic Fog Nozzle . . . . . . . . . . . . . . . . . . . . . . . . . 1578–4 Varying Flows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1578–5 Nozzle Teeth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1668–6 Water Triangle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1698–7 Hose Friction Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1728–8 TA Fog Fighter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1768–9 TA Fogfighter Cut-away . . . . . . . . . . . . . . . . . . . . . . . . 1778–10 TFT Automatic Cut-away . . . . . . . . . . . . . . . . . . . . . . 179

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Preface xiii

PrefaceThis introduction is being written at the beginning of the

21st century, 50 years after almost all fire departments in theUnited States switched from using smooth-bore nozzles to fognozzles. Yet arguments are being made today to return tosmooth-bore nozzles. Andrew Fredericks, in his article “LittleDrops of Water, 50 Years Later”, concludes with the followingstatement: “Fifty years after Layman’s ‘Little Drops of Water’, it’stime to admit that fog nozzles are not the answer.”1 In a recentbook published by the NFPA, authors Bernard J. Kleene andRussell J. Sanders conclude, “The reality is that there is little needfor fog streams during offensive structural fire fighting.”2

On the other side of the debate, Paul Grimwood notes howEuropean fire departments have created and used a “new-wave”3-D water fog attack. He says this is “…a new approach that hasbeen evaluated, developed, and proven scientifically.”3 Thus,European fire departments have integrated the 3-D fog attackinto their strategy and tactics so that fog nozzles play a crucialrole in initial fire attack on almost all structure fires. Grimwood’sargument is backed by Commander John P. Farley’s (US Navy)report on a series of tests conducted at the US Naval ResearchLaboratory. These tests compared the effectiveness of the tradi-tional straight-stream direct attack with the 3-D fog attack. Farleyconcluded the following: “… the offensive fog attack strategy isthe best method to safely maintain a rapid, continuous, andaggressive response to a fire when entry to the fire can be madebut direct access to the fire seat cannot be gained.”4

The US Navy in 1994 officially approved and adopted thenew 3-D fog attack for shipboard fire fighting.

This book explains the proper use of fog nozzles to providethe safest and most effective means of attack for certain types offires. It also explains how fog nozzles have been misused, leadingto the call by some for abandoning fog nozzles altogether. In ourwork we analyze the fire environment to determine the scientificfacts and principles that govern fire behavior and water behav-ior. We also analyze more than 50 years of experience in usingfog nozzles. However, neither experience nor trial-and-errormethods alone necessarily lead to the correct conclusions.Research is needed—research that involves very careful observa-

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tions and systematic analysis, all of which is based upon a thor-ough knowledge of scientific facts and principles.

Thus, the heart of this book is the presentation of researchprojects dealing with the use of fog nozzles. Though most of theresearch was conducted in the United States, this work is not wellknown nor recognized. This lack of knowledge leads to the mis-use of fog nozzles, and the calls to abandon fog nozzles com-pletely. However, research tells us that fog nozzles can be usedsafely and effectively. Our book presents the strategy and tacticsneeded to use fog nozzles safely and effectively.

We acknowledge Paul Grimwood’s help in writing the sec-tion on 3–D gas–cooling pulse tactics that are widely used inEurope. Grimwood, retired from the London Fire Brigade(England), is an author and authority on the use of fog nozzles,and he provided most of the information for the section onEuropean research. A wealth of information is available on hisWeb site: www.firetactics.com. He can also be reached by e–mailat firetactics@aol.com.

We also acknowledge the cooperation of StewartMacMillan, president of Task Force Tips. He freely made avail-able the booklet published by Task Force Tips, “A Firefighter’sGuide to Nozzles”. Much of the information in chapter 8 isobtained from this booklet.

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Notes1Andrew Fredericks, “Little Drops of Water, 50 Years Later”, Fire Engineering

(Vol 153, No. 2, 3, Mar. 2000), p. 130.

2Bernard J. Kleene and Russell J. Sanders, Structural Fire Fighting, (Quincy,Mass., NFPA, 2000), p. 277.

3Paul Grimwood, “New Wave 3–D Water Fog Tactics”, Fire Engineering (Vol153 No. 10, Oct. 2000), p. 99.

4John P. Farley,“Fog Attack for Ship Fires”, Fire Engineering (Vol 147 No. 3, Mar.1996), p. 48.

Notes xv

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CHAPTER 1The Beginning

Fog nozzles have been in existence formore than 100 years. Several early fog nozzleswere invented in the 19th century; by the 1930s,industrial fog nozzles were imported into theUnited States from Europe. These primitive noz-zles changed the fog pattern by rotating the bar-rel, although this also changed the flow rate. Asthe United States produced more and more cars,trucks, and diesel locomotives, the refining, pro-duction, and use of petroleum productsincreased very rapidly along with the problem offighting Class B fires. Solid–stream nozzles wereworthless for fighting Class B fires; in fact, theiruse worsened the situation.

By 1925, the oil fields of Santa Fe Springs,California, had become well known as one of theworst fire problems in the United States.Battalion Chief Glenn G. Griswold was then cap-tain of Engine Company 127, Santa Fe SpringsFire Station, in the Los Angeles County FireProtection District. Because Captain Griswoldhad the advantage of being a hydraulic engineer,he began the task of creating new types of noz-zles. Griswold created three types of fog nozzles,and by 1930 the California Fog Nozzle Companywas producing these nozzles. These nozzleswere later modified to become the U.S. Navy fognozzles that are still in use today.

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The Safe and Effective Use of Fog Nozzles2

The Indirect Method of AttackThe first real research on the use of fog nozzles was con-

ducted from 1943 to 1946 as a result of fires encountered duringWorld War II. Chief Lloyd Layman, of the Parkersburg, WV, FireDepartment became Commandant of the U.S. Coast Guard FireFighting School at Fort McHenry Training Station, Baltimore,Maryland. He conducted 20 experiments onboard a Liberty shipin its machinery, or engine, room. This space measured 50ft (15m)long, 53ft (16m) wide, and the height varied from 22ft to 32ft (6.7mto 9.7m). The net atmospheric volume (minus the machinery vol-ume) was approximately 65,000ft3(1,840m3). Fuel oil, from 5,000galto 7,000gal (18,925L to 26,495L) was released in the bilge space,providing approximately 1,800ft2 (167m2) of burning surface.Most of the fuel oil was below the steel floor plates, thereby pre-venting any water from being applied directly to the fuel oil. Thefuel oil was allowed to burn for at least 30min to provide the worstpossible fire onboard this ship.

These experiments used the Navy’s low–velocity fog nozzle,illustrated in Figure 1–1. The nozzle was attached to a short, 3ft(0.9m) applicator that was in turn attached to a 1.5in (38mm) hoseline with 100psi (6.9bar) nozzle pressure. In the early tests, twolines were used that flowed about 168gpm (635Lpm). In later tests,only one line was used; it flowed 114gpm (431Lpm). The fog noz-zles were lowered through a skylight near the aft bulkhead,allowing the water to be applied into the upper part of themachinery room some 28ft (8.5m) above the deck plates.

Closing the air–intake openings was the first and mostimportant step taken in these experiments. This restriction in

Fig 1–1: Navy Low–Velocity Fog Nozzle with Applicator

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The Beginning 3

oxygen supply reduced the fuel mass loss rate and minimized therate of heat release. Only one opening could not be closed–theopening between the smokestack and the stack casing, with anarea of 54ft2 (5m2).

Immediately after the 30min burn when the fog attackbegan, there was an out rush of smoke from the exhaust open-ing. A mixture of smoke and condensing steam followed. Thenthis changed to condensing steam, and within a few minutes theamount of condensing steam began to decrease. Water contin-ued to be applied for at least 25min to a maximum of 40min untilno more condensing steam appeared. During this entire time thethermocouples recorded a continuous decrease in temperaturethroughout the machinery room to below 300°F (149°C). The fueloil was cooled below its flash point of 200°F (93°C), with the tem-perature of the steel cooling to around 212°F (100°C).

Chief Layman realized that he had created a new method ofattack that he called “the indirect method”. He wondered how theburning fuel oil could be cooled and extinguished without apply-ing water directly to the burning fuel surface. After considerablestudy, he reached the following two conclusions:

• Rapid generation of steam within the confined spacecreates a violent atmospheric disturbance within thespace.

• Each cubic foot of steam generated within a confinedspace demands a cubic foot of that atmospheric space.1

Layman stated this “theory of indirect application andatmospheric displacement” as follows:

The cooling action of water in the form of finely dividedparticles at the upper atmospheric level within a highly heatedconfined space is not limited to the immediate area. The injectionof water into a highly heated atmosphere results in rapid gener-ation of steam, thereby creating an atmospheric disturbance ofsufficient force to distribute unvaporized particles throughoutthe space. Unvaporized particles are brought into contact withheated materials located beyond the immediate area and at thesame time contributing to the atmospheric disturbance byexpanding into steam. It appears that this action continues until

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The Safe and Effective Use of Fog Nozzles4

the surface temperature within the space is reduced to approxi-mately 212°F (100°C), the boiling point of water.

Rapid generation of steam increases the atmospheric pres-sure within the space––each cubic foot of steam demanding 1ft3

of atmospheric space. A building is not air–tight, therefore, theinterior and outside pressures are quickly equalized by an escapeof atmosphere from the higher to the lower area. If the volume ofsteam generated within the space exceeds the net atmosphericvolume of the space, most, if not all, of the original atmospherewill be displaced by steam. When the surface temperature with-in the space has been reduced to approximately 212°F (100°C),the boiling point of water, steam generation ceases.

At this time steam within the space starts to condense andcool air from the outside enters filling the void created by theprocess of condensation. This in draft of cool air from the outsideatmosphere tends to increase the rate of condensation and con-tinues until the process of condensation ceases. At this time, amajor part, if not all, of the atmosphere within the space consistsof normal air.2

The key to Chief Layman’s explanation is the statement thatunvaporized particles of water are blasted throughout the firearea and brought into contact with burning fuels throughout thespace, thereby cooling the fuels and extinguishing the fire. If thiswere not the case, the indirect method would not work.

This new method of attack was an achievement of greathistorical significance since it was the first alternative to a directattack using solid–stream nozzles. The term “indirect method”probably should be thought of in its simplest meaning, that is, asnot the direct method of attack with solid streams then in use.Layman states that unvaporized particles are brought into con-tact with burning fuels located beyond the immediate area ofapplication, thereby exerting cooling throughout the entire area.Thus, by steam expansion, water is brought into direct contactwith all of the burning fuels. In reality, what Layman called anindirect attack is nothing more than a direct attack. Unvaporizedparticles of water are brought into direct contact with all of theburning surfaces by steam rather than by direct application froma fog nozzle. While it might seem to be contradictory to say thatan indirect attack is really a direct attack, in essence that is whatactually happens.

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The Beginning 5

These experiments have been referenced repeatedly in sub-sequent years. The most frequent mention has been made of thefact that all but one of the air intake openings were closed. Manypeople have said that a fog attack (on land) would not workunless the structures were completely closed. However, oneshould be cautious in drawing any conclusions about structurefires based upon these early shipboard experiments because thecircumstances were simply too different from what is found instructural firefighting. The volume (85,000ft3; 2,400m3) was muchlarger than the volume of an average–size house (20,000ft3;566m3). The floor, walls, and ceiling of the machinery room weresteel, capable of being sealed air–tight almost to the theoreticalmaximum. The low–velocity Navy fog nozzle had a reach of about5ft (1.5m) in a semispherical shape in front of the nozzle. With a22ft to 32ft (6.7m to 9.7m) ceiling height, no water was applied any-where near the burning fuel oil surface. The net atmospheric vol-ume of the machinery room required 325gal (1,230L) of water tocompletely fill that space full of steam. The water was applied atthe rate of 114gpm to 168gpm (431Lpm to 635Lpm), requiring 2min to3min to apply that amount. In fact, water was applied for an aver-age of 30min, providing anywhere from 3,500gal to 5,000gal(13,247L to 18,925L) in these experiments. None of this dataapplied to structural firefighting, but it provided the knowledgeon which further research was based.

As interesting as these experiments are, further experi-ments were needed to find out how to use fog nozzles safely andeffectively for structural firefighting.

Parkersburg ExperimentsLayman further concluded that much more work needed

to be done to adapt his new method of attack to structural fire-fighting. When he returned to Parkersburg, West Virginia, aschief of the fire department, he experimented from 1947 to 1951.

Beginning in 1947, Layman took two years to train andequip the members of the Parkersburg Fire Department with theskills and equipment necessary to successfully use his newmethod of attack. Although Layman did not provide any detailsof this training in his book, the training certainly included the

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The Safe and Effective Use of Fog Nozzles6

fundamentals of fire behavior and water behavior as presented inthe first two chapters of his book.

Layman’s most notable contribution here is his classifica-tion of three phases of structural fire development:

Phase I: Incipient or smoldering periodOxygen level = 21%

Phase II: Flame production periodOxygen level = 21% to 15%

Phase III: Smoldering periodOxygen level < 15%.

Chief Layman discussed in detail the equipment required tomake a fog attack. The following nozzles were used.

• The Elkhart Mystery Nozzle––This nozzle was the indus-trial type with a rotating barrel that provided anadjustable fog pattern from straight stream to wideangle (60°). Even though the nozzle could be shut off byrotating the barrel, Layman used a Wooster Brassshut–off valve so the nozzle could be shut down quickly.At 100psi (6.9bar), one nozzle delivered 65gpm (246Lpm)fog and 60gpm (227Lpm) straight stream. The other nozzledelivered 90gpm (340Lpm) fog and 70gpm (265Lpm) straightstream.3

• The Elkhart Jumbo Mystery Nozzle––A master streamnozzle with a rotating barrel. Delivery rate 425gpm(1608Lpm) at 30° fog and 350gpm (1324Lpm) straightstream. (See Figure 1–3)3

• Rockwood Booster Nozzle–Flow rate on this nozzle was18gpm (68Lpm) in a fixed fog pattern and 18gpm (68Lpm) asa 1/4in (0.6cm) solid–stream nozzle. Impinging jets pro-duced the fog. (See Figure 1–4)4

• Navy Low–Velocity Heads (Rockwood SprinklerCo.)––These heads were attached to an applicator or acellar pipe. One head delivered 114gpm (431Lpm) and theother head delivered 54gpm (204Lpm). (See Figure 1–1)

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Fig 1–2: Elkhart Mystery Fog Nozzle

Fig 1–3: Elkhart Jumbo Mystery Nozzle

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One interesting thing that Chief Layman did was to weldthe Elkhart Mystery nozzles so the barrel could not be rotated toprovide a fog pattern wider than 30°. He believed this setting pro-vided the optimum reach and the best fog, that is, the best size ofwater droplets. All of his firemen were instructed to use the 30°fog pattern when making a fog attack.

However, Chief Layman recognized that the equipmentproblem had not been solved with the use of these nozzles. So headded the following:

This system of firefighting offers a real challenge to inven-tors, designers, and manufacturers of firefighting equip-ment. They should approach this problem with a compre-hensive understanding of the natural laws that govern theextinguishing action of water and its proper tacticalemployment on the fire ground. Progress in the art of fire-fighting demands practical equipment that will enable thefire service to utilize the vast extinguishing action of watermore effectively in attacking and extinguishing fire.5

Thus Chief Layman’s pioneering research established afoundation for safe and effective use of fog nozzles. He lookedforward to further research that would establish the most effec-tive use of fog nozzles.

Fig 1–4: Rockwood Booster Nozzle

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Case HistoriesIn his book, Layman presented six case histories. Detailed

reports and photographs were made on all working structurefires in Parkersburg. To give a clear picture of how the fog attackwas conducted, the first case history is presented here in somedetail. The other five case histories are also summarized.

Case History 1This fire occurred in a one–story dwelling in Parkersburg in

May 1949. The 1st floor of 1,800ft2 (167m2) was divided into twoapartments from front to rear with a short common hallway anda common bath at the rear. There was a semi–finished basementwith an interior stairway and another inside stairway leading tothe attic from the west–side apartment where the fire occurred.The west–side apartment also had a small rear porch with noaccess to the ground. The fire started in the kitchen from an over-heated refrigerator electric motor.6 (Insert Figure 1–5)

Upon the arrival of the first fire truck, the kitchen and rearporch were involved in fire. Heavy smoke filled the west–sideapartment and the attic. Firefighters broke the west–side windowand made their initial attack. Using a ladder to gain access to theporch, they made a direct attack on the rear porch. Chief Laymandescribed the initial attack as follows: “Immediately there was aviolent expulsion of smoke followed by a mixture of smoke andcondensing steam. The entire house was enveloped in a cloud ofsmoke and condensing steam.”4 Two 1.5in (38mm) lines were usedin the attack, both with high–velocity fog nozzles flowing approx-imately 54gpm and 65gpm (204Lpm and 246Lpm). Less than 200gal(757L) of water were used to extinguish the fire. Approximately

Fig 1–5: 2000 16th Street

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125gal (473L) were used in the attack through the kitchen window,which lasted about 2min. Approximately 75gal (284L) were used inthe attack on the exterior fire on the porch, leaving less than 5gal(19L) of water on the kitchen floor and a small area of the bed-room floor.

The volume of the west–side apartment and the attic was11,000ft3 (311m3). The 125gal (473L) of water applied through thekitchen window produced approximately 25,000ft3 (707m3) ofsteam based upon a 90% conversion rate. This was enoughsteam to replace the inside atmosphere of the apartment twotimes. Needless to say, the conclusion drawn by Chief Layman isfully justified: “The most practical and effective method of con-trolling and extinguishing this type of fire is by the proper appli-cation of the necessary volume of water in the form of finelydivided particles.”5

This 1949 fire was the first recorded use of water fog inextinguishing a Class A fire. As with Class B fires, the resultswere spectacular. The fire was extinguished with a very smallamount of water in a very short period of time.

A conclusion from this case history is that a fire does nothave to be completely confined for a fog attack to be effective.This fire had burned through to the outside rear porch and hadalso burned through the rear attic window.

Case histories 2–6The second fire occurred in a vacant two–story house

with an unfinished attic with several gables. The initial attack wasmade from the inside stairway at the top of the stairs. Fifty gal-lons (189L) of water were used, being converted to 10,000ft3

(283m3) of steam. The volume of the attic space was 4,000ft3

(113m3). Again, this volume of steam was enough to have twocomplete changes of atmosphere in the attic. The nozzle operatorwas forced to retreat from his position at the top of the stairs,although he returned and used an additional 50gal (189L) of waterto control the attic fire. The third fire occurred in a warehousethat was divided into two sections––a west section of 30,000ft3

(849m3) net volume and an east section of 27,000ft3 (764m3). Theceiling height was 16ft (4.9m) on the west end and 19ft (5.8m) onthe east end. The fire started from a rubbish pile at the rear of thebuilding that spread into the warehouse and burned through the

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roof at the rear. Four 1.5in (38mm) attack lines were used to extin-guish the fire. One line was used exclusively to protect exposuresand to extinguish the trash fire at the rear. Two lines were usedto make a direct attack through two of the four burned–out win-dows in the east section. The fourth line was used to make anindirect attack through the transom of a door leading into thewest section. The fourth line used 270gal (1,021L) in the indirectattack that converted to 54,000ft3 (1,528m3) of steam. The volumeof the west section was 30,000ft3 (849m3) net. Again, this is veryclose to two complete changes of atmosphere for this section ofthe warehouse. Using four lines, the attack successfully extin-guished the fire.

The fourth fire was in an ordinary one–story dwelling inwhich fire involved three rooms with heat spreading to the otherrooms. The net volume of the house was 8,400ft3 (238m3). The ini-tial attack was made at the rear bedroom window and then pro-gressed to the rear porch where an attack was made through thekitchen door. About 85gal (321L) were used, which produced17,000ft3 (481m3) of steam. That volume was sufficient to providetwo complete atmospheric changes within the house. The firewas extinguished using a single attack line.

The fifth fire occurred in the basement of a small house. Thebasement measured 33ft � 24ft (10m � 7m) with a net atmospher-ic volume of 3,500ft3 (99m3). There were not very many com-bustibles in the basement. The fire started when a 1gal (3.8L) jugof gasoline was dropped, resulting in gasoline vapors beingignited by a pilot light. The initial attack was made through abasement window with a 1.5in (38mm) attack line flowing 65gpm(246Lpm) for 20s, thereby flowing 20gal (75L) of water. Twenty gal-lons vaporizes to 4,000ft3 (113m3) of steam. This volume just aboutequals the volume of the basement. This fire was extinguishedvery quickly with little damage to the house.

Finally, the sixth fire occurred in a commercial buildingwith a three–story section in front and a one–story sectionbehind. The fire started on the 1st floor near the elevator shaftand spread upward through the 2nd and 3rd floors and outthrough the roof. The attack was made with two 2.5in (64mm) lineswith solid–stream nozzles flowing 220gpm (832Lpm) each. The firstline quickly knocked down the fire on the 1st floor at the base ofthe elevator shaft. The second line was taken to the roof of the

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one–story section and was used to attack the fire through a sec-ond–story window. The window had heavy metal bars that couldnot be removed. Thus, the solid stream was broken up to someextent by these bars.

The attack through the 2nd floor window blacked out thefire, and the nozzle was shut down. Then the fire reappeared andthe nozzle was opened again; the flames were extinguished. Thisattack continued for about 7min, flowing about 1,500gal (5,678L)of water. The net volume of the 2nd floor was 25,000ft3 (707m3).The net volume of the 3rd floor was 33,000ft3 (934m3).Vaporization of 125gal (473L) was needed for the 2nd floor, and165gal (624L) were needed for the 3rd floor. Layman estimatedthat anywhere from 300gal to 500gal (1135L to 1892L) were vapor-ized out of the 1,500gal (5,678L) applied.

Chief Layman was dissatisfied with this attack––particular-ly with the amount of water used. He concluded these things:

1. A single 1.5in (38mm) line equipped with a 65gpm (246Lpm)high–velocity fog nozzle would have provided sufficientrate of application to have extinguished the fire on the1st floor.

2. A single 1.5in (38mm) line equipped with a 90gpm (340Lpm)high–velocity fog nozzle would have provided a suffi-cient rate of application to have displaced the originalatmosphere and extinguished surface burning on 2ndand 3rd floors and in the cockloft, provided the cone ofwater particles had been directed into the upper stratumof the interior atmosphere through the burned–out win-dow.

3. If an indirect attack had been made through theburned–out window using a 90gpm (340Lpm) high–veloc-ity fog cone, equal or better results would have beenobtained with one–third to one–fifth the volume of waterthat was applied with the solid streams.7

Three conclusions can be drawn from these six case histo-ries. First, there is a definite relationship between the volume ofwater applied and the net atmospheric volume: 2:1 in four ofthese fires and 1:1 in the fifth Class B fire. In the sixth fire, much

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more water was applied through solid–stream nozzles than wasneeded to fill the net atmospheric volume full of steam.

Therefore, an indirect attack probably requires a volume ofwater that provides two atmospheric changes in the fire volume,but only one atmospheric change is needed for fire control. If theoriginal contaminated atmosphere is displaced by steam, then asthe steam condenses the inflow of cooler air means the atmos-phere consists of normal air. So a second displacement is notneeded. In fact, there is no way for a fog nozzle to displace nor-mal air with steam because normal air is not hot enough to pro-duce steam. What is needed is a fog attack that uses a volume ofwater equal to the volume of the fire.

Second, in five of the six case histories only one line wasused to control the structure fire. This is true of the commercialbuilding since the fire line was used only briefly on the 1st floor.The only exception is the warehouse fire. In four cases, fire wasextinguished in adjacent rooms, or spaces, without any waterbeing applied to these areas. This is called the indirect effect ofthe indirect attack. The indirect effect is especially effective inareas above the fire floor, which explains why the indirect effectis not limited to the immediate area, or room, where the water isapplied. Remember Layman’s explanation of why this happens.Unvaporized particles of water are blasted throughout the firearea, including adjacent areas, so that little drops of water arebrought into contact with burning fuels throughout the space.

Finally, the flow rate needed to control a one–room struc-ture fire is well below 100gpm (378Lpm). Layman’s data indicatethat flow around 50gpm (189Lpm) is sufficient for such fires. One1.5in (38mm) fully open attack line provides too much water forsuch a fog attack.

Chief Layman summarized the fundamentals of the indirectmethod of attack as follows:

1. Degree of confinement and concentration of excessiveheat are important factors in this method of attack.

2. The initial attack should be made within the area of majorinvolvement.

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3. Atmospheric displacement will occur only on and abovethe floor where an indirect attack is made.

4. The progress of an indirect attack can be estimated read-ily by observing the volume of smoke and condensingsteam coming from the building.

5. Injection of water particles should continue withoutinterruption until the volume of condensing steam com-ing from the building has decreased to a major degree.

6. After an indirect attack has been executed in the propermanner, personnel may enter and operate within thebuilding––perhaps with some discomfort due to highhumidity rather than high heat.

7. An indirect attack should always be made from a posi-tion that will enable personnel to avoid injuries fromheated smoke and steam.

8. When openings are made, they should be small; a door-way is an undesirable type of opening.

9. If the attack is made through a window or otherlow–level opening or from an interior stairway, ahigh–velocity cone should be used.

10. A fire in a cockloft or unfinished attic may be attackedby making a small opening in the ceiling below andinserting a straight applicator fitted with a low–velocitynozzle.

11. Where an attack must be made from a floor above, acellar pipe should be used; personnel should be with-drawn before the attack is made.

12. A high degree of dispersion of water particles withinthe upper stratum of the interior atmosphere is animportant factor in obtaining rapid heat absorption anda high percentage of conversion.

Layman added to point 12 that considerable skill and confi-dence are required to obtain a high degree of dispersion when

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using high–velocity nozzles in an indirect attack. Besides recog-nizing that the equipment problem had not been solved, Laymanalso recognized that the most effective flow rate posed a difficultissue for which there is no definite formula. He was limited, ofcourse, by having nozzles whose rate of flow varied with therotation of the barrel.

Many statements have since appeared in print that do notaccurately reflect Layman’s views. He did not advocate the exclu-sive use of the indirect method of attack. He said that fires in thefirst phase of development have not generated enough heat tojustify an indirect attack. He clearly stated that such fires must belocated and extinguished by a direct attack. He added, “An expe-rienced and capable officer should have little difficulty in deter-mining if the situation demands a direct or indirect attack.”7 ChiefLayman discouraged the use of booster lines in making an indi-rect attack. His reason: “The volume of water per minute is toosmall to produce satisfactory results in larger spaces exceptunder the most favorable conditions.”8

Chief Layman also said that he was frequently asked aquestion about the indirect method of attack: “What is the effectof steam from an indirect attack upon occupants in a building?”Chief Layman said that he had never heard of any adverseeffects. He added, “The much more rapid flame suppression withindirect application makes it possible to reach endangered per-sons more quickly so as to be able to remove them to safety andrender aid as necessary.”9

1950 “Little Drops of Water”By 1950, Layman’s work had come to the attention of a

number of officials in the fire service. Officials of the NationalFire Protection Association (NFPA) became interested, and theylater published two books by him. Also, officials of the WesternActuarial Bureau, Chicago, Illinois, decided to explore the use offog nozzles. As a result, Layman was invited to address the annu-al Fire Department Instructor’s Conference in Memphis,Tennessee. His speech marked an historic turning point for thefire service in the United States. On January 11, 1950, he gave aspeech entitled “Little Drops of Water”, promoting his new

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method of fog attack. He concluded that “Little if any progresscan be made in improving the tactical employment of water infirefighting operations until the gross ineffectiveness of the solidstream method of application is recognized.”11

Chief Layman’s speech was not only heard by the attendeesat the FDIC Conference, but also it was read the following monthin Firemen magazine. The NFPA reprinted this article and wide-ly circulated it.

The Exploratory Committee onthe Application of Water

The Advisory Engineering Council of the National Board ofFire Underwriters met in Detroit in May 1951. R.D. Hobbs, man-ager of the Western Actuarial Bureau (W.A.B.), authorizedRichard E. Verner, manager of the W.A.B. fire prevention depart-ment, to appoint a committee to conduct tests of the new indirectmethod of attack. In 1951, Verner appointed a committee knownas the Exploratory Committee on the Application of Water.Emmett T. Cox of the W.A.B. was named chairman, and the com-mittee was comprised of 33 members who represented fire insur-ance, engineering, inspection, rating organizations, the fire serv-ice, and fire training agencies.

The Exploratory Committee selected Miami, Florida, as thesite where the first tests would be conducted. Chief Henry Chaseof the Miami Fire Department was a member of this committee;his department had been using fog nozzles for some time. Also,the Miami Fire Department had a fully instrumented buildingavailable. The tests were conducted from October 29 throughNovember 2, 1951. Interestingly, the Miami Fire Department pro-vided a real fire as well for the members of the committee toinvestigate. On October 28, a fire occurred in an automobilerepair garage, completely involving the 4,800ft2 (446m2) structure(one story) before the alarm was sounded. Two 1.5in (38mm) lineswith adjustable fog nozzles controlled this fire. The members ofthe committee found this very instructive since the fire was con-trolled quite effectively by the use of fog nozzles.

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The test building was two stories of fire–resistive construc-tion featuring concrete walls, ceiling, roof, and windows withmovable concrete shutters. The building had 17 fixed thermo-couples––eight on the 1st floor and nine on the 2nd floor––withan 18th movable thermocouple. Wooden partitions divided the1st floor into eight rooms, and each room had a thermocouple.The fog nozzles used had different gpm capacities but were usu-ally set at a 30° fog pattern. Nozzle pressure was 100psi (6.9bar),and the fuel load was approximately 10lb/ft2 (4.5kg/m2).

One purpose of the tests was to verify the indirect extin-guishing effect of fog nozzles. A second purpose was to identifytraining problems in teaching the new method. The tests werenot designed to determine why the indirect effect was producedor to develop techniques for maximum effectiveness.

Four tests were held, with the first two tests involving oneroom on the 1st floor. Test 3 involved the entire 1st floor, and test4 involved the entire 2nd floor. Test 4 utilized a greater flow ratethat produced much better results than test 3. Only one attackline was used on each test. Table 1–1 summarizes the results ofthese tests.

Test Time Flow Rate Water used(min) (gpm) (Lpm) (gal) (L)

1 11.0 28 106 308 1,165

2 4.8 85 321 408 1,544

3 19.9 85 321 1,692 6,404

4 7.5 180 681 1,350 5,109

The committee did not draw any conclusions about thetime, flow rate, or amount of water used. Their conclusions wererelated to the original purpose of the tests:

Table 1–1: The Miami Tests

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1. In all of the tests, the indirect effect of the fog or spraystreams was clearly apparent. The water vapor penetrat-ed all parts of the structure.

2. In one demonstration, the Miami Fire Department extin-guished a fire using new men who had just completedbasic training. Based upon this, the committee main-tained it was unnecessary for firefighting forces to haveextensive training to use the technique properly.

3. The results of the tests and demonstrations indicated sufficient effectiveness of water fog or spray to warrantadditional study and tests under other circumstances.

4. Since extensive training in the use of the technique to prevent increased fire was proven unnecessary, thecommittee concluded fire departments should beencouraged to use the method when opportunity waspresented.

The report ended with a broad range of recommendationsfor further study. Still, given the limited objectives of these Miamitests, further testing was needed to establish the most effectivemethods for using fog nozzles.

In an attempt to make the tests more realistic, in 1952 a sub-committee of the Exploratory Committee directed a significantseries of tests in Kansas City, Missouri. This was the first timethat tests were conducted in dwellings with common furnishings.The three test buildings were small: one 23ft � 32ft (7m � 10m) andone 22ft � 30ft (7m � 9m) one–story structures and a two–story22ft � 40ft (7m � 12m) structure. The construction was frame andstucco, or block walls, with lath and plaster interior walls andceilings.

All of the tests used a 1in booster line with a Rockwood fognozzle. In three of the tests, two booster lines were used. The ini-tial attack was followed up by a direct attack to extinguish thefire. These tests represented real progress in establishing theeffectiveness of fog nozzles with a time of 60s or less for aone–room fire, a flow rate less than 50gpm (189Lpm), and less than50gal (189L) of water used.11 Table 1–2 shows the test results.

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Test Lines Time Flow Rate Water used(s) (gpm) (Lpm) (gal) (L)

1 1 20 25 94 8.0 31

2 1 180 25 94 75.0 282

Attic 1 42 25 94 17.5 66

3 2 80 50 189 66.0 250

2nd Floor 2 60 50 189 50.0 189

1st Floor 2 180 50 189 150.0 567

The Exploratory Committee conducted or supervisedabout 40 more tests or demonstrations during the next sevenyears. In addition, individual members of the committee attend-ed and reported on more than 100 other tests. State fire schoolsor individual fire departments conducted many of these tests.The result of all of this activity was the widespread adoption ofthe indirect method of attack and the almost universal use of fognozzles.

As fog nozzle acceptance increased, members of theExploratory Committee also participated in a series of nozzletests from 1952 through 1959 sponsored by the NFPA and theInternational Association of Fire Chiefs (IAFC). A photographicsubcommittee of the Exploratory Committee also produced fourfilms: “Using Water Wisely”, “Master Spray Stream Problems”,“Fog Against Fire”, and “Let’s Try Fog”. Members of the photo-graphic committee also assisted in producing films by otherorganizations.

The Exploratory Committee certainly did its job thorough-ly. Not only did it explore the new indirect method of attack andthe use of fog nozzles, but it also exerted a profound influenceupon numerous organizations throughout the United States.

Table 1–2: The Kansas City Tests

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SummarySubstantial progress was made from 1943 to 1959 in estab-

lishing the effectiveness of fog nozzles. In 1943, experiments wereconducted onboard a single Liberty ship at the Coast GuardTraining Station in Baltimore, Maryland. By 1959, tests anddemonstrations had been held throughout the United States bythe Exploratory Committee. The result of this activity was thatalmost all fire departments switched from using solid–streamnozzles to using fog nozzles in fighting structure fires. This wastruly a revolutionary change for the fire service.

The first experiments at the Coast Guard Fire School standin stark contrast to the subsequent experiments. The 20 experi-ments onboard the Liberty ship had a typical application time of30min, a flow rate of 114gpm or 168gpm (431Lpm or 636Lpm), andused 3,500gal to 5,000gal (13,247L to 18,925L) of water. If thesenumbers had truly measured the effectiveness of fog nozzles,then that would have been the end, not the beginning.

The Parkersburg and Kansas City experiments advancedthe use of fog nozzles. A time of 1min to 2min was typical,depending upon whether one or more rooms were involved in afire. The flow rate varied from 65gpm to < 100gpm (246Lpm to <378Lpm) with 50gal to 100gal (189L to 378L) used. The Kansas Citytests used a booster line that had a flow rate of 25gpm (94Lpm).These tests indicated that for a one–room fire, a fog nozzle couldbe used to control a fire in seconds with a flow rate of 50gpm(189Lpm) and using less than 50gal (189L) of water. Still, these testsdo not establish an exact mathematical relation between the vol-ume of the fire and the volume of water used.

The Parkersburg tests clearly indicate that the indirectmethod of attack was not as effective as it should have been. Thefact that a volume of water was used that equals two net atmos-pheric changes indicates an effectiveness of 50% for the indirectmethod. However, these tests do establish an indirect effect forthe use of fog nozzles. That is, the rapid steam expansion affectsnot only the room where water is applied but also adjacent areasthat have been heated more than 212°F (100°C). This atmospher-ic displacement increases the effectiveness of the attack andgreatly shortens the time of attack since one line from one posi-tion can control a fire in adjacent areas. Thus, it is not necessary

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to move the nozzle to different positions or to use several attacklines at different positions.

The key is Layman’s explanation that unvaporized drops ofwater are blasted throughout the fire area, including adjacentareas, thereby cooling the burning fuels. This new method ofattack provides an indirect application of water in one locationand then steam blasts unvaporized particles of water throughoutthe entire fire area. The water, in turn, directly cools the remain-ing fuels. In essence, an indirect attack is a direct attack through-out the fire area. If you understand why this statement is true,then you understand Layman’s theory of the indirect attack andatmospheric displacement.

This historic research provides us with the foundation formore modern inquiry, giving us the basic format for newresearch. Modern researchers, as we will see, have producedexcellent findings using Layman’s experiments as a startingpoint.

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Notes1Lloyd Layman, Attacking and Extinguishing Interior Fires

(Quincy, Mass., NFPA, 1955), p. 36.

2Ibid, p. 36 ff.

3Ibid, p. 58.

4Ibid, p. 59.

5Ibid, p. 70.

6Ibid, p. 70.

7Ibid, p. 138.

8Ibid, p. 40.

9Ibid, p. 145.

10Ibid, p. 146.

11John D. Wiseman, The Iowa State Story, (Stillwater, OK, FireProtection Publications, 1998), p. 46

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Bengtsson, Lars–Goran, Report 12019, LundUniversity l999, Sweden.

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Carlson, Gene “Lloyd Layman’s Theory: Its Timehas Come and Gone”, Fire Engineering, Vol.135 No. 2 Feb. 1983.

Chitty, Richard, Report 5–94, UK Research andDevelopment Group, (FRDG) UnitedKingdome (Great Britain).

Clark, David “Let’s Get Something Straight”,Illinois Fire Service Institute, Champaign IL,Summer 1990.

Clark, David “Straight Talk about Nozzles andFire Attack”, Illinois Fire Service Institute,Champaign IL, unpublished newsletter.

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The Safe and Effective Use of Fog Nozzles190

Clark, Frederick B. “Fire Hazards of Materials – an Overview”,National Fire Protection Association Handbook 17th Edition.Quincy MA: NFPA 1991.

Clark, William F. Firefighting Principles and Practices. SaddleBrook N.J.:” Fire Engineering 1991.

Comeau, Ed “Roof Collapse Kills Three”, National Fire ProtectionAssociation Journal, Vol. 93 No. 4 July–August 1999.

Darwin, R.L. et al Post–Flashover Fires in ShipboardCompartments Aboard Ex–USS Shadwell, Phase VI,Boundary and Compartment Cooling. Mobile AL: NavalResearch Laboratory 1994.

Davis, Larry Rural Firefighting Operations, Vol. 2. Ashland MA:International Society of Fire Service Instructors, 1986.

Farley, John P. et al Phase I – Full Scale Offensive Fog AttackTests. Mobile AL: Naval Research Laboratory 1997.

Farley, John P. “Fog Attack for Ship Fires”, Fire Engineering, Vol.147 No. 7 July 1996.

Fire, Frank Combustibility of Plastics. New York: Van NostrandReinhold 1991.

Fitzgerald Robert W., “Structural Integrity during Fires”.National Fire Protection Association Handbook 17th Edition.Quincy MA: NFPA 1991.

Fleischman, Charles, NIST–GCR–94–846, National Institute ofStandards and Technology, 1994, University of California,Berkley, CA.

Fornell, David P. Fire Stream Management Handbook. SaddleBrood N.J.: Fire Engineering 1991.

Grant & Drysdale D.. Report 1/97 UK Fire Research andDevelopment Groups (FRDG), United Kingdome (GreatBritain).

Grimwood, Paul “New Wave 3–D Water Fog Tactics”, FireEngineering Vol. 153 No. 10 Oct 2000 p. 99.

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Bibliography 191

Grimwood, Paul Fog Attack. Redhill UK: FMJ InternationalPublications LTD, 1992.

Hickey, Harry R. Hydraulics for Fire Protection. Quincy MA:National Fire Protection Association, 1980.

Huggett, Clayton, “Estimation of Rate of Heat Release by OxygenConsumption Measurements” Fire and Materials, Vol. 4 No.2, Feb 1980, p. 54.

Kleene, Barnard J. and Sanders, Russell J. Structural FireFighting. Quincy MA: National Fire Protection Association,2000.

Knapp, Jerry and Delisio, Christian, “Energy–Efficient WindowsFirefighters Friend or Foe”, Firehouse, Vol. 22 No. 7 July1977, p. 74 ff.

Knopt, Richard A “Fog Streams Compared with StraightStreams”, Fire Chief , Vol. 23 No. 7 July 1979, p. 36.

Lauren, Anders, personal communication, 1990.

Layman, Lloyd Attacking and Extinguishing Interior Fires.Quincy MA: National Fire Protection Association, 1955.

Leonard, J.T. et al, Post–Flashover Fires in Simulated ShipboardCompartments, Phase I Small Scale Studies, Chesapeake BayDetachment Fire Test Facility, Naval Research Laboratory,1991.

Lie, T.T. “Fire Temperature Time Relations”, SFPE Handbook ofFire Protection Engineers. Quincy MA National FireProtections Association, 1995.

Nelson, Floyd W (Bill) Qualitative Fire Behavior. Ashland MA,International Society of Fire Service Instructors, 1991.

Richman, Harold “Improving Interior Fire Attack”, FireCommand Vol. 53 No. 7 July 1986, p. 18.

Royer, Keith, “Water for Fire Fighting”, Iowa State UniversityEngineering Extension Service. Ames IA: Bulletin 18, undat-ed.

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The Safe and Effective Use of Fog Nozzles192

Royer, Keith “Test Fire for Exploratory Committee onApplication of Water”, Iowa State University EngineeringExtension Service, 1959.

Royer, Keith “Report on Story City Fire Test” Iowa StateUniversity Engineering Extension Service, Bulletin, 1959.

Rosander, Mats and Gielson, Kristen, Fire Magazine UK, October1984, p. 43 – 46.

Sardqvist, Stefan, Report 7003, Lund University, 1998, Sweden.

Scheffey, J.P., Siegmann, C.W., Toomey, T. A., Williams, F.W.,Farley, J.P, Phase II – Full–Scale Offensive Fog Attack Tests,NRL/MR/6180–97–7944, U.S. Naval Research Laboratory,1997.

Sutherland, B.J., Report 99/15, University of Canterbury, 1999New Zealand.

Task Force Tips, A Firefighter’s Guide to Nozzles, Valparaiso IN:Task Force Tips , 1995.

Tour & Andersson Hydronics AB, Fogfighter. Sweden Ljing:Tour & Andersson Hydronics, 1994.

Tuomisaari, Maarit, Suppression of Compartment Fires with aSmall Amount of Water VTT (National Research Laboratory)Finland.

Wiseman, John D. The Iowa State Story, Stillwater OK: FireProtection Publications, 1998.

Fog k Biblio 189-192 1/16/03 10:59 AM Page 192

Index

A3-D pulse attack, 146

3-D water fog attack, xiii-xiv,9-11, 71, 74-83pulsating flow, xiii-xiv, 78compartment fire, 76 gas cooling, 76-80, 83 atmosphere displacement,76-77 fire suppression, 76-77defensive/offensive tactics,77, 81-83 ignition, 77, 81simulation, 77, 80 contraction of gases, 78-80pushing the fire, 79, 82fog pattern, 79-80heat transfer, 80 benefits, 81 oxygen level, 81 free radicals, 81 myths/misconceptions, 81-83spray pattern, 82 personnel safety, 82 thermal balance/imbalance,82 flow rate, 82-83ventilation, 82 water-hammer effects, 82-83 amount of water needed, 83

Access to fire, xiii, 67, 120-122

Air draft, 4, 76

Air-intake opening, 2-3, 5, 14,76 draft, 4, 76size, 14

Akron Brass Turbojet nozzle,142

Amount of water calculation,133-138

Amount of water needed, 26-28, 33-36, 39, 68, 83, 118-120, 129, 132-138 fundamental principle, 26-28 counterproductive, 34-35right amount, 39 calculation, 133-138

Application method, 39-41,124-125, 144-150fog pattern, 40nozzle rotation, 40-41attack methods, 124-125,144-150

Application rate. SEE Flowrate.

Applicator attachment, 6

Art of firefighting, 139-142

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The Safe and Effective Use of Fog Nozzles194

Atmosphere displacement,3-5, 9-14, 20-21, 55, 76-77turbulence, 3-4pressure, 4 volume, 5, 9-14

Atmospheric pressure, 4

Atmospheric volume 5, 9-14

Attack method selection, 124-125

Attack methods, 124-125, 144-150selection, 124-125 directattack, 144-145 straightstream off ceiling, 1453-D pulse attack, 146

indirect attack, 146WIN attack, 146combination attack, 146-147bulldozer attack, 147deluge attack, 147methods to avoid, 148-150

Attack progress, 14

Attic/cockloft fire, 14, 121-122

Automatic nozzle hydraulics,169-170

Automatic nozzle, 140-141,156-158, 162-163, 169-170,173hydraulics, 169-170

Available fire flow (AFF), 33

BBalance/imbalance (thermal),

24, 33-39, 41, 45-47, 67, 69-70, 82test fire results, 36-39convection, 36-39

Ball valve, 44

Barrel rotation, 1, 8

Benefits (fog attack), 81

Bibliography, 189-192

Bilge space fire, 2

Blitz attack equipment, 176-179

Booster lines, 15

Boundary cooling, 64-65

British thermal unit, 27-28

Bulldozer attack, 147

CCalculation, 28-32, 133-138,

171-173rate of flow, 28-32needed fire flow, 133-138hydraulics, 171-173

California Fog NozzleCompany, 1

Calorimeter, 67

Case histories, 9-15

Cellar pipe, 6, 14

Chain reaction, 92

Chemical bond, 94, 100

Class A fire, 9-10, 66

Class B fire, 1, 11-12

Clear burning, 24

Coast Guard Fire School, 2-5,20

Cockloft/attic fire, 14, 121-122

Combination attack, 39-42,146-147, 149right amount of water, 39

Fog l Index 193-206 1/16/03 11:00 AM Page 194

Index 195

right tool, 39-40right application, 39-41gallonage formula, 39constant-flow nozzle, 39-40large-volume nozzle, 40fog pattern, 40nozzle rotation, 40-41

Combustion elements, 94

Combustion products, 95-96

Combustion rate, 103-105

Combustion, 91-97, 102-105elements, 94combustion products, 95-96incomplete combustion, 96-97plastic combustion, 102-105rate, 103-105

Compartment fire, 59-68, 76missile propellant, 59flashover, 59-61steady-state fire, 59, 66-67fire temperature, 59-60, 62-64, 67ventilation, 59, 61-64fuel surface area, 59, 61-62fire hazard, 60, 66fire spread/growth, 60-61,63-66training, 60fire extinguishing

equipment, 60, 66heat flux, 60, 63, 67fuel load, 60-62fire stages, 60-61fire behavior, 60-61stoichiometric burning, 61fuel oil, 62-64experiments, 62-68flow rate, 64-65, 68boundary cooling, 64-65personnel safety, 64fire extinguishment, 66-68thermocouple, 67

calorimeter, 67flowmeter, 67knockdown, 67thermal balance/imbalance,67control time, 68extinguishment time, 68

Condensation (steam), 3-4, 9,14, 37

Confined fire, 13, 113, 131-132

Conservation (matter andenergy), 37, 89, 95

Constant-flow nozzle, 39-41

Constraints (tactics), 130-132water distribution, 130confinement, 131-132amount of water, 132

Contraction (gas), 78-80calculating, 78-79

Control time, 68

Convection/thermal imbal-ance, 36-39

Conventional nozzlehydraulics, 168

Cooling effect, 3-4, 21, 64-65,76-83, 115-118

Counterproductive wateramount, 34-35

DDefensive/offensive tactics,

77, 81-83

Deluge attack, 147

Des Moines, Iowa, test fire,36-39

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The Safe and Effective Use of Fog Nozzles196

Design (fog nozzle), 155-158

Dimensional reach, 5

Direct attack, xiii, 9, 15, 66,68-71, 144-145, 149

Dispersion rate, 14

EElkhart Brass Selecto-flow

nozzle, 141

Elkhart Jumbo MysteryNozzle, 6-7

Elkhart Mystery Nozzle, 6-7

Endothermic process, 26

Engine/machinery room(ship), 2-3

European research, 73-88,186firefighting equipment, 73-77, 81-833-D water fog attack, 74-83Scandinavian research, 84-85flow rate, 85-87notes, 88

Exothermic process, 26

Expansion ratio, 27, 29

Experiments, 2-5, 16-19, 23,33-34, 62-68Miami, 16-18Kansas City, 18-19Iowa State University, 33-34U.S. Navy ResearchLaboratory, 62-68

Exploratory Committee onthe Application of Water,16-19, 23

Miami experiments, 16-18Kansas City experiments,18-19

Explosion, 24, 76

Extinguishment, xiii, 3-8, 60-68, 76-77, 113-127equipment, 5-8, 60, 66-68experiments, 66-68time, 68

FFactory Mutual Laboratories,

27

Finland experiments, 84-85simulation, 84test fires, 84

Fire access, xiii, 67

Fire behavior, 6, 23-25, 60-61,71, 115-118fire stages, 24-25

Fire Department Instructor’sConference, 15-16

Fire Department Occupa-tional Safety and HealthProgram, 150

Fire development, 6, 24-25,97-99phases, 6, 24-25

Fire environment, xiii, 99-100

Fire extinguishing equipment,5-8, 60, 66-68

Fire extinguishment experi-ments, 66-68

Fire extinguishment, xiii, 3-8,60-68, 73-77, 81-83, 89-111,113-127, 139-144equipment, 5-8, 60, 66-68,

Fog l Index 193-206 1/16/03 11:00 AM Page 196

73-77, 81-83experiments, 66-68fire hazard, 66Class A fire, 66straight-stream attack, 66fog attack, 66steady-state fire, 66-67access to fire, 67thermocouple, 67fire temperature, 67calorimeter, 67flowmeter, 67knockdown, 67heat flux, 67thermal balance/imbalance,67flow rate, 68control time, 68extinguishment time, 68

Fire flow, 29, 33, 122-123,133-138needed, 29available, 33calculation, 133-138

Fire hazard, 60, 66, 68

Fire spread/growth experi-ments, 63-66flow rate, 64-65boundary cooling, 64-65personnel safety, 64

Fire spread/growth, 24-25,60-61, 63-66, 103-105experiments, 63-66

Fire stages, 6, 24-25, 60-61,97-99, 115-118

Fire suppression, 76-77

Fire Technology Laboratory(Finland) research, 84-85simulation, 84test fires, 84

Fire temperature, 59-60, 62-64, 67-68

Fire tetrahedron, 92-94

Fire triangle, 91

Fire volume, 13

Firefighting (scientific foun-dation), 89-111law of conservation, 89heat energy, 89-90combustion, 91-97, 102-105free radicals, 95combustion products, 95-96incomplete combustion, 96-97fire development, 97-99fire environment, 99-100plastics overview, 100-101plastic combustion, 102-105plastic fires, 103uncertainty, 103-105Thornton’s rule, 105-108window glass, 109-110summary, 110notes, 111

Firefighting equipment(Europe), 73-77, 81-83training, 73-74, 76, 83tactics/strategy, 74, 77, 81-83personnel safety, 74, 763-D water fog attack, 74-76offensive firefighting, 74-76air draft, 76heat release rate, 76flashover, 76smoke, 76explosion, 76compartment fire, 76

Firefighting equipment, 5-8,60, 66-68, 73-77, 81-83European, 73-77, 81-83

Index 197

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Firefighting plastic, 103-105uncertainty, 103-105

Firefighting, xiii, 3-8, 60-68,73-77, 81-83, 89-111, 113-127, 139-144equipment, 5-8, 60, 66-68,73-77, 81-83scientific foundation, 89-111art of, 139-142

Firemanship TrainingProgram, 23

Flame production phase, 6

Flashover, 3, 24-25, 59-61, 68,71, 76

Flow rate, 1, 5-6, 13, 15, 28-39, 44, 64-65, 68, 82-83, 85-87, 122-124, 133-138, 176-177, 181-183calculation, 28-32, 133-138

Flowmeter, 67

Fog attack equipment, xiii, 1-22, 39-40nozzles, xiii, 1-22

Fog attack, xiii, 1-22, 39-40,66, 69-71, 143-144equipment, xiii, 1-22, 39-40tactics, 143purposes, 143-144

Fog nozzle concept, 1-22history, 1indirect method of attack,2-5Parkersburg experiments,5-8case histories, 9-15little drops of water speech,15-16Exploratory Committee onthe Application of Water,16-19

summary, 20-21notes, 22

Fog nozzle design, 155-158

Fog nozzle mechanics, 153-180nozzle devices/mechanics,154-155fog nozzle design, 155-158smooth-bore vs. fog noz-zles, 158-160nozzle reaction, 160-163nozzle myths, 163-165fog nozzle teeth, 165-167shut-off valves, 167hydraulics (conventionalnozzles), 168hydraulics (automatic

nozzles), 169-170hydraulics formula, 171-173variable flows, 173-176blitz attack equipment, 176-179notes, 180

Fog nozzle teeth, 165-167

Fog nozzles, xiii, 1-22, 39-40,66, 69-71, 143-144, 153-180attack equipment, xiii, 1-22,39-40concept, 1-22; mechanics,153-180

Fog pattern, 1, 6, 40, 44, 69,79-80, 139

Fog stream delivery, 6, 79-80

Fog vs. smooth-bore nozzles,158-160

Free radicals, 81, 95

Fuel load, 60-62, 64

Fuel oil fire, 2-5, 62-64

The Safe and Effective Use of Fog Nozzles198

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Fuel surface area, 3, 59, 61-62,98-99, 104

Fundamental principles, 26-28, 126, 129amount of water, 26-28tactics, 126, 129

GGallonage formula, 27-30, 39,

41, 181

Gas contraction, 78-80

Gas cooling, xiv, 71, 76-80, 83

General rate-of-flow formula,29-32, 181-183Grimwood rate-of-flow formula, 181-183

Glass, 109-110

Grimwood rate-of-flow for-mula, 181-183

Griswold, Glenn G., 1

HHeat absorption, 14, 26, 29,

37

Heat concentration, 13

Heat energy, 89-90

Heat factor, 15, 26

Heat flux, 60, 63, 67

Heat of combustion, 105-108

Heat production, 27

Heat release, 3, 26, 76, 108,117heat release rate, 76

Heat transfer, 80

High-velocity cone, 14

History (fog nozzles), 1

Homeostasis, 90

Hose friction loss, 172

Hydraulics, 1, 168-173conventional nozzles, 168automatic nozzles, 169-170formula, 171-173

IIdeal rate of flow, 33, 38-39,

44

Identity error, 31, 42-43Iowa rate-of-flow formula,42-43

Ignition, 24, 64, 77, 81, 97-98

Imbalance (thermal), 24, 33-39, 41, 45-47, 67, 69-70test fire results, 36-39convection, 36-39

Incident commander, 114

Incipient phase, 6

Incomplete combustion, 96-97

Indirect attack, 2-5, 9-14, 17-18, 20, 41, 49-55, 74, 146steam attack, 9-11principles, 13-14indirect effect, 13, 17-18, 20vs. direct method, 41criticisms, 49-55

Indirect effect of indirectattack, 13, 17-18, 20

Insulation materials, 71

Interior attack, 50

Index 199

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International Association ofFire Chiefs (IAFC), 19

Iowa rate-of-flow formula,29-32, 41-43

Iowa State University experi-ments, 33-34

Iowa State Universityresearch, 23-57, 184-185fire behavior, 23-25

fundamental principle, 26-28metric section, 28-29 Iowa rate-of-flow formula,29-32identity error, 31, 42-43experiments, 33-34thermal balance, 33-36pushing a fire, 36-37, 46-49key test fire, 36-39combination attack, 39-41shut-off valve, 44-45turnaround tactics, 48-49misinformation, 49-55notes, 56-57

KKansas City experiments, 18-

20

Key test fire (Iowa StateUniversity), 36-39

Kinetic energy, 89-90

Knockdown, 38, 67

LLarge-volume nozzle, 40

Latent heat, 90

Law of conservation, 37, 89,95

Layman, Lloyd, 2, 15-16, 21,55, 184

Layman’s theory, 15-16, 21, 55

Liberty ship experiments, 2-5,20

Limitations (indirect method),49-50

Liter formula, 28-29

Little drops of water speech,15-16

Low-velocity fog nozzle, 2

MMachinery/engine room

(ship), 2-3

Major involvement area, 13

Measure units, 28-29

Mechanics (fog nozzle), 153-180nozzle devices, 154-155nozzle design, 155-158

smooth-bore vs. fog noz-zles, 158-160nozzle reaction, 160-163nozzle myths, 163-165fog nozzle teeth, 165-167

shut-off valves, 167hydraulics (conventionalnozzles), 168hydraulics (automatic noz-zles), 169-170hydraulics formula, 171-173variable flows, 173-176blitz attack equipment, 176-179

The Safe and Effective Use of Fog Nozzles200

Fog l Index 193-206 1/16/03 11:00 AM Page 200

notes, 180

Method selection, 124-125,148-150avoid, 148-150

Metric formula, 181

Metric section, 28-29liter formula, 28-29

Miami experiments, 16-18, 23

Misinformation, 49-55indirect method, 49-55limitations of application,49-50interior attack, 50solid-stream nozzle, 50-51steam generation, 51-55water behavior, 51-55occupant safety, 53-54personnel safety, 54unvaporized particles, 55Layman’s theory, 55atmospheric displacement,55

Missile propellant, 59

Myths/misconceptions, 81-83,163-165fog attack, 81-83; nozzle,163-165

NNational Board of Fire

Underwriters, 16

National Fire ProtectionAssociation (NFPA), 15-16,19

Navy Low-Velocity Heads, 6

Needed fire flow (NFF), 29,122-123, 133-138calculation, 133-138

Nelson, Floyd W. (Bill), 23,184-185

NFPA 1500, 150

Nozzle devices/mechanics,154-155

Nozzle myths, 163-165

Nozzle reaction, 160-163

Nozzle rotation, 40-41, 130

OOccupant safety, 15, 47, 53-54,

63-64

Offensive firefighting, 74-76

Oil field fires, 1

Opening size (air intake), 14

Oscillation (fire behavior), 25

Outstanding firefighting, 148

Overhauling, 24, 36, 38

Oxygen level, 3, 6, 27-28, 81,91-92, 113

PParkersburg experiments, 5-

8, 20

Parkersburg FireDepartment, 5-8

Personnel safety, 14, 47-49,54, 64, 68, 70-71, 74, 76, 82,120-122, 149-150

Phases (fire development), 6,24-25

Index 201

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Plastic combustion, 102-105fighting plastic fires, 103uncertainty, 103-105

Plastics, 100-105combustion, 102-105firefighting, 103uncertainty, 103-105

Polyethylene, 101

Polyvinyl chloride, 101

Post-attack cool, 24, 37

Post-attack warm, 24, 37

Preplanning procedure, 32

Pulsating flow, xiii-xiv, 78

Pushing a fire, 36-37, 46-49,79, 82, 149thermal imbalance, 46-47vaporization, 47turnaround tactics, 48-49

RRate of flow, 1, 5, 13, 15, 28-

39, 44, 64-65, 82-83, 85-87,122-124, 176-177, 181-183calculation, 28-32

Research summary, 181-188rate-of-flow formulas, 181-183Layman’s research, 184Iowa State Universityresearch, 184-185U.S. Naval ResearchLaboratory research, 185European research, 186summary of facts/

principles, 186-187summary of conclusions,187notes, 188

Research, xiii-xiv, 2-21, 23-57,59-72, 73-88, 181-188Liberty ship experiments, 2-5, 20Iowa State University, 23-57U.S. Navy ResearchLaboratory, 59-72Europe, 73-88summary, 181-188

Right amount of water, 39,118-120, 132-138calculation, 133-138

Right application, 39-41fog pattern, 40nozzle rotation, 40-41

Right place, 120-122

Right tools, 39-40

Rockwood Booster Nozzle, 6,8

Rotating barrel, 6

Royer, Keith, 23, 184-185

SScandinavian research, 84-85

Finland, 84-85Sweden, 84-85

Scientific foundation (fire-fighting), 89-111law of conservation, 89heat energy, 89-90combustion, 91-97, 102-105free radicals, 95combustion products, 95-96incomplete combustion, 96-97fire development, 97-99fire environment, 99-100plastics overview, 100-101plastic combustion, 102-105

The Safe and Effective Use of Fog Nozzles202

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fighting plastic fires, 103uncertainty, 103-105Thornton’s rule, 105-108window glass, 109-110summary, 110notes, 111

Sensible heat, 90

Ship experiments, 2-5, 20

Shut-off valve, 44-45, 167ball type, 44turbulent flow, 44flow rate, 44ideal rate of flow, 44fog pattern, 44thermal balance, 45

Simulation, 77, 80, 84-85

Size (air-intake opening), 14

Smoke, 3, 9, 14, 76

Smoldering, 6, 24-25phase, 6

Smooth-bore nozzles, xiii,153-155, 158-160, 163-165vs. fog nozzles, 158-160

Solid-stream nozzle, 1, 4, 6,11-13, 20, 50-51

Spray pattern, 82

Stages (fire), 6, 24-25, 60-61,97-99, 115-118

Steady-state fire, 24, 59, 66-67

Steam attack, 9-11

Steam expansion, 4, 9-11, 14,20, 26-27, 29, 113ratio, 27, 29

Steam generation, 3-4, 9-11,13-14, 26, 29, 38, 51-55, 113

Steam volume, 3-4, 10-11

Steel, 3, 63

Stockholm Fire Brigade(Sweden) research, 84-85simulation, 85test fires, 85

Stoichiometric burning, 61

Straight stream off ceiling,145

Straight-stream attack, xiii, 9,15, 66, 68-71, 145, 153-155off ceiling, 145

Strategic principles (fogattack), 113-127fire behavior, 115-118right amount of water, 118-120right place, 120-122needed fire flow, 122-123time period, 123-124method selection, 124-125fundamental tactical

principle, 126notes, 127

Strategy/tactics, xiv, 8, 48-49,74, 77, 81-83, 113-127, 129-151fog attack, 113-127fundamental tactical

principle, 129constraints, 130-132water distribution in firearea, 130confined fire application,131-132of water, 132needed fire flow

calculation, 133-138art of firefighting, 139-142fog attack tactics, 143fire attack purposes, 143-144attack methods, 144-150

Index 203

Fog l Index 193-206 1/16/03 11:00 AM Page 203

methods to avoid, 148-150notes, 151

Structure fires, 3-15, 20, 23-25, 109-110, 120-122case histories, 9-15

Success and failure, 23-57Iowa State Universityresearch, 23-57fire behavior, 23-25fundamental principle, 26-28metric section, 28-29Iowa rate-of-flow formula,29-32identity error, 31, 42-43thermal balance, 33-36pushing a fire, 36-37, 46-49key test fire, 36-39combination attack, 39-41shut-off valve, 44-45 turnaround tactics, 48-49misinformation, 49-55notes, 56-57

Surface temperature, 3-4

Sweden experiments, 84-85simulation, 85; test fires, 85

TTactical constraints, 130-132

water distribution, 130confinement, 131-132

amount of water, 132

Tactics/strategy (fog attack),113-127fire behavior, 115-118right amount of water, 118-120right place, 120-122needed fire flow, 122-123time period, 123-124method selection, 124-125

fundamental tactical principle, 126

notes, 127

Tactics/strategy, xiv, 8, 48-49,74, 77, 81-83, 113-127, 129-151fog attack, 113-127fundamental tactical principle, 129constraints, 130-132water distribution in fire

area, 130confined fire application,131-132amount of water, 132needed fire flow

calculation, 133-138art of firefighting, 139-142fog attack tactics, 143fire attack purposes, 143-144attack methods, 144-150methods to avoid, 148-150notes, 151

Task Force Tips equipment,xiv, 85

Temperature (fire), 3-4, 24-25,59-60, 62-64

Test fires, 62-64, 84-85

TFT nozzle, 173

TFT Ultimatic nozzle, 85

Thermal balance/imbalance,24, 33-39, 41, 45-47, 67, 69-70, 82test fire results, 36-39 convection, 36-39

Thermal conductivity, 63

Thermal trap, 36-37

Thermocouple, 3, 17, 67

Thermoplastics, 100-101

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Thermoset plastic, 100

Thomas curve, 62

Thornton’s rule, 105-108

Time period, 123-124, 129,139

Time-temperature graph, 24-25

Training, 5-6, 17-18, 23, 60,73-74, 76, 83

Turbulence, 3-4, 44, 69

Turnaround tactics, 48-49

UU.S. Coast Guard Fire

Fighting School, 2

U.S. Navy ResearchLaboratory experiments,62-68, 185test fires, 62-64fire spread/growth, 63-66fire extinguishment, 66-68

U.S. Navy ResearchLaboratory research, 1, 59-72, 185compartment fires, 59-68experiments, 62-68, 185conclusions, 68-70summary, 71notes, 72

Units of measure, 28-29

Unvaporized particles, 3-4,13, 21, 55, 84-85

VValve. SEE Shut-off valve.

Vaporization, 3, 26, 37, 47

Variable flow nozzle, 173-176

Ventilation, 59, 61-64, 71, 82,149

WWater amount, 118-120, 132-

138calculation, 133-138

Water behavior, 6, 51-55

Water distribution (fire area),129-130, 139

Water fog attack, xiii-xiv, 9-11, 71, 74-83pulsating flow, xiii-xiv, 78compartment fire, 76gas cooling, 76-80, 83atmosphere displacement,76-77fire suppression, 76-77defensive/offensive tactics,77, 81-83ignition, 77, 81simulation, 77, 80contraction of gases, 78-80pushing the fire, 79, 82fog pattern, 79-80heat transfer, 80benefits, 81oxygen level, 81free radicals, 81myths/misconceptions, 81-83spray pattern, 82personnel safety, 82

Index 205

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thermal balance/imbalance,

flow rate, 82-83ventilation, 82water-hammer effects, 82-83amount of water needed, 83

Water injection, 3

Water needed, 26-28, 33-36,39, 68counterproductive, 34-35right amount, 39

Water supply systems, 74

Water-hammer effect, 82-83

Water-steam ratio, 11-14

Western Actuarial Bureau(WAB), 15-16

Wide-angle fog attack, 148-149

WIN attack, 146

Window glass, 109-110

Wooster Brass shut-off valve,6

World War II fires, 2

The Safe and Effective Use of Fog Nozzles206

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