OVERHEAD CRANE OPERATOR SAFETY TRAINING

Transcription

1 OVERHEAD CRANE OPERATOR SAFETY TRAINING 1

2 TYPES OF OVERHEAD CRANES Floor Mounted Jib Bridge Crane Monorail Crane Wall Mounted Jib Here is an assortment of overhead cranes. Take pictures of the different types you may have at your facility and put them on this page. You may also replace other pictures and drawings in this presentation. To do so: 1. Download a picture from a digital camera or scan a picture onto your computer. 2. Click on the insert button on the toolbar above and select picture>from file and then go to where the picture is stored on your computer. Click on that file and it is inserted on the current slide. 3. You may crop it, downsize it, add borders and lighter or darken it. It s easy and adds immensely to the presentation. 4. You may also create a hyperlink from a smaller picture to a picture that takes up the whole slide to see the details better. To do this, a) right click on the picture, left click on action settings, select hyperlinks, and then scroll down to the slide where the full size picture is. A good place for it is at the end of the slide show. Be sure to create a hyperlink back the the original slide to ease in navigating back and forth between slides. 5. Many of the pictures in this presentation have hyperlinks to a full size picture at the end of the presentation. Once you have created a hyperlink, it will stay with that slide no matter what order you put the slides in. 2

3 OVERHEAD CRANE REGULATIONS 29 CFR Overhead cranes and gantries 29 CFR Overhead hoists ASME B30.2 Overhead and gantry cranes (Top running bridge, single or multiple girder, top running trolley hoist) ASME B30.11 Monorails and underhung cranes ASME B30.16 Overhead hoists (underhung) ASME B30.17 Overhead and gantry cranes (Top running bridge, single girder, underhung hoist) These are the main standards concerning overhead cranes but certainly not all of them. Many States have additional standards as do some industries such as Maritime, Mining, Offshore oil platforms, etc. We have included only the two OSHA standards and the B This is because the are almost identical when it comes to operation and inspections. 3

4 TYPES OF INSPECTION FREQUENT: Frequent inspections are visual inspections and examinations by the operator or other designated personnel. Records are not required. Inspection intervals are: Daily to monthly PERIODIC: Periodic inspections are visual and audio inspections and examinations by designated personnel making records of external conditions to provide the basis for continuing evaluation. 1 to 12 month intervals 29 CFR (j)(1)(ii) Inspection procedure for cranes in regular service is divided into two general classifications based upon the intervals at which inspection should be performed. The intervals in turn are dependent upon the nature of the critical components of the crane and the degree of their exposure to wear, deterioration, or malfunction. The two general classifications are herein designated as "frequent" and "periodic" with respective intervals between inspections as defined below: (j)(1)(ii)(a) Frequent inspection - Daily to monthly intervals (j)(1)(ii)(b) Periodic inspection - 1 to 12-month intervals. 4

5 DEFINITIONS OF SERVICE Normal Service: Involves operations of the crane with randomly distributed load within the rated load limit or uniform loads of less than 65% or rated load limit for no more than 25% of the time for a normal work shift. Heavy Service: Involves operation of the crane within the rated load limit that exceeds normal service. Severe Service: Involves operation of the crane in normal or heavy service with abnormal operating conditions. 1. Some cranes are used more than others. 2. The frequency of service is a key factor in determining how often the crane should be inspected and serviced. 3. Even cranes that are not used need to be inspected, lubricated and maintained. Especially cranes that are out in the weather all year or in corrosive environments. 5

6 INSPECTION CHECK LIST MONTH Date Completed: Inspected by: INSPECTION AREA INSPECTION RESULTS Unsat. N/A Comments Sat. Supporting Structure Welds Bolts Bridge Rails & Alignment Trucks & Wheels Motor & Drive Train Brakes Stops & Limit Controls Trolley Wheels Motor & Drive Train Brakes Stops & Limit Controls Rails & Alignment Hoist Wire Rope Condition Rope Reeving Chain Condition Brakes & Ratchets Equalizer Sheaves Hoist Limit Control Functional Operation Electrical Control Markings Control Functions Warning Alarms Power Disconnect Control Pendants Festoons Load Block Sheaves Pins Swivel Hook 1. This is a sample of the inspection booklet found on your CD. You can print one out for every crane. There are two versions, this one, and one that has check boxes at the bottom of the page for the operator to initial that he has performed a pre-shift inspection. 2. This is a good time to go out to one of the cranes in your facility and do an inspection of it. 3. Pre-shift inspections do not have to be lengthy. You are basically looking for obvious things that might be wrong with the crane. 4. Monthly or yearly inspections, of course, should be thorough and performed by a competent individual. 6

7 SUPPORTING STRUCTURE CHECKING FOR TIGHTNESS Note The Accumulation Of Dirt And/or Paint Cracks In Paint Or Dirt Build-up Often Is Caused By Loose Bolts. 1. Check all fasteners for loose, stretched, missing, or broken fasteners. 2. A good clue is checking for cracked paint around the fastener that shows there has been movement. 3. Sometimes a build up of dirt or grease can do the same thing. 4. Using a torque wrench to check for tightness does not always work. Corrosion could give you a false reading. 5. Replace a loose or stretched bolt rather than tighten it. It probably has been damaged. 6. Be sure to replace the bolt with a grade 8 or better. 7. If there are other bolts near by that show signs of looseness, then replace them all. 7

8 CRACKED WELDS Inspect Welds For Cracks 1. Check cracks in the structure and in all welds. 2. A crack in a weld will always start on the end and work itself along the entire weld until it fails completely. 3. Many times a crack in the paint will be a clue to a weld that is failing. 4. If caught early, the crack many times can be ground out and re-weld. 5. Before welding on any part of the crane, make sure you have a certified welder and if it is on a structural part of the crane you should get the manufactures procedure. 6. Also, try to determine why it cracked in the first place. Is the crane being overloaded or used improperly. 8

9 BRIDGE SYSTEM Support System Span Structure Bridge Trucks Bridge Rails Power Panel Bridge Drive 1. Climbing up a and checking the bridge system is normally not part of the daily inspection. Use these slides to familiarize the student with the components of the bridge crane and how they work together to make a successful lift. 2. Many of these components can be inspected from the ground as the crane is being operated. If something seems wrong, then a closer look would be warranted. 9

10 BRIDGE TRUCK DRIVE Motor Brake Final Drive Shaft Drive Motor Drive Wheels 1. Climbing up a and checking the bridge system is normally not part of the daily inspection. Use these slides to familiarize the student with the components of the bridge crane and how they work together to make a successful lift. 2. Many of these components can be inspected from the ground as the crane is being operated. If something seems wrong, then a closer look would be warranted. 10

11 DRIVE COUPLINGS Check Couplings for: Loose bolts Loose or missing keys Cracks 1. Climbing up a and checking the bridge system is normally not part of the daily inspection. Use these slides to familiarize the student with the components of the bridge crane and how they work together to make a successful lift. 2. Many of these components can be inspected from the ground as the crane is being operated. If something seems wrong, then a closer look would be warranted. 11

12 DRIVE MOTOR BRAKE Brake Drum Brake Shoes Brake Solenoid 1. Climbing up a and checking the bridge system is normally not part of the daily inspection. Use these slides to familiarize the student with the components of the bridge crane and how they work together to make a successful lift. 2. Many of these components can be inspected from the ground as the crane is being operated. If something seems wrong, then a closer look would be warranted. 12

13 WHEEL ALIGNMENT FOR BRIDGE CRANE WHEELTREAD WEAR AT AN ANGLE HEAVY WEAR WHEEL FLANGE WEAR 1. Climbing up a and checking the bridge system is normally not part of the daily inspection. Use these slides to familiarize the student with the components of the bridge crane and how they work together to make a successful lift. 2. Many of these components can be inspected from the ground as the crane is being operated. If something seems wrong, then a closer look would be warranted. 13

14 TROLLEY SYSTEM Trolley Trucks Hoist Machinery mounted on trolley 1. Climbing up a and checking the bridge system is normally not part of the daily inspection. Use these slides to familiarize the student with the components of the bridge crane and how they work together to make a successful lift. 2. Many of these components can be inspected from the ground as the crane is being operated. If something seems wrong, then a closer look would be warranted. 14

15 MONORAIL CRANE TROLLEY TROLLEY WHEELS CENTERED ON BEAM TROLLEY WHEELS FUNCTION SMOOTHLY WHEELS IN GOOD CONTACT WITH BEAM FLANGE 1. Climbing up a and checking the monorail system is normally not part of the daily inspection. Use these slides to familiarize the student with the components of the bridge crane and how they work together to make a successful lift. 2. Many of these components can be inspected from the ground as the crane is being operated. If something seems wrong, then a closer look would be warranted. 15

16 WIRE ROPE CONSTRUCTION WIRE ROPE Wire Rope Replacement WIRE STRAND Broken Wires: 6 randomly distributed broken wires in one lay, or three broken wires in one strand in one lay. Loss in Diameter: Reduction from nominal diameter of: 1/64 for dia. up to & including 5/16 1/32 for dia. 3/8 to & including 1/2 3/64 for dia. 9/16 to & including 3/4 PROPER WAY TO MEASURE WIRE ROPE DIAMETER 1. Wire rope comes in various sizes and construction. The most common is the right regular lay wire rope of the 6X19 class. 2. The strands of a wire rope are made up of several wires twisted together. 3. Several strands are twisted together to form the wire rope. 4. Common wire rope will have either a fiber core or an independent wire rope core or IWRC. For lifting purposes, IWRC is recommended because it resist crushing. 5. The designation, 6X19, refers to the basic construction. The 6 stands for the number of strands, not counting the core, that are used in the rope. The 19 refers to the number of wire in each strand. 6. When measuring the diameter of wire rope, make sure to measure across the stands and not the flat area between the strands. 29 CFR (h)(2)(i) In using hoisting ropes, the crane manufacturer's recommendation shall be followed. The rated load divided by the number of parts of rope shall not exceed 20 percent of the nominal breaking strength of the rope. (or a 5:1 safety ratio) 16

17 WIRE ROPE STANDARDS FOR SHEAVE & DRUM RATIOS D = Diameter of drum or sheave d = Diameter of wire rope Ratio = D / d ASNE/B30.5 MOBILE CRANES Minimum Ratios Drum Sheave Load Hoist Boom Hoist Load Block 16 ABRASION RESISTANCE Increases with larger wires Decreases with smaller wires FATIGUE RESISTANCE Decreases with fewer wires Increases with more wires 1. Point out the trade-offs between abrasion and fatigue resistance. 2. Show how sheave size and wire rope diameter relate to each other and the effects they have on wire rope life. 3. Review how sheaves are dimensioned. 17

18 WIRE ROPE INSPECTION FATIGUE FAILURE FATIGUE BREAKS Heavy loads over small sheaves STRAND KNICKING Repeated bending, normal loads BIRDCAGE Accentuated with heavy loads KINKED WIRE ROPE Sudden tension release HIGH STRAND Crossed lines on drum Improper socketing, kinks 29 CFR (m)(1) Running ropes. A thorough inspection of all ropes shall be made at least once a month and a certification record which includes the date of inspection, the signature of the person who performed the inspection and an identifier for the ropes which were inspected shall be kept on file where readily available to appointed personnel. Any deterioration, resulting in appreciable loss of original strength, shall be carefully observed and determination made as to whether further use of the rope would constitute a safety hazard. Some of the conditions that could result in an appreciable loss of strength are the following: (i) Reduction of rope diameter below nominal diameter due to loss of core support, internal or external corrosion, or wear of outside wires. (ii) A number of broken outside wires and the degree of distribution or concentration of such broken wires. (iii) Worn outside wires. (iv) Corroded or broken wires at end connections. (v) Corroded, cracked, bent, worn, or improperly applied end connections. (vi) Severe kinking, crushing, cutting, or unstranding. 18

19 DRUM INSPECTION 1. Check to make sure the wire rope is spooled properly on the drum. 2. On lagged drums, make sure the rope hasn t jumped a groove which could damage the rope. 3. Check to make sure the dead end is secured properly. 4. Never hoist down to the point that there would be less than 2 wraps left on the drum. 5. Check oil often. 19

20 HOIST MACHINERY HOIST DRIVE TROLLEY TRUCK CHECK DRUM GROOVES FOR WEAR 1. Check to make sure the wire rope is spooled properly on the drum. 2. On lagged drums, make sure the rope hasn t jumped a groove which could damage the rope. 3. Check to make sure the dead end is secured properly. 4. Never hoist down to the point that there would be less than 2 wraps left on the drum. 5. Check oil often. 20

21 HOIST MACHINERY CHECK RUNNING SHEAVE FOR WEAR SINGLE REEVED DRUM CHECK CLEVIS WEAR VERIFY FUNCTIONING LIMIT SWITCH CHECK EQUALIZING SHEAVE FOR WEAR DOUBLE REEVED DRUM 1. Check running and equalizing sheaves for wear and free movement. 2. Check the limit switch to make sure it stops the hook or load if two-blocked. 3. Check the oil often, especially if you detect any leakage. 21

22 INSPECTING SHEAVES CHECK FLANGES FOR CHIPS, CRACKS, WEAR CHECK GROOVE WEAR CHECK BEARINGS FOR WOBBLE, GREASE, EASE OF ROTATION 150º CONTACT MEASURE GROOVE WORN GROVES PROPER SIZE GROVE 1. Check for bearing wear and lubrication. 2. Check the flanges and treads. 3. Show how to use a sheave gauge. 4. Sheaves can only be repaired per manufacture s procedures. 22

23 CHAIN HOIST Pocket Wheel Chain Guide Bent Links Stretched Links Worn Links The chain hoist should be checked for the following: 1. Bent links (Usually a sign that it has been used to wrap around a load and bent on sharp corners) 2. Stretched links. The links will be sucked in slightly on the sides. Also, measure 5 links and check that measurement during your annual inspection. 3. Chain should not be rusted or brown. If the crane is in a corrosive atmosphere, be sure to oil it often. 23

24 HOOK INSPECTION CHECK FOR: [ Wear [ Deformation [ Cracks & Sharp Nicks [ Modifications [ Safety Latches [ Swivel Wear & Lubrication [ Hook Shackle Mousing Cracks & Twisting Wear & Deformation Opening Up Wear & Cracks 1. Hooks with threads and nuts need to have threads inspected periodically. 2. Hooks can only be repaired per manufacturer s procedures. 3. Wear in excess of 5% in the neck of the hook and 10% in other areas including the bow of the hook is cause for removal. 4. An increase in the hook throat opening of more than 15% is cause for removal. 5. Any twist in the hook of more than 10% is cause for removal. 6. The hook safety latch should be present and function properly. Accident Employee Killed When Struck By Loose Crane Hook At approximately 8:15 am on January 29, 1990, employee #1 was working on a large steel panel weighing approximately 2,608 pounds and measuring 22 feet long and 6 feet wide. The panel was supported by an overhead crane chain and hook and was set on metal horses at an angle. The hook slipped off of the steel panel and struck employee #1 on the head, resulting in his death. 24

25 HOOK INSPECTION Throat Opening 10 o Twisted Hook 10 percent Maximum Allowable Wear 15% 1. Hooks with threads and nuts need to have threads inspected periodically. 2. Hooks can only be repaired per manufacturer s procedures. 3. Wear in excess of 5% in the neck of the hook and 10% in other areas including the bow of the hook is cause for removal. 4. An increase in the hook throat opening of more than 15% is cause for removal. 5. Any twist in the hook of more than 10% is cause for removal. 6. The hook safety latch should be present and function properly. 25

26 CRANE BLOCK SIDE PLATE BOLTS TIGHT SHEAVE GROOVE NOT WORN, SHEAVES TURN FREELY SHEAVE PIN & BEARING TIGHT HOOK NUT TIGHT & THEADS INSPECTED PERIODICALLY SHEAVE PIN KEEPER IN PLACE AND TIGHT SAFETY LATCH FUNCTIONING CHECK FOR DISTORTIONS OR WEAR HOOK ROTATION & SWIVEL SMOOTH & TIGHT 1. The sheaves and bearings need to be inspected as discussed earlier. 2. The side plates and any additional weights attached to the their sides need to be inspected for loose or missing bolts or other fasteners. 3. The hook should rotate freely on the swivel bearing. Check for excessive movement. 4. The hook shank and nut should be separated periodically and the threads inspected for corrosion and other damage. The lose of more than 20% of the treaded area due to corrosion is cause for removal. 5. The safety latch must be in place and functioning properly. 26

27 ELECTRICAL CONDUCTORS Check Conductors for: Loose fasteners Burned surfaces Dirt and corrosion Electrical connections Current Collectors ride on this surface Always lock out the crane before working around the electrical conductors. 27

28 CURRENT COLLECTORS Electrical Conductors Check Collectors for: Good spring tension Collector surfaces are not corroded or burned Electrical connections Ease of movement Current Collectors ride against conductors Always lock out the crane before working around the electrical conductors. 28

29 FESTOON SYSTEMS CABLE TERMINATION ELECTRICAL CONNECTORS TIGHT PROPER CABLE TENTION FREE TROLLEY MOVEMENT INSULATORS IN GOOD CONDITION STRAIN RELIEF ADJUSTED FOR CORRECT LENGTH 1. Festoons need to be checked for proper cable tension, free trolley movement and wire connections. 2. Also, make sure there are no pinch points during bridge or trolley movement. 29

30 PENDANT AND CONTROLS ALL CONTROL FUNCTIONS CLEARLY LABELED 1. Many times the pendant controls get dropped or banged up during operation. 2. Never use the pendant to pull the crane around. 3. Use a strain relief chain or cable to protect the wires from pulling out. 4. Make sure all controls are marked and legible. 5. Check for buttons that are broken or stick. 6. Always check the emergency stop button on the pendant. 30

31 SAFE CRANE OPERATIONS MAX. SWL 10,000 lbs MAX. SWL 10,000 lbs Know the SWL of the crane and never exceed it ACME 5 TON Follow all placards, warning labels and signs on machine 1. The safe-working-load of the crane should be easily visible to the operator. 2. The safe working load would be the maximum load of the weakest link on the crane. For example: If the maximum SWL of the hoist was 5 tons, then the SWL, but the beam that it was hung under was good for 7 ½ tons, the SWL of the crane could not exceed 5 tons and if stenciled on the beam, it should reflect the 5 ton rating. 3. All warning labels on the crane including crane operation instructions must be on the crane and legible. 29 CFR (b)(5) Rated load marking. The rated load of the crane shall be plainly marked on each side of the crane, and if the crane has more than one hoisting unit, each hoist shall have its rated load marked on it or its load block and this marking shall be clearly legible from the ground or floor. 31

32 LOCK-OUT OUT TAG-OUT DANGER DO NOT OPERATE ALWAYS DE-ENERGIZE ELECTRICAL SYSTEMS BEFORE INSPECTING AND WORKING ON THEM. Before adjustments and repairs are started on a crane the following precautions shall be taken: 29 CFR (l)(2)(i)(a) The crane to be repaired shall be run to a location where it will cause the least interference with other cranes and operations in the area. (b) All controllers shall be at the off position. (c) The main or emergency switch shall be open and locked in the open position. (d) Warning or "out of order" signs shall be placed on the crane, also on the floor beneath or on the hook where visible from the floor. (e) Where other cranes are in operation on the same runway, rail stops or other suitable means shall be provided to prevent interference with the idle crane (l)(2)(ii) After adjustments and repairs have been made the crane shall not be operated until all guards have been reinstalled, safety devices reactivated and maintenance equipment removed. 1. The emergency shut off musts be visible and accessible. 32

33 SAFE CRANE OPERATIONS Acme Bridge Crane Operation and Maintenance Manual Read and understand the operators manual ACME CORPORATION The Operator and Maintenance Manual should be available and every person that operates the crane should have read the safe operations section. 33

34 SAFE CRANE OPERATIONS Acceptable methods of determining weight You may find the weight from: Determine the weight of the load from accurate sources Data on manufacturing label plates. Manufacturer documentation. Blueprints or drawings. Shipping receipts. Weigh the item. Bill of lading (be careful) Stamped or written on the load Approved calculations Never use word of mouth to establish the weight of and item! 1. Knowing the weight of the load is essential to safe overhead crane operations. With mobile cranes, picking up a load that is too heavy could cause the crane to tip. Not so with overhead cranes. Severe damage could result in trying to lift a load that exceeds the SWL. 2. There are many ways to learn the weight of a load. The most accurate is, of course, weighing it yourself. 3. If you do weigh an item, be sure to mark the weight somewhere on the load for the next guy that has to lift it. 4. There will be times when you just have to make an a guess. Using the best calculations that you can, come up with an estimate and then double it. It it is well within the capacity of the crane, go ahead and make the lift. If by doubling it, it is within 75% of the capacity of the crane, then you should weigh it. 34

35 SAFE CRANE OPERATIONS MAX. SWL 10,000 lbs MAX. SWL 10,000 lbs ACME 5 TON Cranes shall not be used for side pulls except when specifically authorized by a responsible person who has determined that the stability of the crane is not thereby endangered and that various parts of the crane will not be overstressed. 5 TON 29 CFR (n)(3)(iv) Cranes shall not be used for side pulls except when specifically authorized by a responsible person who has determined that the stability of the crane is not thereby endangered and that various parts of the crane will not be overstressed. 1. Side pulling on a crane may cause the wire rope on the drum to cross and be susceptible to kinks and crushing. 2. It could also put stress on the trolley causing damage. 35

36 SAFE CRANE OPERATIONS MAX. SWL 10,000 lbs MAX. SWL 10,000 lbs ACME 5 TON 5 TON Never hoist a load over the heads of employees 29 CFR (n)(3)(vi) The employer shall require that the operator avoid carrying loads over people. 1. Never allow a rigger to stand under a load as it descends for the purpose of controlling it. 2. Use a tag line instead. 36

37 SAFE CRANE OPERATIONS MAX. SWL 10,000 lbs MAX. SWL 10,000 lbs ACME 5 TON The employer shall insure that the operator does not leave his position at the controls while the load is suspended. 5 TON 29 CFR (n)(3)(x) The employer shall insure that the operator does not leave his position at the controls while the load is suspended. 1. Always put the load down and secure it before leaving the area. 37

38 SAFE CRANE OPERATIONS MAX. SWL 10,000 lbs MAX. SWL 10,000 lbs ACME 5 TON The operator shall test the brakes each time a load approaching the rated load is handled. The brakes shall be tested by raising the load a few inches and applying the brakes. 8,750 lbs 29 CFR (n)(3)(vii) The operator shall test the brakes each time a load approaching the rated load is handled. The brakes shall be tested by raising the load a few inches and applying the brakes. 1. As brakes become worn, they may stop a smaller load, but not one at or near capacity. 2. It is good practice to load test your crane at least every 3-4 years. 38

39 SAFE CRANE OPERATIONS MAX. SWL 10,000 lbs MAX. SWL 10,000 lbs ACME 5 TON The load shall not be lowered below the point where less than two full wraps of rope remain on the hoisting drum. 5 TON 29 CFR (n)(3)(viii) The load shall not be lowered below the point where less than two full wraps of rope remain on the hoisting drum. 1. You never want to run out of hoist line. Many cranes have automatic stops that can be set so this will not happen. Still it is good practice to check you line when lowering loads down close to the limit of your line. 39

40 SAFE CRANE OPERATIONS At the beginning of each operator's shift, the upper limit switch of each hoist shall be tried out under no load. 29 CFR (n)(4)(i) At the beginning of each operator's shift, the upper limit switch of each hoist shall be tried out under no load. Extreme care shall be exercised; the block shall be "inched" into the limit or run in at slow speed. If the switch does not operate properly, the appointed person shall be immediately notified. 1. The upper limit switch will keep the load or hook from being pulled into to hoist, possibly parting the line. 2. Never use the limit switch to operate lower your load. 40

41 SAFE CRANE OPERATIONS Read and understand the operators manual Follow all placards, warning labels and signs on machine Know the SWL of the crane and never exceed it Determine the weight of the load from accurate sources If an estimate of the load is near the max. capacity of the crane, then use a dynamometer to measure the exact weight Use a loud signal, such as a whistle, horn or bell or verbal warning to alert employees of crane movement Never hoist a load over the heads of employees Never use limit switches or end stops as operating controls Begin each shift by testing the upper limit switches Avoid running the crane into the end stops or limit switches Never walk backward when guiding a load Summary of safe crane operations 41

42 SAFE CRANE OPERATIONS Never hoist two or more separately rigged loads on a single hook even if the combined weight is within the capacity of the crane Never wrap the hoist line around the load Never electrical load and/or hoist-limit switches or warning devices Start lifts slowly and avoid shock loading Always place the hook directly over the center of gravity or the designated lifting point Use taglines to help maneuver the load Never use taglines to swing the load Before hoisting the load, check for loose parts that might shift or fall On cranes with wire rope hoist lines, there should never be less than two wraps on lagged (grooved) drums and three wraps on unlagged When lifting near or at capacity, test the brakes after the load is raised a few inches Suspend and transport loads at a level that allows the operator a clear view Never drag slings, cables or chains across the floor Summary of safe crane operations 42

43 SAFE CRANE OPERATIONS Cab-operated overhead cranes: Enter and exit cab only through approved access ways Never walk along runway tracks Never climb or jump from one crane to another Use both hands to climb access ladder Keep unnecessary items out of the cab Complete the pre-shift inspection checklist before operation Know the location of emergency shutoff switches Know emergency evacuation routes Place all controls in the OFF position before turning the main switch ON Maintain a portable fire extinguisher in the cab Never move the cab without a signal from the designated signal giver Avoid bumping crane and carriage stop blocks If a power failure occurs, place all controls in the OFF position Park the cab in an approved, designated position Summary of safe crane operations 43

44 HAND SIGNALS Multiple Trolleys Bridge Direction Trolley Direction Move Slowly Lower Load Raise Load Stop Emergency Stop 1. Hand signal charts should be posted in the work area. 2. Always have one person designated as the signal giver. 3. Use clear precise motions. 4. Review each hand signal and any other hand signals you might be using 5. Anyone can give the emergency stop signal. 44

45 WIRE ROPE SLING INSPECTION 1. Wire rope slings are to be inspected on a regular basis and a record kept of these inspections. Refer to the inspection card for inspection criteria. 2. As of July 2000 wire rope slings are to have a tag which indicates the lifting capacities of the sling for vertical, choker, and basket hitches. 45

46 COMMON CAUSE FOR REMOVAL Severe wear, abrasion or scraping Kinking 1. Kinking in the eyes and other parts of the wire rope sling is nearly always the result of it going around a pin or pick point that is of a less diameter than the rope itself. 2. Using slings with thimbles in the eye will prevent this. 3. It is not recommended using a wire rope sling in a tight choker. 46

47 FLEMISH EYE Separate rope into 2 part, 3 adjacent strands and 3 adjacent strands and core. These 2 parts are re-laid back in opposite directions to form an eye and the ends are secured with a pressed steel sleeve. 1. The Flemish eye is also know as a Molly Hogan or a Farmers eye. 2. The strength of the eye is in the wrap and not the steel sleeve. 3. They may be used with a thimble also. 47

48 TURNBACK EYE PRESSED STEEL SLEEVE 1. Turnback eyes are made by bring the rope back onto itself and crushing a steel sleeve around it. 2. The strength of the eye is in the sleeve and if not done properly may pull out. 3. Turnback eyes are not recommended for lifting. 48

49 TYPES OF TERMINATIONS 1. Wedge sockets are very handy if you are changing blocks or hooks often. 2. Slings should not be used that have eyes made with wire rope clips. 3. Eyes made with wire rope clips may be used to terminate the dead end of the hoist line. 49

50 CHAIN SLING INSPECTION 1. Chain slings are to be inspected on a regular basis and a record kept of these inspections. Refer to the inspection card for inspection criteria. 2. Chain slings are often used to hold steel while it is being welded. Always check to make sure no heat damage has occurred. Heat damage can be detected by discolored metal. 50

51 SYNTHETIC SLING INSPECTION 1. This slide and the next two show the different types of sling damage that can occur. Refer to the inspection record of additional inspection criteria. 2. Synthetic slings are required to be inspected on a regular basis and a record kept of such inspections. 3. Never tie a knot in a flat sling to shorten it. 4. Never use synthetic slings around high heat sources or hot work. 5. When taking a sling out of service, cut the eyes in it or destroy it. If you don t it may find its way back into service. 51

52 SYNTHETIC SLING INSPECTION 1. The manufacturer s tag should be on the sling and contain the SWL. 2. This tag must also be legible. 3. Nylon slings are also susceptible to damage through ultra-violet light. Always keep your slings out of the sun when not in use. 4. Wet nylon slings can be used but lose 15% of their strength. 52

53 SHACKLES DEFORMATION BOLT SUBSTITUTION WEAR 1. Shackles must be load rated and have the WLL written on them along with the manufacturer and country where they were made. 2. Only shackles of the screw pin or bolt type may be used for lifting. 3. If a shackle is used as a permanent part of the hoist line, then it must be moused closed or use the bolt type with a cotter pin. 4. Shackle that only use a cotter pin to keep the pin in are not legal for lifting. When inspecting them, look for: Wear Deformation Pin or bolt substitution Non-rated shackles Worn threads on the pin 53

54 SHACKLES IN-LINE 45 DEGREES 90 DEGREES LOAD Side Loading Reduction Chart For Screw Pin & Bolt Type Shackles Only Angle of Side Load Adjusted Working Load Limit 0 In-Line 45 from In-Line 90 from In-Line 100% of Rated Working Load Limit 70% of Rated Working Load Limit 50% of Rated Working Load Limit DO NOT SIDE LOAD ROUND PIN SHACKLES 1. The working load limit, WLL, shown on the shackle is for vertical loads. 2. Round pin shackles are ones which do not have a nut on the end of the pin and should not be used for lifting.. 54

55 EYE BOLTS WRONG! DO NOT REEVE SLINGS ONE EYE BOLT TO ANOTHER. LOAD ON BOLT IS ALTERED. DIRECTION OF PULL In-Line 45 Degrees 60 Degrees ADJUSTED WORKING LOAD Full Rated Working Load 30% of Rated Working Load 60% of Rated Working Load CAUTION! STRUCTURE MAY BUCKLE FROM COMPRESSION FORCES. 1. The rated capacity of a eye bolt drops significantly when pulled other than vertically. 2. Emphasize the dramatic drop to the students. 3. Threading a sling through the eye bolts increases the stress on the eye bolts by two and should never be done. 55

56 BELOW-THE-HOOK LIFTING DEVICES BALANCED C HOOK COIL LIFTING HOOK BALANCED PALLET FORK TELESCOPIC COIL GRAB 1. These are a few of the types of below-the-hook lifting devices. There are many more. 2. Be careful of home-made lifting devices. 3. Any lifting device must be load rated and have a manufacturer s nomenclature plate on it indicating its weight and SWL. 4. Add pictures of the different types of lifting devices you have at your facility, including: spreader and lifting beams, plate clamps, barrel clamps or hooks. 56

57 SLING ANGLES Tension in slings Sling Angle Compression in load Stresses in the slings and the load increase as the sling angle decreases 1. When slings are brought together and form a hitch arrange as shown above the stresses in the slings increase and a compression force on the load is created. 2. As the sling angle decrease the stresses in the sling and on the load increase. 57

58 SLING ANGLES 1000 lbs 500 lbs 500 lbs 575 lbs lbs 1000 lbs 1000 lbs 1000 lbs 705 lbs 705 lbs lbs 1000 lbs 1000 lbs 1000 lbs 5735 lbs 1000 lbs 5735 lbs 5 1. Review each of the different sling angle configurations and point out the increase in the stresses. 2. Sling angles of 60 degrees are the best to use because of the minimal increase of stress in the slings. When required to use smaller sling angles, slings need to be selected based on the increased stress and not on the weight of the load. 3. When the sling angle is 30 degrees for a 1000 lbs load, the compression loads which are crushing the load will be 866 lbs. Depending on the structural strength of the load, it may be damaged. 58

59 SLING ANGLES 500 lbs 500 lbs Load in each sling leg = 500 x Load Angle Factor Factor of Angle A A H A L 1000 lbs 1000 lbs 1000 lbs Sling Angle Degree (A) Load Angle Factor = L/H Load On Each Leg Of Sling = (Load / 2) X Load Angle Factor 1. All that is need to calculate these stress is the weight of the object and a measuring tape. 2. As shown in the slide above, the length of the sling is divided by the height of the sling connection to the top of the load. 3. The answer is then multiplied by the portion of the load it is to support and this will be the stress in the sling. Example: If my sling was 8 feet long and the height H was 4 feet, 8 divided by 4 equals 2. The portion of the weight the sling is to support is half of 1000 lbs or 500 lbs. 2 X 500 = 1000 lbs which is the stress in the sling. 59

60 ESTIMATING WEIGHTS Acceptable methods of determining weight You may find the weight from: Data on manufacturing label plates. Manufacturer documentation. Blueprints or drawings. Shipping receipts. Weigh the item. Bill of lading (be careful) Stamped or written on the load Approved calculations Never use word of mouth to establish the weight of and item! 1. Knowing the weight of the load is critical to a safe lift. 2. Not all information is reliable. 3. The surest way to find the weight is to weigh the load. 4. If the object is solid and made up primarily of one material then you could calculate the weight. 60

61 ESTIMATING WEIGHTS Calculating the weight To find the weight of any item you need to know its volume and unit weight. Volume x Unit weight = Load weight Unit weight is the density of the material Unit weight is normally measured by pounds per cubic foot. 1. Anytime you calculate the weight it is really only an estimation. But it will get you in the ball park. 2. Always error on the safe side in your calculations. 61

62 ESTIMATING WEIGHTS Here are some examples of common materials and their unit weight: The unit weight is: pounds per cubic foot METALS Aluminum Brass Bronze Copper Iron Lead Steel Tin MASONARY Ashlar masonry Brick, soft Brick, pressed Clay tile Rubble masonry Concrete, cinder, haydite Concrete, slag Concrete, stone Concrete, reinforced MISC. Asphalt Glass TIMBER Cedar Cherry Fir, seasoned Fir, wet Hemlock Maple Oak Pine Poplar Spruce White pine Railroad ties LIQUIDS Diesel Gasoline Water EARTH Earth, wet Earth, dry Sand and gravel, wet Sand and gravel, dry It s wise to have similar cheat sheets for materials that you handle frequently. 2. Knowing the unit weight of different materials helps in weight estimation. 3. Knowing the difference between steel (490 lbs), reinforced concrete (150 lbs), and wood (25-65 lbs) is useful. 62

63 CALCULATING VOLUME Volume of a cube Length x Width x Height = Volume 8 ft long 2 ft high 8 ft x 4 ft x 2 ft = 64 cubic feet 4 ft wide If the material was cedar, then all we would have to do to determine it s weight would be to multiply the unit weight of cedar x 64. Unit weight x Volume = Weight 34 lbs. X 64 cubic ft. = 2,176 lbs. 1. Cubes are easy to calculate. 2. Finding the weight is as simple as multiplying the volume of the cube by the unit weight of what it is made of. 63

64 CALCULATING VOLUME Volume of a cylinder Pi x Radius Squared x Length = Volume 10 ft long π x Radius² x Length = Volume 3.14 x 1² ft x 10 ft = 31.4 cubic ft 2 ft wide If the material was reinforced concrete, then all we would have to do to determine it s weight would be to multiply the unit weight of reinforced concrete x lbs. X 31.4 cubic ft. = 4,710 lbs. 1. The volume of a cylinder is a little more difficult, but not rocket science. Having a scientific calculator and knowing how to use it is a good idea. 2. Again, just multiply the volume in cubic feet by the unit weight to find the weight of the load. 64

65 CALCULATING VOLUME Volume of pipe 8 ft long Calculating the volume of pipe is a bit trickier but it is just simply subtracting the volume of the hole from the volume of the pipe. 1 in. thick If the pipe were one inch thick, three feet wide and 8 feet long, then we would figure the volume of the entire pipe and subtract the volume of the hole to get the the volume of the material. 3 ft wide 3.14 x (1 ½ ft.)² x 8 feet = total volume of pipe (56.52 ft³) 3.14 x (1ft 5 in.)² x 8 feet = volume of hole (50.41 ft³) ft³ ft³ = 6.11 ft³ Volume of material x unit weight = total weight If this pipe were steel then the unit weight would be 490 lbs x 490 lbs = 2,9994 lbs. 1. Finding the volume of a pipe is not too much different than finding the volume of a cylinder. You just have to do it twice and then subtract the volume of the hole from the total volume of the pipe. 2. It is helpful to know how to change fractions into decimals. Calculators are a must for this. To change 1 foot 5 inches (or 17/12ths) into a decimal, simple divide 12 into 17 which would be

66 CALCULATING VOLUME For thin pipe a quick way to *ESTIMATE the volume is to split the pipe open and calculate the volume like a cube. The formula would be: π x diameter = width, so: π x diameter x length x thickness x unit weight = weight of object 3.14 x 3 ft x 8 ft x 1/12 ft (or.08 ft) x 490 lbs = *3,077.2 lbs 8 ft long 1/12 ft = 1 in. thick 3.14 (π) x 3 ft diameter = 9.42 (width) 1. This is only an estimate and should not be used with thick pipe. 2. Simply spit the pipe down the middle and open it up into a thin plate. 3. Then calculate the the volume of the cube that is created. 4. To find the width, multiply pi times the diameter. 66

67 WEIGHT TABLES Weight tables are an excellent way to calculate load weight. If you are handling certain materials often, then having a chart that gives you the weight per cubic foot, cubic yard, square foot, linear foot or per gallon. Here are a few examples: METAL PLATES STEEL PLATES weigh approximately 40 lbs per sq. ft. at 1 inch thick. 1/2 inch thick would then be about 20 lbs. per sq. ft. A steel plate measuring 8 ft. x 10 ft. x 1/2 inch would then weigh about 3,200 lbs. (8 x 10 x 40 lbs = 3,200 lbs.) BEAMS WEIGHT TABLES Beams come in all kinds of materials and shapes and lengths. STEEL I-BEAMS weigh approximately 40 lbs a linear ft. at 1/2 inch thick and 8 inches x 8 inches. If it were 1 inch thick then it would be 80 lbs a linear ft. If it were 20 feet long at 1 inch thick then it would weigh about 1,600 lbs. (20 ft. x 80 lbs. = 1,600lbs.) 67