Document k6KDxeEgzbMK1owK5pNjXjRgV

26th National Safety Congress NATIONAL SAFETY COUNCIL, Inc. KANSAS CITY, MISSOURI OCTOBER 11 to OCTOBER 15, 1937 Municipal Auditorium SC-ETM-0750 I Foreword THE Transactions of the Twenty-sixth National Safety Congress. 1937, are published ov the National Safety Council in two volumes. This, the first, contains the general, the special subject, and the Industrial Section sessions. The second volume contains the sessions of the Child Education, Home Safety. Street and Highway Traffic. Commercial Ve hicle and Transit Sections. All industrial members of the Council automatically receive Volume I. Volume 11 is sent to members believed to be inter ested chiefly in the sessions it covers. Other Council mem bers. however, may obtain it upon request. Many members have found it worth while to distribute copies of the Transactions to supervisors, foremen, ami others in an administrative or sti|>ervisoiy position who ntav make practical use of them for reference purposes. The fol lowing quantity prices arc quoted on extra copies: 1 to 10 copies of the large volume (Volume 1). $2 each: 11 copies or more. $1.75 each: copies of the smaller volume (Volume 11), 75 cents each. THE Transactions are published as a condensed record of the proceedings at the National Congress. The papers of each session or division of the Congress have been edited carefully to eliminate extraneous matter and to abbreviate the less essential portions because of space limitations. Thus the material herein presented is not a verbatim report of all the speeches presented at the Congress, but rather an abridged version made as compact as |iossiblc, vet without injury to the technical as|>ects of any address. The original manuscripts arc on file in the Council's Ilureau of Informa tion. where they are available for additional reference. Where illustrations were Sent liv the speakers to the Council, these also are on file. The National Safety Council at its Congresses seeks l' eliminate from discussion matters which are not pertinent to the aim of the Congress or which are contrary to Council INilicies. It cannot accept responsibility for the views ex pressed either in the papers presented or in the discussions based upon the pajicrs. NATIONAL SAFETY COUNCIL, Inc. 20 North Waclcer Drive Chicago Contents Council Officers and Directors..................................................... 4 Council Purposes and Policies............................................... 9 Annual Meeting of Members....................................................... 11 Annual Banquet.............................................................................. 31 Subject Session*-- After Work Accidents........................................................... 33 Agricultural Safety................................................................ 41 Community Safety Organisation....................................... SI Fire Prevention ..................................................................... 59 Health Servicein Industry.............................................. 71 Industrial Dusts..................................................................... 85 Industrial Fumes, Oases and Vapors.................................. 99 Industrial Safety Lectures.....................................................109 Maintaining Interest in Safety............................................. 141 Pressure Vessels ..................................................... 157 Safety Fundamentals ............................................................. 173 Safety Inspectors .................................................. ...............183 Safety Training ...................................................................... 193 Safe Use of Acids.................................................................... 201 Aeronautical Section......................................................................211 A.S.S.E.--Engineering Section........................................ .221 Automotive and Machine Shop--*Power Press Sections......... 225 Cement and Quarry Sections..........................................................249 Chemical Section ............................ 271 Construction Section......................................................................285 Food Section.................................................................................. .307 Industrial Nursing ......................................................................... 323 Marine Section...........................................................:...................341 Meat Packing, Tanning and Leather Industries Section....... 371 Metals Section................................................................................ 381 Mining Section....................................................................... . --401 Paper and Pulp Section.................................................................. 429 Petroleum Section .........................................................................489 Power Press Section.......................................................................535 Public Utilities Section.................................................................. S37 Quarry Section............................................................................. ..557 Refrigeration Section.................................................................... 559 Rubber Section .......................... 577 Safety Equipment Section...................................................................581-- Steam Railroad Meeting.................................................................587 Textile Section ...........................*.................................................601 Wood Products Section.................................................................611 Index.................................................................................................. 621 572 Twenty-sixth Xational Safety Conyress tlicr Jc>>cnim? oi fatigue, increasing oi effi ciency and decreasing of the accident hazard. Working Hours Those who have had actual and practical exjtcrience know that In some instances shortening oi the day's work has actually resulted in an increase in the amount of work dune. One occupation will he found far more fatiguing tlian another. Our pres ent interest is centered upon over-fatigue which is recognized as being causative of accidents. There arc in general use many labor-sav ing devices, the operation of which produce much noi*c and vibration and require high si*eed attention on the part of the o|ierators. Such inventions unquestionably save much labor and yet they have a tendency to greatly increase fatigue. Monotony, another cause of emotional fa tigue. deserves consideration under this (leading. Kest periods have been found to prevent and relieve fatigue when inter spersed with the day's work. Tiicsc res! pernwls may often In; of no more than five or ten minutes* duration and their fre quency governed hv the monotonous nature of the employment. Actual experience of industries where such rest periods have been instituted has shown that fatigue has been lessened, production increased, and accidents minimized. Noise Though .scientific experiment has not vet demonstrated that working under conditions of continuous noise is productive of fatigue, it is generally accepted as an axiomatic fact. Kxceedingly loud noises, those of a droning nature rapidly repeated, and monotonous noises arc particularly prone to induce fa* tigue. It would appear that the character and quality of noise is of the greatest importancc and. where they cannot be elimi nated. etTorts at changing or supplanting the character of sound have met with remark able success. By means of loud shakers installed throughout many factories in Germany the rhythm of music has been used lo overcome the hum of machinery. The practice is just beginning to permeate American industry; in Knglidt an<l South American factories it has been in vogue tor some time. Posture Incorrect posture is a most important fac tor in the causation of fatigue and its attendant accident hazards. Man having as sumed the upright position, all studies of posture must consider this as being his normal attitude. A perpendicular line drawn alongside of the standing figure should pass through the center of the car. the center of the shoulder, center of the hip, center of the outside of the knee, and center of the ex ternal malclous at the ankle. Such a posture requires the minimum of physical exertion lor its maintenance since the parts of the body arc so sui>criniposed upon each other that the force of gravity replaces much muscular effort. The correct seated posture maintains the above relation with the head, torso ami hips; the thighs are at an angle of approximately ninety degrees with the body, while the knees arc flexed so that the feet rest firmly and comfortably upon the floor. When work requires that the body be inclined forward so as to accommodate itself to a desk or machine, this position should he assumed hy a pivoting at the hip joints and not hy per mitting a slouch in the spinal column. The general ill effects of an improper sit ting posture result from the disturbances of function of the organs of the body resultant upon a flattened chest, rounded shoulders, obliteration of the natural curvatures of the spine, protrusion of the abdomen, removal of the natural support provided for the heavy abdominal viscera by a natural shelv ing of the spine where these organs rest and arc retained hy the abdominal muscles, undue stress upon supporting ligaments, rc-^ tardation of circulation, undue pressure upon that sensitive area surrounding the lower aid of the spine and the coccyx, and undue pressure upon the nerves, arteries and veins passing through the popliteal space at the back of the knee joint. When, due to im proper posture, the heart's action is impeded there is noted a diminution iti both the quantity and quality of the blood's supply with a corresponding depreciation in avail able oxygen and glycogen accompanied by a retention of the "fatigue substances.** The invariable result is a rapid manifestation of fatigue symptoms. The subject begins to feel sleepy, yawns frequently, responds but sluggishly to external stimuli, lags in the performance of work, becomes inefficient, and is far more liable to accidental injuries Refrigeration Section 573 Many workers have been provided with no scat whatever, others with improper scats or chairs which do not admit of adjustment cither to the individual's anatomy or to the work entailed. Due to the exceedingly in efficient character of such scats, piece work ers can rarely be induced to use chairs of ordinary construction while doing their work. Muscles will respond to an enormous amount of action Iwforc manifesting symp toms of fatigue. When, however, during muscular action, oxidation ha- lccn incom plete and the supply of glycogen inefficient, a rapid increase of the "fatigue substances'* will occur in the muscle cells and fatigue will increase in direct proportion to the re duction of muscular efficiency. Muscles tliat have liecomc fatigued will not W accurate in directing movements; there will lie incoordi nation of action with other muscles--this uncertainty of movement and mm-conccrlcd action increases the accident hazards of the individual as the elements of fatigue increase. Safety Control In Air Conditioning By A. G. HILLEN Engineer, Carrier Corporation, Chicago In our discussion we will ileal only with the safety control which should lie practiced in engineering design, which constitutes safety in material, safety in controls, and safety in physiological reactions of the oc* cujiants of the space. To obtain these safety measures the designing engineer must be selective in the materials used and lay out the system to produce comfortable condi tions without hazards to the occupants. The engineer operating the system must maintain in ihc conditioned area the tcnqK.-rnfiiri*s and humidities to produce comfort. In comfort conditioning, refrigerating ef fect is required to produce cooling and dchunullifying of air, which in the majority of eases calls for a refrigerating machine. The refrigeration machine is used either for the direct expansion of the refrigerant in the path of air or for the cooling of water to cool the air. The types used today arc ab sorption, rotary, reciprocating, centrifugal and steam ejector water vapor. Absorption systems are seldom used for air conditioning and the rotary* type is seen infrequently. The most commonly used refrigerants arc freon, ammonia, carbon dioxide, sulphur di oxide, methyl chloride, water vapor and carrcnc. Due to their toxic or irritant values, in ease of a leak, methyl chloride, ammonia and sulphur dioxide arc seldom used in air conditioning. Carbon dioxide is used less and less, due to its high working pressure and the high temperature of condensing water found in some sections of the country. This leaves freon and carretic a- the most generally used refrigerants, and while they are similar in some respects they are quite different in oicrating characteristics within the cooling range required for comfort air conditioning. Freon is used in a reciprocating com pressor which produces the cooling at a differential in pressure. IhiiIi high and Imv side atiovc atmospheric; while carrcnc is used in a centrifugal machine which pro duces its cooling at a dilTVrenlinl of %`acinim. Of course, water is sometimes used as a refrigerant. It is used in the steam ejector and water vapor centrifugal machines. To produce the refrigerating effect, cooling water to 50 degrees, a very low vacuum is required, approximately 292 inches of vacuum. Water, without n doubt, is the safest refrigerant which could lie used, hut has its limitation* due to its refrigerating characteristics. Freon and carrcnc arc considered safe refrigerants. Both are considered non-ex plosive, non-flammable, and non-toxic. The National Hoard of Fire Underwriters has made an clalioratc report entitled "The Comparative Ufc, Fire and Explosion Haz ards of Common Refrigerants.'* Due to the safety of freon, it is acceptable lo use for direct expansion work, as under normal operating conditions the amount of refrigerant leak would lie so readily diffused and diluted that it would not he harmful. Since with the use of freon the refrigerating 574 Tzccnty-sixth XatiiWul Au/V/v Congress eiiect i- produced Iiv a differential in pre-* sure, both high and low being al*uvc atmo-plicric prc->uro, any leakage of the refrigerant is outward. prH'e-*. In this type, explosion proof motors and starters must be used. The fans should al*o he cquipjH'd with cop|*cr scrolls to pre vent the generation of a static spark. The centrifugal machine using earrenc rnol* water or hrinc direct. This refrigerant i* not C5jecially suitable 1*r the direct ex pansion in coils of an air conditioning sys tem. With this type of refrigeration the refrigerant is kept entirely within the Itounds of the refrigeration apparatus room and does not eome in contact with the air Wing cooled sir otherwise conditioned. The centrifugal machine using carrcne is always at a vacuum on the cooler or evaporator side where the refrigerant is evaporating; lienee any leak age. no matter how slight, is inward rather Ilian outward, which clTcclivcIv prohibits the r*cafo of the refrigerant ga* into the sur rounding apparatus room. In certain ca-e* ammonia ha* Wen. and i* still Wing, permitted for use a* a refrigerant in air conditioning, such as in meat packing, breweries, and other industries, where the occujiancy in relation to tloor area is rela tively small. It presents a definite hazard when u*ed in direct expansion coils in the path of air. and certainly riioutd not In* used in any form as a refrigerating medium in an air conditioning system for auditorium* or public building*. In those industrial e-tahli-luncnl- men tioned. where ammonia i- tt-cd for imliMrinl and commercial purpose*. it riiotild never be utilized for comfort conditioning except by mean* of the indirect sy*tem. namely, cool ing hrmc or water which in turn i* u*ed The space requirements to permit ade quate servicing of equipment is another detail requiring careful study hy the design ing engineer. He should exercise care am! .thought in the locution and spacing of the apparatus. Conservation of space is some times over-emphasized, making it hazardous for the oftcrating engineer to render the re quired service to motors, compressors, etc. Safely control begins with the first nut or l*olt that is manufactured for the apparatus, right on through to the rigging and installa tion of the equipment which necessarily must he regulated hy insurance companies, under writers and city ordinances, etc. One particular detail in the installation of re frigerating and air comfitinning apparatus is often overlooked, and that is the safe work ing stres*cs of the floors U|H>n which the equipment is Win? erected. In many case* it has lccn found that the floor load was designed for 100 to 150 pounds !>cr square foot ami not suited for the actual equipment of over twice that weight which was in stalled. Then too, suitable vibration absorb ing pads of cork or rubier, or mechanical types using j-prings, should l*c installed to absorb the hazardous vibration that some time* exists. Belt guards ami pipe raifs around apparatus liavc often been neglected due to lack of cxicricncc or "penny wise and pound foolish" economy. for comfort conditioning. Standard refrigerating apparatus requires the installation of certain safety devices to Must Adapt to Conditions protect equipment against overload, break down and lire. Kverv installation should Controlling of sound level in air condi have high ami low pressure gauges so that tioning iu*t:ilIatioti* has Weome quite im portant. Such in*tnllution* as broadcn*ting an inspector or operator can determine at a glance if the pressure* arc within the safe studio*, sound stage*, theatres and court houses require sound treatment. The engi neer dc*igtiing the system should make certain that the material* ued in sound treatment in duct- arc fireproof. There ha* limit* of operation, l.ikcwisc, every motor driven compressor should have the proper parting equipment with overload relays ami under voltage relays to stop the apparatus in case of overload. lufii a tendency toward u*ing an acou-tiral material in*idc a duct to perform the func tion of iuMitation and -ound absorbing. Thimatcrial likewise should W fireproof, other wise a hazard is alway.- present. Where water is used for condensing pur poses a positive supply should be provided. If this is pumped, the electric?) hookup should he such tliat the apjiaratus will not operate unless there is sufficient and con Air conditioning in*tallatiou- play an im- tinuous supply of water to prevent building tHirtan: part in plant* where .-olvents with up of high refrigerant pressure 1>cyond safe cxplo-ivc* arc used in the manufacluritig limits. A simple electrical hookup or a water ration Section .*v; failure >witch can lie installed at nominal Co-t. Then too, thermometer.' are important -o that the operator or in*pcclor can make proper check-up at any time. Safety relief valve- of the pop type .-hould Ik: provided on the comlcu-cr and connected to outside: -uitaMc plug*. *cl to relieve at a rea>*mally low temperature riiould Ih* provided to pre vent excess pressure and possible explosion of the condensers and receiver in case of lire. Safety relief valve* of the pop type only should he installed between the suction ami di-chargc connections of the compressors as well as combination high and low prcsMirc cutout to .-top the compressor should the di*charge valve he shut otT. Where shell ami tulie apparatus is used tor chilling water, safety relief valves of the pop type should likewise lie connected to the outride to pre vent explosion in ease of fire because of exces*ivc ires-lire. All motors on all air conditioning appa ratus riiould he provided with suitable safety .-witches as well as overload ami undervoltagc starter protection. Where automatic temperature control is used, safety thermo-tats and regulating thermostats niu*t l*c provided to -afeguard the operation ol the equipment a- well a* to prevent excc*svc heating or excessive chilling in either -tnnuht or winter time. In certain manufacturing, process condi tioning, >pecia1 mechanical laboratories, theatre projection ImhiIIis. atul wherever duct work extends . through fire wall-, -uituhle fusible link dampers must he pro vided on 1mdli sides of the wall to automati cally close olT in case of fire, thus retarding spread of smoke, fumes, or fire. Drafts Must Be Avoided It i* ncee*sarv that the designing engineer lake precaution* to distribute the air in the conditioned area so that draft* will not occur on the (Kvupnuts of the room. The suggested maximum velocity over a person at rest i* 50 feet per minute. The design of outlets ami method of distribution should l>c such that this maximum is not exceeded. This is particularly true in air romfifioning in*dila tion* in hospitals. Sufficient outside air for ventilation should always l*c taken through the air conditioning equipment to dilute odor* and smoke which may occur in an air conditioned space. This naturally require- rchealcrs and preheater* where the system is in-tailed for year 'mum! air conditioning. In ho-piial in-tallatiou.-, c-pccially in o)*crating room*, the air .-upplied should preferably lc all outside air. in a|>artincul liou-c- *pecial prccaulinushould he taken to avoid the contaminated air from one or more a|iarlments Wing re distributed throughout the building; thus eliminating, or. at least minimizing the possibility of contagious diseases Inring transmitted. The system of control for preheater* should be such that they will not freeze up due to low temperature outside air and the reheaters should Ih* -ized of Mifiicieut ca pacity to heat the conditioned space to the desired winter temperature. Automatic con trol of temperature and humidity must Ih* installed to obtain the correct condition* in the occupied space. The engineer operating the sy*tem should he thoroughly instructed and competent P* n|cralc the air conditioning system correctly. The conditions maintained within the con ditioned area should eliminate the spectacu lar over-cMling which is so often resorted to In conditioned space*. A differential of 15 degrees with a relative humidity of 50 per cent, when outride tcmjHTature* are 05 de gree*. are coii-idcrcd ideal condition* for comfort. A* the om*idc temperature increase* this differential should iucrea-e -lightly and a- the outside temperature decrcn-e* the tem perature differential riiould decrca*e. Thi* i* particularly desirable in public building* tor the Comfort of the continuous rn'cnpant*. as well a* those who enter only to -lav a .-hort time In-fore returning to outdoors. This will avoid the shH*k so often ex]H*ricnccd due to the tin* great change in temperature. From Ihc safety |mint of view the record of the air conditioning industry is an excel lent one. for the public interest ill safely ha* in mo-t case* l*ccn adequately protected. With the increased use of refrigeration for comfort conditioning, even greater precau tions arc being taken in the development of proper refrigerant* and control. Has Safety Value There arc a munlier of applications in which air conditioning has had a definite safety value. In the operating rooms of 576 Twenty-sixth Xational Safety Congress hospitals where air conditioning is installed, the doctors and nurses arc comiortable. which tends to promote a steadiness of the nerves. The freedom from perspiration avoids (he possibility of a wound infection from that source. Since some types of anesthetics are definitely known to have ex* plosive characteristics, it is important to prevent the generation of a static condition tltat may prove disastrous. This is accom plished hv maintaining a relative humidity of 50 |*er cent at which condition static is en tirely eliminated. In mines, air conditioning has been lienefinal to the health and well being of the men working. In deep mines, without air condi tioning. temperatures and humidities are excessive, which frequently cause prostra tions. In shallow mines the roof and walls are at a temperature of approximately 50 degrees the year ruund and in the summer, when moist air is induced for ventilation, rapid condensation occurs and accumulates oti the shale nck which increases the liazard due to falls, lty supplying dehumidified air will) a dewpoint equal to or below the shale rock tcmjteraturc, moisture condensa tion will not occur, disintegration and falls are minimized. Many air conditioning installations have Ik.ch made in industrial plants where excodvc process heat is generated, such as enameling rooms where materials to l*e enameled are at inten-ive temperature*. Air conditioning has reduced the mtmlier ol prostrations and hence benefited the health and increased the comfort of the employees. Another important application is the re moval of dust and small particles of irritant chemicals, such as arc found in uncondi tioned match factories, some departments ol chemical, paints and pharmaceutical plants. In the manufacturing of rayon, an acid solvent is required in the process. Unless an exhaust system is lied into the air con ditioning system, the acid fumes contaminate the air, producing unhcalthful working con ditions. The fumes affect the throat and eves in jiarticular. Fuse loading departments in ammunition plants is another application where air con ditioning produces safety for employees. The humidity is kept high enough to prevent a static spark. Cooling and dchumidifving in summer eliminate perspiration from the worker's hands, which prevents the powder from adhering to the steel dies. Some lacquering processes require a sol vent having explosive properties. Since in !>omc plants doing this tyi*e of work the solvent has explosive properties, and dchumidifying is required, an exhaust system is installed ami sufficient outside air sup plied to prohibit an explosive mixture. Humidification in tobacco plants keefw down dust, winch otherwise would he 1haz ardous to employees. In the drying process of manufacturing matches, uniform drying, which requires air conditioning, prexentflaring or sparking when ignited. .-IPJOURXMEXr Rubber Section Officers 1936-37 General Chairman--J. M. Kerrigan, t\ S. Kuhltcr Reclaiming Co., Inc., Ituffalo. N*. V. I `itv-C/wioMun in Charge of Program--K. A. Huu.ooc, Corduroy Rubber Co., (irand Rapid*, Mich. Secretary--K. \V. Morsk, The Firestone Tire and Rubber Co., Akron, Ohio. Xe:es Letter Editor--Oliver Hopkins, l.\ S. Rubber Products, Inc* Providence, K. I. Engineering Committee Chairman--J. (.. Holm, The Goodyear Tire ami Rubber Co., Akron. Ohio. Health Committee-- Ilk. \V. S. Ash. U. S. Rubber Products, Inc* Detroit, Mich. I)r. J. Xkwton Shirley, Arrow Mutual Liability Insurance Co.. Watertown, Mass. Membership Committee Chairman--Pai*i. Van* Ci.ekk, Van Clecf Profilers. Chicago. III. Publicity Committee Chairman--W. H. MapKav, Dunlop Tire & RuMut Corp., Ituffalo. X. Y.' Statistics Committee Chairman--I). G. Wki.oi. Hewitt Ruhlter Corp., Buffalo. X. Y. Members at Large-- Ralph S. Fakxim, l*. S. Ruhltcr Products. Inc., Detroit. Mich. John L. Griper, American Hard Rubber Co., flutter, X. J. John J. Lock, The General Tire Jt Kubl*cr Co.. Akron. Ohio. John* E. Lovas. U. S. Rubber Products. Inc.. Passaic. X. J. Ukiiax L. Moi.hr, Inland Div., General Motors Corp., Davlon. Ohio, W. P. Spantox. American Hanl Rubber Co., Akron, Ohio. C. W. l*FKnm. Ohio Ruhlier Co.. Willoughby. Ohio. Past General Chairmen-- . K. W. I'n K, C. S. Rubber Products, Inc., Xew York, X. V. A. M. Diktr., I*cnnsyh-ania Rubber Co.. Jeannette, Pa. C. F. Horan. llood Rubber Company, Watertown, Mass. ). T. Kidney. *rhe C.oHKlyear Tire and Rubber Co.. Akron. Ohio. H. W. Low. Miller Rubber Products Co.. Inc., Akron, Ohio. W. L. Schneider. The 1*. F. Goodrich Co.. Akron. Ohio. Ciiaki.es !'. Smith. U. S. RiiMxt Reclaiming Co.. Inc., Ihiffab*. X. Y. Officers Elected for 1937-38 Genera! Chairman--J. M. Kerrigan, U. S. Rubber Reclaiming Co.. Inc., Buffalo. X. Y. riv-c7Miriiim in Charge of Program--R. A. Hi:i.i.ock, Corduroy Rubber Co.. Grand Rapids, Mich. Secretary--K. \\\ .Morse, The Firestone Tire and Rubber Co., Akron, Ohio. Xews Letter Editor--Oiiver Hopkins, V. S. Rubber Products, Inc., Providence, K. I. Engineering Committee Chairman-'), (i. Pni.u, The Goodyear Tire and Ktihhcr Co., Akron, < >hto. ` * Health Committee-- Du. W. S. Ash. I*. S. Rubber Products, Inc., Detroit, Mich. Dr. .1. Xiavtox Siuri.kv. Arrow Mutual Liability Insurance C., Watertown. Mass. 577