Presentation on slings

1. TYPES OF SLINGS
• WIRE ROPE SLINGS
• WEBBING SLINGS
• WEBBING ROUND SLINGS
• CHAIN SLINGS

2. WHAT IS A WIRE ROPE ?
WIRE ROPE IS MADE OF NOS. OF STRANDS LAID HELICALLY AROUND A
CENTRAL CORE.
BASIC COMPONENTS OF WIRE ROPE SLINGS
• THE CORE : CORE IS IN THE CENTRE OF WIRE ROPE CONSISTS OF
FIBRE – NATURAL OR SYNTHETIC, STRANDED WIRE OR A COMPLETE
“ INDEPENDENT WIRE ROPE CORE”
•THE MULTI WIRE STRANDS THAT ARE HELICALLY LAID AROUND THE
CORE.
•THE INDIVIDUAL WIRE THAT FORMS THE STRANDS.

3. CLASSIFICATIONS BASED ON TYPE OF
CONSTRUCTION:
• REGULAR LAY
• LANG’S LAY
• DIRECTION OF LAY
• LAY LENGTH
IN REGULAR LAY THE WIRES ARE LAID IN ONE DIRECTION AND
STRANDS IN OTHER DIRECTION SUCH THAT THE VISIBLE WIRES
APPEARS RUNNING PARALLEL TO THE ROPE AXIS. IN THIS
CONSTRUCTION A ROPE UNDER TENSION MAY ROTATE AS THE
STRANDS UNWIND BUT AT THE SAME TIME THE WIRES IN THE
STRAND ARE BEING TWISTED MORE TIGHTLY AND BALANCE IS
THUS REACHED BETWEEN THE TWO OPPOSING ROTATIONAL
FORCES. ON RELAXATION OF TENSION ON THE ROPE, IT WILL
RETURN TO ITS NORMAL STATE.

4. IN LANG’S LAY THE WIRES AND STRANDS ARE LAID IN SAME DIRECTION
SUCH THAT THE VISIBLE WIRES RUN AT AN ANGLE OF 30 DEGREE TO THE
ROPE AXIS.
THE DIRECTION OF LAY OR ROTATION OF THE STRANDS IS NORMALLY
RIGHT HAND ( UNLESS OTHERWISE STATED).
THE LAY LENGTH OF A ROPE IS A LENGTH WHICH ONE STRAND MAKES
ONE HELICAL REVOLUTION AROUND THE CORE.

5. STORAGE PROCEDURE OF WIRE ROPE SLINGS IN
MAINTENANCE UNIT
• ENSURE THAT SLINGS ARE MARKED WITH SAFE WORKING LOAD ( SWL),
VALID COLOUR CODING AND WITHOUT ANY VISUAL DAMAGE. NO DAMAGE
SHALL BE ACCEPTED.
• LIGHT DUTY SLINGS ARE BETTER TO BE STORED AND HUNG SO THAT THEY
DO NOT TWIST.
• HEAVY DUTY SLINGS ARE TO BE STORED ON WOODEN SUPPORTS SEPRATELY
ONE FROM OTHER.
• IN MOBILE CRANE OPERATION SLINGS NEED TO BE CARRIED IN THE CRANE
ITSELF, NECESSARY SUITABLE BOXES WITH LIDS TO PROTECT SLINGS FROM
DUST AND RAIN ARE PROVIDED AT THE CONVENIENT PLACE ON THE CRANE.
• AFTER USE EACH SLINGS MUST BE WIPED DRY, CLEANED AND LUBRICATED
PERIODICALLY WITH ACID FREE LUBRICANTS FOR e.g. OKS 451 OR
EQUIVALENT.

6. CARE AND HANDLING OF SLINGS
 SLINGS ARE VERY MUCH PRONE TO WEAR AND TEAR DURING USE AND
STRORAGE AND AS SUCH, CARE SHOULD BE TAKEN WHILE HANDLING THE
SLINGS. THESE SHOULD BE PERIODICALLY EXAMINED FOR DEFECTS AND
DETERIORATION.
 ALL SLINGS, BELTS, SHACKLES SHALL BE VISUALLY INSPECTED FOR WEAR
AND TEAR, CUTS BEFORE ANY LIFT.
 SELECTION OF SLINGS SHOULD ALWAYS BE OF GREATER CAPACITY THAN
THE ACTUALLY NEEDED TO LIFT THE LOAD.
IN RELIANCE IT IS RECOMMENDED THAT THE LOAD (TENSION) ON
SLINGS, BELTS, SHACKLES SHOULD NOT EXCEED 50% OF THE MARKED
SAFE LOAD.
MATERIAL HANDLING WITH MORE THAN ONE SLING
* IT IS RECOMMENDED THAT THE ANGLE OF SPREAD BETWEEN THE LEGS
OF THE SLING SHOULD NOT EXCEED 60 DEGREE ( i.e. THE ANGLE BETWEEN
A SLING AND LOAD SHOULD BE MORE THAN 60 DEGREE).
THIS REQUIREMENT CAN BE MET BY INCREASING THE LENGTH OF LEGS OF
THE SLINGS OR BY USING A CROSS BAR AND ATTACHING THE SLING LEGS TO
EACH END.

7. LOAD 1000 KG.
TENSION
577 KG
TENSION
577 KG
60DEG.
SLING
ANGLE
LOAD 1000 KG.
VERTICAL
SLING
ANGLE
TENSION
500 KG.
TENSION
500 KG.
TOTAL TENSION 1000 KG.
NO INCREASE OF TENSION
LOAD 1000 KG.
LOAD 1000 KG.
TENSION
1000 KG
TENSION
1000 KG
TENSION
707 KG
TENSION
707 KG 30DEG.
SLING ANGLE
45DEG
.SLING
ANGLE
TOTAL TENSION 1414 KG.
INCREASE OF TENSION IN SLING BY 41%
TOTAL TENSION 2000 KG.
INCREASE OF TENSION IN SLING BY 100%
TOTAL TENSION 1154 KG.
INCREASE OF TENSION IN SLING BY 15%
EFFECT OF SLING ANGLE (MEASURED FROM LOAD) ON
LOAD(TENSION) IN THE SLING

8. BASKET HITCH ARRANGEMENT
BASKET HITCH: - A BASKET HITCH IS MADE BY PASSING SLINGS UNDER
THE LOAD WITH THE WEIGHT OF THE LOAD EVENLY DISTRIBUTED ON TWO
OR MORE LEGS.

9. CHOKER HITCH
CHOKER HITCH: - A CHOKER HITCH IS MADE BY PASSING THE SLING
ENTIRELY UNDER THE LOAD.
ONE LOOP OF SLING IS HOOKED THROUGH THE SLIDING HOOK FORMING
A SLIP NOOSE. THE OTHER LOOP OF THE SLING IS PLACED ON THE HOIST
HOOK OF THE CRANE.

10. STRAIGHT PULL: IT IS MADE BY ATTACHING ONE END OF THE SINGLE
SLING DIRECTLY TO THE LOAD WITH A HOOK OR SHACKLE. THE LOOP ON
THE OTHER END IS PLACED OVER THE CRANE HOIST HOOK. WHEN MORE
THAN ONE SLING IS USED, THE RIGGING IS CALLED BRIDLE SLING, MOST
BRIDLE SLINGS HAVE TWO TO FOUR LEGS.

11. EFFECT OF SHARP EDGES OF THE LOAD
• A COUPLE OF INCIDENCES AT SITE HAVE HAPPENED WHEN
SHARP EDGES OF THE LOAD HAVE CUT THROUGH THE BELTS AND
CAUSE THE LOAD TO DROP. ENSURE THAT SLINGS ARE WELL
PROTECTED BY e.g. FITTING WOODEN BEAMS BETWEEN LOAD
AND SLINGS.

12. INSPECTION PLAN OF WIRE ROPE SLINGS
FREQUENT CHECKS OF RUNNING ROPES WHILE IN SERVICE
• A VISUAL INSPECTION IS RECOMMENDED FOR ALL WIRE ROPES / SLINGS
WHICH CAN BE EXPECTED TO BE IN USE DURING THE DAY’S OPERATION.
• INSPECTION SHOULD BE USE TO MONITOR PROGRESSIVE DEGRADATION
AND TO DISCOVER SEVERE DAMAGES SUCH AS
- DISTORTION, KINKING, CRUSHING,UN-STRANDING, BIRD
CAGING AND REDUCTION OF DIAMETER
- GENERAL CORROSION
- BROKEN OR CUT STRANDS
- NUMBER, DISTRIBUTION AND TYPE OF BROKEN WIRES
- EVIDENCE OF CORE FAILURE
- END FITTING WEAR / ABRASION

13. PERIODIC INSPECTION EVERY MONTH
PERIODIC INSPECTION SHOULD INCLUDE ALL ITEMS LISTED UNDER
FREQUENT INSPECTIONS PLUS THE FOLLOWING,
I. INSPECT FOR REDUCTION OF ROPE DIAMETER BELOW NOMINAL
DIAMETER.
II. INSPECT FOR SEVERLY CORRODED OR BROKEN WIRES AT END
CONNECTIONS.
III. INSPECT FOR SEVERELY CORRODED , CRACKED, BENT, WORN
OR IMPROPERLY APPLIED END CONNECTIONS
IV. INSPECT WIRE ROPE IN AREAS SUBJECTED TO RAPID DETERIORATION
SUCH AS SECTIONS IN CONTACT WITH SADDLE, EQUALISER SHEAVES
OR OTHER SHEAVES WHERE WIRE ROPE TRAVEL IS LIMITED.

14. STATUTORY INSPECTIN BY A COMPETENT AUTHORITY
THE LIFTING TACKLES (SHACKLES, SHEAVE PULLEY BLOCKS & WIRE ROPES,
SLINGS etc.) TO BE THOROUGHLY EXAMINED BY A COMPETENT PERSON
AUTHORISED BY CHIEF INSPECTOR OF FACTORY ATLEAST ONCE IN EVERY
PERIOD OF TWELVE MONTH. THE COMPETANT AUTHORITY SHOULD BE
REQUESTED BY THE USER PLANT TO SUBMIT THE TEST CERTIFICATE ALONG
WITH THEIR OBSERVATIONS ON THE CHECKS CARRIED BY THEM.

15. REPLACEMENT PHILOSOPHY OF WIRE ROPE AND WIRE
ROPE SLINGS
REPLACEMENT IS BASED LARGELY ON REMAINING STRENGTH OF
WIRE ROPE SLINGS IN USE AFTER PROPER INSPECTION AND
EVALUATION.
WIRE ROPE SLINGS SHALL BE TAKEN OUT OF SERVICE WHEN ANY
OF THE FOLLOWING CONDITIONS EXISTS,
•IN RUNNING ROPES, SIX RANDOMLY DISTRIBUTED BROKEN WI RES
IN ONE LAY OR THREE BROKEN WIRES IN ONE STRAND IN ONE LAY.
• KINKING, CRUSHING, BIRD CAGING, OR ANY OTHER DAMAGE
RESULTING IN DISTORTION OF ROPE STRUCTURE
•EVIDENCE OF ANY HEAT DAMAGE FROM ANY CAUSE.
• REDUCTION FROM NOMINAL DIAMETER FOR MORE THAN :
- 1/64 inch for diameters up to and including 5/16 inch
- 1/32 inch for diameters 3/8 inch to 1/2 inch inclusive
- 3/64 inch for diameters 9/16 inch to ¾ inch inclusive
- 1/16 inch for diameters 7/8 inch to 1 1/8 inch inclusive
` - 3/32 inch for diameters 1 ¼ inch to 1 ½ inch inclusive

16. MEASUREMENT OF ROPE DIAMETER

17. WEBBING FLAT SLINGS
THESE ARE POLYESTER SLINGS CONSIDERABLY LIGHTER THAN A METAL
PRODUCT OF COMPARABLE LIFTING PERFORMANCE AND AS A ONSEQUENCE
ARE BOTH SAFER AND EASIER TO HANDLE.
THE MAIN SAFETY AND HANDLING ADVANTAGES ARE:
- DO NOT WEAKEN WITH AGE.
- ABSORBS SHOCKS.
- NO CORROSION PROBLEM.
- EASIER TO INSPECT. - IF IT LOOKS ALL RIGHT, IT IS ALL RIGHT.
- LESS WEIGHT MEANS EASIER, QUICKER WORKING, LESS RISK OF
INJURY.
- BECAUSE OF THE SUPPLENESS OF POLYESTER, WEB SLING
ACCOMMODATES IRREGULARITIES OF LOAD.
- LESS RISK OF DAMAGE TO SENSITIVE OR PAINTED SURFACES.

18. WEBBING ROUND SLINGS
ROUND SLINGS MADE FROM 100% HIGH TENACITY POLYESTER FIBER. THE
CORE IS A JOINT LESS HANK OF PARALLEL YARNS PROTECTED BY A TOUGH,
TWIN WALLED WOVEN TUBULAR COVER. ALL SLINGS ARE CLEARLY MARKED
WITH THEIR W.L.L.
ADVANTAGES OF WEBBING SLINGS
THE MAIN SAFETY AND HANDLING ADVANTAGES ARE:
- DO NOT WEAKEN WITH AGE.
-ABSORBS SHOCKS.
-NO CORROSION PROBLEM.
-EASIER TO INSPECT. - IF IT LOOKS ALL RIGHT, IT IS ALL RIGHT.
-LESS WEIGHT MEANS EASIER, QUICKER WORKING, LESS RISK OF INJURY.
- BECAUSE OF THE SUPPLENESS OF POLYESTER, WEB SLING ACCOMMODATES
IRREGULARITIES OF LOAD.
-LESS RISK OF DAMAGE TO SENSITIVE OR PAINTED SURFACES.
- SAVINGS IN STORAGE COSTS (SYNTHETIC SLINGS REQUIRE MUCH LESSER
SPACE TO STORE COMPARED TO STEEL WIRE ROPES AND CHAINS).
- PARABILITY: THESE ARE THE ONLY SLINGS, WHICH ARE REPAIRABLE. IF THE
OUTER COVER IS DAMAGED OR TORN, SIMPLY REPAIR IT BY RETURNING IT TO
THE ORIGINAL SUPPLIER ONLY. NO ATTEMPT SHOULD BE MADE TO REPAIR
IT BY ANY OTHER SOURCES.

19. DISADVANTAGES OF WEBBING SLINGS.
1. CAN BE EASILY CUT OR DAMAGED IF USED UNPROTECTED OVER
SHARP EDGES.
2. CAN NOT BE USED IN TEMPERATURES EXCEEDING 80 DEGREE
CELSIUS.
3. HIGHER INITIAL COST COMPARED TO CONVENTIONAL SLINGS BUT
PAY BACK PERIOD IS VERY QUICK.
THE ABOVE DISADVANTAGES CAN BE OVERCOME BY
- USE OF ANTICUTTING WEAR PADS, IF THE LOAD TO BE LIFTED HAS
SHARP EDGE
- IF ROUGH/ABRASIVE SURFACE IS EXPECTED, USE ANTI-ABRASIVE
PADS.
- IF TEMPERATURE OF THE LOAD BEING LIFTED ARE LIKELY TO
EXCEED 80 C, LOOK FOR SPECIAL HEAT /TEMPERATURE RESISTANT
PADS.

20. 1 INSPECTION OF WEBBING SLING/ROUND SLING
FREQUENT INSPECTION/CHECKS.
INSPECTION IS VISUAL - "IF IT LOOKS ALRIGHT, IT IS ALRIGHT". IN CASE OF
DAMAGE TO THE YARNS THE SLING HAS TO BE TAKEN OUT OF SERVICE.
PERIODIC MONTHLY INSPECTION
LAY DOWN THE SLING IN A WELL LIT AREA, ON A FLAT SURFACE
(TABLE OR GROUND) AND FOLLOW THE FOLLOWING STEPS:
1. INSPECT THE ENTIRE BODY ALONG THE LENGTH OF SLING. OBSERVE FOR
CUTS, ABRASIONS AND DAMAGE TO THE OUTER COVER IF ANY. IN CASE
ANY OBSERVED, INSPECT OF THE CORE YARN INSIDE HAS BEEN CUT OR
DAMAGED, REMOVE THE SLING FROM SERVICE TO HAVE IT INSPECTED BY
AN AUTHORISED REPRESENTATIVE OF ORIGINAL MANUFACTURE. A VIEW
OF DAMAGED SLING IS SHOWN BELOW.

21. 2. CHECK "OVERLOAD TELL TAILS" LENGTH IF PROVIDED. IF THEY
APPEAR TO HAVE SHORTENED FROM THE LAST INSPECTION, THEN
THE SLING MAY HAVE BEEN SUBJECTED TO OVERLOAD. IN CASE
THEY HAVE DISAPPEARED THE SLING HAS BEEN SERIOUSLY
OVERLOADED AND REQUIRES INSPECTION BY AN AUTHORISED
REPRESENTATIVE OF MANUFACTURER/SUPPLIER. A VIEW OF
OVERLOAD TELL TAILS ARE SHOWN IN FIG..

22. SOME IMPORTANT CHECKS PRIOR TO LIFT THE LOAD USING
SLING
 ENSURE THAT LOAD IS FREE FROM ADHESION. THIS CAN BE ACHIEVED BY
USE OF JACK etc.. IF IT IS NOT POSSIBLE TO CONCLUDE THAT THE LOAD IS
FREE e.g. DURING DISMANTLING OPERATION, ADD 100% TO THE LOAD AND
CHECK LOADING CAPACITY OF THE SLING.
 INSPECT VISUALLY THE LIFTING LUGS FOR ANY ABNORMALITY / DEFECTS.
 FOR ECCENTRIC LOAD WITH UNKNOWN CENTRE OF GRAVITY ALWAYS
DETERMINE CENTRE OF GRAVITY BY TRIAL AND ERROR WITHOUT LIFTING
THE LOAD COMPLETELY OFF THE GROUND.
 IT IS NOT ALLOWED TO USE THE CRANE FOR DRAGGING THE LOAD,
BECAUSE THIS CAN CAUSE THE CRANE TO TOPPLE. THE LIFT LINE SHOULD
HANG VERTICALLY FREE FROM ANY OBSTRUCTION ABOVE THE CENTRE OF
GRAVITY OF THE LOAD.

23. TYPES OF SHACKLES
 SHACKLES ARE SIZED BY THE DIAMETER IN THE BOW SECTION –
NOT THE PIN. THE PIN IS SLIGHTLY LARGER TO ACHIEVE THE SAME
STRENGTH AS THE SHACKLE BODY.
 ONLY DROP FORGED, QUENCHED AND TEMPERED – ALLOY STEEL
SHACKLES SHOULD BE USED. THREE TYPES OF SHACKLES ARE USED
FOR RIGGING,
1. ROUDND PIN SHACKLES CAN BE USED IN TIED DOWN,
TOWING, SUSPENSION OR LIFTING APPLICATIONS
WHERE THE LOAD IS STRICTLY APPLIED IN-LINE.
CAUTION – DO NOT SIDE LOAD ROUND PIN SHACKLES
2. SCREW PIN SHACKLES CAN BE USED IN ANY APPLICATION
WHERE A ROUND PIN SHACKLE IS USED. IN ADDITION, SCREW
PIN SHACKLES CAN BE USED FOR APPLICATIONS INVOLVING
SIDE-LOADING CIRCUMSTANCES.
CAUTION – REDUCED WORKING LOAD LIMITS ARE REQUIRED
FOR SIDE LOADING APPLICATION. DO NOT ALLOW
SCREW PIN TO BE ROTATED BY A LIVE LINE, SUCH
AS CHOKER APPLICATION.

24. 3. BOLT-TYPE SHACKLES CAN BE USED IN ANY APPLICATION WHERE
ROUND PIN OR SCREW PIN SHACKLES ARE USED. IN ADDITION THEY CAN
BE USED WHERE THE LOAD MAY SLIDE ON THE SHACKLE PIN CAUSING
THE PIN TO ROTATE.
CAUTION – ANGLE LOAD MUST BE APPLIED IN THE PLANE OF BOW.
NEVER EXCEED 60 DEGREE INCLUDED ANGLE.
 USE BOLT TYPE AND SCREW PIN SHACKLES ONLY FOR SIDE ANGLE
LOADING. HOWEVER ADJUSTED WORKING LOAD LIMIT CHART MUST BE
REFERRED TO ARRIVE AT LOAD CAPACITY OF THE SHACKLES.

25. FOR SCREW PIN AND BOLT TYPE SHACKLES ONLY
ANGLE OF SIDE LOAD
FROM VERTICAL IN-LINE OF ADJUSTED WORKING LOAD LIMIT
SHACKLE
0° IN-LINE * 100% OF RATED WORKING LOAD LIMIT
45° FROM IN-LINE * 70% OF RATED WORKING LOAD LIMIT
90° FROM IN LINE * 50% OF RATED WORKING LOAD LIMIT

27. INPECTION OF SHACKLES:
FIG. SHOWS THE AREA OF A SHACKLE THAT REQUIRES SPECIAL
ATTENTION DURING INSPECTION. IF ANY PART OF THE SHACKLES IS WORN
BY MORE THAN 10% OF ITS ORIGINAL DIAMETER OR IF THE LEGS HAVE
OPENED UP, DESTROY IT.
FIG. - SHACKLE INSPECTION AREA

28. INCORRECT APPLICATION CORRECT APPLICATION

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