Introduction: Materials needed to conduct this training: White board, black board or presentation tablets. Projector

Transcription

1 1

2 Introduction: Materials needed to conduct this training: White board, black board or presentation tablets Projector Student Manuals printed out for each participant Notepad or scratch paper Calculator for each participant Rigging cards or reference materials Load charts of the types cranes you will be working with Test Sheets, Answer Sheets and Answer Key Several relevant accident profiles, or personal stories to share 2

3 Introduction: The word rigging (from Anglo-Saxon wrigan or wringing, "to clothe") originally was a word used to describe the mechanical sailing apparatus (sails, masts, ropes, blocks and pulleys) used to propel a sailing boat or ship through the water. Today, the word rigging is used to describe any gear that is used for lifting. 3

4 Introduction: The quality of the material rigging gear is made from has changed drastically over the years. However, the principals of rigging remain the same. 4

5 Introduction: Improper rigging practices have led to the deaths and injuries of many individuals. These are often due to riggers not knowing the correct method of securing certain loads, loading rigging components beyond their lifting capacities, and getting caught between unpredictable moving loads. As part of this training we will analyze many of these accidents to discover what could have been done to avoid them. 5

6 Introduction: Here we see the cranes and rigging used to lift the Space Shuttle in California onto the back of a carrier jet to fly it to Cape Canaveral, Florida. It all looks very complicated but during this training we will be learning many of the same principles. 6

7 Rigger Qualifications: Riggers must be trained and experienced. They must know how to: Determine the weight of the load and its center of gravity 7

8 Rigger Qualifications: Understand the stresses put on rigging gear when used in different configurations 8

9 Rigger Qualifications: Select, inspect, and use slings and hardware suitable to the load 9

10 Rigger Qualifications: Direct the crane and the load in a safe, efficient manner 10

11 Standards: There are many standards that govern crane operations and rigging in the workplace. The main standards this training uses are from ASME and OSHA. Remember, some states and even cities have their own standards that may be even more stringent. It is your responsibility to know which standards apply in the jurisdiction you will be working in. 11

12 Class Outline: This training will be broken up into the following categories: Determining the Weight of the Load; Sling Angles and Stresses; Center of Gravity; Basic Sling Hitches; Types of Lifting Slings; Lifting Hardware; Below the Hook Lifting Devices; Communication; 12

13 Discovering Weights of Loads: In this section we will discuss the importance of knowing the weight of the load before attempting to lift it. This is the single most important precaution in hoisting and rigging. Everything depends on it, from using the load chart of the crane to picking the right capacity slings and rigging gear to lift it. We will discuss methods of determining the weight of loads; the unit weights of common materials; how to calculate the volume of the load; and the challenge of lifting loads out of water. 13

14 Rigging Cards: Each of you will have a rigging card. These cards are very useful out in the field and are filled with useful information. We will practice using these throughout the training and during the practical evaluation. 14

15 Acceptable Methods of Determining Weight: Often the weight of the load can be obtained from data on manufacturing label plates, manufacturer documentation, blueprints or drawings, shipping receipts, bill of ladings, stamped or written on the load and other dependable sources. *When such information is not available, it will be necessary to weigh the load or calculate its weight. Never use word of mouth to establish the weight of the load. *Question on written test: The best way to discover the weight of a load is to weigh it. a. True b. False 15

16 Discussion: How much does this boulder weigh? What rigging equipment or conditions depend on knowing the weight of the load? 1. Does the crane have sufficient capacity to make the lift? Remember, you need to know the capacity of the crane for the radius you will be picking or placing the load, not just the maximum capacity of the crane. 2. What is the ground bearing strength where the outriggers will be situated? Is it soft soil or pavement? Will you need additional pads or mats placed under them? 3. How may parts of line will the crane need to use? The capacity of the crane is limited to the number parts line it is configured for. For example: On some cranes, 1-part line is limited to 10,000 lbs. If the load you are lifting is 25,000 lbs, then you would need to go to at least 3-parts line. 4. What slings and hardware will need to be used to rig and lift the load? 16

17 Calculating Weight: To find the weight of any item you need to know its volume and unit weight and multiply them together. The unit weight is the density of the material and is normally measured in pounds per cubic foot. The time taken to calculate the approximate weight of any object, whether steel, plates, columns, girders, castings, bedplates, etc., is time well spent and may prevent a serious accident. 17

18 Determining Weight Exercise #1: You will be lifting and setting a number of ecology blocks which are made of reinforced concrete. Each one is 2 x 2 x 6. Using your rigging card and calculator determine: What is its unit weight? What is its volume? What is its weight? 18

19 Determining Weight Exercise #4: What is its Circumference? (Pi x Diameter = Circumference) What is its Area? (In this instance the Circumference is now its width. Width x Length = Area What is its Estimated Weight? (20 lbs x Area = Total Estimated Weight) 19

20 Determining Weight Exercise #5: If we take our ecology block which weighs about 3,600 lbs and is 24 cubic feet and submerge it in water it will displace about 24 cubic feet of water. Using your rigging card what is the approximate weight of water? How much weight does the crane see when lifting this load under water? 20

21 Sling Angles and Stresses: In this section we will discuss Sling Angles and the additional stress put on slings as the angle from the vertical decreases. As part of this training we will practice calculating these stresses using load angle factors. We will also practice calculating the stress on slings of unequal length and slings and come-alongs while drifting loads. 21

22 Double-Vertical Sling Stress: If we use two slings to lift 1,000 lbs and their legs are vertical (90 ) then each sling will see exactly half the load or 500 lbs. 22

23 Double-Vertical Sling Stress: Using a spreader bar is one example of using two vertical slings to pick up a load. 23

24 Double-Vertical Sling Stress, Reduced: And things go south as the angle of the slings are decreased to 5. Now, there is an astounding 5,735 lbs of stress on each leg of the sling! If we were using two slings whose capacities were 1,000 lbs in the vertical, (which would be plenty to pick up 1,000 lbs in the vertical or even at 60 ) there is a very good chance those slings would fail if we use them at such an angle. Caution: Never use extreme sling angle when lifting loads. The ideal angle to use is 60. Never use a sling angle below 45. ASME standards prohibits using sling angles under 30 unless approved by a professional engineer. 24

25 Sling Angles and Stress Exercise #1: What is the stress in each sling if a 3,000 lb load is lifted at 45? (Remember, multiply the load angle factor by ½ the load) 25

26 Calculating Stress in Slings of Equal Length: To calculate the load angle factor of slings of equal length, just divide the length of the sling by the vertical distance from the hook down to the load. (L/H) 26

27 Discovering the Center of Gravity: Is this section we will discuss the importance of knowing where the Center of Gravity is in the load and how to rig to it. We will cover: Finding the Center of Gravity by Trial & Error; Inverse Proportion to Distance Formula; We will show the importance of Rigging to the Center of Gravity; How to determine the stress of Slings of Equal Length; and How to determine the stress of Slings of Unequal length. 27

28 Center of Gravity: *The center of gravity (CG) as it pertains to rigging, is the center of the load s weight distribution or the point in the load around which all weight is evenly distributed, no matter how it is turned or rotated. *Question on written test: Center of gravity is: a. In the physical center of an object b. A point in an object around which all its weight is evenly distributed c. The tipping point of an object when it is lifted d. The balancing point of an object 28

29 Inverse Proportion to Distance Formula: This formula will find the center of gravity of the load on a horizontal plane rather than in every direction and is good for long, wide loads where a two-legged bridle will be used to lift it. It is a simple formula that just requires that you know the weights of A & B and the distance between their center of gravities which is Z. 29

30 Center of Gravity Exercise #1: It helps to work it out one step at a time. We don t need a calculator to know that 2/3 rd of 21 is 14. And when it comes down to it, we really need a tape measure to estimate where 2/3 the distance to B is from A. 30

31 Center of Gravity Exercise #2: OK, let s work this out together and see how you did: First, we will determine the combined CG for parts A & B using the inverse proportion to distance formula. You already noticed that there is some information missing, didn t you? The distances between the center of gravities. That s ok, you don t need it. 1. Total weight of A & B is 400 lbs lbs = 600 lbs 2. Divide Part A weight by the total weight of A & B: 400 lbs / 600 lbs = 2/3 (.66) 3.The distance between the CG s of part A & B is 2/3 rd the distance from B to A. 4. Mark that spot on a direct line between the two. 5. Now using their combined CG we will continue. 31

32 Determining the Center of Gravity in all Three Directions: Determining the Center of Gravity in all three directions seems a little more mind boggling but just takes a little more time. Once you determine the CG in the horizontal, then calculate in the vertical. Draw a straight line between the two and the combined CG will be in the middle. 32

33 Center of Gravity Above the Pick Points is More Unstable: This knowledge is especially important for lifting pallets, skids or the base of any object since they all have a tendency to want to topple. If you are attachied below the center of gravity you want to make sure the center of gravity is well within the triangle formed by the slings to make the pick. It is not hard to see that the example on the right looks a lot like a swing on a swing set and only a fool would try to sit on one without holding on tight! The higher you grab on the easier it is to keep from falling off. So, remember, if the attachments are above the center of gravity the load will be more stable. And if the attachments are below the center of gravity the load will be more unstable. 33

34 Hitches Used for Rigging: Here we will be discussing the three most common hitches: 1. The Vertical Hitch which would include the single vertical, and 2, 3, & 4 leg bridles. 2. The Choker Hitch, including the single-wrap and double-wrap 3. The Basket Hitch including the true basket, reduced basket and double-wrap basket. 34

35 Three Basic Hitches: *The three basic hitches are the Vertical Hitch, Choker Hitch and Basket Hitch. From these there are a multitude of variations that will allow the rigger to safely control the load during a lift. Typically, the choker is about 75% of the vertical capacity and the basket is double the capacity of the vertical. Riggers should always remember that the type of hitch that s used to lift a load can greatly affect the rated capacity of the sling. *Question on written test: Which of these is not one of the three basic hitches used in rigging? a. Timber hitch b. Choker hitch c. Basket hitch d. Vertical hitch 35

36 Capacity Tags: Slings are required to have the tag showing the capacity of these hitches that they can be used for. The tag should also contain information regarding the manufacturer, description of the sling, material it s made from and its size. If the tag is illegible or missing it should be replaced or the sling taken out of service. 36

37 Vertical Hitches: Vertical hitches are either single-leg or multiple-leg bridles. 37

38 Angle of Choke: Another reduction that must be considered is due to the angle of the choke (not the angle of the leg of the sling). If the load is hanging free, the normal choke angle is approximately 135 degrees. This is a true choker hitch and is about 75% of the capacity of the vertical hitch. When lifting and turning a load using a choker hitch, it is not uncommon to have a severe bend at the choke. When a choker hitch is used at an angle of less than 120 degrees, you must reduce the hitch s rated capacity as shown in the chart at right. 38

39 Types of Chokers: These are the different variations of chokers that are commonly used. 39

40 Discussion: What type of slings are being used? Answer: Two round slings and one chain fall (come-along) What hitches are being used? Answer: Single-choker hitches What deductions need to be made? Answer: One deduction for the sling angle and one deduction for the extreme choke angle What is the chain fall used for? Answer: To adjust the legs of the slings over the center of gravity so the load will come up level Is it ok to used the chain fall in this manner? Answer: As long as it is load rated and within the capacity of this pick Why is it rigged the way it is? Answer: This pipe will probably be bolted onto another pipe and needs to be lifted level. The one area of concern is the choker hitch on the left that could slip upwards during the lift. 40

41 Slings Used for Rigging: In this section of the training we will discuss the different types of slings and the materials they are made from. Synthetic Slings: are more pliable and easier to handle than metal slings. Because they are made of soft materials they will not damage loads. The most common types of synthetic slings are: Flat slings made of nylon, polyester or dacron; Round slings that are usually made from polyester; and Rope slings that are made from a multitude of materials such as polypropylene, spectra, and other newer, stronger materials that rival wire rope for its strength. Wire Rope Slings: are typically constructed from high-carbon steel which comes in different grades, including Improved Plow Steel (IPS), Extra Improved Plow Steel (EIPS) and Extra-Extra Improved Plow Steel (EEIPS), which designate the nominal strength of the wire rope. EIPS is most commonly used in the manufacture of wire rope slings. Chain Slings: are your best choice for lifting materials that are very hot. They can be heated to temperatures of up to 1000 o F; however, when alloy chain slings are consistently exposed to service temperatures in excess of 600 o F, operators must reduce the working load limits in accordance with the manufacturer's recommendations. 41

42 Synthetic Flat Slings: Synthetic slings offer a number of advantages for rigging purposes. The most commonly used synthetic web slings are made of nylon, dacron, and polyester. They are light weight and easy to handle. They will conform to any shape, hold it with a tight, non-slip grip, and will not mar, deface or scratch delicate surfaces and will absorb heavy shocks without damage. *They are not affected by mildew, rot or bacteria, and will resist some chemical action and have excellent abrasion resistance. *They are not affected by grease or oil. They are non-sparking, non conductive and can be used safely in explosive atmospheres and are unaffected by temperatures up to 180 F. The disadvantages are that they are subject to tears, cuts, and snags. *Sunlight, moisture, weld splatter and temperatures above 90 C (194 F) damage both nylon and polyester slings. *Question on written test: Nylon slings are subject to damage from UV light but polyester slings are not. a. True b. False *Question on written test: Synthetic flat slings are not affected by mildew, rot, bacteria, oil or grease. a. True b. False 42

43 Inspection of Flat Slings: The first thing you want to check for when using a sling or inspecting it is to see if it has a capacity tag and that it is legible. Most tags will eventually become hard to read with time so when buying slings make sure they have a sturdy capacity tag that will stand up to normal wear and tear. 43

44 Discussion: Should this sling be discarded or does it still have some life? Can you de-rate it for lighter picks? 44

45 Inspection of Flat Slings: Do not be tempted to lengthen or shorten synthetic flat slings by tying knots.

46 Inspection of Flat Slings: Weld splatter is also lethal to synthetic slings. Do not weld anything hung from a sling. Keep synthetic slings away from areas where hot work is taking place. 46

47 Inspection of Flat Slings: Inspect the eyes of slings for cuts, chaffing and wear. 47

48 Synthetic Round Slings: Synthetic round slings are very popular because of their flexibility, light weight and how they conform to a variety of shapes and loads. They are not as stiff as flat slings and hang on hooks and shackles without bunching up. Normally, they are made from polyester yarns that are protected in a Kevlar jacket. *This jacket will protect the load bearing yarns from cuts, snags and chaffing but will not protect them from high heat. *Question on written test: Polyester round slings are ok to use around hot work since they have a Kevlar jacket that protects the load bearing fibers inside. a. True b. False 48

49 Inspection of Synthetic Round Slings: Most round slings are in an endless configuration and have a jacket that protects the load bearing, polyester yarns inside. Because they are made of synthetic materials they are prone to cuts, snags, and damage to the protective jacket covering. This jacket is often made of a strong material such as Kevlar, which protect the load bearing, polyester yarns within. 49

50 Inspection of Synthetic Round Slings: Check the sling for snags or cuts in the jacket which are usually caused by wrapping the sling around sharp corners without protecting the sling with softeners or chaffing material. Never lay loads on top of slings or attempt to pull the end of slings out from under the load or pallet. 50

51 Inspection of Synthetic Round Slings: Make sure the capacity tag is on the sling and is legible. 51

52 Discussion: What do you see in this picture? What would you do different? 52

53 Synthetic Fiber Rope Slings: The rope is bought in reels and slings can be fabricated as needed for all types of loads. The fabrication of these slings falls under the guidelines of chapter 9-4 of ASME B30.9 titled slings. 53

54 Inspection of Synthetic Rope Slings: Here are a variety of synthetic fiber rope slings that are used to make slings and for other uses. As you can see there is a significant discrepancy between what the size of the rope is and its capacity. 5/8 propylene has a safe working load of 1,100 lbs (5:1 safety factor) 5/8 spectra has a safe working load of 7,300 lbs (5:1 safety factor) 8mm (0.7 ) dynamica has a safe working load of 14,000 lbs (5:1 safety factor) 54

55 Fabrications of Synthetic Fiber Rope Slings: When thimbles are used in fabricated fiber rope slings it is important the eye is whipped up close to the thimble to prevent it form moving or coming out. 55

56 Wire Rope Sling Inspection: Eventually, all wire ropes slings deteriorate to the point that they are no longer safe for use. The frequency of inspections, extent, and criteria for condemning wire ropes slings vary greatly for each type of service and environment. As a sling suffers from the rigors of continued service both the design factor and the sling's ultimate strength are reduced. If a sling is loaded beyond its ultimate strength, it will fail. For this reason, older slings must be more rigorously inspected. Wear gloves when handling wire rope. 56

57 Wire Rope Sling Inspection: Pay special attention to broken wires and corrosion near the swage or fittings. Any broken wires in this area is reason to retire the sling. This area is very stiff and prone to breaks. Keep the sling lubricated. 57

58 Wire Rope Sling Inspection: Although every rope sling is lubricated during manufacture, to lengthen its useful service life it must also be lubricated "in the field." There is no set rule on how much or how often this should be done. It depends on the conditions under which the sling is used. The heavier the loads, the greater the number of bends, or the more adverse the conditions under which the sling operates, the more frequently lubrication will be required. Bottom line, if it looks dry or brown, then it needs to be lubricated Note: Using the sling several times a week, even at a light load, is a good practice. Records show that slings that are used frequently or continuously give useful service far longer than those that are idle. 58

59 Discussion: Here is a classic example of D/d. The diameter of the wire rope sling is more than the eye of the hook, causing the eye of the sling to kink. The hook eye is also bent which means it was bent around a sharp corner or was in a tight choker while lifting a heavy load. Using a thimble would have prevented the damage to the eye of the sling. 59

60 Chain Sling Inspection: All chain slings must be visually inspected prior to use and should be thoroughly inspected link-by-link at least once per month. A written record of the most recent periodic inspection shall be maintained and shall include the condition of the sling. Written records are not required for frequent inspections. Closely examine each link. Remember, just one bad link can cause the chain to fail. Under no circumstances should a chain be used for hoisting unless it has been closely examined for defects or wear. 60

61 Chain Sling Inspection: Every chain should carry a small metal identification tag bearing a serial number and its safe working load. A log book should also be kept for the chain, identifying its characteristics and setting up an inspection schedule. Identification Requirements Each sling shall be marked to show (a) name or trademark of manufacturer (b) grade (c) nominal chain size (d) number of legs (e) rated loads for at least one hitch type and the angle upon which it is based (f) length (reach) (g) individual sling identification (e.g., serial numbers) 61

62 Chain Sling Inspection: Be particularly careful in determining link wear at the point where the links bear on each other. A caliper should be used for measuring and the degree of wear at the most worn link must be determined during the inspection. 62

63 Rigging hardware: In this section we will cover the operation, inspection, and maintenance of detachable rigging hardware used for load-handling activities. The most common of these are: Shackles, eye bolts, swivel hoist rings, swivel eye bolts, turnbuckles, come-alongs, wire rope clips, wedge sockets, master rings, links, hooks and rigging blocks. 63

64 Shackles: There are many types and styles of shackles and will divide them up into 3 common categories. Anchor Shackle: The most common, is excellent for attaching to master rings, hooks, pad eyes, eye bolts and wire rope slings. Synthetic Sling Shackle: Has a wide bow that accommodates wider, flat sling that tend to bunch up on anchor shackles. Chain Sling Shackles: Perfect for use with chain. 64

65 Shackle rigging practices: ASME B Rigging Practices (for shackles) (a) The screw pin threads shall be fully engaged and tight, and the shoulder should be in contact with the shackle body. 65

66 Shackle rigging practices: ASME B Rigging Practices (for shackles) (b) If a shackle is designed for a cotter pin, it shall be used and maintained in good working condition. * (i) For long-term installations, bolt-type shackles should be used; if screw pin-type shackles are used, the pin shall be secured from rotation or loosening. Question on written test: For long-term installations, if screw pin-type shackles are used, the pin should be secured from rotation or loosening. a. True b. False 66

67 Shackle rigging practices: ASME B Rigging Practices (for shackles) (g) If the shackle is to be side loaded, the rated load shall be reduced according to the recommendations of the manufacturer or a qualified person. 67

68 Shackle inspection: ASME B Removal Criteria (shackles) Shackles shall be removed from service if damage such as the following is visible and shall only be returned to service when approved by a qualified person: (c) excessive pitting or corrosion (f) a 10% reduction of the original or catalog dimension at any point around the body or pin 68

69 Shackle inspection: ASME B Removal Criteria (shackles) Shackles shall be removed from service if damage such as the following is visible and shall only be returned to service when approved by a qualified person: (g) incomplete pin engagement (h) excessive thread damage (i) evidence of unauthorized welding (j) other conditions, including visible damage, that cause doubt as to the continued use of the shackle 69

70 Eye bolt identification: ASME B Turnbuckle, Eyebolt, and Eye Nut Identification Each turnbuckle, eyebolt, and eye nut shall be marked to show (a) name or trademark of manufacturer (b) size or rated load (c) grade for alloy eyebolts 70

71 Eye bolt considerations: For shouldered eye bolts, it is ok to side pull, but the capacity will be greatly reduced. Never pull opposite the plane of the eye, it will deform. 71

72 Swivel hoist rings: ASME B Swivel Hoist Ring Identification Each swivel hoist ring shall be marked to show (a) name or trademark of manufacturer (b) rated load (c) torque value ASME B Swivel Hoist Rings (a) When used in a threaded hole, the effective thread length shall be 11 2 times the diameter of the bolt for steel. For other thread engagements or engagement in other materials, contact the swivel hoist ring manufacturer or a qualified person. (b) When used in a through-hole application, a nut and washer shall be used. The washer and nut shall be in accordance with the swivel hoist ring manufacturer s recommendations. The nut shall be fully engaged. (c) The bushing flange shall fully contact the load surface. (d) Spacers or washers shall not be used between the bushing flange and mounting surface of the load. (e) The swivel hoist ring shall be tightened to the torque specifications of the manufacturer. (f) The swivel hoist ring shall be free to rotate and pivot without interference during load-handling activities. (g) The load applied to the swivel hoist ring shall be centered in the bail to prevent side loading. (h) Any attached load-handling component shall be narrower than the inside width of the bail to avoid spreading. (i) Components shall be in good working condition prior to use. Alterations or modifications shall comply with para (a). (j) Ensure that the swivel hoist ring WLL meets or exceeds the anticipated angular rigging tension. (k) Shock loading should be avoided. 72

73 Swivel hoist rings: *The best hardware for angled lifts is the swivel hoist ring. The swivel hoist ring will adjust to any sling angle by rotating around the bolt and the hoisting eye pivots 180. *The capacity is the same at every angle. *Question on written test: The best hardware to attach to if you are using slings at angles is: a. Shouldered eye bolt b. Swivel nut c. Round pin shackle d. Swivel hoist ring *Question on written test: Swivel hoist rings have the same capacity no matter what angle they rigged to. a. True b. False 73

74 Hook safety latch kits: Always have replacement safety latch kits on hand. 74

75 Below-the-hook lifting devices: There are no end to the number of specialty below-the-hook lifting devices that are used for lifting. Most are available from different distributors and others are designed for individual lifts by qualified engineers. We will only briefly describe the most common of these including the following: Lifting beams and spreader bars Plate clamps and lifters Barrel clamps and hooks I-beam and pipe clamps Pallet forks Lever hoists and chain hoists Load indicating devices 75

76 Lifting Beams and Spreader Bars: The terms lifting beam and spreader bar are often used interchangeably, but, technically, they are different. Lifting beams have a pick point (sometimes adjustable) that is attached to the beam and are useful where overhead space is limited. The beam must be strong to withstand bending since the pick point is attached somewhere toward the center. Spreader bars can also be adjustable but the pick points are toward the end of the bar and the middle part of the bar does not support the load but spreads the slings outward and so don t need to be as sturdy. Lifting beams and spreader bars should be designed and fabricated by a qualified person and clearly marked with their weight and designed working loads Always follow manufacturer instructions and only use them for their intended purpose. 76

77 Pipe lifters: Pipe lifters are useful for lifting pipe without having to dig under it in order to attach the slings. Make sure you use the right lifter for the diameter pipe you are lifting. C-hook pipe lifters come in all sizes and capacities and can be inserted into the pipe for lifting. 77

78 Lever hoists & chain hoists: Chain hoists, come-alongs, and other rigging devices require secure anchorage points. Anchors may be overhead, in the floor, or at lateral points in walls or other structures. The arrangement may involve columns, beams, beam clamps, welded lugs, slings, or block and tackle. Whatever the method, be certain of the loads involved and the anchorage required. When should you inspect the materials hoists? Inspect hooks, ropes, brakes and limit switches for wear and damage every working day. Replace items not operating properly. Tag defective items and remove from service for repair by a competent person. Post the safe load limit on the hoist. Check the upper and lower hooks to see that they swivel. Replace any worn chain or wire rope immediately. Keep wire ropes and chains lubricated. How should you use a materials hoist safely? Hoist from directly over the load. If not centered, the load may swing when lifted. Hang hoists solidly in the highest part of the hook area. Rigged this way, the hook support is directly in line with the hook shank Lever operated hoists can be used to pull in any direction, but a straight line pull must be maintained. Side pulling or lifting increases wear and sets up dangerous stress levels on hoist parts. Only one person should pull on hand, chain and lever hoists. When loading the lower hook, place the load directly in line with the hook shank. Loaded this way, the load chain makes a straight line from hook shank to hook shank. 78

79 Crane communication: Signaling is an important part of crane operation, but is often not treated with the respect it deserves. Signalers must be used whenever: Operator cannot see the load Operator cannot see the load s landing area Operator cannot see the path of travel of the load or of the crane Operator is far enough away from the load to make the judgment of distance difficult The crane is working within a boom s length of the approach limits to powerlines or electrical equipment. Where loads are picked up at one point and lowered at another, two signalers may be required one to direct the lift and one to direct the descent. Hand signals should be used only when the distance between the operator and the signaler is not great and conditions allow for clear visibility. Telephone or radio communications between operator and signaler can be extremely effective. 79

80 Hand signal chart: There should be a hand signal chart posted in the area of operation 80

81 Wire Down, Hoist Down, Lower Load: The wire down signal is made by pointing your index finger down and moving it in a wide circular motion. Remember, the crane operator needs to be able to distinguish between all of the different hand signals. Often you will see a signal person point his hand down and rub his fingers together like he is a chef seasoning some hot dish in the skillet. If he has a glove on and the lighting is not optimal it would be very difficult to know that he wanted you to wire down.

82 Stop: The stop is given by extending your arm and bringing it across your body in one quick motion. (It is not recommended that your use the common stop signal of clinching your hand and raising it above your head. This is not an easy signal to see from far distances or in dim lighting.) Although, this is not the emergency stop signal, the operator should obey it no matter who gives it.

83 Dog everything: This is a useful signal that tells the operator to take his hands off the controls and wait for further directions. This signal is a carry over from the friction crane days where they would use a pin (dog or pawl) to secure the rotation, boom and winch, holding everything as is till further notice.

84 Overhead Crane Hand Signals: Travel bridge or tower: Stand behind the load and signal like your pushing in the direction of desired travel. Travel trolley: Point your thumb in the direction of desired travel. 84

85 Voice Signals: 29 CFR states: (a) Prior to beginning operations, the operator, signal person and lift director (if there is one), must contact each other and agree on the voice signals that will be used. Once the voice signals are agreed upon, these workers need not meet again to discuss voice signals unless another worker is added or substituted, there is confusion about the voice signals, or a voice signal is to be changed. (b) Each voice signal must contain the following three elements, given in the following order: function (such as hoist, boom, etc. ), direction; distance and/or speed; function, stop command. (c) The operator, signal person and lift director (if there is one), must be able to effectively communicate in the language used. 85