i
^.'^>..^,f^^-,^
■^1
A SYMBOL OF SAFETY
THE GIGANTIC COMBINATION OF FURNACE AND RAM
In order to learn essential facts about the fire endurance of various types of columns, this unprecedented ap- paratus was constructed at a cost of many thousands of dollars. It consists of a furnace surmounted by a hydraulic ram of enormous power. Here is created a heat of the intensity of a conflagration, while, simultaneously, the ram exerts a downward thrust equal to the weight of many stories. The results of its use have been epoch- making in the structural industry. (See pp. 27-28, 83-87, 262-263)
A SYMBOL OF SAFETY
AN INTERPRETATIVE STUDY OF A NOTABLE INSTITUTION ORGAN- IZED FOR SERVICE— NOT PROFIT
BY HARRY CHASE BREARLEY
GARDEN CITY NEW YORK
DOUBLEDAY, PAGE & COMPANY 1923
PREPARED UNDER THE DIRECTION OF
THE BREARLEY SERVICE ORGANIZATION
copyright, 1923, by underwriters' laboratories, inc.
Permission is hereby granted to editors to reproduce in recognized periodicals, such as newspapers, class or trade journals, maga- zines, etc., any of the text or illustrations appearing in this book.
CONTENTS
CHAPTER PAGE
I. Humanity and Hazard i
II. The New Note of Precaution 8
III. The Physical Side of Fire Prevention ... 12
IV. The Genesis of Underwriters' Laboratories . . 17 V. The Home of the Laboratories 24
VI. The Significance of the Label 30
VII. Winning the Label 36
VIII. Fighting Fires That Are Not Prevented
1. Detection and Extinguishment 46
2. Alarm Appliances 47
3. Standpipes and Hose Stations 49
4. Sprinkler Equipment 50
5. Fire Hose 53
6. Hydraulic Tests 57
7. Chemical Extinguishers 59
IX. Building to Last, Not to Burn
1. Studying Burnable Conditions 66
2. Roof Coverings 69
3. Windows 73
4. Doors and Shutters 77
5. Columns 83
6. Walls and Floors 88
X. Safeguarding "The Universal Servant"
1. The Universal Servant 93
2. What Is the Relation of the Laboratories to the
Electrical Industry? 94
3. The Practical Viewpoint .98
4. The "Worst Treatment" Test 102
5. Rubber, or What? 104
V
Contents
CHAPTER PAGE
X. Safeguarding "The Universal Servant" — Continued
6. The Electricity of the Skies 107
7. "Economy" vs. Safety 109
8. The Growth of the Electrical Department , . iii
XI. A Department That Outgrew Its Name
I. Correcting "The Defects of Their Qualities" . 119
1. The Handling of Hazardous Liquids .... 122
3. Dealing with Hazardous Gases 128
4. Miscellaneous Devices 131
XII. The Study of Chemical Problems
1. The Department of Chemistry 135
2. Tests of Hose and Wire 137
3. Miscellaneous Activities 139
4. Special Investigations 147
XIII. How Safes Are Made Safe
1. An Emergency Article 151
2. Preliminary Inspection and the Explosion Test. 154
3. The Endurance Test 157
4. The Fire and Impact Test 161
5. The Follow-up Work 165
XIV. Making Burglary More Difficult
1. Matching Wits With Burglars 168
2. Grading the Alarm Systems 174
3. A Typical Local Mercantile Alarm System . . 176
4. Central Station Burglar Alarm Systems . 180
5. Mechanical Resistance 182
6. False Alarms, "Super-Burglars" and "Yeggs" . 184
XV. Protecting Life and Limb
1. Playing a Double Role 188
2. Ladders and Other Things 1 89
3. Safety Appliances 197
XVI. The Safety of Cars and Their Passengers
1. The Start of the Schedule 203
2. " Carding " for Fire Safety 208
3. Autpmobile Appliances 214
vi
Contents
PACK
CHMTER
XVII. Certifying Aircraft and Pilots
I. The Newest Department 221
1. Planes, Parts and Accessories 224
3. Pilots ^^9
XVIII. Underwriters' Laboratories and Human Welfare 234
APPENDIX
I. Details About Labels 249
II. Underwriters' Laboratories and Instruction in
Fire Protection Engineering 249
III. Standard Specifications for Fire Tests and Clas-
sification OF Building Materials and Con- struction "^S^
IV. Demerits and Periodic Summaries 252
V. Special Forms of Service 253
VI. Typical Labels ^54
VII. Organization ^55
VIII. The Councils ^55
IX. Aeronautical Forms ^57
X. Underwriters' Laboratories' Bibliography
A. The Printed Reports ^5^
B. The Standards ^59
C. Lists of Inspected Appliances and Card Reports
Thereon ^6°
D. Miscellaneous ^"°
E. Index of Selected Articles from "Laboratories'
Data" ^60
XL Tabulated Summary of Column Investigation
Results ^°^
XII. Typical Underwriters' Laboratories* Specifica- tions ^"4
XIII. A Typical Standard — That for Safes and Insu- lated Cabinets ^o"
Index ^^5
vii
ILLUSTRATIONS
PLATES
The Mighty Combination of Furnace and Ram . . Frontispiece
FxaNG fAGB
A One-Quart Extinguisher and a "Standard" Fire .... i
The Service Test on Sprinkler Heads 3
At the Helm Since 1893 10
A Momentous Meeting of the Board of Directors .... 11
A Consultation in the President's Office 18
Feeling the Pulse of the Electrical Industry 19
A Busy Morning at the New York Laboratory 28
Building and Doctoring the Equipment 29
The Birth of the Famous Label 34
Extinguisher Operation Test 2S
Inspecting the Inspectors of Underwriters' Laboratories . . 40
Inspecting Armored Cable at the Factory 40
Testing a Sprinkler Lever 41
Testing an Automatic Fire Alarm System 46
Vibration and Pressure Impulse Tests 47
Some "Horrible Examples" 50
Determining the Stress on a Sprinkler Link 51
Operating Tests on Automatic Sprinklers 51
Tests on Automatic Sprinklers 54
Factory Inspection of Cotton Rubber-Lined Fire-Hose • • ■ SS
A Valve Which Gives an Alarm 58
Testing the Strength of a Gate Valve Stem 59
How Strong Is the Extinguisher Shell? 62
Testing a 33-Gallon Chemical Extinguisher 63
A "Close-Up" of a Conflagration 66
Extraction Apparatus for Rubber and Roofing 67
How Accurate Are the Pressure Gauges ? 67
Testing a Metal Window Frame 74
ix
Illustrations
PACING PAGE
Fire-Stream Test on Metal Window Frame 75
Work That Keeps Inspectors Constantly Traveling ... 82
Pressure Up to 200,000 Pounds 83
The Effects of Corrosive Agents go
Oxy-Acetylene Welding Section 91
High-Potential Test of an Electric Water Heater .... 98
Testing Armored Cable 99
Breakdown Test of Rubber-Covered Wire at Factory . . . 102
Measuring the Actual Resistance of Wire Insulation . , . 103
Searching Out the Qualities of Rubber Insulation .... 106
Physical Testing of Rubber 107
Short-Circuit Test of a Large Fuse no
Testing a Small Electric Lighting Plant iii
Performance Test for Enclosed Switches 114
A Test That Means Sixteen Years of Usage 115
Learning What Would Happen in a Fire 122
Studying Gasolene Supply Devices 123
Safety Requirements in Oil-Burning Equipment .... 126
Forty Degrees Below Zero in Chicago 127
Studying the Safety of Acetylene Generators 130
Operating Tests on Acetylene Relief Valves 131
General Analytical Laboratory 138
Preparing Rubber Specimens for Tests 139
When Will a Match Take Fire Through Heat Alone? . . . 142
Analyzing Gases 143
Learning About the "Flash Point" 146
Making Micro-Photographs 147
Preparing an Explosive Vapo-Air Mixture 147
Reading Furnace Temperatures 158
Calibrating the Thermo-Couples 159
Hot Work 162
About to Be Dropped 163
Forestalling the "Yegg" 178
Attacking a Bank Vault Alarm in the New York Office . . 179
"Red Hogan" and "The Omaha Kid" 184
Enabling Bankers to Sleep Peacefully 185
Wired Glass and the Wall Street Bomb 194
X
Illustrations
FACING PACE
Recording Air Velocities in Spray Painting Booth .... 195
Better Than Losing Fingers 200
Protecting the Eyes of Workmen 20 1
A Corner in the Automobile Engine Laboratory .... 210
A Windshield Visor on the "Shimmy Table" 210
Guarding Against Head-Lamp "Glare" 211
Will the Bumper Protect Your Car? 218
A Locking Cylinder After ioo,oco Operations 219
WTiy Automobiles Are Stolen 219
LINE CUTS
The First Certificate of Airworthiness for a Hydroplane The Standard Time-Temperature Control Curve A Report on a Labeled Lightning Rod Installation
A Page of Typical Labels
Certificates for Registered Pilots and Aircraft The "Yellow-Boy" or Factory Inspection Blank The "Pink Shp" or Notice of Defects.
227 250
253 254 257 279 282
XI
INTRODUCTION
EKING back over an eventful thirty years to the time when Underwriters' Laboratories consisted of one table, two chairs, and a few dollars' worth of simple electrical testing machines, it can be said that there was no suspicion in the mind of the one en- gineer who constituted the "force," that the institution would ever develop to anything like its present scope. Instead of this he merely was conscious of the task then in hand and was determined to make the required tests with all possible care, in a spirit of perfect fairness, and to express no opinion which was not first reviewed by competent field engineers working in separate territories.
Thus the work started not with a dream but with a purpose, which usually is the safest basis for a start. Ever since that first day this purpose has been steadily maintained, which is, I believe, the principal reason for all subsequent growth. For this reason, too, the growth of the institution has been solid.
If our work has expanded, it has been because of the expanding requirements of fields in which we are active. No new departments have been created and no new equipment has been added until the need for them has become clearly apparent. We have been too busy dealing with the practical problems of the present, to spend much time in speculating about the future. Of late years, however, there have been increasing indications that the work of Underwriters* Laboratories is coming to be regarded as having a significance far be- yond anything that could originally have been believed — a signifi- cance that undoubtedly applies more to the future than to the past.
At the present time. Underwriters' Laboratories has grown into
xiii
Introduction
remarkably wide and diverse relationships. Its connections run to many industries and to thousands of plants, as well as to many under- writing and technical organizations. It has been interesting to note the fundamental basis of common interest that exists among all these as regards our investigations and to realize that their interests and our interests are firmly bound up with the still larger interests of the general public. In the last analysis, it is the general public which is served by every activity of the institution.
Underwriters' Laboratories has been developed through the zeal and abilities of many devoted men. A few of these have passed on, but most of them, I am glad to say, are still with us. The spirit of rare harmony and enthusiasm which has prevailed has made it possi- ble to consider the institution not as an assemblage of men and equip- ment, but as a distinct organism, which has grown up out of the ideals of the many who have built their lives into its activities. Its purpose has never been commercial, and the men who have contributed so freely of their best have lacked the incentives of purely personal am- bition. With self-effacing devotion they have performed tasks the effect of which on public welfare is now seen to be incalculable. Any one who comes in contact with the real spirit of the institution will, I think, be impressed with the fact that it exists "for service, not profit."
The author of this book has been given every opportunity to make a study of the work of Underwriters' Laboratories, in order that he might convey an idea of its extent, diversity and significance, in so far as this is possible in a single volume. This is a story that never has been told, and I cannot doubt that a general understanding of our work will have a marked and helpful bearing on the development
of its largest usefulness.
W. H. Merrill,
President, Underjvriters' Laboratories, Inc,
XIV
CHAPTER ONE Humanity and Hazard
IF HUMANITY had been content to leave things as it found them, men still would be naked savages, few in numbers, and exposed to the usual hazards of nature, such as storms, food shortage, and the attacks of wild beasts. Old age as we know it would be rare and violent deaths the rule. This is the situation today as regards a large part of the animal kingdom; for many thousands of years it must have been the only condition of life know^n to our early ancestors.
But, of course, these very earliest types are hardly to be considered men; they were really a kind of pre-human animal. Man was 72ot man until he began to meddle^ or, in other words, to seek to change the conditions that he found about him.
The chief motive for this activity was self-preservation, that is to say, the desire to escape from hazard. For ages its results were crude and bungling — rough shelters to protect from storms, skin clothing to resist the cold, primitive weapons for defense and also for use in hunting. In each case, at the start, these things must have been more or less accidental discoveries but they worked, after
I
A Symbol of Safety
a fashion, and there was something in the man brain that recognized their advantages and sought to improve them. Thus was established the principle of meddling with nature, or of experimenting as we like to call it. Out of it grew science and civilization.
Although in time civilization came to take account of many other things, hazard has remained always one of its largest concerns. The great human warfare against hazard is a remarkable story of changing conditions — of conditions that changed slowly at first but later with an ever-increasing speed.
Today we realize that much progress has been made. Violent deaths are now the exception; we are able to protect ourselves from storms; wild beasts are virtually conquered; the defense from cold has reached a point where men can face the rigors of a polar winter; the race has learned to produce food in quantity and to store it against a time of shortage and, as a practical result, millions now live in some degree of comfort where once there were only scattered groups all engaged in a day-by- day struggle for existence. This is one side of the picture.
But the picture has another side that is less reassuring. We have exchanged the few natural hazards of our early ancestors for a bewildering number of artificial dangers that have grown up with the progress of civilization. Everything today is on a vastly greater scale. Man- made towns are swept by conflagrations springing from
2
A ONE-QUART EXTINGUISHER AND A "STANDARD FIRE'
with gasolene soaked cotton waste and. when burn ng 'l^-^cf ^ 'VLf ^Tsee nn 59 63) guisher. One extinguisher must completely control the hre. ibee pp. r>a <m)
THE SERVICE TEST ON SPRINKLER HEADS
Guarding millions of human Jives, automatic sprinklers receive a thorough scientific investigation at the Laboratories, as shown in several other photographs and explained in Chapter 8. But, as in the case oi every other device, there must be a practical service test. Here it is. The engineers call it the Uistnbution lest, to distinguish it from the Operation Test, which has to do with temperature and positiveness of operation. (See page 51)
Humanity and Hazard
man-caused fires. Man-made buildings collapse and bury scores. Man-made ships sink at sea and man-made trains crash in collision. Man's faithful servants: fire, steam, electricity and the processes of chemistry, which he has called forth from the realm of nature, frequently escape their bounds and work havoc. As the result of thousands of thousands of years of meddling with nature, man has thus exchanged the old natural world for a new and artificial world of tremendous potentialities and un- numbered perils. Thus new and complex hazards are by-products of science. If man is now surrounded by such a diversity of dangers it is needless to state that these have not been sought but have arisen unsought and some- times unrecognized in the course of efforts to improve conditions of human life.
The history of science is one of splendid achievement. It is inspiring to realize that a two-legged animal with no natural tools but his ten fingers has been able to equip himself with powers that surpass in almost every respect those formerly imputed to gods and wizards. A man in a powerhouse throws a switch and a dark street, miles away, flashes instantly into brightness. An aviator springs into the air and clear across the Atlantic, from Newfoundland to Ireland, in a single day. The President delivers an oration in Arlington, Virginia, and every word, every inflection, is heard with the utmost distinctness by thousands in New York and in San Francisco. An au-
3
A Symbol of Safety
dience In comfortable theatre chairs cHmbs the peaks of the Andes, penetrates the jungles of Borneo or summons the world's most famous men to appear on the screen for its inspection.
The astronomer with his spectroscope is able to detect the composition of stars so distant that their light must travel for hundreds of years in order to reach us. The eye of the eagle and of the fly are so far surpassed by the telescope and the microscope that comparison is absurd. The engineer turns deserts into farms and orchards or opens a channel for ocean shipping through a range of mountains. The synthetic chemist improves on the ma- terials of nature in more than one important instance.
In agriculture, commerce, industry and daily life the story is similar. Everyone is better fed, better housed and better dressed through the results of scientific re- search; quantity production now places within the reach of the poor such privileges that could not have been at- tained by the rich of a generation ago.
The inventive skill that applies the discoveries of science to human service Is doubtless more active at pres- ent than In any previous time. At any moment, many thousands of men are deeply engrossed with models, at drawing-boards, or In laboratories seeking to perfect their devices and processes. An Increasing stream of patents flows from the Patent Oflice. Great as have been the changes of the past few decades, those of the coming
4
Humanity and Hazard
generation bid fair to surpass them. The process of change appears to be steadily increasing its speed.
We have paid wilHng tribute to the magnificent achieve- ments of science because the following pages must con- cern themselves more particularly with their attendant hazards. In so doing, we shall strive to sense something of the complexity of these hazards and their tremendous cost in life and property. We shall examine also the work of a remarkable institution that employs science to limit the destructiveness of science and to render her service to the race the subject of less apprehension.
We have already spoken of the man in the powerhouse with his potent switch. He is merely one of that great army of electrical operatives who have come into being because, in 1831, a scientist named Faraday inaugurated the Age of Electricity by his discoveryof the principle upon which the dynamo is based. But Faraday probably had no suspicion that his interesting laboratory experiments were to make it possible for man to bring so incalculable a force into his daily service. There is no need to catalog the variety, extent and value of modern uses of electricity; they are too much a matter of our every-day life, but occasionally we feel the paralysis that falls upon a com- munity when its electrical service is interrupted.
Indispensable as it is, however, the widening use of electricity has carried widening hazard; each year, its toll of life and property is formidable. Safeguarding and
5
A Symbol of Safety
protective methods are being made the subjects of con- stant study both inside and outside of the industry, as we shall later have occasion to note. Theoretically, it should be possible to free the use of electricity from hazard; prac- tically, such an achievement seems to be far distant.
This is the age of other wonders besides electricity — gasolene, for example. Humanity called for an illuminant to replace the fast-disappearing whale-oil of two or three generations ago. Science found this illuminant in the newly-discovered petroleum deposits of Pennsylvania after it had been learned how to free the oil from certain by-products. One of these was a volatile fluid that seem- ed to have no special value except for cleaning until in- ventors realized that its dangerous explosive power could be used to drive machinery. Soon gasolene came into the daily use of millions of people. Thereupon, along with service, it brought a universal hazard of which our fathers knew nothing; it, also, has exacted a mounting toll of life and property.
There is a similar story to tell with regard to many other of the splendid, dangerous gifts of science. No sooner have we seized upon some new facility than we are likely to learn that nature may exact a serious price for its use.
One evidence of this is found in fire losses which, in the United States, increased more than one thousand per cent. between 1865 and 1922, while the population increased but two hundred per cent. A study of fire causes shows that a
6
Humanity and Hazard
large part of that loss can be traced to comparatively new devices and processes. The marked increase in loss of life and in bodily injury through accident is another result of material progress. Such things are inevitable but they are not necessary, which is merely a paradoxical way of stating that our swiftly-developing civilization thinks more of using than of safeguarding; they are inevitable only so long as this state of mind holds control.
CHAPTER TWO
The New Note of Precaution
THE eager search for new powers and new tools still is dominant but, rather recently, there has begun to be sounded a new note of precaution. Slowly, it is coming to be realized that material progress, like other things, is subject to the laws of economics and must not be purchased at too high a price. Conservation there- fore is engaging an increasing amount of attention. It is already finding expression in many ways.
Among the most inspiring stories of the last few years are those that deal with great movements for conservation such as those for checking epidemics, utilizing waste, conserving the forests, limiting floods, preventing acci- dents and, in particular, that for combating the enormous losses from fire.
Fire prevention on any important scale is practically of the present century. For ages fire was regarded as a thing to be fought, not prevented, and attention was concentrated upon the training and equipping of fire departments, which, in America, with their constant opportunities for service, became famous for speed, skill and daring. Figuratively speaking, the American fire
The New Note of Precaution
alarm never is silent. Fifteen hundred fires each day means an average of more than one for every minute, night and day, 1,6^ days in the year. When losses reach a yearly total of nearly half a billion dollars in absolute destruction, as has been the case, and when to this is added the distressing loss of thousands of human lives, it can be seen that even the efforts of the best-trained and best-equipped fire-fighters are not sufficient; it becomes imperative that an effort be made to limit the number of fires — to fight them before they break out.
Such considerations led at last to the inception of a movement that is among the most remarkable of the present generation — the great campaign of fire prevention. Originally promoted chiefly by the fire insurance interests, it soon grew into a nation-wide cooperation of individuals and organizations working by many methods, but to a common end. This is not the place to trace the history of this movement but a few of its achievements may be told.
Today in a number of states, all public schools are required by law to teach the rudiments of fire prevention to their pupils; Fire Prevention Day (October 9), pro- claimed by the President of the United States and by the governors of the various states, is observed with appropri- ate exercises of public instruction in thousands of com- munities; building codes are being made increasingly rigorous; standards for electrical and other forms of in-
9
A Symbol oj Safety
stallation have been worked out in great detail and widely promulgated; manufacturers are finding a growing market for safety appliances and the popular mind is becoming responsive as never before to the thought of protection from fire hazard. This is indicated by the large amount of attention now being devoted to the subject in news- papers and magazines and in meetings of business and civic organizations.
Many do not yet realize that fire prevention was officially enlisted in the service of the government during the World War and that it played an important role in many de- partments. All government properties engaged in war work were inspected and safeguarded by fire prevention engineers, and all new construction made large use of inspected materials and supplies. This was true in the case of camps, warehouses, navy yards, shipyards, termi- nals, docks and all other centres of war activity, where interruption by fire might have interfered with military efficiency. It was true also in the case of thousands of privately-owned plants engaged upon government con- tracts. In all these cases hazards were noted and sugges- tions made for their correction.
Such efforts met with general success. When one considers the high pressure of war production and trans- portation, with congested space, hastily-improvised facili- ties, inexperienced operatives, and the large handling of inflammables and explosives, the small proportion of fires
lO
The New Note of Precaution
is noteworthy. Among the privately-owned plants, how- ever, the recommendations of the fire-prevention engineers occasionally were neglected, sometimes with disastrous results. In one case, for example, the proprietors of an ammunition plant disregarded the safety instructions and the resulting fire and explosion destroyed millions of dollars' worth of munitions. Such exceptions merely prove the rule.
People who read the statistics of American fire loss often ask, "after all, does fire prevention prevent?" The an- swer of the war is unmistakable: fire prevention does pre- vent— when it is given a chance.
We are justified in regarding this whole question as the conflict of two contending forces.
Lined up on one hand are the vast combustibility of our millions of frame buildings and our square miles of wooden shingles; the national carelessness of an optimistic, pro- gressive people, impatient of detail; the rapid growth of congested city life with its attendant fire hazard; the universal employment of electricity, gasolene and other modern utilities; the enormous increase in the use of cigarettes; and sundry other elements, including the evil torch of incendiarism.
Against these are arrayed the various factors of educa- tion, legislation and enforcement already indicated, and, recently summoned into combat, the mighty and resource- ful hand of science.
II
CHAPTER THREE
The Physical Side of Fire Prevention
FROM the foregoing summary it will be seen that fire prevention is a two-fold problem involving both psychological and physical factors. The first of these deals with human ignorance and carelessness and lies generally outside the province of this book. The second concerns the environment of people, the buildings in which they live and work, the tools they use and the forces they employ. It also is capable of sub- division into two parts, viz.: Fire Causes, and Burnable Conditions.
A fire is born, then it tries to grow. There is a world of almost romantic interest hidden under each of these simple statements. Fire is such a living thing; it has such a universal fascination; it is so necessary to our daily lives, yet holds such possibilities of terror and destruc- tion. Fire is inextricably a part of all human history. From the earliest ages, all tribes of man seem to have possessed the art of making fire, while no other kind of animal ever has acquired it. Some writers even classify man simply as "the fire-making animal". What is Fire? How is it caused?
12
The Physical Side of Fire Prevention
Fundamentally, fire is the heat-light effect of chemical action. This means that when chemical action produces temperature that is sufficiently high to render luminous some of the solids or gases affected, we see what we call fire. Fire, then, involves chemical change, which is to say, the destruction of something, a liberation or recombina- tion of its elements and a high degree of heat in the process.
Decay is a kind of slow fire; it involves chemical action and produces heat, as is shown by the warmth of rotting compost, but this heat is not sufficient to produce light. The oxygen that we draw into our lungs enters into chemi- cal combination with certain elements in our body and gives us our bodily warmth. Both these occurrences differ from actual fire chiefly in degree. Thus Fire is not only our familiar companion but is, in a sense, closely related to our own life processes.
One of the most interesting features of fire is the multi- plicity of ways in which it is caused. The presence of infectious disease means that actual germs have been preserved and transmitted; with disease there is an absolute continuity from the first case to the most recent one. Not so with fire. One moment there is no fire and the next moment it springs into being. A pile of oily rags lies quietly in a corner. There is neither spark nor match. Presently the rags begin to smoke; then suddenly burst into flames. In another book the writer has had occasion to describe the latency of fire as follows:
13
A Symbol of Safety
"Fire possibilities exist on every hand; they are found in the most unthought-of places. It is natural to associ- ate fire hazard with a box of matches but who would look for it in a glass of water? Yet potassium or sodium thrown into water bursts at once into flames, while a few drops of water on gray, rocklike calcium carbide produce acetylene gas. Many fires have been caused by water. Fire is continually originating in the most unexpected ways — by the spark from an accidental hammer blow in a room containing gasolene fumes, even by the well-meant action of a hospital nurse in oiling the body of a live-steam victim and covering him with blankets — in this case, spontaneous combustion cost the life of the patient.
"Invention is a constant hazard; new devices and proc- esses are continually introducing elements of the greatest danger. The versatile but highly inflammable celluloid is a case in point. There is also a lacquer used in shoe manufacturing and known to the trade as 'dope'; it is prepared from celluloid scrap and its use in a wooden shed was the starting point of the thirteen-million-dollar Salem conflagration in 1914. The giant new industry of moving pictures was not generally supposed to be hazardous until disastrous fires and serious loss of life resulted from it. There is a well-recognized fire hazard in incubators, in curling-irons, in rain-coat manufacture, in various polishing, cleaning and sweeping compounds, and in countless other products and processes.
14
The Physical Side of Fire Prevention
" Wi th the daily use of fire for purposes of cooking, ligh t- ing, heating, commerce, industry, art, science or pleasure by almost every individual in every community; with sparks borne by the winds from smoke-stacks and chim- neys; with barns and houses burned by lightning; with the omnipresent commercial electricity always ready to transform itself into fire through some defect in trans- mission, and with fire hazard lurking unseen in the in- cessant stream of devices emanating from the busy brains of our inventors, there can be small wonder that appalling destruction marks the pathway of man's most useful servant. "
Thus, intentionally or unintentionally, fires are con- stantly being caused. Next they try to grow. The tiniest flame is ambitious to become a conflagration and will do so if it have the chance. It is a common saying among fire-fighters that t\\Q first five minutes at a fire are more im- portant than the next five hours. Fanned by a strong wind fires sometimes spread with such speed that people have been run down by flames in the open. The spread of fire is a question of combustible conditions, and these will be discussed in the following pages, notably in the chapter on building materials. However, one fact must not be overlooked in considering either cause or spread — at every phase of its existence^ Fire is subject to natural laws. There is nothing truly mysterious about it; it is a proper subject for scientific study. It is perfectly possible to learn
15
A Symbol of Safety
all the ways in which fire may be caused and so to learn how not to cause it; it also is practicable to determine the factors governing the spread of fire and to use this knowl- edge in preventing the spread. Thus fire prevention and fire resistance on their physical side are strictly matters of applied science.
It is for this reason that Underwriters' Laboratories originally came into existence although its work has now grown, naturally and logically, to include the fields of accident and burglary prevention and automobile and aeronautic safety as well.
i6
CHAPTER FOUR
The Genesis of Underwriters' Laboratories
I IKE many other important influences of American life, Underwriters' Laboratories was, in a way, an — # outgrowthof the World's Fair of 1893. This great exposition, which gave a pronounced impetus to American architecture, which opened the eyes of the public to the coming dominance of electricity, which exerted a profound influence on manufacture, transportation, mechanics and art, and which, perhaps, first taught the American people to think in international terms, also furnished an oppor- tunity for the germ of a protective idea to take root and begin to grow.
In 1893, William H. Merrill came to Chicago to serve as an electrician of the Chicago Underwriters' Association, his special task being that of solving some problems in con- nection with automatic fire-alarm service in Chicago and of inspecting the electrical installations at the World's Fair, which were altogether unprecedented in scope and importance. He brought with him the laboratory idea that was later to germinate. This he had suggested to the Boston Board of Fire Underwriters before coming to Chicago, but they had not felt warranted in authorizing
17
A Symbol of Safety
its establishment. In Chicago, however, certain tests became necessary and a small room was taken on the third floor of Fire Insurance Patrol Station No. i on Mon- roe Street. Here, abov^e the horses of the salvage corps, were installed a bench, a table, some electrical measuring instruments and a few chairs, the whole "plant" repre- senting an investment of about $350. The staff con- sisted of Mr. Merrill, one helper and a clerk.
Thus began an activity which in thirty years has grown to embrace the services of two hundred engineers and other inside employes, 250 outside inspectors, a plant containing fifty-five thousand square feet of floor space in Chicago,* and branch laboratories in New York and San Francisco, a Canadian organization under a Dominion charter, offices in 141 cities and a connection in London.
The original work, as already stated, was purely local but the principle of growth was in the germ and it soon was extended to embrace the territory of the Western Union — an insurance organization, not the historic telegraph company. It then assumed the name of the Underwriters* Electrical Bureau, and operated under the auspices of both the Western Union and the Chicago Board. It was not long before the quality of the work began to attract attention outside of its original territory. This, together with the reports issued on electrical fires and the inaugura- tion of model report blanks, so favorably impressed the
*Work is about to begin on a 40,000 square foot addition to the Chicago plant.
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The Genesis of Underwriters' Laboratories
National Board of Fire Underwriters that that body decid- ed to make a small allowance to the Electrical Bureau which thereupon became recognized as the Electrical Bureau of the National Board and operated on a some- what increased scale.
Then came a new impulse from an outside source that started development along a collateral line, as has been the case from time to time ever since.
The story has often been told of the engineer who, in 1892, while experimenting with an electrical furnace in a North Carolina town, failed to secure the results he sought but found in the furnace when it cooled a dark gray, brittle substance, then strange but now well known as calcium carbide. The engineer threw the apparently use- less stuff into a stream and was astonished to see the water bubble vigorously from the generation of gas. Thus was discovered the valuable gas, acetylene, widely used today for illumination, welding and other purposes. Its obvious utility quickly led to the manufacture of crude generators which in turn showed a disconcerting tendency to explode and cause fires. Thereupon, insurance companies were forced to give them attention, and Mr. W. C. Robinson, then sprinkler inspector for the Chicago Underwriters' Association, was detailed to study this new hazard also under the auspices of the Union Committee. As this work required testing facilities, it seemed reasonable that the two lines of investigation be brought together and that the
19
A Symbol of Safety
committee's work be extended to include the whole field of fire protection and fire prevention engineering.
Presently it developed that similar work on acetylene was being carried on in Boston and in Atlanta, and con- flicting reports began to appear. Consolidation was again ** indicated," as the surgeons say, and the result was the formation of the Committee of Consulting Engineers of the National Board of Fire Underwriters and the con- centration in Chicago of the testing work. This com- mittee specialized in the hazards of heating and lighting as electrical work had been nationalized by the formation of the Underwriters' National Electric Association.
Now had come the time for much larger quarters and a two-story brick building, at 67 East Twenty-first Street, was selected. This building, which had served as a boys* school and gymnasium, and seemed spacious beyond all dreams of future need, was outgrown within a decade.
The next definite advance was in connection with the National Fire Protection Association, which body formed a Committee on Devices and Materials to work in the field of fire-protection appliances. There ensued a gradual development of personnel, facilities and range of operation. At no time was there any effort to grow but rather a concentration on the quality of the service to be rendered. The result was inevitable for the work won rapid recognition in electricity, acetylene, gasolene and other hazards and began also to be felt in the field of
20
The Genesis of Underwriters' Laboratories
protective appliances, hand fire extinguishers, fire doors and fire windows.
One of the contributing factors to this growth was the lack of uniformity in the opinions of others who were supposed to be expert in some of these fields. When the judgments of authorities differed it obviously was neces- sary that there be some court of last resort such as could be found only in an adequate laboratory, where tests could be made without previous bias and their results could be certified. Thus the work progressed quietly and steadily. From time to time, as required, new apparatus was secured and additional engineers, specialists in various branches of the testing, were drawn into the staff.
By November, 1901, the institution had outgrown the committee form of organization, and was incorporated as "Underwriters' Laboratories, Inc." under the laws of Illinois, the state granting a charter "to establish and maintain laboratories for the testing of appliances and to enter into contracts with the owners and manufacturers of such appliances respecting the recommendation thereof to insurance organizations."
The National Board of Fire Underwriters had become so deeply convinced of the value to the insurance business of the work of Underwriters' Laboratories that, in 1903, it made a general appropriation for the purpose of building up the institution along broader lines. It now became possible to secure a site on East Ohio Street and to erect
21
A Symbol of Safety
a really fire-proof building as a home for the rapidly ex- panding activities and incidentally as a demonstration to architects and contractors of the possibilities of safety construction. This building was enlarged by successive additions until it extended over the entire l6G ft. of property frontage and, in 1923, reached a total floor space of 55,000 sq. ft. Later, some idea will be given of the unique aggregation of testing facilities thus created.
In 1906, there occurred another important extension of the Laboratories' work; this was the inauguration of a label service for the purpose of certifying the results of this work as it affected individual products. It involved a natural corollary of inspections at factories. This work, hereafter to be described, grew out of the need for aiding manufacturers to secure continued recognition of the safety standards once established through the test of their products. Naturally, this involved continued contacts and was received with great favor by the various indus- tries affected. Therefore there grew up a staff of in- spectors, operating from branch offices in sixty-eight different cities and visiting thousands of factories.
The most important of these branch offices is that in New York which passed under the charge of Vice- President Dana Pierce in 191 2. Since then it has grown into an important testing station and the inspections made between Trenton, New Jersey, and Bridgeport, Con- necticut, are all directed from this office.
22
The Genesis of Underwriters' Laboratories
This account touches but a few of the high spots in thirty years that naturally have been crowded with detail. However, it is difficult to draw the members of the Laboratories' staff into reminiscence. Their thoughts are little concerned with the past in comparison with the interests of the swiftly-expanding present and the in- definitely greater requirements of the future.
23
CHAPTER FIVE
The Home of the Laboratories
THE building at 207 East Ohio Street does not "look the part," at least to the layman. Fancy the disappointment of one whose imagination has been stirred by such expressions as "within its walls science is fighting the battle of civilization with fire," who has been told that materials are here given the fiery test of "artificial conflagration," who has thought of the vast uproar and confusion caused by human hazard in its many forms of fire, casualty and crime, and who has therefore visioned the place where these hazards are grappled with as something flaming and thunderous, something between a steel works and a cataclysm, when he finds — what? A long, low, "academic-looking" build- ing of brown brick and terra cotta with no suggestion of a thrill in its many windows. It might be a school, it might be a library — almost anything but the scene of in- tensive scientific encounter that he knows it to be.
He goes inside and receives an impression of the quiet, busy intentness of many people at tasks whose meaning at first is not clear to him. He sees that some are engaged with reports arid correspondence, while others are making
24
The Home of the Laboratories
use of a great variety of apparatus to which they are giv- ing absorbed attention, with frequent jottings on record blanks. Presently, however, this silent, orderly activity begins to inspire in him a new sense of values, and under the guidance of some one acquainted with the institution, he commences to understand.
There are long rows of offices opening from central hall- ways, there are benches where chemists stand before racks of jars and bottles and are busy with test tubes or bunsen burners. There are myriad electric devices and sundry stretching and straining machines. There is the long vista of the hydraulic laboratory, with its complica- tion of pipes, valves and tanks. There is a succession of furnaces of various sizes and shapes, some of them with glowing mica peepholes, which speak of the intense fires that rage within.
Many other things there are, and, most impressive of all, perhaps, is the mighty column-testing apparatus whose installation has marked an epoch in structural engineer- ing. Little noise is to be heard; there is no rushing about, nor, on the other hand, is there any sign of loitering, for each person is seen to be giving his entire attention steadily to the task in hand, although the nature of this task may not at first be clear to the visitor.
A very early impression is sure to be that the entire building is more than merely fire resistive. It actually \s fire-proof y which is a term that rarely can be used with
25
A Symbol of Safety
accuracy. Indeed, It is doubtful whether any other im- portant building in America is so nearly loo per cent, in safety from fire hazard. An architect or a builder could spend considerable time profitably in studying the solution of this problem as here portrayed. He would see the way in which wood has been eliminated without loss of beauty, for some portions, particularly the spacious tile-lined office of the President, were designed to serve as object lessons in the possibility of combining attractiveness with safety. He would see how all vertical and horizontal openings have been safeguarded, so that even a "theoret- ical" fire could not go far; and then he would see what might appear like superfluous fussiness, namely, a full equipment of automatic sprinklers in the ceilings of the rooms. It is hardly to be expected that an occasion will ever arise that will call these sprinklers into action, but here again the purpose is largely that of an object lesson. In other words. Underwriters' Laboratories must practice what it preaches and adopt every provision for safety.
Mr. Kohlsaat, the famous journalist, in telling of his experience one night in a London hotel during a war-time air raid, says that he asked a chambermaid the next day why he had not been aroused and called to the base- ment for safety, as the hotel employes had been, and she answered artlessly: "Oh, but you are not under the Em- ployer's Liability Act. " The 170 members of the Labora- tories' Chicago staff have the satisfaction of knowing that
26
The Home of the Laboratories
their protection is more substantial even than that afford- ed by a "liability act".
Throughout the building, at numerous points, will be found many devices and materials undergoing test. Some of these tests have a touch of the spectacular, as, for example, that in which a mass of flames is hurled, under forced draft, against the surface of a sample of roofing; that of dropping a red-hot safe from the height of a third story upon a pile of bricks; or that of turning the full force of a fire stream upon the surface of a fire door that has been taken incandescent from the testing furnace.
On the other hand, tne great majority of investigations are perfectly matter-of-fact in appearance and mean little to the layman without an explanation. Some of them will be discussed more fully in succeeding chapters. But there is one piece of apparatus already mentioned that is sure to capture the attention of any visitor, even though he may not see it in operation. This is the gigantic com- bination of furnace and hydraulic ram that is used in de- termining the qualities of columns.
Imagine a room seven feet square and twelve feet high, built up of heavy masonry and surmounted by a huge hydraulic ram that rears itself forty-five feet above — a ram of such enormous power that it might have pulled the building from its foundations, had not special founda- tions been constructed to support it. Within this room, on many occasions, there has been created a heat equal in
27
A Symbol of Safety
Intensity to the most terrific conflagration, and, simultane- ously, the ram has exerted a downward thrust equal to the weight of many stories. Some of the blackened and dis- torted columns that have been submitted to this ordeal are to be seen In the courtyard. Their appearance re- moves any doubt as to the thoroughness of the test.
The Important work that takes place In the New York office of Underwriters' Laboratories must also be included In a general Impression. This rapidly growing branch occupies two floors of Its own building at No. 109 Leonard Street and now conducts something more than one-half of the total work done by the Laboratories in the examina- tion and test of electrical and signal devices. This is largely due to the fact that a large proportion of the man- ufacturers of electrical goods are located In the East.
The New York office has an especially designed and very well-equipped testing house for short-circuit tests on fuses adjoining a sub-station of the New York Central Railroad at KIngsbrldge in upper New York. At this sub-station facilities are provided for fuse tests by means of a very large storage battery with complete equipment of protective devices, instruments and the like, with which these important tests can be conducted rapidly and safely.
The laboratory equipment of the New York office includes many types of apparatus for electrical tests and also for certain of the tests of the Casualty, Automobile and Burglary Protection Departments.
28
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BUILDING AND DOCTORING THE LABORATORIES' EQUIPMENT
In testing thousands of different devices in ways not previously tried, it often is necessary for the Laboratories to invent its own testing apparatus, and to build it in its own well-equipped Plant Depart- ment. The machine shop is also called upon to maintain in perfect condition the thousands of pieces of electrical, physical, chemical and hydraulic testing apparatus at 207 East Ohio Street
The Home of the Laboratories
Few visitors wish to make a quick passage through the various departments of the Chicago testing station, since the themes for interesting discussion so abound on every hand, and one readily comes to realize why and how this institution has become so central in the entire campaign for human safety. The lasting human impression is likely to be a composite memory of a smooth-faced, specta- cled, youngish-looking man — a typical testing engineer — with a frown of concentration between his eyebrows, intent upon an indicator in the absorbing task of "finding out about something."
29
CHAPTER S IX
The Significance of the Label
WHEN it is stated that the annual output of the Underwriters' Laboratories' labels increased from fifty million for the year 191 5, to fifty million per month in 1922, it is obvious that the label plays an important part in the affairs of the Institution and is of vast significance to the public. What then is the label?
The label is a certificate of character awarded to an inanimate object. It is an epitome of the technical skill, costly equipment, wide experience and thoroughgoing methods of investigation that have been concentrated upon that object in the process of searching out its every point of weakness; it is, therefore, the one best means of bringing to the buyer and user the opinion he desires as to the merit of appliances.
Some of the chapters which follow will give a slight idea of the gruelling tests that often'precede the award of the la- bel, and explain the feeling of satisfaction with which thousands of manufacturers view its attainment. Like everything else connected with the institution, however, the label is entirely and intensely practical; its purpose is
30
The Significance of the Label
as far as possible removed from sentiment, for it is con- crete evidence to officials, inspectors, contractors, mer- chants and the general public that the labeled product has been awarded a recognized standing in its relation to fire and accident hazards.
Now the label is one of several forms of recognition of a device made or service rendered by a Laboratories' client, but it is the most important, and the best known. In several industries it has come about that it is the first thing looked for by prospective purchasers. One reason is that it does not only mean that samples of the goods have been tested 07ice. but that year after year these goods must continue to maintain their quality, or they will forfeit their rights to the label.
"Are these goods approved?" asked several of the fifty-odd electrical dealers attending a Brooklyn auction early in 1922, as a case full of receptacles was put up. "Sure," was the glib reply, whereupon the bidding grew spirited and the lot brought ten dollars a hundred. Later the buyer discovered that the receptacles were not included in the Laboratories' Electrical List, and he be- came indignant. "You should have heard the storm of complaint, " said a witness. " Most of those present were the cheapest kind of dealers, but even they knew the value of Laboratories' listing; the dumfounded auctioneer took back the box, put it up again, and the highest he could get was four dollars a hundred. " The next item was
31
A Symbol of Safety
a lot of plug-type fuses. Someone asked if they were "standard," and again the ignorant auctioneer took a chance on saying "yes," whereupon the same thing hap- pened, the public forcing the auctioneer to call off the sale.
This episode shows strikingly the value of Laboratories' listing to the jobber or dealer. But how about the manufacturer? Does he welcome the operation of the Label Service in his plant ? A single instance will indicate.
The manufacturer in question has plants throughout the country, in twelve of which the Label Service was operated. He told the vice-president of the Laboratories that he had an excellent product and wanted to keep it so. These plants had received from him the most particular specifications as to design, construction, and inspections. He felt that his requirements were even stricter than those of the Laboratories. Under these conditions the visits of the Laboratories' inspectors seemed to him superfluous.
However, such visits were a condition of the use of the label and the inspectors as usual took nothing for granted. To the manufacturer's amazement, they found that his admirable instructions were disregarded, that in certain plants the test methods and apparatus did not conform to the established standards laid down by him, that not one of his own inspectors was rejecting defective products, and so on. This revelation brought about a shake-up, and it took three years for every needed change to be effected; but today the manufacturer belongs to the
32
The Significance of the Label
growing class who use the Label Service for their own benefit^ for the sake of their reputation, as a check upon their own inspectors, as a means of maintaining their poHcy covering their product, as a tonic to their production de- partments, and as a good influence on esprit de corps in their own forces — quite regardless of the sales value of Laboratories' listing.
However, the significance of the label goes far beyond its value to manufacturers. Underwriters' Laboratories was established by the insurance companies for purposes of pure self-interest; it is primarily a servant of under- writing, and the way in which it also has become a servant of industry and of the public is an interesting story.
Here, then, in the background is the great institution of insurance which affects the welfare of every community through its sale of protection to millions of firms and individuals.
It is hard to comprehend the vastness of insurance oper- ations. In the fire insurance field alone the stock com- panies carry a total of about eighty billion dollars of cover- age, and to this must be added the very large aggregate of casualty and automobile insurance. Even the newest subject of Laboratories' investigations, that of aeronautic safety, is already represented by a respectable amount of insurance on airplanes and their cargoes.
First and last, therefore, one may visualize the entire burnable property of the United States throughout its
Z2>
A Symbol of Safety
three million square miles of extent and try to realize that all of this unimaginable wealth is, in a sense, tied together by a network of insurance contracts that provide financial security to the holders of more than thirty million separate policies. This financial security is based on payment in case of fire or accident, but its value does not wait upon disaster, for it also forms one of the chief foundations for the credit system upon which business is dependent. Thus, in a real sense, the interests of all business in- stitutions and all homes — in other words, of the entire population, are dependent on the operations of the in- surance companies. But the companies are not mines of wealth, they do not originate the payments which they make — they transmit them, because their ability to pay is due to the premiums collected by them from the policy holders. The rates of these premiums, on which the whole efficiency of insurance depends, are worked out in accordance with carefully prepared schedules represent- ing the many elements of hazard. Now, it is easy to see that if premium rates were not based upon a real under- standing of such elements of hazard, they would be noth- ing more than guesses, and guessing belongs to gambling, not to underwriting. If the guesses were too high, the public would be overcharged for its security; if they were too low, the security would disappear. In either case the public would be the loser and the business of underwriting would be short-lived.
34
THE BIRTH OF THE FAMOUS LABEL
More than 500.000,(XJO labels each year are required by the manufacturers of labeled products, and the picture shows the use of a machine for stamping, numbering and cuttmg off brass labels such as are commonly seen on fire extinguishers, fire doors and other products. The automatic features were designed by Underwriters' Laboratories, which now has under construction an improved machine oi its own design that will largely increase the output
EXTINGUISHER OPERATION TEST
Two engineers of the Department of Gases and Oils are asking certain pertinent questions of a 2?-Rallon extinguisher. How far will it throw a stream? For how long? At what pressure under various temper- atures? What is its reaction to litmus paper? If the range prove to be from 30 to 35 feet; the duration, from 60 to 65 seconds; the maximum pressure, from 85 to 100 pounds per square inch; and the stream prove not acid to litmus, this test is considered satisfactory.
The Significance of the Label
Thus it can be seen that the insurance companies and the millions of policy holders have an identical interest in obtaining accurate knowledge of the elements of hazard that must be considered in fixing rates. With contracts rep- resenting billions of dollars at stake there is no room for prejudice and no room for superficial judgment. This fact led to the establishment of Underwriters* Labora- tories, an institution devoted to the obtaining of accurate knowledge. The companies may be said to be backing the thoroughness, impartiality and technical skill of the Laboratories with billions of dollars of policy contracts, while the policy holders, in turn, are backing the com- panies with their premiums.
So much for a purely business consideration, but the policy holders have an additional stake in the efficiency of this work in the fact that their lives, as well as their property, are affected.
It is well within the truth to say that thousands of lives are saved each year as a direct result of the busy imper- sonal labors of the engineers and inspectors on the staff of Underwriters' Laboratories. This explains why the label that epitomizes these labors and makes their findings known to the public has become a subject of nation-wide importance.
2>S
CHAPTER SEVEN Winning the Label
ONE day a boy came into the New York branch of Underwriters' Laboratories, staggering under the weight of a "fire door." He lowered it to the floor, caught his breath, and then told the astonished engineers that he had been sent to get the door labeled and would they please hurry up about it, because the manufacturer had "a customer who was waiting." Of course, the manufacturer was due for a disappointment; the Laboratories' processes cannot go forward at such a dizzy speed. However, the request was only an extreme illustration of a frequent misunderstanding. Many peo- ple do not appreciate that safety investigations involve delays that cannot be avoided. It is a serious matter to say that a certain product or process is free from hazard- ous quahties, or that it will furnish protection if protection be Its purpose. Guessing is quick and easy but where human lives are at stake, or where insurance companies are backing the use of processes and products with their policy contracts, guess-work must be eliminated.
The first essential, therefore, is thoroughness. Listing
3^
Winning the Label
is never awarded to a product so long as there remains a fragment of doubt in the minds of the engineers as to its performance under all the conditions which it may meet in actual use. These conditions may be normal and safe in ninety-nine per cent, of the cases but how about the remaining one per cent.^ Do they hold possibilities of hazard? If so, the product must be given the test of such conditions; hence, at various points in the following pages, reference will be found to "worst treatment" tests. The Underwriters' label is not easily won, but when won, // means something. In saying this, however, a qualification must be emphasized: labels do not necessarily imply the highest attainable qualities; rather they certify the attain- ment of definite and adequate standards. There is noth- ing to prevent any manufacturer from producing better goods than are required by the Laboratories' rating — many of them do — but if they fall below the requirements they forfeit their right to the label.
The second essential of all procedure is complete im- partiality. Any manufacturer whose product complies with the Laboratories' Standards may secure listing, and the keenest rivals meet upon absolutely common ground. To insure this, it is necessary that every step of the testing, inspection and label service for each product be worked out in full detail and rigidly applied to all makes of that product. Consequently, the body of standards and rules has grown to large proportions, yet no one can read them
37
A Symbol of Safety
carefully without realizing that they are both practical and just; they epitomize the technical knowledge and the wide experience of the engineering staff.
This entire activity is focused on a single purpose — that of determining degrees of hazard in order to point the way to the reduction of hazard. This is true of all materials and devices that represent inherent hazard, and it is no less true of protective devices whose failure to work at some critical time may result in disaster. Listing means that the degree of hazard, or the degree of prevention of or resistance to hazard has been determined. The label, when awarded, is a certificate of rating in these respects.
How, then, does the Laboratories operate?
Let us suppose that a manufacturer produces a new line bearing upon some form of hazard — fire hose, it may be, or an electrical device, or a safe, or a roofing material, or an automobile lock, or some other of the thousands of different devices and products that come within the range of the Laboratories' operation. Presently, a prospective customer inquires as to " the label". " I carry insurance,** he says, **but I can't afford to have my place burn down. You say your device is free from hazard, but I can take no chances. If it has been tested and listed by Under- writers' Laboratories I can feel sure."
Thereupon the manufacturer realizes that the Labora- tories' rating has a sales value, and he starts out to secure it. From this time he passes through a variety of steps,
.38
Winning the Label
some preceding the tests themselves, some related to the tests and still others which are supplementary.
The Laboratories* engineers are practical men who have seen many devices fall under test and know what to look for; therefore, they are able to make expert criticisms which often are of the utmost value to the manufacturer In making the necessary Improvements. In hundreds of cases successful devices and products have owed no small amount of their success to the preliminary criticism given by the Laboratories' engineers.
Let us assume, however, that the product in question has passed through these preliminary conferences and now has been submitted for regular test. From this point there begins a series of gruelling experiences — real man- size tests — calculated to "try the soul" of any device. Said the Italian janitor of the New York office as he saw the conclusion of a six-thousand operation test on a batch of switches: "So you do alia you can to busta machine, and if you no can busta you pass it?" Or, as one of the engineers laconically phrased it: "We give it hell." In other words, the device is submitted to tests that will reproduce every conceivable service condition — both probable conditions and those that may be improbable, but still are possible — for the product Is destined to go out into a world of careless people and unforeseen emer- gencies and its qualities must be learned In advance.
In some of the succeeding chapters, glimpses will be
39
A Symbol of Safety
given of these strenuous processes. They are summed up in voluminous reports that bristle with technical terms and prove that there has been nothing superficial, nothing haphazard in arriving at conclusions. Ultimately, it probably will have been shown that the product under discussion is entitled to a classification rating: A, B, C, or, perhaps, D, as the case may be, and each class is so care- fully defined* that the mere use of a letter carries a definite meaning throughout the trade.
At this point the "submittor" of the device — to use the Laboratories' term — is frequently in a state of excite- ment and sometimes forgets that the engineers are abso- lutely impersonal when it comes to their work. One over-anxious submittor, having at last seen his device pass the prescribed tests, after modifications suggested by four engineers had been made, presented each of them with a thousand-dollar watch as a token of his apprecia- tion. The dumfounded engineers turned in the four- thousand-dollar indiscretion to the president of the Laboratories, who promptly sent for the manufacturer. After a stormy hour in the private office, the manufacturer left, carrying his four watches, and never thereafter at- tempted to repeat his offense.
One important part of the whole process is the ''report to Council." In the appendix will be given some idea of the various councils, including recognized authorities of wide experience, who review the findings of the Labora-
40
INSPECTING THE INSPECTORS OF UNDERWRITERS" LABORATORIES I„ .hi, piclure .he ^'•^ri'^l'^tTi^.^^t^l^^^'i^r^SicSSn'i.'S'i 'blln^SS "h^lieS".
INSPECTING ARMORED CABLE AT A FACTORY
The Laboratories- inspector is here shown ^'^^^^^^ ^il^^r.V'^^n^i^C ^^^^^^^^^^
which is widely used in wiring residences , ^l^^'i, 'f ?,".%°' ^^ '^V^clins the rubber-covered copper
SPRINKLER LEVER
^r^^ltv?^^® °i sprinklers are sent to Underwriters' Laboratories for investigation. In this case the ?^=?,rfivLo .f- 'ever which IS a part of a spnrikler of special design is being tried in a 10,000-pound Olsen Tto ;1 f .1 K "^- Ukimately, it will be forced to give way, its deformation being indicated on the dial, and Its strength being shown by the sliding weight now being adjusted by the operator's right hand. (See p 50)
Winning the Label
tories* engineers before classifications and labels are finally awarded. These Councils include the Fire, the Electrical, the Casualty, the Automobile and the Burglary Protection Council, and vary in size from eight in the case of the last named to forty-eight in that of Electricity. These au- thorities must be satisfied as to the accuracy of the con- clusions reached, and, if so satisfied, the Laboratories' stage of the investigation may be said to have been passed.
It will be appreciated that certain samples of the prod- uct under investigation have proved their worthiness as the result of these tests. However, since these particular samples will not be ofl'^ered for sale, it now becomes es- sential to make sure that the actual commercial product will be kept up to sample. Therefore, the work passes into the follow-up service stage; it becomes a factory in- spection matter. All over the United States are the plants which produce materials and devices that have been listed, and to these plants there come at various intervals some one or more of the 250 Laboratories' inspectors, operating from a far-flung system of branch offices.
There are three forms of follow-up work, namely, "reexamination service," "inspection service," and "label service"; certification labels are used only in connection with the last named.
The oldest and simplest is the reexamination service, in which the Laboratories makes examinations and tests of the appliances one or more times yearly. Products
41
A Symbol of Safety
such as acetylene generators, electric welding machines, fire pumps, etc., come under it.
The inspection service is similar but much more thor- ough, and its cost is billed monthly to the manufacturers served. Sprinkler equipment and other devices on which it is impracticable to affix labels come under this form. In most ways it is similar to the label service.
For label service, after Council action, an engineer from the interested technical department visits the factory to make sure that it is prepared to produce the device in commercial form; then the Label Service Department provides an inspector in the locality and makes up a special "procedure" handbook to guide the inspector in making his examinations and tests at the factory; in other words, the inspector cannot act arbitrarily, for every action is prescribed in this handbook, a copy of which is furnished to the manufacturer.
The manufacturer may be urgent for labels, but these cannot be given prematurely. When the first lot of goods has been manufactured, a careful examination of it is made, every item being checked against the procedure handbook in conference with the official of the manufac- turing company who is designated to come in contact with the inspectors. Then, and not till then, the first lot of the labels is delivered.
Thereafter factory inspections are made regularly, pref- erably when lots are ready for shipment, but sometimes
42
Winning the Label
by surprise. No changes even for improvement may be made in the device, nor may it be manufactured at another factory, without first consulting the Laboratories.
This, in brief, is the story of the winning of the label. * * *
The preceding chapters have glanced at the growth of human hazard from the few natural dangers encountered by primitive man to the innumerable perils of our com- plicated modern life. They have shown that man always has been compelled to give thought to protection from these perils, and that, in so doing, he has gradually evolved what may be called standards of safety. In particular it has been noted that the increase of artificial perils since science became a servant of humanity, has led at length to the creation of a scientific institution for the purpose of making a study of these perils and of the protective de- vices with which man's ingenuity has met them.
Finally, it has been shown how the work of this institu- tion has led to the certification of quality in the case of thousands of products related to fire or some other form of hazard, thus making it possible for individuals and com- munities to attain a larger degree of security for life and property.
It now remains to show something of the way in which this remarkable activity has both broadened and intensi- fied. It has broadened as more and more forms of hazard have come within the scope of its inquiries; it has intensi-
43
A Symbol of Safety
fied, because the practical nature of its work has led to a constant increase in the volume of demand for its tests. Thus, it has grown into departments, each with its trained specialists who are kept busy in their respective fields.
Work of this character is constantly reacting to the flow of new ideas, issuing from the busy minds of thou- sands of inventors and taking their forms in the products submitted by thousands of manufacturers. In so doing, the engineers constantly are learning new facts through studying new problems, and from time to time they are able to deduce additional laws. As a by-product to the investigation of specific articles, there is a growing accu- mulation of practical knowledge which, in turn, flows back into the industries afi^ected and makes possible a constant improvement of their products.
The comparatively new profession of fire-prevention engineering is now being placed upon a solid foundation of knowledge, much of which is the outcome of work in the Laboratories' departments. Even more than this, it is already showing a tendency to sub-divide and intensify, as has been the case in the Laboratories itself. Thus, there are fire-prevention engineers and specialists in the electrical field, in the structural field and in the field of hydraulics, to mention only three. The day is rapidly approaching when specific courses of this nature will be given in many institutes of technology.
The following chapters will show how department after
44
Winning the Label
department has been born to meet some recognized need, has trained its own specialists, has acquired or devised its own apparatus, and has begun to affect the conditions of great industries. In order to obtain this view, it will be necessary to consider in succession the work of the various departments of Underwriters' Laboratories.
45
CHAPTER EIGHT
Fighting Fires that Are Not Prevented
I. Detection and Extinguishment
IN SPITE of disheartening loss statistics, there can be no doubt that fire prevention does prevent in thousands of cases each day. On the other hand, the conditions of modern hfe and the vast inertia of human ignorance and carelessness involve hazards so widespread and continuous that the contest sometimes seems to be a losing one. Fire Prevention prevents fires, but the time when it can really prevent Fire, in its destructive sense, is still far distant. Therefore, civilization must long con- tinue to devote much time and money to fighting the fires that are not prevented. This subject is a large factor in the work of Underwriters' Laboratories.
Fire fighting consists of two elements — detection and extinguishment, and both of them have led to a multi- plicity of devices and appliances, some of them automatic and some associated with human operation. For con- venience we may take up detection for first consideration. Fire always announces itself in course of time by means of smoke, smell, sound, the sight of flames or the sensation
46
TESTINX; AN AUTOMATIC FIRE ALARM SYSTEM These two New York Ofiice engineers are trying out an automatic electrical system^ which not only gives an alarm iiT^he event of lire [n fhe buflding in wh.ch it is installed but announces the floor or room where fire is Sineoutbrmean' of coded taps on the fire gongs. Such systems require painstaking study to determine SveLTs of^ratL ^e elec'^rical test here shown is ^ supplementary one this system ha^.ng originaaiy been tested by installing it on the ceiling of a room in which actual fires vvere lighted while several engineers
observed its operation
VIBRATION AND PRESSURE IMPULSE TESTS
pfff"r?«"n/ whlh">°^^^''' sprinklers and pressure gauges may be subjected to a variety of conditions the
effects of which it is important to learn in advance. In the picture, a hydraulic engineer is making tit!
by means of a motor-operated vibration and pressure impulse machine
Fighting Fires that Are Not Prevented
of heat, but this may be at a time too late to prevent destruction. The art of fire detection is that it be dis- covered in its earliest stage when loss may still be pre- vented. To this end, there has been a wide development of fire-detection systems and here again the classification is two-fold; viz.: those based on automatic signaling by the fire itself, through its effect on some mechanism; and those which are accessory to the work of a watchman or patrol, such as time-recording clocks, pull-boxes, etc. Both classes may be good or bad in design, well or poorly made, in order or out of order at the time of need, as with most things mechanical, but both of them are charged with so serious a responsibility that possible failure must be guarded against in advance of the emergencies when such failure would be disastrous. It is the work of the Laboratories to determine, and thus to aid in correcting, all liability to failure.
2. Alarm Appliances
In fighting fire, it first must be discovered. Therefore, automatic alarms in great variety have been devised on the principle of making fire tell on itself. This it never hesitates to do when the right conditions are provided.
Fire can thus be made a much better fire watchman than are the mere humans employed for that purpose. Indeed, human watchmen so frequently are inefficient that there has been much discussion in insurance circles
47
A Symbol of Safety
of what is familiarly known as "the watchman evil." For example, a watchman smelled smoke one Saturday night, but failed to find where it came from and told the Sunday watchman that it was due to a banked boiler. The smoldering fire was permitted to burn all Saturday night and during Sunday and Sunday night as well. On Monday morning the attention of a passerby was at- tracted by smoke pouring from the windows. This passerby ignored the assurances of the watchman and called the fire department, which succeeded in extinguish- ing a fire that was rapidly becoming serious.
In another case a night watchman was disturbed in his slumbers by the persistent ringing of a bell attached to the automatic fire-alarm system. There was a fire, and it was trying to tell on itself, but the watchman was not able to draw the inference; on the contrary, he climbed on a chair and stopped the ringing by forcing the blade of his pen- knife alongside the clapper of the bell. Then he went quietly back to sleep. Two or three hours later he was awakened by the dense smoke with which the room was filled and went down to the street for fresh air. There, wandering about, he found another watchman supposed to be on duty in an adjoining building, and this man offered to go back with him and seek an explanation of the strange phenomenon. Putting his hands on the wall, he found that the bricks were hot. ''Perhaps," said he, "there is a fire!" On this possibility they turned in an
48
Fighting Fires that Are Not Prevented
alarm, but some ^50,000 worth of damage was done before the firemen could subdue the flames.
These are merely a few cases out of many indicating the fallibility of depending on human vigilance and the desir- ability that fire be made to summon outside assistance. For such reasons, inventive ingenuity is always active in this field, and fire-alarm systems are under constant investigation by Underwriters' Laboratories. One type in wide use is operated by a valve attached to the auto- matic sprinkler system. As soon as a sprinkler head is opened by the fire the motion of the water causes an alarm to sound.
On the other hand, much of the work on alarm systems and devices is done by the Electrical Department, and the electrical circuits on some systems are remarkably complicated as, for example, in the case of those known as "non-interfering" by means of which several alarms may be sent in simultaneously from different points with- out interference at the central station.
J. Standpipes and Hose Stations
Iron standpipes and hose connections are to be found in the hallways of most tall buildings. Their necessity is too obvious for comment, for imagine the awkwardness of having to carry hose up many flights of steps in fighting fires on upper floors. Whether these systems be of the "wet" type, in which water pressure is constantly main-
49
A Symbol of Safety
tained, or of the "dry" type, into which water must be turned before fire streams are available, it is evident that the pipe itself must be good, that the hose stations at- tached to it on the various floors must be convenient and easy to operate and that these hose stations must be made as nearly "fool proof" as possible.
An ordinary investigator might think it sufficient merely to look things over and, perhaps, to give the system a trial operation in place. Not so with the Laboratories' engineers. They make micro-photographs of the iron or steel to learn of its structure; they test its strength and elasticity by means of powerful tension and compression machines; they carefully examine the inner surface be- cause roughness means friction, and friction under some circumstances may cause the stream to fall short of the flames it is desired to extinguish. So, too, with the hose stations. Their various requirements must be investigat- ed with great care in view of the fact that they are likely to be used by inexperienced people laboring under excite- ment— a point never to be overlooked in making tests.
4. Sprinkler Equipment
"The manufacturer who today builds without provision for automatic sprinkler protection almost wilfully en- dangers not only his plant but the life of his employes," so says the Secretary of the National Fire Protection Associ- ation. Automatic sprinkler equipment is undoubtedly the
50
SOME "HORRIBLE EXAMPLES" However good a sprinkler head may oriKinally have been, it cannot operate if seriously corrocied or if heavily loaded with dust, lint or other foreign material. This cabinet contains heads taken from ac- tual service. One was gummed by flying varnish, another was clogged by a wasp s nest and still others were seriously corroded or otherwise impeded. They form an object lesson in the importance ol in- spection and maintenance
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DKTEUMINING THE STRESS ON A SPRINKLER LINK
The operator has his eye fixed on a very sensitive Ames dial, while his left hand slowly increases the weight on the beam of the weighinc; machine, and a pencil in his right hand records the exact point of release. Note the number of sprinkler heads visible in this photograph. The Laboratories uses 15() of each ty[>e in order to determine uniformity of oiieration and other characteristics
OPERATING TESTS ON AUTOMATIC SPRINKLERS
Sprinklers must be responsive to heat, but all the conditions of their response must be known in ad- vance of the emergency which will call it into play. The illustration shows a gas-heated, water- jacketed, cylindrical oven, where the temperature is raised according to a predetermined standard temperature-rise curve. The temperature at which the link fuses and the behavior of the operatmg
mechanism are carefully noted
Fighting Fires that Are Not Prevented
greatest single device for reducing fire loss, and In thou- sands of buildings may be seen the familiar little sprinkler heads, quietly awaiting the time when heat from a fire may melt a small piece of fusible metal and allow water to gush forth in a drenching shower. It is estimated that 20,000,000 people are now under the daily protection of sprinklers and that during the past twenty-seven years this form of protection has successfully controlled 95.7 per cent, of 26,888 recorded fires.
So highly is the sprinkler esteemed by insurance com- panies that they make large reductions in premium rates where it is employed, provided that it be of approved type. This qualification is important, for there are "sprinklers and sprinklers." Inventors have been especially busy in this field and hundreds of devices have been submitted to Underwriters' Laboratories for test; and tests they have received, tests so searching in regard to the many qualities required that the Laboratories' standard for sprinklers alone is a book of about thirty thousand words. These tests occur almost continuously and the visitor to the Laboratories is apt to find them in some stage of process. He may see the hydrostatic-pressure test, during which a steadily increasing pressure searches out the weak points in the sprinkler, or the "water-hammer" test, whereby four thousand vigorous hydraulic blows are delivered, followed by investigation for leakage; or, he may see some one of the "installation," "accuracy of release" or
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A Symbol of Safety
"excessive stress" tests. He may see sprinklers tested after having been subjected to chlorine or nitric acid fumes or coated with calcimine, as might easily be the case in actual use. He may see them struck with hammers or thrown on cement floors, under the specifications for "rough usage" tests. He may see them tested for distribution, in order to learn the exact area of floor or ceiling that they will cover with spray, or mechanically tested for strength, or he may see uniformity tests made upon 150 or more samples, and other efforts made to determine all of the points of possible weakness or inef- ficiency, which might spell life or death in a fire emergency. In view of this, it will hardly surprise him to learn that out of the hundreds of types submitted, only some fifteen heads have the final listing.
The qualities of the sprinklers, when once determined and rated, are made the subject of factory inspections, as with most other lines, but the most remarkable feature of the Laboratories' workon sprinklers consists in taking heads for test from buildings throughout the country, where they have been in service for months or years, as the case may be. This service involves from four to five thousand samples each year and is performed without cost to the owners of the buildings. Reports are sent to the insured, to the interested inspection department and to the sprinkler companies concerned, however, it must be added that the name and address of the assured are deleted from the copies
52
Fighting Fires that Are Not Prevented
sent to the sprinkler companies. As a result of such tests the Laboratories makes definite recommendations to the owners of the buildings as to whether the heads should be retained or taken out.
5. Fire Hose
In 191 1, President Merrill, in speaking before the Fire Underwriters of the Pacific, said:
We find [fire hose] manufacturers making a monstrous mystery of their wares, analysts proving them rotten or unfit for use and gossips busy with details of scandal about the reasons why inferior hose is delivered, when superior is supposed to be paid for from the public treasuries.
There is perhaps no single item of municipal supplies whose purchase has been associated with more irregulari- ties than this vital factor in public safety. It is a matter of common gossip that a well-known politician in one of our great cities was conceded the fire-hose graft as his own personal reward for political services, and similar condi- tions were to be met in many other cities. As a result, it is not astonishing that, times without number, length after length of defective fire hose purchased with the good money of the taxpayers burst as soon as water had been turned into it. Under such circumstances, fires that might readily have been controlled have grown to large proportions and a ghastly list of human victims is charge- able to defective hose.
S3
A Symbol of Safety
For example, on January lo, 1908, fire broke out in the Parker Building on Fourth Avenue, New York City, and the firemen were hampered by the fact that forty-two different lengths of fire hose burstunder the water pressure. This undoubtedly was one of the reasons why the fire caused heavy damage before it was brought under control; still worse, it was one of the reasons why three firemen lost their lives and fourteen others received serious injuries.
Sometimes similar conditions prevail in the equipment of private plants. A characteristic instance of this kind occurred several years ago in a Pennsylvania cement- manufacturing plant, where a fire broke out in a bunker, presumably from a locomotive spark. The fire was quickly discovered and the plant's fire-squad coupled up the plant's expensive new hose and turned on the water, whereupon the hose burst in five or six places and the fire merely gained headway. The disgusted squad hurried to uncouple the hose and threw in another length, which immediately burst like its predecessor. Ultimately, the loss amounted to ^7,000 which was almost entirely due to the failure of the hose.
In this case the plant management had "specified and paid for" hose inspected by Underwriters' Laboratories, but had neglected to "look for the label," and the dishonest dealer had substituted a worthless product.
Fortunately, such conditions are becoming less frequent today, a fact that is largely due to the widespread in-
54
TESTS ON AUTOMATIC SPRINKLERS
It is said that automatic sprinklers are guarding the lives of 20.000,000 people, therefore, the tests as lo their efficiency are of supreme importance. In the picture, the engineer at the left is making a leakage test, while the one at the right has plunged another sprinkler into a hot liquid maintained at a certain temperature in order to observe, by means of a stop watch, how many seconds will elapse before it operates
FACTORY INSPECTION OF COTTON RUBBER-LINED FIRE HOSE
In this work, every single 50- fr. length of hose produced by the manufacturer for labeling is subjected to ^'%?^S" f pressure under the eye of the Laboratories' inspector— 300 lbs. per sq. in. for single-jacketed and 400 lbs. for double- or multiple-jacketed. The Laboratories' inspector is shown observing the performance of the length nearest to him on the test table. He watches for elongation, twist, warping, rise from level of table, security of couplings, etc.
Fighting Fires that Are Not Prevented
sistence on "Underwriters' fire hose, " or labeled hose com- plying with the standards laid down by Underwriters' Laboratories.
The "monstrous mystery" referred to by Mr. Merrill has been dispelled by the clearness of the Laboratories' requirements for municipal fire hose. For instance, the first requirement is that the fifty-foot sections be stenciled in indelible letters and figures at least one inch high, with the trade name, the month and year ot manufacture, and the words "tested to 400 pounds"; the Laboratories' label must also be firmly attached near an end. It serves more than one purpose, as a crooked jobber found out to his deserved sorrow when he tried to pass off as new a lot of old hose on which the stenciled dates had been altered. The prospective customer became suspicious and notified the Laboratories' local office, where he was informed that the labels had been affixed to a War Department supply some years earlier.
Fire hose is such an important product that it comes under the " 100 per cent, inspection " system of the Labora- tories; that is to say, every section of hose sold with the Laboratories' label attached to it has been inspected and tested individually at the factories by the Laboratories' inspectors. Each length of hose, before being labeled, must withstand a pressure of 400 pounds per square inch, without leaking, sweating, breaking cover threads, short- ening, rising from the level of the test table or warping
SS
A Symbol of Safety
more than twenty inches, nor may it twist excessively under the strain, and, if it does twist, it must do so in a direction to tighten the coupHng. One full length out of every ten must be tested ivhile kinked and it is required that its cover threads shall resist a pressure up to 300 pounds per square inch. From every lot of sixty sec- tions, one is selected and a three-foot sample is subjected to hydraulic pressure that is steadily increased until the hose is forced to burst, a point which may not occur below 600 pounds to the square inch. Finally, the manu- facturer must guarantee to the municipality that the hose is made according to the best principles of hose construction, that it is free from defects of material and workmanship and that if, at any time within three years, the rubber parts of any section burst or show cracks or harden, because of defects, such hose shall be replaced with new hose at a cost equal to such per cent, of the original cost as the time elapsed is of three years.
Preceding such factory inspection, however, and from time to time thereafter, thoroughgoing tests of test samples are made at the Laboratories itself, and these are in the hands of the Chemistry Department, since they concern themselves chiefly with the character of the rubber and cotton employed. This is because the rapid de- terioration to which some hose is subject is largely due to inferior quality in its materials.
56
Fighting Fires that Are Not Prevented
The tests concern themselves with minute but highly essential details, as laid down in the rigid specifications. For example, it is provided that the rubber lining of a two- and-one-half inch double-jacketed cotton rubber-lined hose must consist of not less than three calendered sheets with a thickness between .058 and .072 in. and "practically free from corrugations ". Similar definiteness applies to all other details, including even the fact that the hose coupling must contain not less than "82 per cent, of copper". Thus no room is left for a shred of "mystery" in the manufacture of fire hose.
These are the reasons why the average fireman is now able to enter a burning building with confidence that the hose upon which his life may depend will not fail him in service.
6. Hydraulic Tests
It is fortunate for humanity that water, the most reliable of all fire extinguishers, should be so plentiful in a world of hazard. The water supply is the most im- portant part of the fire-fighting system of every commun- ity, and its pipes, valves and fittings come in for extensive tests at Underwriters' Laboratories. This is why the institution contains an elaborate hydraulic laboratory.
Back of the work of firemen, sprinklers and standpipes there must be the means by which they are supplied with water; these involve pumps, hydrants, valves and, in
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A Symbol of Safety
some cases, complicated supervisory systems, all of which keep the Laboratories* hydraulic engineers busy through- out the year. Offhand, one would think that any valve could be examined and tested in a few hours, but alarm valves require each about four weeks of steady work by the engineers, and dry-pipe valves likewise present many problems for consideration before the Laboratories can render an opinion. The ideal alarm valve must cause a gong to ring or a signal to flash, or both, but it must ignore false alarms. This problem, by the way, has never fully been solved, though in some cases Laboratories* engineers have, at manufacturers' requests, devoted months to development work on this device. As to dry-pipe valves, they are used in premises that may become cold enough for the water to freeze in the fire-fighting system. This invention is quite as remarkable in its way as is the alarm valve. It must hold back the water until a sprinkler opens, when it must immediately open in turn, so that as few precious seconds as possible will be lost while the water rushes to the point of fire. Only five of these valves have received favorable opinion and have been listed by the Laboratories.
The importance of such listing is shown by such in- stances as the following:
"When fire broke out in a sash and door factory, the two i2-in. alarm bells in the outside of the building and the 6-in. bell in the stableman's dwelling did not operate.
58
A VALN'E WHICH GIVES AN ALARM
Fire not only should cause the flow of water from the sprinkler, but it also should send in its own alarm. An alarm for this purpose is here shown under test in the interesting hydraulic laboratory, and the minimum flow of water required to make it operate is being de'ermmed. The device under test is the small rectangular box in the right-hand margin of the picture
TESTING THE STRENGTH OF A GATE VALVE STEM
Here is another view in the hydraulic laboratory. The gate valve is seen on the floor, with one flange
securely bolted to the steel platform, while pressure is being exerted on its bronze stem by means ot a
lever, the extent of the strain meanwhile being measured by a sprmg balance
Fighting Fires that Are Not Prevented
No less than forty-seven sprinklers were found to have opened, so that the dry-pipe valve must have been too slow in operating. "
Ask any hydraulic engineer specializing in pumps whether he has ever heard of Underwriters' Laboratories and he will probably answer: "Why, the approved fire pumps are all commonly known as Underwriters* pumps. '* That tells the story. As a matter of fact, some manufac- turers use that characterization in their catalogs and put big brass plates on their labeled pumps, bearing the word UNDERWRITERS in large letters. There are hun- dreds of water pumps on the market, but only a few "Underwriters' pumps," the principal points of difference being that the latter embody almost every known im- provement making for durability, reliability and instant operation. It is regrettable that many owners of tall buildings do not realize the necessity for providing fire pumps in addition to the supply tanks, and that some owners do not even have the latter.
7. Chemical Extinguishers
Ten cents' worth of baking soda in a five-cent tube — such was the so-called fire extinguisher sold for three dollars to the owners of the Iroquois Theater in Chicago in 1904. A mechanic testified that in its incipiency the terrible fire, which cost over six hundred lives, could have been put out with a small stream of water, but the "extinguish-
59
A Symbol of Safety
er" was used as per directions until it was too late even for hose streams.
Labeled fire extinguishers effectively put out a fire in a New York subway car in July, 1922, at a point far below street level. Passengers painfully climbed seventy- foot ladders, ambulances and fire engines rushed to a scene of confusion, and at first there were sensational reports that fumes arising from the use of the extin- guishers had poisoned the lungs of the passengers. Later, experts from the Transit Commission and the U. S. Bureau of Mines reported that the "smoke and fumes were principally from burning insulation, paint and other organic matter" and that there was no evidence that poisonous gas was generated through the applica- tion of the extinguishers used.
If it were not for the establishment of rigid standards certified through labels, frauds would doubtless be per- petrated upon an ignorant and unthinking public, which buys make-believe extinguishers and imagines defects in good ones.
The importance of this whole subject of what are com- monly called ** first-aid" fire extinguishers can hardly be over-estimated since they are used in fighting scores, possibly hundreds, of small fires every day in the year. The number of cases in which efficient extinguishers, promptly applied, have prevented incipient blazes from becoming serious, is beyond computation; the sense
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Fighting Fires that Are Not Prevented
of security that most people feel in their presence is undoubtedly due to the high average of their performance. This, in turn, has been influenced by the fact that in this class of product, more perhaps than any other, the general public has learned to "look for the label" of Underwriters' Laboratories. More than six million of these small hand-operated extinguishers have so far been labeled and the present rate of labeling (1923) is about three hundred thousand a year.
Thus, in factories, stores, public buildings and hun- dreds of thousands of homes the eye has become accus- tomed to the familiar two-and-a-half-gallon copper extin- guisher or the smaller one-quart device, both of which hang on the walls in silent readiness for immediate action. To these must be added the well-known fire-pail which renders important service in every community.
The words "immediate action" explain most of the tests that are made on first-aid fire extinguishers by the Department of Gases and Oils which has them in charge. Such extinguishers do not protect by their presence but by their use. This use is generally in the hands of ama- teurs, in a state of excitement, and is made during the precious "first five minutes." There is no time to tinker, adjust or study; the whole device must be swift and efficient when the emergency occurs and it is the business of the engineers to find out whether it is likely to be.
For example, some fluids are subject to freezing unless
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A Symbol of Safety
kept in sufficiently warm places and, naturally, a device cannot be used when frozen. In spite of warnings and directions very many extinguishers are allowed to freeze by careless owners and the question as to the degree of permanent impairment resulting from such freezing is important to determine. The freezing may weaken the device in a way that will not become apparent until there is an attempt to use it in a sudden fire emergency, when it may give way with serious results.
On the other hand, if the extinguisher be torn apart by the freezing, the solutions when melted will run out and advertise the fact, thus giving the owner ample warning that the ruined device should be replaced. Even in such a case the general temptation is to have the extinguisher repaired, and where this is done, without proper knowl- edge of the problems involved, the general results give a false sense of security. A sample of such an experience was recently brought to the attention of the Labora- tories in a report to the effect that a labeled extinguisher had exploded, as a result of which the device was secured and carefully examined. This examination disclosed the fact that the vertical seam had evidently been torn apart by freezing, and the repair had been made by springing the edges together and simply soldering them without any attempt to secure further strength than that given by the solder. When this device was used, the soldered joint, of course, failed and threw the extinguisher parts
62
HOW STRONG IS THE EXTINGUISHER SHELL?
In the operation of a soda acid chemical extinguisher, a considerable gas pressure is developed within the shell in order to force out the stream. It is important to make sure that the shell will not burst, and it therefore is subjected to a pressure of 385 pounds per square inch in the test here shown. Then its dis- tortion is carefully measured, after which the pressure is gradually increased until the shell is forced to break, the exact bursting pressure being recorded
TESTING A 33-GALLON CHEMICAL EXTINGUISHER
This important type of "first aid" apparatus is frequently equal to the task of subduing a fire. In the
picture, it is under test as to the pressure developed in the tank and the nature and carrying power of its
stream. Students from the Armour Institute of Technology are seen as interested spectators
Fighting Fires that Are Not Prevented
with considerable violence, but fortunately without in- jury to the operator.
There have been many efforts to find some practicable way to lower the freezing point of extinguisher contents, but many tests have failed to show a depressant that is free from objection. For example, a solution of common table salt, while it will lower the freezing point, is sure to produce corrosion and resultant weakness.
As an example of this, a number of years ago an ex- tinguisher exploded and an examination of the fragments indicated that the metal at the water level had been eaten away to almost paper thinness, except, of course, at the double thickness of the longitudinal joint. When this extinguisher was operated the pressure generated was sufficient to tear away the dome of the extinguisher.
This, of course, is but one of the many points concern- ing the two-and-a-half-gallon extinguisher which call for careful investigation in painstaking tests.
The one-quart tetrachloride type works on a different principle and calls for tests of a different character. Its fluid has the important virtue of being a non-conductor of electricity, hence is often used in this connection.
In their development the engineers of the Gases and Oils Department made use of many different types of fires to demonstrate the limitations and value of this type of device. Electrical fires, consisting of arcs produced under high voltages and heavy current, were attacked
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A Symbol of Safety
with devices of this kind with results which indicated the value of the non-conductive liquid and the smothering effect of the vapors formed. Tests were made at the stations of some of the larger electric lighting concerns in Chicago and New York, and the effectiveness of this type of extinguisher for electrical fires was thoroughly demon- strated. Fires in inflammable liquids also were attacked in order to indicate what a single device of this type would do; such tests included liquids in tubs and liquids spread on the floor and absorbed by various kinds of fab- rics such as burlap, cotton batting and cotton waste. In all of these tests the engineers of Underwriters' Labora- tories were constantly exposed to the products of com- bustion and the fumes given off from the extinguisher, but, although the engineers were many times forced to flee from the test room by the smoke and fumes, at no time was any engineer injured or materially in- capacitated.
"The work of the Laboratories," to quote one of the staff, "may be considered as similar to that of a clearing house for many varieties of fire extinguishers, which if described would provide an interesting volume. It might be expected that invention has practically ex- hausted itself along these lines, but such is certainly not the case. Hardly a day passes by that some thought or idea in methods in connection with extinguishing fires is not presented. New chemicals are presented, and more
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Fighting Fires that Are Not Prevented
frequently well-known chemicals in new combinations are submitted for consideration. "
A great deal of research and improvement work has been done by Underwriters' Laboratories on all kinds of chemical extinguishers from the one-quart size up to the automobile chemical fire-engine.
The preceding pages indicate but a few of the main features of Underwriters' Laboratories' work with regard to fire-fighting equipment. In most American cities fire-fighting is in the hands of professional fire departments which employ large apparatus that is tested in the locality of its use by engineers of the National Board of Fire Underwriters. Fire hose and alarm systems are the main items affecting the work of fire departments that receive inspection at the Laboratories, although of course all such matters as sprinklers, valves, standpipes and even portable chemical extinguishers are part of the fire- fighter's problems.
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CHAPTER NINE
Building to Last, Not to Burn I. Studying Burnable Conditions
jk CURRENT joke among New Yorkers before 1897 /jk was that the only fire-proof building in the city jL jL. stood on the corner of Fifth Avenue and Forty- Second Street. If curiosity prompted one to investigate he would find the "fire-proof" building to consist of the Reservoir — a massive stone wall enclosing and impound- ing 24,000,000 gallons of water.
The reservoir was demolished at last to make way for the Public Library, and the question as to whether New York now has even on&completely fire-proof building is open to debate. Certainly many buildings are more or less fire resistant, but a much greater number seem to burn so readily as to suggest that the city's streets are lined with thousands of prepared bonfires, awaiting only the touch of flames.
This also is true in all other American cities and towns, and with the usual run of country buildings, but it is conspicuously untrue with regard to many foreign coun- tries. Indeed the contrast between fire losses in America and Europe is so striking as to indicate the existence of very fundamental reasons which, on investigation, prove
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A "CLOSE-UP" OF A CONFLAGRATION
That is practically what is pictured here, in so far as it applies to the fire-resistance of roofing If your house were covered with these shingles, how well would it be protected.- The roofing itself answers this question by its behavior under many tests, one of which is here shown. Gas burner flames are being driven against the sample by the wind from a powerful blower, while observers note how long it takes to ignite, whether glowing fragments are detached, etc.
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HOW ACCURATE ARE THE PRESSURE (iAUGES?
Merely to look at this small piece of apparatus one would hardly imagine that it is capable of exerting pressures up to 25.0()fi pounds per square inch, in checking the accuracy of a gauge (See p. 253)
EXTRACTION APPARATUS FOR RUBBER AND ROOFING
"Rubber" is not necessarily rubber. There are countless adulterants which affect its qualities. This is an important matter in fire hose, insulated wire and other products. Similar conditions apply to the saturating and coating compounds used in roofing. The photograph shows a chemist placing a sample of rubber in a flask preparatory to extraction with acetone. For obvious reasons this room is ventilated by means of a powerful exhaust fan and the visitor hardly notices the variety of odors
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to be three-fold, viz. : our traditional American carelessness as compared with the thrift and precaution of an older civilization, our larger employment of hazardous devices and processes, and, chiefly, the highly combustible char- acter of our buildings.
It is but a few generations since our forefathers found themselves on a new continent, abounding in forests which ofi^ered an apparently endless supply of inexpensive building material. It was Inevitable that frame con- struction should come into general use, and it was a natural consequence that fires should become so fre- quent that Americans looked on them as more or less matters of course — **acts of God" — although better- built Europe did not so regard them. Characteristic American optimism was willing to "take a chance" in the matter of fire hazard but the results finally grew sobering, even to optimism. Then it was realized that buildings must be built to last, not to burn, and architects and engineers gave a very tardy recognition to the importance of the subject of fire prevention.
Before long they found themselves handicapped by lack of information. They knew that a single brick or block of stone would not burn, and assumed that a building of brick or stone would not burn, but were distressed to find that such buildings often proved to be fire-traps. Apparently it would be necessary to master other factors before fire-proof or even fire-resistive construction could be
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thought of. This was a matter of Hfe and death to thou- sands and of vast property values. How, then, might this knowledge be obtained ?
The study of conflagrations revealed much, but the re- sults might be misleading because of the uncertain con- ditions of the fire. After each big fire, manufacturers were stimulated to produce new forms of roofing, partitions and other structural material which were confidently labeled "fire-proof" until another conflagration might show the fallacy of the claim.
Finally it came to be realized that there was no possi- bility of checking the nation's mounting fire-waste unless severe fire conditions could be produced under control and under expert observation for the purpose of testing and de- termining the qualities of various building materials before they were actually employed.
Underwriters' Laboratories began this work in 1903 and it soon grew into one of the principal activities of the institution. Today, the tests of building materials have included a great variety of products representing thou- sands of different manufacturers and the Laboratories' influence is felt in the whole field of building design and construction. Probably generations must elapse before American towns can be rebuilt along safer lines, but the steps already taken in that direction are appreciable and many of these steps are directly traceable to tests con- ducted on East Ohio Street.
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It has been a rather fanciful dream of the Laboratories that buildings might some day be constructed entirely of labeled materials and completely equipped with labeled installations so that the buildings as a whole would be entitled to bear the label of the Laboratories. That this is not wholly imaginative is shown by the fact that the main testing station on East Ohio Street ap- proximates such conditions of safety. From every stand- point it has been safeguarded to a degree that makes fire hazard almost unthinkable.
The subject of building material tests is well worthy of a closer view and a glance will now be given at some of its sub-divisions.
2. Roof Coverings
Most conflagrations are associated with wooden shingle roofs. The original fires may be due to many causes; to Mrs. O'Leary's cow (if this famous animal ever really existed), to shoe-heel lacquer in a Salem workshop, even to the overflow of a river causing the sudden slacking of lime in a Georgia basement. In most cases, however, the fire is trifling until it begins to travel, and its favorite method of travel is from roof to roof.
A general conflagration is a terrifying thing. It calls to mind great clouds of acrid smoke, a roaring advance of wind-driven flames, and a rain of flying sparks and brands upon the roofs in its pathway, so that these latter
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sometimes begin to burn blocks ahead of the main fire. With it all, there is the panic-stricken activity of the threatened inhabitants rushing to escape or to save what they may of their possessions. A conflagration is the most dramatic event in American city life; it is of all- too-frequent occurrence, yet it is almost unknown in European cities with their solid buildings and their slate, tiled or metal roofs upon which sparks or brands merely burn themselves out.
But America is a land of wooden shingle roofs — millions of them; they are a tradition of our history because they are cheap, easily applied and easily repaired.
However, the accumulated lessons of fires became so unmistakable that, rather less than twenty years ago, there developed a great demand for durable, inexpensive, fire-resistant roofings to replace the wooden shingle.
Demand is usually followed by supply, and soon manufacturers produced various forms of roofing that were marketed as "fire-proof". In actual fires, these did not always substantiate this claim and the underwriters, by whom roofing is regarded as an important element in influencing the spread of fire, realized the need for exact knowledge on such a vital matter. As soon as the question of roofing began to affect insurance rates, both users and manufacturers saw the necessity for an authoritative judgment and Underwriters' Laboratories, in 1906, began to make roofing material a subject of test and classification.
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At first the tests were rather crude, the principal one being the dropping of red-hot cast-iron discs on the roofing samples. Nevertheless, so carefully were the observa- tions made that there has been no instance in which labeled roofing, in use, has failed to fulfill the requirements of its classification.
Ultimately the investigation developed into its present form in which a careful and standardized study is made into various questions of design, construction, practicability, durability and other items as well as into the direct ques- tion of ability to resist heat and flames.
The items in the resulting report represent a greal deal of work. For instance, "Physical Tests" really includes also some thorough chemical tests. To the untrained eye, there is little difference between a piece of rag-felt roofing saturated with a coal-tar pitch and a piece of asbestos- felt roofing impregnated with asphalt, but they have different properties. Even the word "asphalt" is not sufficiently definite because there are asphalt deposits in Trinidad, Utah and elsewhere, from which many varieties are extracted, each of which has certain properties, and the various manufacturers have formulas of their own for mixing their saturants, impregnating compounds and coatings. The Laboratories must know just what the test samples consist of, so that year after year it may check up on the manufacturer.
The fire tests are three-fold: Frequently roofing en-
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counters severe heat without being touched by fire brands, and sometimes bursts into flames from the heat alone. This is tried out in the first test, in which a drum-shaped gas-fired oven is heated until the bottom plate glows red at iioo° F. Then the roofing, which is laid on a wooden deck as in use, is moved to within ten inches of this plate and is subjected to the heat until flames appear on the under side of the deck. Everything is standardized, as in all other tests, in order that each make shall be tried under the same conditions.
The next test involves burning brand exposure. A standard brand is ignited, placed on the roofing sample and allowed to burn itself out. Some roofings fail under this test as is shown by the burning of the roof boards; with others, the boards are uninjured. Every detail is recorded carefully and photographs are taken.
Then comes a more severe exposure, that of wind- driven flame. This is really spectacular, for a roaring mass of flame impelled by a twelve-mile wind from a blower, leaps from a thirty-six-inch burner and attacks the surface of the roofing. This test continues until the roof deck boards are ignited. The time is noted as well as the rate of the spread of flame over the roof covering during the test. The blower, by the way, is used in con- nection with the other tests, and the twelve-mile rate was determined upon after studying the weather reports of many years.
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When roofing has undergone these and still other or- deals and has been recorded and photographed, there is no longer room for guesswork as to the claims of its manu- facturer; its fire-resistant qualities are known and the classification label awarded to it by the Laboratories shows exactly what can be expected of it by the public.
J. Windows
On the night of March 15, 1922, the upper eight floors of the Burlington Building in Chicago were swept clean of their contents in a great fire that involved fourteen buildings. This fire caused much discussion because of the fact that the Burlington Building had been considered a fine example of modern fire-resistive construction and many people jumped to the conclusion that the theories of fire-prevention engineers had been disproved.
Investigation showed, however, that these theories had been proved, not disproved. The building was an excellent example of safety construction with one fatal exception. There was nothing astonishing in the per- formance of any of the materials which made up that building; steel, brick, terra-cotta, hollow tile, plaster block, bronze, marble, wired glass, window glass and wood.
The whole trouble was that these last-mentioned ma- terials, window glass and wood, were used where they should not have been used. On each floor of the Burling- ton Building facing Clinton Street there were nineteen
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ordinary glass windows in wooden frames. From the ninth to the sixteenth floor these all were damaged very early by the heat from across the street. About thirty minutes after flames broke through the roof of the build- ing where the fire originated — two hundred feet from the Clinton Street side of the Burlington Building, J. C. McDonnell, Chief of the Bureau of Fire Prevention, "noticed that the wooden window frames of the Burling- ton Building were igniting" and on Clinton Street he "found window glass falling like a hail storm."
Almost immediately after these windows failed, the combustible contents of every upper floor were burning. In a few minutes the wooden flooring, doors, frames, etc., also were burning.
In expert discussions of this fire (or rather of these simultaneous fires on the upper floors) the opinion has been expressed that light combustible objects were ignited by the radiant heat from across the street even before the window glass cracked. This fire was merely a striking example of the facts that fire frequently makes its entrance to a building through the windows and that window pro- tection must never be neglected where there is the chance of exposure from outside.
In 1903 Underwriters' Laboratories began to test "fire- windows." Not a single so-called "fire-window" passed. "They failed miserably." Underwriters' Laboratories' tests were considered a joke. The majority of manufac-
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TESTING A METAL WINDOW FR,\ME
The frame set with panes of wired glass is subjected for one hour to the intense heat of roaring gas flames. Almost immediately, the glass cracks in many directions. Somewhat later, the iron frame- work begins to bend inward slightly toward the flames. In the picture, the one-hour exposure is nearly completed and an observer at the right is taking the measurements of the distortion of the window frame. A little above his measuring device there is a suspended pole on which strips of cloth are hung at various distances in order to show the effect of the radiated heat on combustible material. One of these strips has just burned and fallen to the floor
FIRE-STREAM TEST ON METAL WINDOW FRAME The movable wall containing the metal window frame has just been rolled from the furnace and the glowing window is being deluged with a fire stream on the side of it which has been exposed to tire, in order to demonstrate whether it will withstand the impact: and the sudden contraction of parts caused by the cooling effect of the water. The back of the furnace, with its complicated system of air and gas controls may be seen at the left
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turers of fire-windows thought that no practical window, acceptable to architects, builders and owners, could ever meet Underwriters' Laboratories' requirements.
These requirements have never been made less severe.
Today, nearly one hundred manufacturers are making windows which actually do meet the requirements.
Before describing the tests to which various types of windows listed by the Laboratories have been sub- jected, it must be made clear that for severe exposures even the most fire-resistive window does not furnish sufficient protection because a window which allows a great deal of light to come into a room will also allow a considerable amount of heat to pass through its panes. Furthermore, even wired glass softens and falls out when subjected to sufficient heat. Therefore, Underwriters* Laboratories does not label windows for "severe exposure".
The label [it declares] is evidence of proper construction of the appliance at the factory. Prospective users should first ascertain from the inspection departments having jurisdiction which type, if any, of wired glass windows will be accepted in the location desired, and should make contracts subject to approval by them of the in- stallation, glazing and automatic attachments.
Even where shutters are used, wired glass windows are usually needed. Shutter protection is either automatic or hand-operated. In the latter case there always exists the possibility of neglecting to close the shutter; in the former, some little time must elapse between the beginning
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of the fire exposure and the automatic operation, and during that time the insufficient protection afforded by a wooden window with ordinary glass may spell disaster.
While the main classification of fire-windows is for "moderate" and for "light" fire exposures, the number of styles and combinations possible is very large, and the number actually manufactured under the Label runs into the thousands.
The testing of a fire-window contains some interesting features. When the many burners have been lighted and the flames begin to roar behind the translucent wired glass, there comes a series of reports, as a network of cracks be- gins to spread over the window. At this point the quali- ties of wired glass are apparent to the veriest layman, for the mesh holds the cracked panes tightly in place.
Soon the metal sash acquires a dull color and a strong radiation of heat comes through the glass. This radia- tion is tested by means of thermo-couples placed at various intervals and by strips of cloth hung before the window. During a test, one or more of these may take fire and fall to the floor, thus indicating that inflammable material may be ignited by radiant heat.
As the blue and golden flames play upon the inner sur- face, the metal sash begins to bend inward toward the heat until at length there is a pronounced distortion. Finally, after an hour's experience of this kind, the window is rolled back from the flames and played upon by a hose
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stream, which causes clouds of steam to rise from the heated surface and soon tears gaps in the softened wired glass panes.
During all this time the engineers have been making careful observations and recording every essential fact.
4. Doors and Shutters
Under "Roofings" and "Windows" we have been con- sidering protection against fires that attack from the out- side, but this is the lesser part of the danger; in the great majority of fires the damage is done by flames that spread from room to room and from floor to floor in the same building. Confine a fire and you render it comparatively harmless. This is one of the chief objects of fire-resistive construction, which is aided by the knowledge acquired by Underwriters' Laboratories in its tests of materials and devices.
Among these tests, those of doors are of exceptional importance. An inside fire always seeks for openings, and all rooms must have doorways. An open door is an in- vitation to a fire as it is to a person, and many doors must be left open much of the time. This is a simple statement of a serious fire problem that has been responsible for thousands of deaths and has given rise to the large in- dustry of fire-door manufacture.
Necessarily a door is part of a wall or partition, but it is a moving part and therefore must be light enough for easy
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operation. In the case of a fire, it may be subjected to heat that will ignite the ordinary wooden door and allow the flames to spread on the other side. The duty of all fire doors is to resist such an attack but these are used under such a variety of conditions that a number of forms have been produced for the market. Many styles and makes have been tested and labeled by the Laboratories. These are grouped according to their use as : (i) "for openings in fire walls"; (2) "for openings in vertical shafts"; (3) "for openings in corridor and room parti- tions"; (4) "for openings to exterior fire escapes," and (5) "for openings in exterior walls " ; this last class includes window shutters.
For Openings in Fire Walls. It occasionally happens that the fire wall in a factory or warehouse obstructs a raging mass of flame which must not be allowed to spread into the adjoining compartment. This exposure some- times lasts for a considerable time and the wall's weakest parts, its doors, come in for a searching test.
Three general types for openings in fire walls are class- ified according to method of operation by Underwriters' Laboratories: the rolling type, the sliding and the swinging types, of which the latter two are considered jointly.
Rolling steel doors, as well as all other listed fire doors, are recognized as standard under the conditions of in- stallation specified in Laboratories' publications.
In this category of doors, those "for Openings in Fire
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Walls" are also the "Sheet Metal Fire Doors" and the "Tin-Clad Fire Doors with 3-Ply Wood Cores," with many makes and types listed under each heading.
For Openings in Vertical Shafts. Next in importance as safeguards to life are the doors "For Openings in Ver- tical Shafts." This does not mean that vertical shafts themselves are less important than openings in fire walls; fire usually spreads much faster vertically than horizontal- ly. But whereas in the case of a fire wall there is but one opening to protect, in the case of a vertical shaft there are two, and one door will do for each. In other words, for a fire occurring on the sixth floor of a building, to spread to the seventh floor it will have to pass through one shaft door, travel up the shaft and pass through a second shaft door.
The doors in this group belong to the counterbalanced, rolling, sliding and swinging types and include steel, tin- clad, sheet metal, hollow metal and metal-clad paneled varieties. Each of these has its peculiar advantages and limitations, which are clearly shown in the reports and the great mass of information growing out of the Labora- tories' thousands of tests is well worth the study of archi- tects, contractors and building owners.
For Openings in Corridor and Room Partitions. Parti- tions used for the sub-division of fire sections of buildings are of considerable value in safeguarding life and prevent- ing the rapid spread of fire through buildings.
As retardants, these doors need not possess the qualifi-
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cations required for the protection of openings in fire walls, in vertical shaft walls or in walls of rooms containing spe- cially hazardous processes, but they should be capable of furnishing a substantial barrier to the passage of fire, and should fulfill all service requirements. This last means a great deal, because these interior partition doors are very frequently used.
Many types and patterns of fire doors listed for protec- tion of openings in fire walls or in vertical shafts are suit- able for corridor or room partitions. These doors can be used in this situation, and Underwriters* Laboratories labels them accordingly.
While in the preceding classes, no glass is allowed, in this class standard wired glass is permitted, but the exposed area of individual glass lights must not exceed 1,296 square inches. The use of glass is, of course, a great convenience in this situation, but when equipped with glass panels, fire doors afford a limited resistance to fire and fire streams.
For Openings to Exterior Fire Escapes. Here we have special reference to the escape of people from burning buildings. This may take place under panic conditions and with but few seconds to spare. What then is the very first requirement for a door so placed? — undoubtedly, that it must be ''capable of being readily operated from the inside of the building."
However, there are additional requirements. Such a
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door is exposed to the weather and must not deteriorate for a long period. Furthermore, it becomes a part of the outside wall of the building and must protect its opening from outside fire exposure. "Only such fire retardants are included in this class," reads the official wording, ''as have been shown by experience and tests to be capable of furnishing a high degree of fire protection against fire ex- posure where mounted on one side of the wall only."
For Openings in Exterior Walls. The final situation for fire doors includes fire-retardant shutters as well. Obvi- ously, the protection furnished in this situation must be against external fires. In congested city districts or In other cases where the neighboring exposure is severe, this protection is of the greatest importance and bears on the fearful conflagration problem.
There is a large variety in listed fire doors and shutters for exterior walls, including some which are almost in- visible when open and which can be used to protect the most beautiful building without marring its appearance. Several types are automatic; in general this implies a fusible link on the outside which melts when exposed to fire and allows the shutter to close. Some of the shutters have a "manual test release" which can be operated by the building superintendent on his periodic inspections, or by officials of the municipality or representatives of insurance companies.
From the foregoing outline of the many types of fire
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doors listed by the Laboratories, it may readily be seen that the Laboratories' work, even though distributed over a number of years, has of necessity been intensive. It has resulted in a great improvement of all kinds of fire doors and shutters, and in the creation of new kinds.
Its effect has been particularly marked in relation to the widely-manufactured tin-clad doors, whose standard of construction is far more exacting today than was the case a few years ago; in fact, the earliest doors of this type showed so much distortion under the fire that they failed to cover the opening. Another difficulty was found in the pufiing of the tin from the pressure of gases formed in the wooden cores. It finally was suggested that a circular hole be cut in the tin on the exposed side of the door. This proved successful; doors provided with such openings re- tained their shape much longer and, during fire tests, the gases could be seen bursting in a jet of flame from the hole.
Sometimes, indeed, the consideration of doors involves other phases than that of fire resistance. One incident is told at the Laboratories of a manufacturer who sub- mitted a rolling door for outside installation in warehouses and barns. He was told that his outside door was all right save in one respect — it was not "sparrow proof". Taking this comment as a joke he disregarded it but in six months confessed his mistake, saying that he was be- ginning to receive many complaints because the con- struction permitted an opening which was promptly ac-
WORK THAT KEEPS INSPECTORS CONSTANTLY TROWELING
Every labeled tin-clad fire door made in over 230 factories must undergo two separate inspections by the Laboratories' representatives: First the wood core is examined, and the final inspection covers the finished door. In addition the inspectors avail themselves of every opportunity to check up on processes of assembly. This inspector, for instance, is examinmg the workmanship and the construction of the seams in the tin covering of a door just being completed
PRESSURE UP TO 200,000 POUNDS Fvprvone knows that there are many grades of concrete and the eye alone cannot judge of their strength Here^ifama?Wne that cannot be dLlived. The concrete buUding ^ock marked •'B/'.s a^ou^ to ^ crushed bv nowerful iaws which are ab e to exert a gradually mcreasmg pressure up to 200,000 pounas^ &)r^ewhe7e^thm tterange the block will fail. This exact point w,ll be noted by the engmeers in bomewnere ^^'^n^'J^^^^^;;^ ^, ho will also report how the block behaved under the pressure
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cepted by sparrows as an invitation to build their nests under shelter from the weather. The nest litter prevented the closing of the door and was an entirely valid point of criticism. This, however, is hardly a typical example.
A door opening, to be satisfactorily protected, should be provided with a labeled door, equipped with labeled hardware and mounted in a labeled frame, although, of course, labels may be applied to doors, hardware and frames separately.
5. Columns
Everyone who saw in the motion picture "news week- lies" the showing of the much-discussed Chicago fire of March 15, 1922, will recall the thrilling collapse of the Atlantic Building. First the walls began to fall from various stories, then the steel columns were seen to sag and, finally, what was left of the building went down while the spectators gasped.
Columns are among the most important elements in the strength of buildings, and the instance just cited is one of many in which the softening of iron and steel under heat has robbed them of strength and led to disaster.
Architects and engineers were long aware that fire pro- tection called for some form of insulating covering for columns and various types were produced; but so many of these failed in use that there finally arose an insistent demand for exact knowledge. Tests made by several
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organizations contributed some data but also indicated that their conclusions were incomplete because of inade- quate apparatus. It came to be realized that in all the world there was no piece of apparatus equal to the tremendous task. Finally the job was taken in hand by Underwriters' Laboratories in cooperation with the United States Bureau of Standards and the Associated Factory Mutual Fire Insurance Companies.
During the years from 191 2 to 191 7, there was erected a huge combination of furnace and press, capable of taking a twelve-foot column, loading it with a 250-ton weight to represent such portion of a skyscraper as it might be expected to support, meanwhile surrounding it with a fire as intense as the fiercest conflagration. In con- nection with this extraordinary test furnace, there were instruments of delicate precision, for measuring and re- cording the loads sustained by the sample column, the temperature of the fire around it, the temperature within the column itself, the amount of sagging, bending and shortening under the influence of heat and pressure, and the distortive and, finally, the disintegrating effect of a fire stream of cold water turned suddenly upon the hot loaded column.
While the mighty machine was being built, representa- tive types of columns and protective coverings were col- lected and during three years more than one hundred complete columns were thoroughly tested. The report
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of these tests fills a printed volume of nearly four hun- dred pages.
The results of the work so far accomplished on columns may thus be summed up:*
The ultimate fire resistance of all representative types of building columns, when loaded and under conditions representing those of actual service in a fire, has been ascertained.
The relative resistance to fire of various materials and methods employed for protecting building columns has been determined.
A great body of reliable data has been provided by means of which the fire endurance of the various columns can be compared; and from this information it has been possible to do a great deal of grading and classifying of types of columns and methods of fire-proofing.
The effect of fire streams on heated columns has been ascertained.
Improvements have been developed in the fire resistance of the insulation and in the methods and conditions of installation.
One of the series of tests conducted by Underwriters* Laboratories alone is of almost dramatic interest.
The lumber interests had been greatly concerned over the apparently poor showing made by wooden columns, for "mill construction," when meeting certain require-
*See also Appendix xi, page 262.
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ments, had always been regarded as better than unpro- tected steel of the same strength. Briefly stated, what astonished all experts was that certain types of wooden columns which were expected to bear a standard load while surrounded by a fire whose temperature was in- creased at a standard rate — and to bear that load for one hour before "failing," the definition of "failure" also being standardized and understood by all concerned — did not live up to expectations; they "failed" after about thirty minutes instead of one hour.
For two years beginning in 1919, further tests were conducted to find out what was wrong and how to correct it, and reports were made. The solution was elusive and was not reached until the fifth report.
In studying the results of the standard tests, it was readily seen that the wooden columns failed at the ends — never in the shaft portion. One phenomenon which might have passed unnoticed was given careful consideration; the end seemed to crush at first slowly and then much more rapidly. Now, this is the commonest of all phe- nomena in all tests of this sort, but it was decided to avoid the destruction of possible evidence and to study what was happening during the slow deformation. Therefore, a number of tests were stopped suddenly at various stages of deformation and, at last, after dissecting a number of samples and studying the appearance of the wood fibers,
the cause was found. From the appearance of these fibers
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at the very ends and at various short distances from the ends, it appeared that certain conditions of moderate temperature brought about an unexpected softening — indeed, an almost plastic condition of the wood at the end.
This overthrew current ideas, being a kind of "failure" which had never been predicted, and the next step was to find the remedy by devising an adequate end protection.
Various theories were tried out and abandoned. Finally experiments were conducted to determine whether a cap which would completely enclose the end of the column with insulating material would give better results, and of ascertaining the best design for such a cap. From the first, it was seen that this was the right direction.
At last, on October 30, 1919, a column failed under test — not at the end but in the shaft portion.
Now began a new series of experiments — on full-size columns, one foot square, just as are used in many build- ings. With the experience previously gained, it was pos- sible to determine just what to do to protect the ends of the columns, and the crowning result of all was a series of tests in which every column failed in the shaft portion — not a single end failure — and, what was most gratifying, the average time of failure was not one hour, which would have entirely satisfied the lumber people, but one hour and a half!
While certain supplementary applications are still under consideration, these tests have had the amazing result
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of showing how the fire resistance of a wooden column may be increased two hundred per cent.
6. Walls and Floors
While structural engineers may consider a building to be a series of platforms enclosed by walls, a fire-prevention engineer is forced to regard them as large boxes in which people live, work or store goods, and which usually con- tain smaller boxes, called rooms. Everybody knows that boxes consist chiefly of sides and these, in the case of rooms and buildings, are the walls and floors. It follows that a building having a high standard of roof, windows, doors and columns may still be highly combustible unless its walls and floors likewise are fire resistive. Naturally these come in for constant study at Underwriters' Laboratories.
Again it must be emphasized that incombustible ma- terial is not necessarily fire resistive in use — // must be rightly used.
A single brick may survive a very hot fire for a consider- able length of time, but a wall made of such bricks may be constructed so poorly that it will not stand up under a typical fire. Another wall, constructed of materials which are able to withstand high temperatures, may lose so much strength under fire that it will no longer support the floor beams. Some walls make a good showing while fires rage against them, only to crack and crumble when struck by the firemen's hose stream.
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At the instance of manufacturers of various materials and of associations and official bureaus, Underwriters' Laboratories is conducting a great number of tests cover- ing types of walls and partitions. Most of this work has not been for the labeling of products, but in the nature of research and classification of familiar types.
Investigations of the fire resistance of building mate- rials have been conducted in Europe and America for more than half a century, by official bodies, architectural and engineering societies, and a great number of commercial bodies and individual firms. The total amount of work performed by Underwriters' Laboratories on the subject of walls, figured in total hours, represents but a small fraction of the whole, but it has proved to be the most important and authoritative.
It will no doubt take several years to complete the classification of walls with regard to fire resistance, strength and fire-hose-stream resistance. Already, a number of types of construction have been classified. That is to say, it is possible to know in advance just how long they will endure in a typical fire before "failing" — the expres- sion "failing" being well defined.
In the field of walls and interior partitions of lesser strength and resistance to fire, the Laboratories has achieved noteworthy results, and it is now possible for the architect to give his client definite assurance as to the performance of listed materials.
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With regard to floors, the problem has been somewhat different because the floor structure of one story involved the ceiling of the story below. Therefore, the chief work of the Laboratories has been not so much that of testing the highly resistant types as of determining the retardant value of ceilings of various fire-resisting materials applied under wooden joist construction, as in frame houses.
The intensely practical nature of the investigation is shown by certain tests that were made in April, 1922. The War and post-war conditions had resulted in a great scarcity of buildings, particularly of dwelling houses. The cost of materials and labor had checked construction, and rents, in consequence, had risen to alarming heights. Newspapers were full of the discussion; it had become a sociological question of the first rank, affecting as it did the living conditions of millions of people.
There was an urgent demand for hundreds of thousands of inexpensive new houses, but the building codes of the various cities very properly forbade the increase in con- flagration hazard that would have come from the usual type of cheap construction.
Here was a serious problem which the Laboratories tackled from an interesting angle. Accordingly, in April, 1922, a number of people were gathered in one of the furnace rooms to witness tests that might prove to be of far-reaching importance.
A section of partition had been inexpensively con-
90
THE EFFECTS OF CORROSIVE A(,ENTS
The durability and reliability of automatic sprinklers may be seriously affected if they become corroded
dfter iitstallation in a building. In this picture sprinklers in the covered glass vessels are being tested in
corrosive gases in order to determine their ability to withstand such action. (See p. 50)
OXY-ACETYLE.NE WELDING SECTION
Welding is required in some of the operations of the Plant Department and an oxy-acetylene torch is in frequent use The operator here shSwn is wearing goggles that have been tested and approved by the
Casualty Department (See p. 201j
Building to Last, Not to Burn
structed by nailing metal lath to both sides of wooden studding and coating the surface with gypsum plaster. This partition was installed in the front wall of the great vertical furnace adapted to such use and subjected to the fierce intensity of gas flames under prescribed conditions.
At the end of the period, the partition was rolled from the furnace and its glowing surface received the full impact of a fire stream as might be the case in a real fire. Nat- urally the power of the stream tore the plaster from the lathing, whereupon it was discovered that the wooden framework beneath had been so well protected as to have suffered less than ten per cent, impairment. In other words, such a partition would have remained relatively good after passing through a one-hour fire of more than ordinary intensity. It was not to be considered "fire- proof", of course, but it would serve as an efficient fire barrier for a period of an hour.
Tests of a floor section of the same general type were made in a horizontal furnace and gave equally good re- sults. In this case the test included loading the floor with weights and taking observations to determine whether there were any sagging beneath the load under the in- fluence of the fire.
The imaginative spectator could easily let his mind travel from the technical atmosphere of such tests and see them in their ultimate human relations. He could picture the construction of great areas of workmen's cot-
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tages where cheap construction made low rents possible and furnished safe and satisfactory living conditions within the reach of small incomes. Such savings in turn translate themselves in terms of bank accounts, content- ment and social security.
Doubtless one must check the play of his imagination within moderation, but doubtless, also, it is true that the heat waves of the testing furnaces at Underwriters' Labora- tories set in motion impulses of sociology, economics and human welfare that travel far.
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CHAPTER TEN
Safeguarding ^*The Universal Servant"
I. The Universal Servant
ELECTRICITY has earned the title of "universal servant." It seems futile to attempt to fix the boundaries of its human service, for these change almost daily. Within the memories of those who are not yet old, it has been viewed first as the subject of interesting laboratory experiments, then, successively, as an agent for transmitting messages, for conveying speech, for produc- ing light, and for furnishing power to be used in transpor- tation and industry. Today it is a household helper, for which uses are announced almost daily, it has a definite place in surgery, and recent investigations into radio phenomena suggest further possibilities of immeasurable value.
Electricity defies limitation, as it still defies definition. Every individual in the land is directly or indirectly de- pendent on some phase of electrical application during almost every day of his life. He utilizes it in his telephone calls, his lights, his transportation, his elevator service; while even the food that he eats and the clothes that he wears probably have involved the use of electricity at some stage of their preparation. This intimacy and universality
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of service make it a matter of deep public concern that the myriad devices and materials through which electricity is applied be rendered efficient and safe.
As is natural under the circumstances, the last genera- tion has seen the growth of a very extensive industry which may roughly be sub-divided into the production^ the distribution and the installation of electrical supplies and which therefore includes the manufacturer, the jobber, and the contractor. Closely related to these groups are the regulatory authorities and, finally, the user whose money supports them all.
The work of Underwriters' Laboratories has become virtually an integral part of the electrical industry; it exerts a direct influence upon eachof the classes mentioned.
2. What Is the Relation of the Laboratories to the Electrical Industry?
The relation of Underwriters' Laboratories to the elec- trical industry is essentially one of service to manufac- turer, jobber, contractor, regulatory authority and user. It also furnishes a common meeting ground for the dis- cussion of questions, tendencies and developments that are of interest to them all. The nature of this service will become apparent in an analysis.
First, as to the manufacturer: The highly technical character of production in the electrical industry makes the fixing of standards a matter of peculiar importance.
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Safeguarding " The Universal Servant'^
Appearances count for so little, and design, workmanship and materials for so much that the layman's judgment is practically negligible. Consequently, there is a large opportunity for manufacturers to bring discredit upon the entire industry by means of inferior goods. Such goods, marketed at the lower prices made possible by their character, would exert a demoralizing influence on the industry were this not powerfully counteracted.
The chief means to this end consists in the fixing and maintenance of standards of quality supported by construc- tion and service tests and by manufacturing inspections. In this work, the Laboratories cooperates with the manu- facturer as an individual and with his trade and technical organizations. These standards, therefore, are the prod- uct of joint effort to which the manufacturer is himself a party; they stipulate certain minimum requirements^ but in no wise limit maximum achievements, and they are not left to shift for themselves but are rigidly maintained through a comprehensive inspection system. As a result the electrical industry is equipped with standards of safety and performance to a degree that would amaze a layman.
Underwriters' Laboratories has separately examined, tested and reported upon more than thirty five thousand different makes and styles of electrical appliances — always at the request of the manufacturers themselves — and its in- spectors make frequent visits to many hundreds of factories.
Second, as to the jobber: With this class, the relation is
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very different. The electrical jobber may not be familiar with the technical values of the goods he sells because such knowledge may not be essential to the making of sales. As a matter of fact, he is in position to shift re- sponsibility on the one hand to the manufacturer who produces these supplies and, on the other, to the con- tractor who installs them. His particular interest is in saleability and, having found that goods bearing the Laboratories' label are more saleable than others, he nat- urally prefers to handle them. He has learned to ''look for the labeV.
Third, as to the contractor: The contractor is the job- ber's chief customer and the man whose work is under inspection. His principal contact is with the owner to whom he is much closer than is the jobber and whose in- terests he must serve because improper installations may not only result in unsatisfactory conditions of use but may also interfere with the owner's safety and his ability to obtain insurance at the best rate. Therefore the contrac- tor must comply with the provisions of a code that is very explicit as to the standards of materials to be employed, and these standards are assured to him by the Labora- tories' label. He knows that the municipal inspector and the insurance inspector will look for the label. This is why the jobber finds it easier to sell labeled goods.
Fourth, as to the inspector: The inspector must review the work of the contractor. He bears a large measure of
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Safe guar di77g " The Universal Servant^'
responsibility because the standing of the installation as to its safety and the insurability of the building depend on his verdict. He is familiar with the regulations and is able to judge of installation work, but how shall he judge as to the character of the materials employed? These materials may easily have important defects of which he has no technical knowledge.
He can tell how a wire should be put into a house but cannot determine the quality of the rubber that is used in its insulation. He can specify whether there should be a switch or a fuse but is unable to judge the character of a particular switch or fuse — whether it is a trustworthy device or a source of danger to the building's occupants. Such things can be determined only by means of adequate tests and the average inspector has not the time for mak- ing tests, the laboratory in which to make them, nor the experience and special training required to give them value.
The inspector, therefore, is glad to throw all responsibil- ity in the matter of materials squarely upon Underwriters' Laboratories by whose rating and label he is guided.
Lastly, as to the user: At least three of the preceding classes must have some degree of technical knowledge; not so the user. In order to be able to pass on the character of the supplies installed for him by the contractor he would have to become an expert judge of such varied arts as those which concern the production of yarns, waxes, rubber, brass and copper goods, automatic machine products,
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porcelain, molded insulations, electrical control of ma- chinery, all the hazards to persons that may be involved in electrical devices and many other things. Obviously, he can at best traverse but little of this vast field of com- plicated technical understanding although his own wel- fare, perhaps his own life, may be concerned in it.
Exactly such things as these are made the subject of minute investigation before labels are awarded by the Laboratories to the goods that the contractor buys and installs. Therefore the relations of that Institution to the millions who employ electricity Is vital and constant although generally unrecognized by them.
J. The Practical Viewpoint
As soon as we leave the field of generalities and attempt a closer view of the Laboratories' Investigations of electri- cal materials and appliances, we are struck by the enor- mous detail and complexity Involved. While electricity is fascinating on Its purely scientific side, the Laboratories' work is controlled by a severely practical viewpoint. It may think in terms of general laws, but it deals with specific materials, and It must always consider these materials as they would be found under the conditions of actual use. Moreover, while the investigators frequent- ly are able to make suggestions that increase the efficiency of the product under test, such suggestions are merely in- cidental; theli* main concern is with safety in use.
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HIGH POTENTIAL TEST OF AN ELECTRIC WATER HEATER
One of the things to guard against in electrical appliances is a possible failure of the insulation which may make the frame "alive" and shock any one touching it. This engineer is therefore subjecting a domestic water heater to a voltage far above what it would receive in service. Incidentally, the engineer himself and other persons are fully protected, because all high voltage parts are in the glass-walled enclosure the doors of which are interlocked with switches that are "on" only when the doors are closed
TESTING ARMORED CABLE
Armored electric cable is irt almost universal use to-day, and its tests include determination of tension and elongation in order to learn how tightly the conductor is held in the armored casing. The sample shown is being subjected to an elongation test by means of a 100-pound weight, and it is required that the armor shall not show a permanent elongation of more than three inches in a three-foot length, after
one minute of this tension.
Safeguarding " The Universal Servant''
What then is the experience of an electrical appliance that has been submitted for test, rating and possibly label ? In thousands of cases it is required to make answer to five searching questions:
First: Is it suitable for the use intended and can
it be properly installed? Second: Are its mechanical strength and durability
adequate? Third: Is it provided with satisfactory insulation? Fourth: Is it free from liability to dangerous heating? Fifth: Has the danger of *' arcing" been provided against? These questions are asked not verbally but by means of various kinds of scientific apparatus under the control of electrical or mechanical engineers or chemists.
First: As to suitability: For example, a given switch may be suitable on a lighting circuit but not to control a motor, or it may be a good switch by itself but have no proper means for connecting it to wiring or conduit or for enclosing its dangerous parts.
Second: As to mechanical strength: For example — how strong should be the metal armor of a 2-conductor No. 14 gauge armored cable? The Laboratories' Standard is spe- cific. It says:
The armor must be of such design that it will not open at any point after having been subjected for one minute to a tension of 150-Ib. on a 3 length. This test to be made with the conductors removed from the armor.
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There follow several more paragraphs which leave no room for misunderstanding, and there also follow minute specifications as to the testing apparatus and procedure. All these precise requirements are involved in answering the simple question: How strong?, for in no other way could the unvarying uniformity of the tests be assured.
Third: As to insulation: The question of insulation is always vital in considering the application of electricity. Defective insulation that permits "leaking" naturally reduces the efficiency of the appliance, but (and this is the especial concern of the Laboratories) it also permits the escape of the current in ways that may be of hazard to life and property.
It may be added that, whereas fires of unknown origin commonly used to be ascribed to "defective insulation," this custom has practically disappeared. The Laboratories has exerted a powerful influence in bringing safety into insulation during recent years.
Fourth : As to heating : One of the large values of electric- ity is its convertibility into heat, but this also constitutes one of its chief dangers when such heat is undesired or excessive. Thousands of fires each year are traceable to overheated electrical appliances. Therefore, one of the principal questions to be asked of any product coming up for inspection concerns its liability to develop heat in use. For instance, the Laboratories, in 191 8, conducted an extensive investigation into the minimum cross-
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Safeguarding " The Universal Servant''
sectional area to be required in certain small parts of plug fuse bases in order to prevent their becoming unduly heated and thus causing inequalities in the performance of the fuses.
Fifth: As to "arcing": The liability to permit an electric arc that is not part of its purpose, is a serious indictment against any device. Such an arc coming in contact with inflammable material may cause a fire, or, if it reach explosive vapor or dust, a severe explosion may result. Many disasters have been caused in exactly this way, and the investigator is required to consider all the conditions under w^hich an unexpected arc may be formed.
In other cases the formation of an arc is an unavoidable feature of the operation of a device and this fact calls for special safeguards.
The device that has successively and successfully withstood thorough scrutiny as to its suitability, strength, insulation, and heating and arcing characteristics, may be considered relatively free from hazard, whatever may be its efficiency in the use for which it was designed. It is, perhaps, natural enough that the inventor, and, to some extent the manufacturer, should be so engrossed with the effectiveness of a product as to give little thought to its freedom from hazard. The average purchaser can- not judge the degree of hazard even when his attention is called to the subject, but the insurance company that assumes the financial risk of indemnifying a loss that may be caused by such a product cannot afford to guess at its
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A Symbol of Safety
liability to create hazard. Underwriters, therefore, give careful consideration to the presence or absence of the label that certifies the tests.
4. The *' Worst Treatment'' Test
The thousands of electrical devices and products which are submitted to Underwriters' Laboratories for test and rating may for convenience be divided broadly into three groups, as follows:
First: Those materials that are purely electrical in their function, such as wires, cables, conduits, switches and the other devices for which there are printed or mimeographed standards.
Second: Miscellaneous devices primarily electrical in their operation, such as heaters, smoothing irons, etc.
Third: Miscellaneous devices that employ electricity incidentally, such as electric pianos, vacuum cleaners, washing machines, and many others.
The first group naturally requires thorough examina- tion, and tests representing the most severe conditions that might be encountered in actual service; the third group requires little more work than that of making sure that its electrical parts are standard, and that it is suit- able and well made; but, between these two extremes, there comes a long list of devices calling for a wide diversity in examination and test. In this class new problems are frequently encountered and it becomes necessary to devise
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BREAKDOWN TEST OF RUBBER-COVERED WIRE AT FACTORY
Many coils of wire taken from the manufacturer's stock are immersed in the steel tank and an electric pressure of 15<XJ volts A. C. isapplied toall simultaneously. It is obvious that the slightest crack or electrical defect will allow current to flow. If it does there will be violent bubbling of the water. This very rarely happens, for the simple reason that the manufacturer's own routine inspections include tests similar to those made
by this Laboratories' inspector
Safeguarding " The Universal Servant'^
new testing methods. To illustrate the practical spirit of these investigations, take the instance of a wash-room device which throws out a blast of hot air for the drying of hands and faces. This being a new device, the engineers had no comparative data as to its purely electrical fea- tures but these were found acceptable after simple tests, one of which was to tie down the foot-switch so as to rep- resent somebody accidentally placing a box or bucket on it and then going away and leaving the current on. The result indicated that near-by combustible materials would not be ignited through overheating under such conditions of misuse.
Outside of purely electrical tests, however, it was neces- sary to make others, such as the "marble test," represent- ing the placing of small objects in the orifice of the machine by mischievous boys. As a result the manufacturers made certain modifications and expressed appreciation of the Laboratories' practical viewpoint.
The "marble test" just referred to is representative of a test principle that is applied to most electrical appliances, and may be called the "worst treatment test". This means that particular attention must be paid to the abuse as well as to the use of a product. Its hazard must be determined in the hands of the careless or unskilled people who form so large an element of the public. It is im- portant therefore that a device be made as nearly "fool- proof" as possible.
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In a motor-driven device, for example, the worst treatment that the motor can receive is that of being stalled with the current on. Accordingly the engineers re- produce this condition in order to observe results, partic- ularly as to whether near-by combustible materials are likely to be ignited. Of late, there have appeared several automatic water heaters of the faucet type. The worst thing that can happen is for the water supply to be in- terrupted while the current is on. This, too, is forced to take place under the eye of the testing engineers and the results are noted. Again there is the safety viewpoint. In the automatic water heaters just mentioned the worst feature from the standpoint of accident prevention is found when there is a possibility that the outer metal parts or the water stream itself may become "live," and the examination and tests are devised accordingly.
5. Rubber^ or What?
The electrical tests of Underwriters' Laboratories are of such number and Interest that volumes would be re- quired to do them even approximate justice. In the limited space at our disposal a closer glance can be taken at but one or two, and among them all nothing is more important than the testing of rubber-covered wire, of which familiar commodity, literally millions of miles have been produced.
Nevertheless, the term "rubber" is not so simple as it
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Safeguarding " The Universal Servant''
sounds; it is applied to a wide diversity of products repre- senting many differences in the natural gum, many diver- sities in the formulas and processes of manufacture, and a wide range in the use of adulterants. These conditions have resulted in some products that are excellent for use in insulation, and others that are conspicuously unfit. As is so often the case in the electrical field, differences of quality may not be apparent to the eye, but can be learned only by means of exacting tests.
Take, for example, the tests of insulation on that popular size of rubber-covered wire known as "Number Fourteen." Everyone is familiar with this material but few have any conception of the ordeal to which it must be subjected before being awarded the coveted label. Before it can qualify, it must stand up before its judges and give sat- isfactory answers to such questions as these:
What is the exact diameter of your copper wire?
Is the copper well centered in the rubber?
Is your rubber wall at least three sixty-fourths of an inch in thickness?
Has your outer covering of cotton braid the proper thickness?
Is it of the proper workmanship and is its weave suffi- ciently close?
Has it received proper saturation?
Are you able to withstand a reasonable amount of bend- ing back and forth?
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What is the quality of rubber used in your insulation?
Will it withstand the prescribed stretching tests as to elasticity, elongation and strength?
How about the chemical tests of your rubber? What will they tell us as to acetone extract, alcoholic potash extract, chloroform extract, ash content and sulphur content?
What is your current leakage when immersed in water?
The answers to these and other questions require the use of various forms of apparatus and the most intensive study. To give the briefest accurate description of the procedure and apparatus in the chemical test alone would require more than ten pages. Yet there is nothing super- fluous about them, because wire of this nature is the familiar pathway of man's "universal servant," ana unfaithfulness on the part of testing engineers might permit this servant to slip from its pathway and use its terrible strength for destruction.
Even after such questions as those cited have been satisfactorily answered and the label has been awarded, similar examinations and tests are repeated frequently on samples taken at the factory by the Label Service Department inspectors, on samples purchased from stock offered for sale, and on installation samples secured from buildings throughout the United States and Canada.
Taken all in all, the Laboratories' influence has been steadily directed not only toward the improvement of materials used for ordinary wire insulation, but, what is
1 06
SEARCHING OUT THE QUALITIES OF RUBBER INSULATION
The "rubber" insulation of electric wire contains substances other than rubber; the Laboratori^ in- sists that it should possess a number of qualities. One of these is "life" and the assistant in the back- ground is observing the degree to which a sample springs back to size after being stretched. I he oper- ator in the foreground is separating the insulation from the copper conductor by stretching the latter until its diameter is reduced sufficiently for the "rubber" to be slipped oft
PHYSICAL TESTING OF RUB15P:R
The sample of insulation irom an electric wire, shown in a preceding illustration being prepared for a physical test. Here the operator is measuring the distance between the white marks, m order to note the number of inches to which the rubber stretches before it is forced to snap. The operator at the other machine is reading the dial of a strength-testing machine which stretches a sample at a predetermined rate. On the table are other samples to be tested
Safeguarding " The Universal Servant''
at least as important, toward the constant, systematic and efficient maintenance of standards of quality by means of adequate and persistent testing. The resulting increase in public safety can hardly be overestimated.
6. The Electricity of the Skies
While the word "electricity" is derived from ** elec- tron," the Greek name for amber, because the scienti- fically-minded Greeks had become interested in the electrical phenomena that are produced when amber is rubbed, mankind throughout most of the ages of the world has known nothing of electricity, save as it has been seen in the lightning's flash. In all lands, it has been the subject of superstitious awe and terror. Its destructive power has been an attribute of the gods. It has been the bolt in the hands of Jupiter Olympus or the flashing hammer hurled by the savage Thor, working annihilation where it has struck.
The destruction wrought by lightning still continues on a vast scale — so much so that millions of dollars are paid in lightning insurance each year. Not long ago an investiga- tion into the cause of some forty thousand rural fires show- ed that more of them were caused by lightning than by all other causes combined; yet this same investigation furnish- ed the interesting information that not one of these fires had involved a building that was properly provided with lightning rods.
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Thus the subject of hghtning rods has become an im- portant consideration of pubHc safety and an item of concern to insurance companies, particularly in the coun- try districts. As such, it is a natural subject of interest to Underwriters' Laboratories, where its investigation practically reverses the viewpoint of most of the electrical tests: Here the purpose is not that of creating, directing or applying the electrical current, but of diverting and dissipating it.
One might be inclined to believe offhand that tests of lightning rods presented a very simple problem. Simple in appearance as they may be, they involve a great deal of work on the part of the Laboratories, which maintains a staff of traveling inspectors to report on installations.
It must be borne in mind that lightning rod equipments are purely electrical, even though they are not wiring devices. The Laboratories has a printed standard for their construction and installation, which is over sixty pages in length; goes into the details of thorough examina- tions and tests of the materials employed; specifies the metals, weights, sizes and shapes of conductors, terminals and fasteners for structures under sixty feet in height, those from sixty to one hundred and fifty feet, and those over one hundred and fifty feet; describes proper installa- tions for various forms of buildings, roofs, steeples, smokestacks, tanks, etc., and describes the two-fold label
io8
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Safeguarding " The Universal Servant''
service procedure — consisting of inspections at factories and reports on labeled installations.
This last feature is very interesting, in that it requires two successive reports: first, one from the manufacturer of the materials employed in the installation, which must be made out within thirty days after date of installation; second, a report from a Laboratories' inspector to whom the manufacturer's report and other information has been referred; the latter not only verifies the first report but checks up the workmanship of the job, examines bends in conductors for cracking or flaking of the protective zinc coatings, notes w^hether provision has been made to pro- tect ground rods so located as to be subject to injury or displacement, makes sure that large metallic objects within the buildings are grounded, does the same for metal fences attached to buildings, and makes recommendations.
When it is found that the Laboratories' requirements for standard installations have not been complied with in all essentials, the manufacturer is notified and must make the necessary corrections within thirty days. He then notifies the Laboratories, which arranges for re-inspection — at the manufacturer's expense.
y. ''Economy'' vs. Safety
It has already been stated that the electrical industry is subject to the intrusion of those manufacturers who are willing to sacrifice quality to price, and the layman, in-
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capable of exercising judgment in such a technical field, must depend upon the expressed opinions of others al- though his own safety may be at stake. As previously explained, the severe tests of thousands of electrical prod- ucts conducted by the Underwriters' Laboratories, and the use of the label to certify these tests to the public, have constituted a safeguard recognized both inside and outside of the industry as a means for maintaining its standards and increasing its efficiency. They have aided the better class of manufacturers in their efforts to eliminate the unfit. As a single extreme instance of the need for eternal vigilance, there was placed upon the market an "electrical toaster" of which its manufacturers doubtless expected a large sale, as it was capable of being offered to the public at the low price of ten cents. In order that it may be realized what would have been their effect on public safety, several passages from Underwriters' Laborator- ies' report are cited:
AN ELECTRIC TOASTER FOR TEN CENTS
***** in which the amount of material is reduced to a minimum and the construction to the simplest form. ***** horizontal type and is simply a rectangular sheet-metal frame supporting several wires across the top, spaced about i| inches apart, and a length of resistance ribbon terminating in a pair of ordinary dry battery bind- ing screws and looped between two narrow strips of asbestos board. The device consumes 580 watts on a iio-volt circuit.
***** Among those hazards may be mentioned the exposed and unprotected heating elements; lack of protection from heat
no
SHORT CIRCUIT TEST OF A LARGE FUSE
Protected by a cage and a partition, this engineer observes the fuse in the former through an opening in the latter, and is about to "throw a dead short" by closing the switch with his left hand. In the event of a disastrous failure of the fuse he can clear the circuit immediately by yanking the rope operating a large toggle switch. Photos taken at the Laboratories' fuse testing station near the Kingsbridge (N. Y.) sub- station of the N. Y. C. R. R.
TESTING A SMALL ELECTRIC LIGHTING PLANT
Thousands of farm houses and suburban homes are employing individual electric lighting plants, wherein an interna! combustion engine drives the electric generator which furnishes the current. Such plants call for a wide diversity of tests as to a number of features. In the picture, the engineer is using a tachometer to record the speed of the generator, and determine whether the electric windings overheat
Safeguarding " The Universal Servant'*
***** surface under the toaster;* * * * * liability of loose strands of the supply wires coming in contact with and making the frame "alive," and the use of supply wires having insulation not de- signed for electric heaters.
There follow the disastrous results of tests under condi- tions representing actual service in a home, concluding as follows :
With the toaster placed on a plain uncovered pine board, with a square of sheet asbestos where a slice of bread would be placed, flames enveloped the toaster in six minutes.
In the 25 minute period over which the foregoing tests were con- tinued, the insulation ***** adjacent to the terminals was entirely destroyed by the heat for a length of about two inches ***** so that the bare strands of both wires could come in con- tact with the edges of the frame of the heater.
Such a "ten-cent" toaster might easily result in a fire costing thousands of dollars to its user.
Similar conditions in greater or less degree are found in numerous other products. There can be no true economy apart from safety, and the label which spells safety is a servant of genuine thrift.
8. The Groivth of the Electrical Department
The foregoing sketch gives but a brief and inadequate glimpse of a work of great scope and complexity that en- gages the entire time of a number of engineers.
It has already been told (Chapter Four) how Under- writers' Laboratories originated in the establishment of facilities for making simple tests of electrical materials
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at the time of the World's Fair in Chicago. From that time to the development of the present many-sided in- stitution, this department has held its place as one of the most extensive and important of all the divisions of work undertaken. The growth, however, has been inten- sive as well as extensive, and is sometimes misunderstood by those not familiar with its genesis and reasons.
It must be remembered that this development has not been in the nature of a restraint imposed on the electrical industry from without but is the result of a process of evolution, both internal and external.
For more than a decade before the establishment of the little Monroe Street testing shop, there had existed rules intended to insure safety in the use of electricity and these, in turn, were the result of the growing number of fires that were electrically caused. Gradually it came to be realized that the reduction of this hazard must be based upon the possibility of specifying the use of electrical goods o( known characteristics, of uniform quality and according to uni- form rules.
The New York Board of Fire Underwriters was the first to issue a printed set of rules to this end, a brief circular, placing great reliance upon the judgment of "surveyors" and the "Inspector". The first printed set of rules of national application was issued by a joint conference of insurance and electrical industry representatives, known as the National Electro-Insurance Bureau. This was in
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1 891 and the title was "The National Code of Rules for Wiring Buildings for Electric Light or Power."
It must not be imagined that the promulgation of that first national code was really effective. Far from it ! Even today, in spite of the admirable National Electrical Code issued by the National Board of Fire Underwriters and constantly revised by the National Fire Protection Asso- ciation, which is a federation of over 130 associations, in- dustrial bodies and governmental bureaus, uniformity of regulation has not yet been achieved throughout the states or even throughout the various counties and town- ships of some individual states.
A glimpse at the situation existing just prior to the in- ception of the laboratory work is given in the following quotation:
Early in 1892, Secretary C. M. Goddard of die New England Insurance Exchange suggested a meeting of electrical inspectors of several underwriters' organizations to consider uniformity of rules. This meeting, held in August of that year, carefully considered this code, section by section, in order to make such changes as the ex- perience of the insurance inspectors indicated were necessary in the interest of the insurance companies.
This effort for uniformity of insurance rules was so successful that another meeting was held in December of the same year, to which the inspectors of all insurance boards in the United States and Canada were invited. At this meeting a permanent organiza- tion was effected and an Electrical Committee appointed, whose duties were to be [a) the care of the rules, {]?) the making of tests, and (f) the giving of information and advice to members.
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Here, then, were two interests, both of them sincerely desirous of promoting safety in the use of electricity, but approaching the problem from different sides. The elec- trical industry was dependent for its growth on public favor which was imperilled by all evidence of hazard, and had the best of reasons for wishing to eliminate such haz- ard. The insurance companies on the other hand had come to regard electricity as a possible source of firs and therefore were forced to study its elements of fire danger. The growth of the use of electricity thus produced a situa- tion that, in 1893, found expression in the establishment of a tiny station for testing electrical supplies in behalf of the underwriters. As a matter of fact, had not the genesis of Underwriters' Laboratories occurred in just this way, some institution resembling it would doubtless have grown from some other acorn. It was a manifest necessity.
There were, of course, large possibilities of clashing through mutual misunderstanding had the original en- counter been unsympathetic. However, the spirit of the Laboratories' work was shown at the outset when Mr. Merrill approached the manufacturers with the request: "Tell me about your problems. I want to know. Tell me about your tests. I want to know what you consider fair. I want to learn your own ideas about minimum requirements and about inspections." Thus were born the Industry Conferences that have played so large
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PERFORMANCE TEST FOR ENCLOSED SWITCHES
The protection afforded by enclosed switches is so important where electricity is used to any large extent, that a number of makes are on the market. One of them is shown receiving a performance lest, in which the load is adjusted by means of a bank of resistance grids shewn in the background. The casing of the enclosed switch is effectively grounded during the conduct of these arcing; tests, repro- ducing the same conditions that would be found in service with conduit connections
A TEST THAT MEANS SIXTEEN YEARS OF USAGE If vou use an electric lamp every evening for sixteen years you will have worked the switch about IJlve th^u^nd times. This machine operates key sockets, pull-cham sockets. P^f button swiches, surface snap switches and other such dev ces, at the rate of about twenty snaps on and off per mmute, while current flows through them and lights the lam^. The switches must comple e s.x thousand cycles of operation and still be serviceable mechanically and electrically
Safeguarding " The Universal Servant'^
a part in the electrical activities of Underwriters' Labora- tories ever since.
Today, in spite of occasional differences of opinion, the growth of the work has been characterized by a really remarkable spirit of cooperation in which the attainment of standards has been registered, rather than forced. Every organization having anything to do with electricity has contributed its share to the growth of Supervision, Regu- lation and Education with regard to the manufacture, installation and use of electrical appliances.
This has involved the development of the famous Na- tional Electrical Code of installation rules, or the "Fire Code" as it is frequently called, and also the National Electrical Safety Code, bearing on safety from accident rather than fire. While the Laboratories' staf? has been intimately associated with other bodies in the develop- ment of both these codes, their discussion lies outside the province of this account.
Supplementary to these, the Laboratories has gradually evolved a great accumulation of detailed rules governing its own requirements and work on electrical appliances — always in conformity with national codes. These rules are known as standards. For instance, there is the Stan- dard for Snap Switches, which is printed; other rules are mimeographed; some, as in the case of new products, are typewritten documents of which only five copies are filed. All these rules have been systematically arranged and codi-
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fied, and they now form part of a third code, which, while of national application, is not called National in order to avoid confusion. It is the Underwriters' Laboratories' Code of Standards for Construction and Test of Electrical Appliances. For the sake of convenience, this body of rules is generally known as "The Standards".
Volume One of the Laboratories* code of standards is a thick book of over 500 loose-leaf pages. It consists only of the wiring device standards which have been printed. These naturally govern the subjects on which the most work has been done — products that have become the recognized staples among the multitude of electrical goods. Besides snap switches, the products covered by the printed standards are as follows:
Rubber-Covered Wires and Cables, Armored Cables and Cords, Cabinets and Cutout Boxes, Knife Switches, Soldering Lugs, Flexible Cords, Renewable Cartridge En- closed Fuses, Electric Ranges, Flexible Non-metallic Tubing, Rigid Conduit, Cartridge Enclosed Fuses, Elec- tric Signs, Panelboards, Cutout Bases, Ground Clamps, Fixture Wires and Heater Cord.
The standards, supplemented by procedure manuals for individual manufacturers, specify every feature of the examinations and tests on electrical appliances and sys- tems submitted to the Laboratories. Moreover, they describe in some detail the nature and scope of the follow- up inspections at factories, and tests of market samples.
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Safeguarding " The Universal Servant^*
Some of the regular tests have been described. For many new products no regular requirements and tests are speci- fied, and it may be said that there is an unwritten volume of the Laboratories' Code — in the brains of the test engineers!
In addition to the Laboratories' code of standards, there is another widely-known compilation which origi- nally appeared at the back of the printed National Code, where it then took up not more than several pages. It is the official list of products — devices, appliances and systems — which have been found to comply with the re- quirements of all three codes. In 1906 it was decided by everyone concerned that this information should be separate from the National Code; and, inasmuch as the Laboratories made the investigations and tests and issued the manifests of compliance in the form of labels, it was selected as the logical institution to take charge. This information is now issued only by the Laboratories, in the form of its semi-annual List of Inspected Electrical Ap- pliances. The April, 1922, edition has over 250 pages, and its index contains more than 250 headings of classes of devices. Names and addresses of the manu- facturers are also given, as well as brief explanatory statements.
Thus from humble beginnings the Laboratories' elec- trical work has grown to its present great proportions and has developed with the electrical industry a cooperative
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relationship of public service that has been summarized by Vice-President Pierce in the following words:
As the Code and as the Underwriters' Laboratories' standards rep- resent the experience of the industry, and have come largely out of the industry itself, so the public respect for them, and the support of them, so far as they are reasonable, and as they are revised to keep pace with the industry, from year to year, must rest — not with the compulsion of the insurance company alone; not with the force of law backed by the policeman, as representing the city inspector; but with the intelligence of the fair-minded, disinterested, and successful electrical industry, confident of its service to the public, proud of its record, and believing in its superiority in rendering a form of service which no group other than the electrical industry can render.
ii8
CHAPTER ELEVEN A Department that Outgrew Its Name
I. Correcting " The Defects of Their Qualities''
THE American mind is naturally inventive, which is one of the chief reasons why it is so hard for pro- tection to catch up with hazard. No sooner does some safety problem approach solution than there may appear on the market a new material or a new device that upsets calculation. Of course, people do not set out to invent hazards. They are working for useful results, and the hazard is incidental, often unrecognized, until it discovers itself. There are mysterious fires, it may be, or unexplained explosions, which, when traced to their causes, are found to have originated in some new form of utility. Then, once more, it becomes necessary to start patiently and painstakingly on the process of obviating such hazards.
It can be stated with certainty that at any given mo- ment thousands of minds at various points are then en- gaged in invention or research. A closed door, which one passes quite unaware, may hide an inventor or a scientist, absorbed in labors which next month or next year may
change the course of some established industry. This is
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true particularly in the unceasing search for sources of power that is increasingly one of the world's greatest problems, but it applies as well to almost every other field of human endeavor. This is one of the reasons why the work of Underwriters' Laboratories does not approach completion, but grows ever more diverse and extensive.
There is a large and very useful group of solids, gases, and liquids which, for want of a better term, may be called "hazardous substances," meaning thereby those having the liability to sudden and violent chemical change. These bring service and peril to mankind in many ways. Their principal service is due to the fact that energy liber- ated through the chemical action can be transformed into power, light or heat; the peril arises from the danger that such liberation may be excessive and uncontrolled. In other words, they "have the defects of their qualities".
Like many other gifts of science, these hazardous sub- stances are comparatively recent associates of mankind. Our great-grandfathers knew gunpowder as practically the sole representatives of the group, and the dictionaries of even one generation ago defined the now indispensable gasolene as "a volatile fluid used for cleaning". Today, however, power-hungry civilization has learned to unlock the immense potentialities for service of which it was so long ignorant but, in so doing, a succession of disasters has warned it of the necessity for developing safeguards through constant, comprehensive scientific research. At
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A Department that Outgrew Its Name
no other place in the world is there so adequate a study of safety methods and appliances for use in connection with hazardous substances as at Underwriters' Laboratories. Much of the nation's recent progress in this direction Is traceable to the work of two of the departments — that of Gases and Oils and that of Chemistry.
The title "Department of Gases and Oils" is used merely for convenience because no more descriptive title has yet been found for the wide and diverse activities of the department. It deals in general with hazardous sub- stances but so, also, does the Chemistry Department, the main difference being that the Chemistry Department's work concerns itself with the inherent properties of these substances while that of Gases and Oils takes into account the mechanical means for producing, storing, handling and utilizing them. Constantly the two departments cooper- ate; often, unavoidably, they overlap. The Gases and Oils Department dates back almost to the beginning of the work of Underwriters' Laboratories, coming next in order to the Electrical Department. It has already been told that the discovery of acetylene at about the same time as the founding of the institution led to the production of crude and dangerous types of generators and the study of their hazards by W. C. Robinson, Mr. Merrill's earliest associate. The testing of acetylene generators has been an important feature of the work ever since, but with it have been grouped an ever-widening range of activities
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in many other fields, including, in particular, that of ** first-aid" fire extinguishers, more fully discussed in the chapter on fire-fighting equipment.
2. The Handling of Hazardous Liquids
The most familiar of the ** hazardous liquids" are gaso- lene, kerosene and other members of the petroleum family; to them may be added the alcohols and ethers, collodion, turpentine, carbon disulphide, paints and oils and their constituents; dryers, lacquers, and various other volatile and flammable fluids, some of which are subject to spon- taneous ignition. The devices and appliances connected with them are so many that it is manifestly impossible to go into a detailed discussion, but two or three instances will give a glimpse of the nature of the tests conducted.
Foremost, of course, comes gasolene, that miracle of liquid energy which is known wherever there are roads to be traveled or farms to be tilled. With a capacity so great that the vapor from one gallon is equal in explosive power to eighty-five pounds of dynamite, its well-nigh universal storage and widespread use present a serious safety problem.
For example, in a recent instance a tank truck stopped at a service station to refill the underground tank. There was a sudden fire of unknown origin. The operator dropped the hose and ran, but soon there was an explosion which enveloped in flames everyone within a radius of
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LEARNING WHAT WOULD HAPPEN IN A FIRE
There are five gallons of gasolene in the glass container of this visible measure discharge device. Would they cause an explosion in case of exix)sure to an outside fire? Apparently not, for when tested with a hot blaze from the vapor of twenty gallons poured into the pan beneath, the glass merely cracked;
there was no explosion
STUDYING GASOLENE SUPPLY DEVICES
The widespread use of visible measure discharge devices indicates the importance of safeguarding them in every respect against gasolene leakage or other defects. At Underwriters' Laboratories they are carefully checked for suitability of materials, arrangement and strength of parts and workmanship, and are subjected to various tests dealing with reliability of operation, leakage in joints, rate of fiow of liquid, the liability to accidental breakage and all other essential points
A Department that Outgrew Its Name
fifty feet. Eight persons died and people two hundred feet away were painfully burned.
The Department of Gases and Oils has spent much time on the obviating of such disasters and has investigated many devices, some of which have presented difficult problems, as in the case of a new type of curb pump in which "during the process of development the manufac- turer consulted with the Laboratories continuously."
The extent of the work thus devolving upon the Lab- oratories may be gauged from a glance at the mere head- ings of the description of the device as given in the Laboratories' 5,000- word report:
Assembly, base, motor, pump, platform, rotary pump, filter, hand drive mechanism, measuring compartment, glass cylinder, dome, cyl- inder guard, valves, operation, locking and interlocking mechanism, pipes and fittings, packing materials, protection of metal parts, hose vent, housing, meter, hose and attachments and electrical equipment.
From the fire-prevention viewpoint the essential fea- tures of the investigation included studies and tests with regard to construction, probability of leakage, strength, deterioration and suitability for use. The usual tests were made as to construction, strength, electrical features, and operation tests, also some special leakage tests. One test consisted in trying to build a pressure in the measuring compartment by various means, and it was noticed that this could not be done — on the contrary, a partial vacuum
was developed. The leakage tests consisted in applying
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pressures of twenty-five or of fifty pounds per square inch, according to the nature and use of the parts, and then watching for leaks. Studies and tests were also made of the Jocking and interlocking mechanisms and safety features. An interesting investigation involved a self-service coin-operated curb pump to which the motorist is to be attracted by a sign that reads: "Help Yourself Gas." On investigation he finds three coin slots, for quarters, halves and dollars, three gauge-glasses with pointers show- ing how much he will get for each coin, as per current rates; also these directions: "Notice, i. Place hose in tank. 1. Drop only one coin in slot. 3. Press button. Gas will be measured, then flow into tank." This device involved an entirely new hazard, for the question was asked: What if it got out of order and failed to supply "gas" after accepting a coin? Might not an irate motor- ist thereupon pick up a rock and vent his spite on the machine, causing leaks and perhaps a fire? Nothing like this problem had ever come within the sphere of the Laboratories, but appropriate tests were devised, and it was ascertained that the machine was reasonably safe- guarded by a mechanical provision for closing the slots whenever there was no gasolene in the supply tank or no compressed air in the system that forced the gasolene up to the measuring compartment. During the investiga- tions— which covered many other items — improvements were made "in practically every detail of construction"
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and the final form of the device was very different from that originally presented.
The use of gasolene in dry-cleaning establishments has led to the development of various automatic and auxi- liary extinguishers to reduce its fire hazard. An impres- sive demonstration of some of these safeguards was made at an Atlantic City cleaning establishment during the May, 1922, convention of the National Fire Protection Association. The gasolene was repeatedly ignited and each time was swiftly extinguished by means of automatic lids, steam jets or foam.
The tremendous utility of kerosene oil, because of its wide distribution, ease of handling, comparative cheap- ness, and the fact that it is not volatile at air temperature, have led to its employment in millions of households, as well as its use for industry and in transportation. Mech- anisms without number have been devised in connection with various phases of its use, and many of these have been tested and listed by the Laboratories. Among them may be mentioned the comparatively recent development of kerosene oil burners for household furnaces.
These tests involved a great responsibility because of the fact that outside underground storage tanks are not always practicable in dealing with homes, and the ad- ditional facts that the devices always must be "ready to run" and not unduly expensive, without sacrificing any of the precautions for safety. In fact, the function of the
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A Symbol of Safety
Laboratories as regards oil-burning mechanisms is some- what different from its policies on most other subjects. It not only strives to eliminate hazards but to make sure that these burners justify the manufacturers' claims as to simplicity and positiveness of operation; this is because burners that tempt the user to tamper with them are almost certain to get out of order and become hazardous.
Briefly summarized, here are some of the direct eflFects of the Laboratories' activities upon the manufacture of domestic oil burners, whether listed or not:
Pipe lines are being better protected from damage.
Oil line joints have been made tighter — metal-to-metal unions of standard type are beginning to be preferred to the gasketed types; litharge, glycerine and shellac are being used increasingly; the use of rubber, which dis- integrates rapidly in contact with oil, and the custom of filling the auxiliary storage tank in the basement, are being discouraged.
Valves are being made of better and safer construction. This is particularly the case with regard to automatic shut-off valves which may sometimes play an important part in safeguarding life and property. For example, during the war a hot billet of steel was dropped upon a feed pipe containing oil under a pressure of loo pounds per square inch or more. The pipe was broken and the oil Ignited, but the automatic shut-off valve immediately operated and the flow ceased at once. As a consequence
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SAFETY REQUIREMENTS IN OIL-BURNING EQUIPMENT
Many motor-driven oil burners are now on the market. Their use has become an important consider- ation in judging of fire hazard. The Laboratories makes frequent tests of such devices. In so far as practicable, they must be noiseless, odorless, uniform and reliable, free from carbonization or other troubles that would lead to tampering, and supplied with all necessary safety features. The tests con- sider supply lines, strainers, valves, automatic cut-off, pre-heating pan, electrical system, generator, air
duct and many other items
^ORTY DEGREES BELOW ZERO IN CHICAGO
This picture does not suggest a winter temperature, yet the engineers here depicted are making carton dioxide snow by the rapid expansion of liquefied carbon dioxide, which is being released from the cyhnder and retained in the bag. Why? In order to learn whether extinguisher fluids will freeze under severe
conditions of cold
A Department that Outgrew Its Name
there was nothing more than a momentary flash of fire instead of an outburst of flame that might otherwise have filled the building. As this accident took place in a munitions factory the catastrophe which might have resulted might well have been of national importance.
Since the average fuel oil bought for domestic use contains sediment, manufacturers have been encouraged to provide strainers of acceptable types, and so to install them that cleaning may be accomplished without dis- mantling the pipe line.
It having frequently happened that manufacturers neglected to consider the rigidity of the burner itself as installed, the Laboratories has brought about the provi- sion of secure attachment means, so that external shocks are now of little consequence.
Burners with moving parts are now being sold with drain pans to catch waste lubricant, thus avoiding the former unsightly and hazardous accumulation on basement floors.
The importance of such work was shown by an analysis of ninety-five fires resulting from fuel-oil systems published in the National Fire Protection Quarterly; among these were the following direct causes:
Broken and defective pipes, fittings and valves 38 Fires Explosions in furnaces or in pipes . . . . 6 ** Broken and defective burners and burner con- nections 5 "
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Oil getting into air pipes 3 Fires
Defective or improperly installed tanks • . 3 **
It is safe to say that in these particular cases the proper installation of improved supplies would have avoided fire. Seven more cases were from overheated oil furnaces and may be ranked as partly preventable by mechanical means while most of the others were chargeable to human carelessness.
J. Dealing with Hazardous Gases
Such fluids as gasolene owe their value as power to the fact that they may be easily converted into gas, but there are also many products that are naturally gaseous at air temperature, and must be handled and used in this form. Among these is acetylene, which, next to electricity, is the oldest concern of the Laboratories. Everyone is familiar with the brilliant white flame produced by acety- lene, that strange-smelling gas that results from the action of water upon gray rocklike calcium carbide. Its il- luminating power and its great convenience have given it a widespread household use, particularly in country districts. It has been much employed for automobile lights and within the past few years the oxy-acetylene torch has shown its value for use in welding and its power to cut through steel as a saw cuts through a board.
Repeatedly this power has been used in saving life.
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At the time of the "Eastland" disaster, when a crowded excursion steamer turned over at her pier in the Chicago River, most of the survivors owed their Hves to the fact that the rescuers were able to cut their way through the metal plates of the vessel's hull.
All this has come about within a single generation and as in many other instances, utility and hazard have de- veloped side by side. For nearly thirty years a succession of acetylene generators and appliances have been sub- mitted in completed form, in model form, or even as in- ventors' drawings to the Gases and Oils Department of Underwriters' Laboratories and have been developed in consultation with its acetylene experts. Indeed it was in connection with the work in this field that the well-known "plan of investigation" was first worked out. The acety- lene industry has benefited by all this work and manu- " facturers often express their appreciation, even in cases where the engineers have insisted on costly changes m design, construction or process.
For example, in the recent case of a "Class A" genera- tor for welding and cutting, ten improvements were made between the time of first submission and the final Council Report, and these changes included the complete redesign- ing of certain important parts, improvements in the m- ternal protection against corrosion and the addition of various safety features that were not in the original design. Some of the tests for these devices are based on reasons
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that would not be apparent to the layman. An example of this is found in the tests of the composition of the metal parts, in which brass with a high copper content is not allowed, because it might be subject to chemical action that would result in the formation of copper acetylide, and copper acetylide is a detonating explosive. Such points as this emphasize the need for wariness and techni- cal understanding in conducting investigations in order that the unconscious public may be shielded from the multiplication of dangers. The degree to which the hazards of acetylene have been reduced is the result of exactly this kind of painstaking attention to details, and the Laboratories' listing of a device stands for searching tests that are calculated to uncover its every defect.
While acetylene generators were the earliest point in the work of this department, other forms of gas generators and appliances had long given concern to the fire insurance companies, as was evidenced in a report by a "Committee on Gas Machines" of the National Board of Fire Under- writers made in the late 6o's. At the present time, both illuminating gas and natural gas, as well as some other forms, are employed in millions of homes as well as in many commercial and industrial establishments, and the Department of Gases and Oils is called upon to deal with many devices having reference to them, as they are the cause of numerous fires and explosions.
Here is a characteristic instance: One night in a printing
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STUDYING THE SAFETY OF ACETYLENE GENERATORS
Full-load operation lest of a medium-pressure small generator, using 1<'^^-Pf ^^^^^/^ ^"L""t !yP^^^^^ IhrouEh a reducing valve, the amount of acetylene bemg measured by