1. BASIC RIGGING

2. MSHA REGULATIONS S 77.210 Hoisting of materials.
(a) Hitches and slings used to hoist materials shall be suitable for handling the type of materials being hoisted.
(b) Men shall stay clear of hoisted loads.
(c) Taglines shall be attached to hoisted materials that require steadying or guidance.

3. MSHA REGULATIONS 56/57.16007 Taglines, Hitches, and Slings
(a) Taglines shall be attached to loads that may require steadying or guidance while suspended.
(b) Hitches and slings used to hoist materials shall be suitable for the particular material handled.
56/ Suspended Loads
Persons shall stay clear of suspended loads.

4. TOOLS OF RIGGING
Hoists
Cranes
Slings
Special lifting devices

5. HOISTS AND CRANES Different types of hoisting equipment
Manual and powered devices
underhung and top running cranes
monorails
various types of jig cranes

6. SLINGS Main purpose is to suspend a load from a hoist
Commonly made of wire rope or welded link chain
Can be constructed from fiber rope,synthetic webbing or metal mesh
Most slings are assembled by sling manufacturers
Can be assembled at the job site

7. The rigging system Load Sling Hoisting equipment
Rigger (Designer and Operator of the system)
= Single, complex rigging system

8. The Rigger Must apply intelligence, common sense and experience
Anticipate what will happen when the load is moved
Thought process must take place before the work is started
Must answer the following questions…..

9. Questions that must be answered by rigger
What is to be done with the load?
What tools are needed?
Do the tools have the capacity to handle the loads and forces involved?

10. Questions that must be answered by rigger
How can the hookup be made?
What will happen when the load is first moved?
What will be the travel path of the load to reach the desired location?

11. Questions that must be answered by rigger
How will the load be set down at the desired location?
What other factors are involved (weather, electrical wires, sloping grades, visibility)?
Are additional personnel needed to control the load safely during the process?

12. Planning a rigging system
Determine the weight of the load
Locating the center of gravity of a load
Distinguishing the force components (horizontal and vertical) at work in a diagonal force(loads at some angles other than 90 degrees to the horizontal)
Limitations of each component of the rigging system

13. Determining the weight of the load
Shipping paper
Manufacturers information attached to the load
Catalogs or blueprints
Tables of weights from manufacturers or handbooks
Make sure the weight has not changed

15. Volume & Area Formulas

16. Calculating an allowable load
Determine the breaking strength of the rope
Load which will cause the rope to break
Refer to standard tables in rigging handbooks
Listed according to the diameter and kind of rope
Design or safety factor usually 5

17. Calculating an allowable load
Find the load limit by dividing the breaking strength of the rope by the design factor
Example-
If the table indicates that the breaking strength of the rope you are using is 27,000 pounds. Dividing this figure by the design factor of 5 gives you a 5400 pound maximum allowable load.

18. Determine the center of gravity
The point at which the load will balance
Whole weight of the load is considered concentrated at this balance point
When suspended from a point, the load tends to move so that the center of gravity is directly below the point of support.
Make sure the center of gravity is located directly below the hoisting hook

19. Determine the center of gravity
Stable load
Balanced about its center of gravity
Directly below the hoisting hook
Unstable load
has a tendency to tip or topple
Creates a hazard to personnel and equipment

20. Before Lifting any load check for hazards
If not directly below the hook the load is unstable
If the sling is free to slide across the hook the center of gravity will shift directly below the hook
If two slings are used one will assume the greater share of the load

21. Before Lifting any load check for hazards
The sling must not be attached to the load at a point lower than the loads center of gravity
Exception to this rule when lifting loads on pallets or skids
Then apex of sling must be above the center of gravity

22. Determining the center of gravity
Marked on the load by manufacturer
Located in catalogs or blueprints
Some objects have lifting lugs
Calculate or estimate it
Make an educated guess and correct through trial and error before making the lift

23. Procedures to determine center of gravity
Connect slings and hoist based on estimate of object’s center of gravity
Take up slack in slings or hoist
Lift the load just enough to check stability
If stable, continue to lift
If unstable, lower load and adjust the rigging
Lift point should be moved closer to end that dips
Repeat until load is stable

24. Horizontal Force
Very often sling legs are attached at an angle less than 900
Then a horizontal force is added to the vertical force
Resulting Combined force is greater than the weight of the load
Horizontal force increases as the angle becomes smaller

25. Horizontal Force
When a sling angle is 300 the total force is twice that of the load
Sling Angles of 450 are not recommended

26. Horizontal Force
Horizontal forces act on the load causing damage by compression or buckling
Horizontal forces are absorbed by using a spreader beam making the sling legs between beam and load vertical

27. Sling Components Hooks Coupling Links Fittings Sling Legs
Can be assembled at the job site but must use recommended components and assembly procedures
May also require some sort of weight test

28. Hook Hazards Attachments should never be field welded to a hook
Heat should not be applied in an attempt to reshape a hook
Can reduce strength of hook
Could result in hook failure at loads lower than the rated load
If handles or attachments are required they should be obtained from the hook manufacturer

29. Purpose of a latch? Purpose is to retain slings in the hook
Not intended to support the load
Should be sturdy enough to retain the sling if the moving load should catch on something
Latches are used to close the throat opening
Must be provided on hoist and crane hooks

30. Reasons For Removing a Hook From Service
Hook throat has increased by more than 15%
Wear exceeds 10% of the original hook section dimension, or there is a bend or twist of more than 10% from the plane of the unbent hook
Hook shows cracks, excessive nicks, or gouges

31. Factors Affecting Wire-Rope Strength
Three major signs of loss of strength
Flat spots worn on outer wires
Broken wires
reduction of rope diameter
Other factors that can reduce strength
Bending the rope over a curved surface
Temperature
Corrosion and environment
Rope fittings or terminations

32. Bending The Rope Over A Curved Surface
Normal curved surfaces that ropes are curved over include sheaves, pins and other curved surfaces
The rope is subjected to bending stress
Reduces rope efficiency/nominal strength by a certain percentage
Efficiency depends upon the:
D = Diameter of curved surface
d = Nominal diameter of rope

33. Example (You will need to refer to Fig. 2-5 and Table 2-1)
Fiber-core 6 x 37 wire rope, 1” in diameter (d)
Sheave with a 30” diameter (D)
D/d ratio is 30/1
Efficiency is 95%
Load Rating dropped 95% from 83,600 lb. To 79,420 lb.

34. Wire Rope Clips Two basic designs
U section contacts dead end of the rope
Tends to crush some wires
Affects strength if u-bolt clip is installed wrong
Fist Grip can be installed either way
Use only forged steel for lifting slings

35. Removal From Service
Rope Distortion such as kinking, crushing, unstranding, birdcaging or core protrusion
Heat Damage from any source
Look for damage from weld and weld splatter
Cracked or deformed end fittings(hooks particularly)
Corrosive failure of one wire adjacent to end fitting

36. Removal From Service One broken or cut strand Pitting due to corrosion
For Single Wire Rope Either:
10 broken wires in a section the length of one rope lay
5 broken wires in one strand within a distance of one rope lay

37. Chain Hazards
Similar force acts on the links if the chain is knotted or twisted
Never shorten a sling by twisting or knotting
Never use bolts and nuts or other fasteners to shorten a sling