Chapter 5 Rigging

1. Chapter 5Rigging Rigging • Calculating Load Weights • Slings • Rope • Webbing • Round (Tubular) Slings • Chain • Rigging Component Inspection • Rigging Equipment Storage • Rigging Component Recordkeeping

2. The shape of a load normally determines its center of gravity.

3. A load lifted outside its center of gravity will shift to create excess side stress on one sling.

4. A load may be unstable and subject to topping if lifting equipment is placed below the horizontal weight center of the load.

5. Stock material weight tables list the weight of materials by ft, sq ft, or cu ft.

6. Numbers may be rounded off to allow rapid material weight calculations.

7. Main sling components include wire rope, fiber rope, chain, webbing, and round sling.

8. Other sling components include rigging hardware attachments such as clips, hooks, eyebolts, shackles, sockets, wedge sockets, triangle choker fittings, and master links.

9. Basic slings include vertical (single-leg), choker, U, basket, and bridle.

10. Tension increases and load capacity decreases as sling legs widen and sling angles are reduced.

11. Fiber rope is constructed by twisting fibers into yarn, yarn into strands, and strands into rope. Wire rope is constructed by twisting wires into strands around a wire core.

12. The diameter of wire rope is determined by the largest possible outside dimension.

13. Moisture, temperature, chemical activity, and bending reduce rope strength.

14. Rope bending efficiency rating increases as the diameter of the pulley increases.

15. The most common wire ropes used for basic rigging are filler wire, Warrington, Seale, and Warrington-Seale.

16. The strength of rope used for safely lifting a load is determined by its breaking strength.

17. Rated strength capacities of 6 19 wire rope are based on the rope diameter and sling.

18. Seizing is the wrapping placed around all strands of a rope near the area where the rope is cut.

19. Common wire rope terminations include thimbles and sockets.

20. Clip connections must be arranged, spaced, and assembled properly to maintain the strength of the rope.

21. Proper installation of a wedge socket has the live end of a rope in line with the socket.

22. Synthetic fibers are generally stronger than natural fibers.

23. Fiber rope is constructed by twisting fibers into yarn, yarn into strands, and strands into rope.

24. Most rope hitching and knotting terminology was derived from nautical (sailing) terms.

25. Whipping is tightly binding the end of a rope with twine before it is cut.

26. A splice is the joining of two rope ends to form a permanent connection.

27. Crowning is a reverse strand splice that is used when an enlarged rope end is desired or not objectionable.

28. An eye loop is a rope splice containing a thimble.

29. Half hitch and double hitch knots are not secure knots, but are the base formation of other knots.

30. A slip knot is a knot that slips along the rope from which it is made.

31. A bowline knot is a knot that forms a loop that is secure but is easy to release.

32. A wagoneer’s hitch knot is a knot that creates a load-securing loop from the standing part of the rope.

33. A timber hitch is a binding knot and hitch combination used to wrap and drag lengthy material.

34. A clove hitch is a quickly-formed hitch used to secure a rope temporarily to an object.

35. A cat’s-paw hitch is a quickly-formed eye for light-duty lifting.

36. A cow hitch is a hitch used to secure a tag line to a load.

37. A scaffold hitch is used to support planks or beams.

38. A blackwall hitch is a hitch made for securing a rigging rope to a hosting hook.

39. Webbing is a fabric of high-tenacity synthetic yarns woven into flat narrow straps.

40. Basic sling types are classified as Type I through Type IV.

41. Sling load capacities vary based on the sling angles.

42. Choker hitch load capacity is based on the angle of choke as the sling body passes through the choke eye.

43. The type of web sling selected and its use must be made with safety as the main consideration.

44. Round slings are slings consisting of one or more continuous polyester fiber yarns wound together to make a core.

45. Chain should be removed from service if the measurement of used chain exceeds 1 1/2% elongation from that of new chain.

46. Each chain, except for hoist apparatus chain, has a periodic embossing of a grade number or letter, indicating its capability.

47. Working load limits for slings using Grade 80 chain can be determined for a 90 vertical load or quad leg load up to 30 pull angle.

48. A shackle is a U-shaped metal link with the ends drilled to receive a pin or bolt.

49. A master link is a chain attachment with a ring considerably larger than that of the chain to allow for the intersection of a hook.

50. A hook is a curved or bent implement for holding, pulling, or connecting another implement.