Document 5bBbRvM88vBEoaa0KJ5Ejr9GV

* V' 1 How to make hoists safe before OSHA knocks __ _ C To get the job done, you have to know your hoisting equipment: what's safe, how to keep it safe, and how to use it safely. It takes a sound safety program to come up with the right approach--before OSHA spells it out in new standards. As we go to press, uncertainty about OSHA requirements has been a "way of life" for industrial users of overhead hoists. So far, OSHA . standards have had little to say about this "bread-and-butter" ma- tpn ole* KonrllifiA artnmma*** " - o - i - -r........... ------ plants across the country. "Overhead hoists", as a category, are briefly treated in construction standards (Subsection 1926.554 of 29 CFR Part 1926). Elsewhere, in the standard for double-girder, top running cranes (Subsection 1910.179 of 29 CFR Part 1910) OSHA says that a "hoist" may be part of a crane, and exerts a force for lifting and lowering. But, a Department of Labor interpretation has ruled that "overhead hoists" are not covered by 1910.179, OSHA's only industrial crane standard. And now there's a growing urgency about hoist safety, in that the employer's responsibility could soon become much more specific. It's no secret that OSHA wants to adopt comprehensive safety stan dards for overhead hoists. They may do it within six months. So the question is: Will you be ready for the OSHA standards? To get ready for OSHA, you have to know your hoisting equipment: what's safe, how to keep it safe, and how to use it safely. That kind of information is basic to an effective safety program. In the past, that kind of information has also been built into most OSHA standards. And, for tunately, much information about hoists is now available in a national __ _ _ *__. _J___I. 1 VTP B30.16--1973 safety standard for Overhead Hoists. The B30.16 safety standard cov ers all power-operated and manual ly-operated hoists for lifting service. It includes electric and air-powered hoists that lift with chain or wire rope. It also includes manuallyoperated hoists that are actuated by a hand chain and that lift with a chain. Excluded are manually-operated ratchet-lever devices. The standard says they are not "overhead hoists." However, the Hoist Manufacturers Institute has specifications for two types of manually lever-operated chain hoists. Also excluded from B30.16 are hoists designed for use in adverse environments. And there is no mention of worm-geared handoperated chain hoists. So this standard does require some further clarification of details. B30.16 can help you Experts tell us that they hope, and expect, that the OSHA hoist standard, when adopted, will be "consistent" with the consensus standard, B30.16. So you can use B30.16 as a general safety guide. You should be aware that B30.16 identifies mandatory rules by the 11SP of thp u/nrH "cKoll" iuu.3 ate smsuiud , Ul dl Q Mlllpiy stated as recommendations. In the past, when OSHA had to quickly adopt a number of national consensus standards, they avoided picking up the "should" material in these standards. But, today, with the pressure off, it is possible that OSHA will give more serious consideration to the ideas behind the "should" material. Also, OSHA might omit some design and construction details over which the employer-user would have no control. This would be consistent with OSHA's aim to stress "performance-type stan dards" rather than "specificationtype standards." Of course, there are some other good sources for help, in getting ready for OSHA's new hoist standard. For example, you can get literature from the Hoist Manufac turers Institute. This organization, with representatives on the B30 committee, helped to prepare the B30.I6 standard and concurs with its provisions. HMI can provide basic hoist specifications to help you promote 54 CTL005957 k!ODrRN MATCSlAi W4*p' I -4 I safety and select the types and classes best suited to your applica tions. For example, HMI specifica tions include those for electric wire-rope and chain hoists, and for hand-operated chain hoists. Also. HMI can provide "Do's and Don'ts" for safe operation of hoists, and the HMI consensus on the National Electric Code. Even though overhead hoists are not yet specifically covered by OSHA, for industrial applications, electric hoists must meet applicable parts of the National Electrical Code. So HMI has published a consensus on what it takes to make an electric chain or wire-rope hoist meet the NEC. Also, the 1975 NEC, just published, contains practical guidelines in Section 610 and could DC auCplCG Dy w jiir\. If you have monorail applications, you will also want to contact ASME for a copy of ANSI B30.ll--1973, Monorail Systems and Underhung Cranes--as well as a copy of B30.16, Overhead Hoists. The B30.11 standard says that manual or powered hoist units must comply with B30.16 safety requirements. Not to be overlooked are the variety of safety devices that are now available as standard or optional features of overhead hoists. And hoist manufacturers can provide checklists, manuals, and recommendations for inspection and maintenance. They can also tell you about testing and repair services. By following this approach, using B30.16 as your basic guide, you can soon develop an effective program for hoist safety. But you have to understand what is safe equipment, what must be done to keep it safe, and how to operate it safely. So here are the highlights--not all the details, but the basic elements in hoist safety. CTL005958 ss r i \ What's `safety right' in the equipment It bears repeating that equipment in two ways: (1) with the "duty- enclosed blocks, upper and lower safety is the key to a sound safety service class of hoists, and (2) with travel limits, chain containers, program for overhead hoists. First, the "duty-service class of inspec load-weighing or indicating devices, your equipment must be "safety tion." load-limiting devices, thermal over t right" for the job. Then people must For example, the Hoist Manufac load switches, latch-type hooks. The be trained to keep it safe, and to use turers Institute has already defined list could go on and on. it safely, as OSHA will soon spell "duty-service classes" for electric Some safety devices protect the out. wire-rope hoists and their applica operator from obvious mistakes, So how do you start? First, by tions, in the HMI 100-74 specifica such as getting fingers into moving considering what's available in tion (expected soon). parts, lifting loads too high, or i safety features, and by matching And the B30 committee is running the wire rope out and nOLSlS tO appiiOUitOtlb. expected to ;oeo re classify hcict- rpwprcino if r>n thp Hriim i Over the years, a surprising inspectton requirements on a more --1 IIC laiwil Utl U Jufiw...t;. u..i. VH.. variety of safety features have been rational basis, considering the boost safety two ways. It secures a built into overhead hoists or made severity of hoist service. sling load. It also serves as a gauge, available as options and accessories. Such a re-classification of inspec showing whether the hook has been Much of this has been written into tion requirements--redefining the sprung and has excessive throat HMI equipment specifications as "frequent" and "periodic" inspec distortion. well as the ANSI B30.I6 safety tions--could specify what is ap B30.16 states that latch-type standard for overhead hoists. propriate for "normal", "heavy", hooks shall be used on hand- In addition, users should, of and "severe" hoist service. operated chain hoists unless the course, consider the special safety Someday, possibly soon, this latch "increases the hazard." characteristics that are inherent in concept may find its way into Latch-type hooks are now called for various types of hoists. Such OSHA standards, as a practical on electric and air-powered hoists, characteristics may suggest which safety guideline for the hoist user. but exceptions may be allowed in type is best for a given application. But. whether or not OSHA adopts the future. But, above all. a user must try to it. the concept can help you to avoid Numerous safety devices can properly evaluate his specific appli over-specifying or under-specifying indicate or limit overloads. These cation requirements, before at a hoist or its inspection require may be standard equipment--more tempting to "match a hoist to the ments. It can help you to protect the often are optional, or available as job." operator from equipment failure, accessories. Thermal overload For example, it may not be and to protect the equipment from switches react to exceptional duty- enough to know that a hoist has the excessive wear. It can also help you service conditions that overheat a load-lifting capacity, headroom, lift, to avoid over-sized equipment, and hoist motor. For example, these and speed that a job requires. You to minimize your investment-- devices will shut down a hoist should also consider the severity of without excessive inspection, test because of excessive running time the duty-cycle, including the special ing, or maintenance. and too frequent slops and starts-- demands of infrequent heavy work-periods.when likely. Safety features available conditions hard on motors, brakes, and controls. New safety concept When you buy a hoist, today, you Many safety features protect the get a "package" of safety devices. operator indirectly. These protect This concept is to match the Among the possible safety features hoists from damage or excessive "duty-service class of application," arc: warning labels for operators. wear that, if undetected, could lead CTL005959 MODERN MATERIALS HANDLING / OCTOBER 1974 1 WARNING LABELS--These call attention of operator to major safety precautions. Q UPPER LIMIT CONTROLS--Prevent loadmL hook from exceeding upper limit of travel. 3 SLACK CHAIN CONTAINERS--Store slack chain so it won't hang in the way. LOAD-LIMITING DEVICES--Sense ^ an excessive ioad and prevent lifting it. A LOAD-INDICATING DEVICES--Sense the load and show its magnitude. 6 1 CTL005960 to accidents,sooner or later. One inherent characteristic of many hand-operated hoists is that they are relatively light and often moved from place to place. Basical ly, these hoists are designed for occasional and light lifting jobs. Inherent hoist characteristics The lever-operated types are highly portable. They often are used by maintenance people, and may be used for "pulling" jobs. Because of the variety of possible applications for hand-operated hoists, there is some risk of accidental overloading or abuse. So the equipment manufacturers offer overload protection devices. One example of an overloadindicating device, on a lever- upcuucu imuici iiulii, id a aycvia! handle. This deflects up to 30 deg to warn of excessive loads. One mechanical load-limiting de vice. on a hand-chain operated spur gear hoist, is a clutched hub on the hand wheel. When the pull on the hand chain is enough to overcome a given torque setting, representing an overload limit, the hand wheel will still turn. But this hub--on the hand wheel and the load wheel--won't turn. So the load wheel won't turn, either. In other words, the hoist will simply refuse to lift a severe overload. No special load brake is needed on a differential hoist or a worm-geared hoist. The differential hoist has a single endless chain over a double sheave. The small differ ence, or "differential" of the two diameters of the double sheave sets up enough friction to keep a load suspended when there is no pull on the hand chain. A worm-geared hoist needs no special load brake, because the load is supported by inherent "friction": the gear teeth cannot rotate the worm. In brief, a separate hand- chain operates a hand-chain wheel on the shaft of which is a worm gear. So a downward pull on either side of the hand chain rotates the power sheave and worm. This design offers greater mechanical advantage than that of the differen tial hoist, and provides accurate positioning. Hoist users may be concerned that a typical differential hoist, as used in the past, has an open bottom block. The question is whether such a design could be in conflict with safety specifications. B30.16 specifies that components must be sufficiently guarded to minimize the possibility of operator injury, and prevent entry of foreign objects. And this point, about guarding, is reinforced by OSHA's *.............. r... .11 __ c::c:a Iv^u:;*:i:vi:i2 ;ui an tux- chines, 1910.212(a): guarding must protect the operator from hazards such as those created by point of operation, ingoing nip points, rotat ing parts... However, an expert believes that an open-design differential hoist-- as pictured in B30.16--has been accepted "as is" for the usage intended: filling a recognized need for an economical chain fall, where there is minimum usage and minimum investment. Obviously, the B30.16 standard needs clarification. Spur-geared hoists have relatively high efficiency and are designed for production service where good hand-hoist speed and ease of operation are essential. A spurgeared hoist may be used with a push-type or geared trolley on a crane or monorail. When headroom is limited, the hoist and trolley may be built together, in a low-headroom unit that provides maximum lifting height. It's worth noting that the B30.I6 standard for electric and airpowered hoists specifies that bot tom blocks be of the enclosed t>p And, hoist makers consider that th vertical entry of wire rope into block is adequate protection for man's fingers. Especially, becau it's safer to hold the block or hook Powered-hoist characteristics While air-powered hoists includ a variety of air-cylinder hoisu_ single-acting, double-acting, ,m air-balanced types--the B30.! standard covers only air-moto hoists. B30.16 does not cover hoists fo operation in adverse environmeni' But air-motor hoists can be safe! used in hazardous areas where .a power cuts the danger of shock' combustion, or explosion. They ab, can be used in corrosive or abrav. contaminants out. Both piston and vane types cv. provide graduated control of spec,: varied by throttling the flow of .r And lightweight portable units .a, available. The piston types provide preci' speed control and would low or load relatively slowly if the ht.n. should fail. Vane types can ! relatively high-speed units. One advantage of air-motor hoi' is that the motors will simply when overloaded. They have an' matic load-limiting capability. Another is that they do c overheat on repetitive operation' Exhaust silencers can hold noise level below 90 dBA. Electric hoists are well-adapt-'*'' busy production-service. The principal components arc ; motor, the gearing system, a >l(' and hoisting-cable or a losprocket (or sheave) and chain. the motor brake and load brake, "up" and (if specified) "down controls, and the operating eon:. Link chain, roller chain, or * rope may be used in hgh' 1 s CTL005961 MODERN MATERIALS HANDLING / Odd'd - f j'inf * t k k iduif llvlw. g. and 130 mu i vi i j I j j. so Ifi mentv sjfc'i ere j-t thisA* ; i j ; i HI H2 Duty-service classification Infrequent or standby General area of application Powerhouse and utilities. Infrequent handling. Hoists used primarily to install and service heavy equipment, where loads frequently approach hoist capacity, with periods of utiliza tion being infrequent and widely scattered. Light . Light machine shop and fabricating industries, and service and maintenance work. Where loads and utilization are randomly distributed, with capacity loads infrequently handled, and where total running time of equipment does not exceed 10-15% of the work period. pCs i.-.s f \pc..` v of : nils ./ prc>. i-: knsc < 1C c.m N- :or.hoi-'* lpK '; j\C .1.. il>. Jo - r.itio-' ho!J " ni.jplc! - its arc n. .!>( ' own"" : iUCO!!!-' 1 IP or " ' lichi 'i- General machine shop, fabricating, assembly, storage and ware H3 Standard housing. Where loads and utilization are randomly distributed, with total running time of equipment not exceeding 15-25% of the work period. High volume handling in steel warehousing, heavy machine shop and fabricating plants, mills and foundries. Manual or auto H4 Heavy matic cycling operations in heat treating and plating opera tions. Total running time of equipment normally approaches 25-50% of work period, with loads at or near rated capacity frequently handled. Bu'k handling of material in combination with buckets, magnets or other heavy attachments. Equipment often cab operated. H5 Severe Duty cycles approaching continuous operation are frequently necessary. User must specify exact details of operation, including weight of attachments. - r,`'0 PAS.'C GPTUPS: ;.^s- 1J2. --aooly to the vast na;oriw c. t'c.o: - ' >."j`or oo".'" y *e;e nest cMsse-i Sy ' --m.; ?r,ri h5--recuse a tnorougn ana1/3'5 c` the ccty-c/cle. In pr,ef. r.Mi then recommencs a fc.-.eatzt on f?.'ecu re Ttvs z.oo'ies it heist utilization z: gene-ally described as 'heavy' or ' see e '. or ;t Ira: crnz'.o'-s cannot be broadly described as "randor" ClithOuivJ " 4 hoists. Link chain is durable and can that will permit operation of the and the supporting structure. The tolerate some side stress {not hoist within its rated capacity, and switch is set for an appropriate lo.J recommended practice). Roller will prevent the lifting of freely- limit. An overload will then actuate chain permits smooth operation for suspended loads that would cause the switch, and this will de-energiae spotting loads. Wire rope is com permanent deformation of a proper the hoist motor and apply the monly used on higher-capacity ly maintained hoist or trolley. brakes. hoists, and is often used for high One load-indicating system uses a Another load-limiting device is an (long) lifts with heavy loads. hydraulic weight-sensor, between electronic unit, easily wired-into the Load-indicating and load-limiting the lower hoist hook and a load hoist. This device works without ; ` devices are available for electric hook. This device will transmit the any connection to the wire rope or hoists. The HMI specification for load signal to a dial indicator. chain that holds the load. It works wire rope hoists defines an "over There's a load-limiting system on the principle that the hoist motor load device": an emergency device that has a switch between the hoist draws a higher current to lift an ! j increased load. When it senses ;n, ]i 1 overload current, a relay is ener i gized to open the "up" circuit and stop the hoist. But a time del.:', makes sure that the relay will not he 1 CO-74- vz. C5S = step-ewe's -.*9 izr :hs -z'a~s z* v.ire-'za rz`3: t.-31 vol: r-e:i utrizai'on `.vn 3n ozsratino 50% cf the tm".* ani :ne maximum pjtidst of starts. actuated by the short period u! surge currents at the start-up of the motor. 'T'k<r,c o mp/*honirul In ul. CaP CSrfc'ii v 1_'5 Lbi'/ !>--.< sa c w > i < v* < 4.1 a v>ujo w *\- j. >. i lilJUUJlg ucvilc uiai jiao i/vi.. cr 35*.='9 . cr "zzz'^" iP.g ;PrSr a9'*a:.'rl2n^^ SC5C;:C3!QnS built-into electric wire-rope an.: <1 '.vim iaz:s acru: you" <nov"* L?/-cyc!e y c,$* 'ibuteJ `hrougr. 2:ns T^s ic--:31 selection crocrGura re- chain hoists as standard equipmerv ..: "k os's00 cu 'ea that . ou cucL'ate ;-.e maan This slip-clutch device is set to er'ective 'aar ' ;:r \c*Jr e re- function within a pre-determine,: vm.Ja usmg an issjmeci range above rated capacity. The device limits severe overloads, an.:, c/ "0 c; "15, carv.e't a!! c!a$s ; n? s*. to a magr.t'jde. etz'ezsea as a on a chain hoist, can prevent damage from a jammed chain. ] i\ r p*::-.; :T --mo' *rrm* . - c1 tre Of course, a chain guide is al- provided to prevent a chain frotwisting on a load sheave. Electric chain hoists are genera! -.s' , > -'J '.u*9 T9 CO05 pow'ered by reversible, intermit'.." (non-continuous) duty, enclo'-- motors. These provide higher n:.>" ing torque and better hen' dissipation than continuous-r.% motors. However, the new HMI spec:.':- tion for electric wire-rope ho - i j includes both intermittent continuous-duty motors. The ion, characteristics must be suitable hoist or trolley service and cap.:" of operation at loads, numbei caries ..me, n ~m,. jcissi'3d :'> vi v :-u go to a h g-e- ?203Clty i ,4i rto.ji o- t- a cuty-Sr". starts, and speeds specified. Hoisting horsepower mu^. course, be ample for the reqn: hoisting speed: the velocity (frM'" < ' 60 CTL005963 MOOERN MATERIALS HANDLING / OCTOBS - I TVr ; !<>* CfUjTf err.T v !.V J f is is no iV itfu-.i OpC O! wurki nv.'t,-? lifi ISC\ Jfl ' cnc uit .ire! : (Jc'.j. I noi V ,*iod -i s be. I pc iipo'<"' SCI ! erm"? t\. ' id'. preslin ; 1 ; C !' ' ,iin l ` ccr-':- ' cm-'' ' ;nhe? ' :r ; ini' 1 - , r r ~ - Its IT * v u'.cd load. And the speed must v j-jple for the workload, including -v Lcquency and height of lifts. kWI points the way \ great service has been per- * i med by the Hoist Manufacturers : Pilule, in developing specification i.Ml 100-74 for electric wire-rope s (expected soon). In this specification, leading -j.-ijlaciurers have defined five ...vvcn of duty-service applications ' * *hich five classes of hoists are -Mtcncd. The five classes: "infre- . ^,*ni or standby duty-service" for Mi" hoists, "light" for "H2" '-vis. "standard" for "H3" hoists, fnr "H4" hoists, and r ui if n t. _ .*. ' 'vi; iui iivww. H.'ist classes and application - have been tabulated, along - s generalized descriptions, in a 1 '! duty-service, classification" - < So you can soon discuss `hit classes of hoists with the lecturers. "-ul experience has proved tis tabulation--for electric * ' pe hoists only--can ade- identify the vast majority of -'lonn in industry: "infrequent nuhy." "light", and "stan- : -for hoist classes HI, H2, and ' "heavy" and "severe" duty: applications require a thor- ":il\ sis of the hoist duty-cycle on specify a class of hoist. ""c H4 or H5 hoist classes may ' TleJ. ".ihtical procedure is clearl::'d in the appendix. It is 'n six major factors that life of mechanical and components and should ' hoist selection: distribution is the proportion Jnd partial loads to be ' 'ncluding attachments. Ex^'--iring |jfe varjes inversely `'"he of the load. A 5-ton Know your duty-cycle requirements Lifting capacity, headroom Speeds, hook travel Work distribution, loads, running times, starts Know available safety features and specifications Product literature, checklists for features, inspection, maintenance Manufacturers association specifications National safety standards and OSHA status Malrh ymir hoist tO the job " The features you need, in the speciric environment The required capacity and duty-cycle capability A safety program to keep it safe, use it safely hoist that handles a mean effective load of 2 1/2 tons will have a bearing life 8 times that of the same hoist used steadily at its rated capacity. Operational time is the total running time of the hoist, per hour or per shift. Work distribution is the opera tional-time distribution, uniformly distributed over the work period or concentrated in a short time span. This factor can have a material effect on electrical components, such as motors, brakes, and controls. Example: a hoist motor designed to operate 15 min. per hr cannot cope with 2 hr of steady operation and 6 hr of idle time. Number of starts and stops has a direct .affect on all electro mechanical devices, including con tactors. brakes, and solenoids. Motor heating is related to allowable running time and number of starts, rather than the mean effective load. Repetitive long lowering generates heat in the electrical or mechanical means for controlling speed. Environmental conditions, such as temperature extremes, moisture, dust, and corrosive fumes are not taken into account unless otherwise specified. How all these factors affect the selection of wire-rope hoists has been evaluated in establishing the HM1 "Hoist duty-service classifica tion." But, in addition, HMI 100-74 says that you need more than generalized descriptions of duty-service appli cations to select an H4 or H5 class of hoist, for "heavy" or "severe" service. First, a thorough analysis of your hoist duty-cycle is a must. Then you can use the technical data in the HMI 100-74 appendix to arrive at the right class of hoist. This approach is recommended to avoid CTL005964 CTL005965 the possibility of inadequate or oversized equipment. Equipment features in B30.16 In B30.16, you will find hoist markings, construction, and installa tion details for hand-chain and electric or air-powered hoists. All of these hoists must have the rated load permanently marked on the hoist or block, and legible from the operating position. Each control element on a powered hoist must indicate the direction of motion. And all these hoists must be permanently marked with identification details. Warning labels must be where . in a readable puauicn, tc display basic information on sate operating procedures. The required information is spelled out. Basic construction features There are numerous similarities in construction requirements for all hoists covered by B30.16. Basically, any properly installed hoist, properly used under normal operating conditions, must be able to cope with loads within the rated load. Load bearing parts must be designed so that the static stress, for the rated load, will not exceed 25% - of the average ultimate material strength, for hand-operated hoists, or 20% for electric or air-powered hoists. And elements provided to give a visible warning of severe overload must be so designed that the static stress for the rated load will not exceed 35% of the ultimate strength. The supporting structure, includ ing trolley, monorail, or crane, must have a load rating at least equal to that of the hoist. The manufacturer's replacement parts must be interchangeable within the original hoist assembly. tions must be approved by the manufacturer. Components must be guarded to minimize entry of foreign objects. Also, to prevent the possibility of injury to the operator of a hand-operated hoist. The noise generated by operation of an electric or air-powered hoist must be controlled, so that the noise level at the operator's station does not exceed 90dBA. Load chain may be roller link or welded link type and must be accurately pitched to pass over load sprockets without binding. It must be proof-tested by the chain or hoist manufacturer with a load at !ccct ?qiwa)enr to one and one half times uic iaiwJ lead, hy the number of parts supporting the load. Load sprockets must have ac curately formed pockets or teeth to MORE ON HOIST SAFETY This series to be continued in the November issue. allow proper engagement of the load chain. And they must be guarded to minimize entrances of foreign objects. Provision must be made to release the chain freely, to prevent jamming. Bottom blocks must be guarded against jamming of rope or load chain. On electric and air-powered hoists, bottom blocks must be of enclosed type, and should also guard the pinch points between the ropes and sheaves. The hand chain on hand chain powered hoists must be guarded so it won't disengage from the wheel. The chain must fit the wheel without binding. And it must withstand three times the pull required to lift the rated load. The load hook must be free to rotate through 360 deg when omnorrinc the rated load. And hooks must be retained in the housing so they can't work loose. The hooks must have enough ductility to open noticeably before failure of the hook under overload. Latch-type hooks must be used, unless--on hand chain hoists--the use of the latch increases the hazard. The braking must be so designed that it will automatically stop and hold loads up to 125% of rated load, when controls are released or actuating force is removed. The braking system for electric and air-powered hoists must also limit the speed of a lowering load to 120% of rated lowering speed for the load. It must have ample thermal capacity L>; ihc required freq'^nny of operation. Ana u must Lc adjustable to compensate for wear. Travel restraints are specified for all types of hoists. The load chain on a hand-operated hoist must be restrained before it can be com pletely run out of the hoist. The restraint must withstand a lowering hand chain force of twice the pull to lift a rated load. Electric and air-powered hoistsmust not let the load hook exceed an upper limit of travel. And they can't be installed where the loaded hook can be lowered beyond the rated hook travel, unless the hoist has a lower limit device. B30.16 also covers specific fea tures of electric and air-powered hoists. These features include electrical design, controls, hoist rope, rope drum, rope sheaves, slack chain storage, power supply and grounding, direction of motion, and power failure protection. Equipment used with hoists can also affect a safety program. Related equipment: a host of slings and other beiow-the-hook devices. A sound safety program also stresses proper inspection, testing, maintenance, and use of hoists.