Mark Pederson

1. Application Engineer ACRP May 10th 2012 Mark Pederson

2. Overview • Lifting Sling Testing • Introduction to Effect of D:d ratio • Single leg tests • Grommet tests • Basket tests • Choker tests • Published Spec Sheet • Inspection Retirement Criteria • Sources for Guidelines • Mechanisms that Cause Damage • Inspection Items • Hardware • Class1 Rope Hardware • Class2 Rope Hardware • Synthetic Rope Specific Hardware

3. Intro to Effect of D/d on Efficiency • The Tighter the Bend the greater the stress Concentration • With High Modulus fibers this effect is more dramatic • Sling on a Pin:

4. Intro to Effect of D/d on Efficiency • Sling on a Pin:

5. Intro to Effect of D/d on Efficiency • Sling on a Pin: • Parallel Core Is effected in a bend

6. Intro to Effect of D/d on Efficiency • Sling on a Pin: • Braided Construction is beneficial

7. Single Leg Testing • Single Leg • Weakest at base of splice • 2:1 D/d recommended • Efficiency > 1x Rope Strength

8. Single Leg Testing • Single Leg • Single leg slings are used to baseline most rope strengths • Theoretical load distributions • There is a true loss in bend around pin but each leg around pin only carries ~½ T

9. Single Leg Testing • Single Leg Testing • Straight Pull • D:d = 8 , 4 , 1 • D/d = 1 did not show significant strength loss, however break occurred at the back of the eye (on the pin)

10. Grommet Testing • Grommet strength is actually <2x rope strength • Current industry recommendations range from 1.6-1.8x entered

11. Grommet Testing • Grommet configuration highlights bending losses

12. Grommet Testing • D/d  Grommet Strength, Bearing size is critical for assuring proper design and maintaining grommet efficiency

13. Grommet Testing • D/d  Grommet Strength, Bearing size is critical for assuring proper design and maintaining grommet efficiency

14. Grommet Testing • A 1.6-1.8x • B 1.7-1.9x • C 1.7x • D 1.75x • Splice Placement on D:d >4 : • Splice area centered on the pin allows the legs to more evenly adjust upon loading. • Two splices do not produce a more efficient sling. • Testing has proven that the splice is more efficient with lower D:d ratios

15. Grommet Testing • Grommet • Weakest on the back of pin • 8:1 D/d recommended • Efficiency ≤ 1.6x Rope Strength

16. Basket Testing • Basket

17. Choker Testing • Current recommendations: • ASME B30.9 80%(PET roundslings) • Flory/Richards* 60% (HMPE slings) • Test Results*: • 12-strand, HMPE fiber • Ranged from 60% - 75% (varied by manufacturer) • Choke Angle is critical • Choker strength

18. Choker Testing • Single leg and Grommet in Choker • 3/8” and ¾”

19. Lifting Sling Table • Layout • Similar to ANSI table layout • 5:1 Safety Factor built in • Common horizontal angles rated for basket lifts • Minimum D/d recommended • Reductions for lower basket D/d • Inspection and retirement Criteria included

20. Sling Table

21. Updated Sling Table • Choker Slings • Adjustable Slings

22. Large Diameter Sling Testing • Tested slings in a large range of sizes • Developed a model that is used to design project specific lifts

23. Overview • Lifting Sling Testing • Single leg • Grommet • Basket • Choker • Published Spec Sheet • Inspection Retirement Criteria • Sources for Guidelines • Mechanisms that Cause Damage • Inspection Items • Hardware • Class1 Rope Hardware • Class2 Rope Hardware • Synthetic Rope Specific Hardware

24. Inspection Retirement Criteria • Inspection Retirement Criteria • Sources for Guidelines • Cordage Institute - International association of rope twine and related manufactures/Suppliers . • Educating on the proper use of products through standards CI 2001-04 “Fiber Rope Inspection and Retirement Criteria • Rope Type, Damage Description, Reference Txt, Reference Picture, Repair , Downgrade , Retire

25. Inspection Retirement Criteria • Inspection Retirement Criteria • Sources for Guidelines • Handbook of fibre rope technology [Book] by Henry A. McKenna, J. W. S. Hearle, Nick O'Hear, Textile Institute (Manchester, England) in Books • Very similar to the Cordage Institute

26. Inspection Retirement Criteria • Inspection Retirement Criteria • Sources for Guidelines • Samson Rope

27. Inspection Retirement Criteria • Mechanisms that Cause Damage Excessive Tension / Shock Loading Cyclic Tension Wear External Abrasion Cutting Pulled Strands and Yarns Flex Fatigue or Bending Fatigue Terminations Knots Axial Compression and Kink Bands Hockle, Twist , Kink or Corkscrew Sunlight Degradation Chemical and Heat Degradation Dirt or Grit Particulate

28. Inspection Retirement Criteria Initial Inspection • IF • Rope Displays Moderate Wear • No history of use • Potential injury or damage to equipment = Downgrade or Retire the rope Samson / Cordage Institute / Handbook of fibre rope technology

29. Inspection Retirement Criteria • Cyclic Tension Wear • IF: • Broken Internal Filaments over Length • Matted Filaments at strand rub areas =Downgrade / Retire Samson / Cordage Institute / Handbook of fibre rope technology

30. Inspection Retirement Criteria External Abrasion • IF: • Rope Cross Section reduced by 10% in whole rope =Downgrade / Retire • IF: • Rope Cross Section reduced by 25% =Repair/ Retire Samson / Cordage Institute / Handbook of fibre rope technology

31. Inspection Retirement Criteria Cutting • IF: • Rope Cross Section reduced by 10% in whole rope =Downgrade / Retire • IF: • Rope Cross Section reduced by greater than 10% =Repair/ Retire Samson / Cordage Institute / Handbook of fibre rope technology

32. Inspection Retirement Criteria • Pulled Strand • Less than 15% of strands are pulled out a repair can be made. • Greater than 20% of strands are pulled out a repair should not be made. Downgrade the rope and retire Samson / Cordage Institute / Handbook of fibre rope technology

33. Inspection Retirement Criteria Flex Wear on Pulleys/ Rollers • IF: • Internal Fusion • Wear on strand crowns • Broken filaments at strand rub points =Downgrade / Retire Samson / Cordage Institute / Handbook of fibre rope technology

34. Inspection Retirement Criteria Flex Wear on Pulleys/ Rollers

35. Inspection Retirement Criteria Spliced Eye • IF: • Cuts • Splice Pulling out • Incorrect Splice • Damaged Thimble =Repair

36. Inspection Retirement Criteria Creep • IF: • Rope Exceeds limits set by manufacture • History of the rope indicates it is a concern =Retire

37. Inspection Retirement Criteria Compression

38. Inspection Retirement Criteria Sunlight Degradation • IF: • Polypropolene, Brittle and broken outer fibers = Retire • Ropes less than 1” diameter, 1yr plus exposure, aramid, nylon, polypro =Retire/ Downgrade

39. Inspection Retirement Criteria Chemical And Heat Degradation • IF: • Known exposure = Retire • Discoloration, Brittle Fibers, Stiff, =Retire

40. Inspection Retirement Criteria Dirt or Grit • IF: • Dirt or Grit is found internally • Broken an powdery fiber present = Retire

41. Overview • Lifting Sling Testing • Single leg • Grommet • Basket • Choker • Published Spec Sheet • Inspection Retirement Criteria • Sources for Guidelines • Mechanisms that Cause Damage • Inspection Items • Hardware • Class1 Rope Hardware • Class2 Rope Hardware • Synthetic Rope Specific Hardware

42. Hardware • Hardware • Class1 Rope Hardware Lower Strength , Higher Elongation Fibers Plastic Thimbles , Non Reinforced Thimbles , Plastic Spools

43. Hardware • Hardware • Class2 Rope Hardware High Strength , Low Elongation Fibers Tubular Thimbles, Reinforced Thimbles, Aluminum Spools

44. Hardware • Hardware • Synthetic Rope Specific Hardware / Shackles • Wide body shackle • Crosby Sling Saver Spool

45. Hardware • Shackles • Standard and Wide Body • Small D/d for Grommets • Quick Easy and readily available

46. Thank you! • Questions