Chain sling


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Chain sling

  3. 3. INTRODUCTIONLearn the basic of chain sling, including the nomenclature, how it is constructed, and howdiameter and lay measurements are made.How to choose the right chain sling for your needs, how to extend sling service life, theimportance inspection, and how to properly store and handle chain sling.BS 4942-BS EN 818-6 gives information on the safe use of chains.Grade 80 (t) is most popular-Grade 80 (t) is the most widely used.Single,two,three or four legRange of end fittings. May be adjustable-Adjustable using shortening clutches.Chain sling can typically be used at maximum load in a temperature range of -40ºC to 200ºC(-30ºC-400ºC) TEMPERATURE SWLMost systems are ―idiot proof‖4:1 factor of safety FOR: –Unit assembly. –Strong AGAINST: –Flexible –Fewer sizes available –Adjustable –Could damage the –Resists most load chemicals –Resists heat
  5. 5. TYPES OF CHAIN Short link Chain for lifting Long link Chain for lashing Calibrated Chain for chain block Stud Marine use (anchor handling)
  6. 6. TYPES OF CHAIN (NO RECOMMENDED FOR LIFTING)WELDED NON-GRADED CHAINS: Thery find use in a variety of light duty applications such as guard rails as a security, tosupport signs and light suspended load and as a curtain chain. Straight Link Coil Chain used with a variety of standard chainattachments. Grade 30 Proof coil- chain for farm, industry and home applications. Great for long chain, cargo lashing, pipe linehangingm tailgatem guard rail, tow and switch chain,Coil-general utility chain made of carbon steel. Uses inluced animal tiechain, agriculture implement chains, platform barrier or guard chains, etc Twist Link or Cross Chains or Machine short linksdesigned for applications where compactness and flexibility are required. It can be used on tailgates, farm equipment, andindustrial equipment. Passing Link Chain with a wide link design. This enables links to pass one another without restriction,thus minimizing tangling and kinking. Extensively used for animal ties, farm machinery, general utility on farms and in industry.High Test Chain with a high tensile strength and excellent wear-resisting properties. This chain is great for load binding, loggingand other applications requiring light weight, long wearing chain of maximum strength. Do not use this chain for overhead lifting.WELDLESS CHAINS: some use include plumbing applications, boats, gates, animal leashes, window sashes, supportfixtures and playground equipment.Double Loop Chain or Tenso a general utility chain for hardware and manufacturingapplications, such as playground and gym equipment, boats, gates, hanging fluorescent lights, swings, porch swings, padlocksetc. Bright zinc finish.. Steel Sash Chain a flat metal chain suitable for many industrial assemblies, it is a stamped, flat link.Operates smoothly over pulleys,chain designed for counter-balanced, double-hung window sashes, arc lamps. Single/doubleJack Chain Light duty wire chain used where high strength is not required. Ideal for suspending flower pots, scales and lightingfixtures, store scales, and most childrens toys. High Test Chain-
  9. 9. TYPES OF SLING ASSEMBLIESAny fitting attached to the sling must be at least as strong as the chain itself..MASTER LINKCan be entirely forged or be welded from round steel. A common link for assembled slings thatallows a safe maximum spread of sling legs without binding. The formed and weldedconstruction is proof tested and stamped with size and WLL. Check that is compatible with thelifting appliance‘s hook (ie-big Enough)SINGLE LEG- Master Link Assembly- a streamlined master ink and coupling assembly used forsingle leg chain slings.TRIPLE OR QUADRUPLE MASTER ASSEMBLIES- these ase designed to construct a triple orquadruple chain sling assembly by attaching 3 or 4 single leg assemblies. They eliminatecumbersome connections created by attaching all legs to a common master link
  10. 10. TYPES OF SLING ASSEMBLIES HOOK- sling hooks must consist of self-locking or sling hooks equipped with a sufficiently strong safety latch, will not open when under direct load and prevents the hook from catching when lifting. Whithout latch when latching hook can not be used With a wide opening to accept large. Celvis hook- with direct connection to chain. C hook to prevent the load from becoming displaced With a swivelling eye to enable rotation Especially for webbing slings. diameter during lifting. Shortening hook. Barrel hook
  11. 11. TYPES OF SLING ASSEMBLIESMECHANICAL CONNECTOR/COUPLER- to connect its various components. Act as aconnection device between master link and chain for multiple leg chain slings, or/and attach eyetype fittings. They provide a high strength attachments to alloy chain assembly.Quick links provide fast ready connections for permanent or temporary applications.Connecting Links are designed for connecting links and chain with the same diameter.Cold Shuts (Proof Coil) used to join chain or attach hooks then the end of cold eye is driven thru eye and peenedover.Screw Pin Anchor Shacklesare ideal for lifting applications where shackles are frequently removed. The pinscrews into position without the use of tools. Not for use if there will be movement or vibration of the pin.Shackles with safety pin are the most secure choice for lifting. The safety pin consists of a round pin securedwith a nut and a cotter pin.Shackles with captive self-locking screw pin have indentations that lock the pin in place as it is tightened. Theyalso have a slight lip on the end of the screw pin that prevents separation from the shackle and eliminates lost pins.Lap Links (Repair Links) Used as a temporary joining device which can be applied with a hammer or vise • Not foruse with high test, alloy or transport chain.
  12. 12. CHAIN SLING-SHORTENING CLUTCHESSHORTENING CLUTCHESChain lengths are only to be reduced by the use of properly constructed shorteners, or clutchesin order to balance the load, length adjustment of the chain sling legs is needed. Consist ofshortening clutches, shortening hooks or quick-acting chain length regulators which lock thechain in place with spring-loaded pegsThere are two basic designs of shortening clutch:One design is shaped like a case grab hook and is virtually foolproof in use.The other design is shaped like a claw and is very efficient in use. Care must be taken whenusing this type of shortening clutch as it possible for this design of shortening clutch to be usedincorrectly. Loaded chain pulling Loaded chain from top of clutch must pull out jaws. Dangerous from bottom of clutch. Claw type of clutch used correctly. Claw type of clutch used incorrectly.
  13. 13. MARKING OF CHAIN SLING Each sling must be fitted with a marking plate displaying the WLL for different loading situations  Safe Working Load (SWL/WLL)  Unique Identity Number/Reference  Date of inspection or Colour code  CE Marking  It must be marked with grade or manufacturers mark
  14. 14. IDENTIFICATION GRADE OF CHAIN SLINGGRADE 30- industrial and agriculture applications including guard rail chain, loggingand load securement. Not to be used for overhead lifting.GRADE 40- is a high-test chain, approximately 50% stronger than Grade 30 chain.Typical uses are load binding, tie downs, and towing.GRADE 60- may be used in rigging and lifting applications.GRADE 70— Links are heat treated. Ideal for transport, load binding, logging andtowing. This chain is 20% stronger than grade 40 chain and about 60% stronger thanGrade 30 chain.Typically used by truckers, loggers and highway crews. . Not to be used foroverhead lifting.RECOMMENDED FOR LIFTINGGrade 80— The most common chain for lifting. Maximum temperature is 400 F.Recommended for overhead lifting.Widely used for slings, magnets, heavy duty dragging and pulling.Grade 100— This chain is approximately 25% stronger than Grade 80 chainMaximum temperature is 400 F. Used in a variety of sling and tie downapplications. Approved for lifting.
  15. 15. IDENTIFICATION GRADE OF CHAIN SLINGThe grade refers to the tensile strength of the chain. This is expressed in newtonsper square millimeter (a newton is approximately 0.224805 lbs).The tensile strength is calculated by multiplying the grade times the area of the twocross sections of a link by the mean stress AREA x GRADE = BREAKING STRENGTH 157.08 mm2 x 800 N=125,664 Newtons 125,664 N x 0.224805 lbs/1N=28,250 lbs 125,664 N 1000=125.66 kN (Kilonewtons) 10.000 N = 1 Tonne 125.66 kN = 12 ,56 Tn
  16. 16. IDENTIFICATION GRADE OF CHAIN SLING THESE ARE THE MOSTLY GRADE USE ON LIFTING CHAIN FACTOR OF SAFETY 4:1  GRADE (T) OR 80 (T), 800, 80, 8, HA PWB or CM  GRADE (P) (P), 40, 4 OR 04  GRADE (L) OR 30 (L), 30, OR 3 Grade numbers must not be confused with tensile strengths of the steels - they bear no direct relation to the tensile strength of the material.Chain - Alloy Steel Grade 60 Grade 75 Grade 80 Wrought Iron Mild Steel HTS 06 Scarf Weld Butt Weld 04SWL 12d 2 18d 2 14d 2 6d 2 6d 2 8d 2Proof Load 24d 2 40d 2 32d 2 12d 2 12d 2 16d 2Breaking Load 60d 2 75d 2 80d 2 27d 2 30d2 40d 2 Marked 4 d = diameter of the bar from which the chain is made when normalised
  17. 17. IDENTIFICATION GRADE OF CHAIN SLINGEXAMPLE CALCULATION• Using d2 factors where ‗d‘ is the nominal size of chain in inches not mm. – (resultant values are in imperial tons)• Grade 30 Chain has: – Breaking Load = 30d2 – Proof Load = 12d2 – SWL = 6d2• Taking a ½ ins diameter Grade 30 chain – B.L. = 30 x ½ x ½ = 30/4 = 7½ Tons – P.L. = 12 x ½ x ½ = 12/4 = 3 Tons – SWL = 6 x ½ x ½ = 6/4 = 1½ Tons
  18. 18. IDENTIFICATION GRADE OF CHAIN SLING BS grade markings Chain Marking to BS EN 818 4 Grade 40 normalised condition. Fine Tolerance Medium Tolerance Grade 04 Grade 40 hardened and tempered. M 4 40 06 Grade 60 hardened and tempered. P 5 50 08 Grade 80 hardened and tempered. S 6 60 M Grade M hardened and tempered. T 8 80 S Grade S hardened and tempered. V 10 100 T Grade T hardened and tempered. ORIGINS OF GRADE MARKINGS Material/ Breaking Proof Load S,W.L. Marking F.O.S. Grade Load (Tons) (Tons) (Tons) 2 2 2 W.I. 27d 12d 6d - 4.5:1 M.S. Grade 30d 2 12d 2 6d 2 3 5:1 30 H.T.S. 40d 2 16d 2 8d 2 4 Normalised 5:1 Grade 40 04 Hardened + Tempered Alloy Steel 2 2 2 08 Hardened +Tempered 80d 40d 20d (Not on calibrated chain) 4:1 Grade 80 HA. CM. KuplexGrade numbers must not be confused with tensile strengths of the steels - they bear no direct relation to the tensile strength of the material.
  19. 19. CHAIN SLING CONFIGURATIONHow lifting angles reduce working load limits of slingsUSING CHAIN SLING SAFELYUnderstand the use of the equipment, the slinging procedures and the mode factors to be applied.
  20. 20. CHAIN SLING CONFIGURATION SINGLE LEG OR REEVABLE SLING IN CHOKE HITCH WLL must be reduced by 20%. Single leg sling attached directly to the load the full WLL may be used under normal working conditions. SINGLE LEG OR REEVABLE SLING IN BASKET HITCH Hook engaged in the top link. Used this way the sling must be regarde as a single leg and the single leg WLL will apply under normal conditions. Reevable sling with both end links engaged on the crane hook. Used in this manner the sling may be regarded as a two leg and the two leg WLL will apply taking account of the included angle. TWO LEG SLINGS-4 LEG SLINGS The included angle between any two diagonally opposite legs and this angle must not exceed 120º. The WLL may be used under normal conditions for slings attached directly to the load. In the choke hitch, the WLL must be reduced by 20%. 3 LEG SLING DIRECTLY ATTACHED TO THE LOAD- the full 3 leg WLL will apply under normal conditions. The angle which determines the WLL is the largest angle between any two legs IN CHOKE HITCH- the WLL must be reduced by 20% ENLESS SLINGS Used to lift awkwarly shaped loads which do not lend themselves to lifting by means of hooks.
  21. 21. CHAIN SLING CONFIGURATION Any choke angle must not exceed 120º and any basket 90º.
  22. 22. CHAIN SLING CHART Size Single Single 2 Leg 3 and 4 Leg Leg Leg 0 – 45 o 45 – 60 o 0 – 45o 45 – 60o (straight) (Choke Hitch) 10 3150 2500 5250 3150 6700 4750 13 5300 4250 7500 5300 11200 8000 22 15000 12000 21000 15000 31500 22400Special Grade 10 4000 3200 5600 4000 8400 6000 13 6500 5200 9100 6500 13650 9750 22 20000 16000 28000 20000 42000 30000
  24. 24. SELECT THE CORRECT CHAIN SLINGChain slings are available in a range of material grades, sizes and assemblies.Determine the maximum WEIGHT of LOADDetermine the TYPE of sling required (by the configuration of the load, endless, single, two, 3 or4 leg)From the WLL charts, determine the size of the body chain for the sling. (Consideration theeffect of the ANGLE shown)Select the matching ATTACHMENTS required (i.e. with shortening clutches, hook, master link)Determine he REACH required to give the desired angle.For use at temperatures exceeding 200ºC or below minus 40ºC refer to the suppliers instructions.Where slings may come into contact with chemicals, particularity acdids or acidic fumes, consultthe supplier.
  25. 25. CHAIN SLING INSPECTIONThe inspection schedule should be based on frequency of sling use, severity of serviceconditions, nature of lifts being made and experience gained on service life of slings usedin similar circumstancesFREQUENT INSPECTIONS- a visual inspection for damage, which should be performedeach day the sling is used.PERIODIC INSPECTION- must be recorded and maintained for each individual sling(OSHA and LOLER at least one every 12 months- bs). A complete link by link andcomponent inspection.INSPECTION1. Clean chain prior to inspection, to more easily see damage or defects.2. Hang chain vertically, if practical, for preliminary inspection. Measure reach accurately.Check this length against reach shown on tag. If present length is greater than shown on tag, there is a possibility that the sling has been subjected to overloading or excessive wear.3. Make a link-by-link inspection of the chain sling for:  Excessive wear.See table.  Twisted, bent, gouged, nicked, worn or elongated links  Cracks in the weld area or any portion of the link. Transverse marking are the most dangeous.4. Check master links and hooks for all of the above faults- hook especially for excessive throat opening.5. Sling showing any of the faults described above should immediately be removed from service and returned to the manufacturer for repair.In general, any linear reduction in section of 10% or more is cause for removal of theattachmente from use.
  26. 26. CHAIN SLING INSPECTIONPRE-USE EXAMINATION OF CHAIN SLINGS • Check ID Number, colour code, and SWL is adequate • Inspect slings, remove twists • Check for stretch/deformation in the individual legs • Distortion of the master link. • Check each leg along its entire length for distortion (bends, twists, elongation and nicks) • Check for wear between links and between chain links and load pins • Check for heat damage and/or chemical attack • Examine end terminations- e.g. Hooks ( opened more than 10% or other deformation, ineffective safety catches) and conectors... • Ensure safety catches function and all load pins secure • Wear between chain links and between chain links and load pins. • Mechanical damage • Corrosion more than 10% of the material thickness. • Evidence of fiel welding or weld spatter • Colour change caused by heat damage is perceived. NOTE: It is recommend that chain slings should not be used for dynamic lift operations.
  27. 27. CHAIN INSPECTION Look for streched, gouged, bent or worn links and componets, including hooks, with open throats, cracks or distorsion. If damaged, remove from service. Twisted Links, Deformed Hardware Wear Nicks, Stretch Cracks
  28. 28. CHAIN INSPECTION-DAMAGES WORN LINK Excessive wear and a reduction of material diameter, especially at the bearing points. See table for minimum allowable mm/ink thickness. To prevent keeping load weights within the rating of the slings being used will give the maximun sling wear life. GOUGED LINKS Indentations on an otherwise smooth link surface. To prevent, protect sling from heavy loads being dragged or dropped onto the chain. HEAT Discolored areas of chain. To prevent high temperatures to affect alloy chain strength at 400ºF. Use table of reductions. STRETCH Indicates the sling has been extremely overloaded or subjected shock loading. Links that do not hinge freely with adjacent link are stretched and must be taken our of service, however, stretch can occur without this indicator BENT LINKS Occurs in only one or two adjacent links. Links will have an irregular shape when compared to other links. To prevent, load edges must be padded to protect both chain and load because are usually the result of the chain going around the sharp edge of a load during a lift. WELD SPATTER Metallic bumps on any link of chain. To prevent the heat from weld spatter can adversaly affect the stregth of a chain link. Slings must be shielded from welding operations.
  29. 29. CHAIN INSPECTION-DAMAGESNICKS AND GOUGES WEAR AND CORROSIONThey usually are located in surfaces under Corrosion,it results in a reduction of link cross-section.compressive stress. They are perpendicular Wear can occur in any portion of a link that is subject toto the direction of stress. rubbing contact with another surface. Check the bearing points of interlink contact and outsides of straight side barrels which may be abraded from dragging chain along hard surfaces or from under loads.
  31. 31. INSPECTION CRITERIA FOR CHAIN SLINGStretchWrought iron Max. 4%Steel and alloy Max. 5%Turn/twistAll chain Max. ½ turn in 12ftWearWrought iron Max. 6 ¼% reductionSteel and alloy Max. 8% reductionMechanical damageCracks, nicks, score marks Tensile area Max. 1 ½% Compressive area Grind out and reject as for wearCorrosionSevere corrosion Reject as for wearHeat effectsUnplanned use in hot Environment Reject if above 350 Degrees C
  32. 32. MAINTENANCE AND CARE OF CHAIN High temperatures • C – care of chain sling • H – heat • A – apply the correct WLL • I – identification • N – never use damage chain sling CARE -Be stored on a rack, in order to extend their life. -Clean periodically, as dust and grift can accelerate wear. -During use, chain slings should not be dragged over abrasive surfaces. Loads should not be rested on the chain sling to avoid damage. MAINTENANCE Maintenance are minimal. Keep chain slings clean and protect from corrosion, dry area (no subject to chemical attack, or extreme temperatures)Balance and abrutp movement Knots, Twist & Kinks Sharp Edges
  33. 33. STORAGE/HOUSEKEEPINGStore slings properly on an A-Frame ( on a rack), not lying on the ground, andprotect chain sling from corrosion during storage. POOR HOUSE KEEPING
  34. 34. CHAIN SLING – SLINGING PRACTICEBE AWARE OF MISUSE• When using shortening clutches, always make sure the chain is correctly seated in the clutch prior to taking the strain.• Never knot the chain to shorten it• Be aware that the capacity of the chain sling decreases when: – The angle between the legs increases and, – The sling is in a choked mode.ALWAYS• Ensure the chain is free from twists before loading.• Use within the rated loads. Apply the correct mode factor.• Secure redundant legs back in the master link to avoid snagging when travelling the load. Back hook free legs to the master link to avoid lashing legs which might accidentally become engaged or become a hazard• Allow personnel ride on loadsNEVER• Shorten the sling by knotting the chain• Join the chain using a bolt• Weld grade 80 chains or components• Hammer a chain to straighten a link• Subject the sling to dynamic or shock loads• Use defective slings or accessories• Leave suspended load unattended. In a emergency cordon off the area.• Overload slings due to the weight of the load or the mode of use.• Trap slings when landing the load.• Drag sling ove floor or attempt to pull trapped slings from under loads.
  35. 35. SAFE USE OF CHAIN SLING-HOOKGRAB HOOKSA conventional grab hook is designed to be hocked back onto the chain ina choker arrangemet. The full WLL can be achieved if the hitch angle is30º or greater.WLL of assembly must be derated by 25%, figure shows why the link inthe slot of a conventional grab hook is stressed more than the adjacentlinks. In addition to carrying its share of the straight tension load, the linkmust also withstand an additional bending caused by contact with the hooksaddle. The links usually fractures in this arrangement at about 75% of thechain‘s normal breaking load.With the CRADLE STYLE GRAB HOOK, the outriger‘s craddle actionreduced bending distortion of the link in the chain slot and the chaintypically develops full stregthBENT/WORN/CRACKED HARDWAREWear of hooks and other fittings usually occurs at the bearing points.Hooks bent more than 10% from the plane of the unbent hook. Hooksopened more than 15% of the normal throat opening.Never point load hooks of lift with hardware on a load edge
  36. 36. SAFE USE OF HOOK OF CHAIN SLINGINSPECT HOOKS PRIOR USEDiscard hooks that are worn more than 10% of the original dimensionDiscard hooks that have an increase in throat or slot opening more than 15% of the originalopeningDiscard hooks that are bent or twisted than 10º degrees from the plane of the unbent hookReplace load pins that are permanently distortedReplace damaged cotter pinsReplace damaged hook latches , distorted or bent. Make sure spring will force the latch against thetip of the hookReplacement load pins to be obtained from the manufacturer of the hookDo not point load hooks-load should bear on the bowl of hook. The latch must never support theload.When attaching more than one sling to the hook of the applianace use a shackle to join the slingsand avoid overcrowding the hook.
  38. 38. SAFE USE OF CHAIN SLINGWhere chain has to pass round a sharp corner, use suitable packing to give the chain someprotection.To ensure a level lift the crane hook should be vertically above the CG of the load. If in doubt,lift just clear of tilts, land the load and re-position the slingAlways have a prepared landing site ready to receive the load.Where appropriate use tag lines to control the load.When lifting operations are finished,slings must be stowed on a purpose made rack where theywill be safe from damage.
  39. 39. SAFE USE OF CHAIN SLING• The use of packing is required with chains No packing – result on supported loads. damaged link• Chain links can be damaged when passed around sharp edges with no packing.• A common bad practice is to ―batten down‖ in order to make the chains grip the load more securely – this simply destroys the chain.• The correct slinging technique should be employed. In this instance double wrap choke hitch.
  40. 40. SAFE USE OF CHAIN SLING• Chains should always be loaded in a straight line and only shortened by using a shortening clutch.• They must never be shortened by knots or by twisting them.• The master link must fit on the crane hook.• When chains are not in use they should always be hooked back to the master link.• Bearers should always be used to ensure the chain can be withdrawn safely on supported loads. If the load is landed onto the chains it will damage them
  41. 41. SAFE USE OF CHAIN SLING• When using chains to lift end heavy loads Equal load in each leg conduct a trial lift.• If the load tilts place the load down.• Re sling the load and lift again.• If the load is still not level repeat as often as necessary until load is level.• This will ensure safety and an equal loading in the sling legs. Increased angle • Be aware of other forces acting upon the load. • As the included angle increases the clamping effect of the chains upon the load also increases. Increased clamping • If the load is fragile it could be damaged/destroyed force by the forces imposed upon it.