Safety Team presents Rigging Inspection Considerations for Industry

Safety Team presents Rigging & Inspection Considerations for Industry Rigging 1

Disclaimer • The following information is for presentation and demonstration purposes only, not intended for actual field application. • This is not a crane and rigging guide or manual. • This presentation is not intended to replace or add on to any regulations or guidelines set for the by the manufacturer or any regulatory agencies. • For crane operation and rigging guidelines always refer to up-to-date equipment manufacturer information, regulatory guide lines, qualified rigging manuals, and proper training. Rigging 2

Rigging Plan Basics • Responsibilities for rigging/lifting setup & execution • Load weight, gravity, # of cranes, load calculations, head room • Work area conditions, crane & rigging inspections done • Lifting equipment/gear appropriate for task • Tag lines needed for control, sling protection used • Correct communications used for the type of lift • Personnel out of the area where the lift is being performed (Safety watch) Rigging 3

Rigging Angles • With a hook, maximum sling angle should be 90° • With a master link or shackle, 120° is maximum angle. • It is allowable to use a shackle in a situation where it is being side loaded, as long as the rated lifting capacity decreases by the percentage shown below. Rigging 5

Eye Bolts • Good working condition • Must be properly engaged into threads • Do not shock load eyebolts • Do not mix SAE and Metric types • Countersink eye bolt holes • Do not overtighten, undercut, or force eyebolts into place • Un-shouldered eyebolts shall only be used for vertical loads (no side loading beyond 5 degrees from vertical). • Only shouldered eyebolts shall be used for angular loading. Rigging 6

Eye Bolts • When used in a tapped blind hole, the effective thread length shall be at least 1 1/2 times the diameter of the bolt for engagement in steel. The first 1/2 diameter length of threads do not fully engage resulting in reduced strength and should never be counted as part of the engaged length of thread. This image shows the tip of an eyebolt with a long unthreaded area nearly 1/2 thread diameter in length. • The eyebolt should not wobble or require extra force while being screwed in.

Eye Bolts When tapped holes are in softer materials additional thread length must be provided to ensure sufficient strength is achieved • Minimum thread engagement for holes tapped through in various materials (ASME B 18. 15): • Steel - 1 thread diameter, • Cast iron, brass, bronze - 1. 5 thread diameter, • Aluminum, magnesium, zinc, plastic - 2 thread diameters If the threads are in a tapped blind hole, an additional 50% of thread length/depth is needed.

Eye Bolts • Only shouldered eyebolts shall be used for angular loading. • Align eyebolts within ± 5º of the direction of pull Rigging 9

Eye Bolts • To help get the eye properly aligned with the sling angle, a shim can be added under the eyebolt shoulder. It is recommended that the shim should not be more than (1/2 turn of the eyebolt) to achieve the correct orientation. • Do not over tighten in an attempt to get it in to proper alignment or to keep it from rotating. • Only firm hand pressure should be used to snug it down Rigging 10

Eye Bolts • Many manufacturers of electric motors warn that the eye bolt supplied on a motor is designed for lifting the motor only and not designed to lift an assembly such an MG set or motor pump assemble. An assembly of this type should be designed and fabricated with engineered lifting points on the assemble base. Rigging 11

Eye Bolts • Eye bolt load capacity is reduced when loaded at an angle. • Note that eye bolts are not created equal, always use WLL and angle load information for the brand of eye bolt being used. • Proper thread engagement is also important for maximum strength. Note that the capacity for Crosby eyebolts is different than the capacity of the Chicago eyebolts, DO NOT use the Crosby table for Chicago eyebolts. Rigging 12

Eyebolt • Do not reeve sling through eye bolts or attachment points. • In this example of a 3/4” eyebolt used at 45 degrees, it has a rating of 1500 lbs. • Because the sling is reeved through each eye bolt, its effective sling angle is reduced to a load angle of around 22. 5 degrees. This now increases the load to over 2, 600 lbs. per sling leg. Rigging 13

Lever Hoist (Chain Fall, Come-along, etc. ) • Come-a-long/Chain Fall (Hand operated) A Come-A-Long is NOT designed for lifting. A lever “hoist” is designed for lifting. Rigging 14

Swivel Hoist Ring • When using a swivel hoist ring, apply the proper torque to the bolt to ensure the hoist ring and bolt will achieve its rated capacity in any allowed position used. • Whenever a bolt-on device is used it is always best to consult with the device manufacturer, or a qualified engineer to ensure the device’s attachment bolts are the right grade for the application, installed, and then tightened correctly. Rigging 15

Sling Load Angle Factor To Calculate Load Angle Factor: L = Load Angle Factor (LAF) H LAF x Load Weight = Total Sling Load = Load Per Sling Leg Number of Slings NOTE: The number of legs used for sling load calculation is not to exceed 3 legs, even when 4 or more legs are rigged. Rigging 16

Sling Angles • When the sling angle can be measured, use a LAF table for your rigging configuration. • Always round the measured value down if it is not on a listed number. – Example: Angle of measure is 34°, round down to 30°. This gives a slightly higher sling load, but will increase your margin for error in the calculations. Sling Angle Degrees 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 Load Angle Factor 1 1. 004 1. 015 1. 035 1. 064 1. 104 1. 155 1. 221 1. 305 1. 414 1. 555 1. 742 2 2. 364 2. 924 3. 861 5. 747 11. 49 Rigging 17

Sling Angle Factor Below are some visual reverences to sling angles and there effect. Rigging 18

Sling Angle Factor • When three or more sling legs are used, the sling angle is measured perpendicular to the centerline of the load line and hook, not in the plane of the adjacent sling. Rigging 19

Sling Angle Factor • When using a choker hitch with multiple sling legs, the sling leg and choke angle must both be factored in to sling load calculations. Rigging 20

Sling Angle DO NOT use a horizontal sling angle less than 60° on an inverted basket. When rigging a sling in an inverted basket, the horizontal sling angle must be greater than 60°, to minimize the possibility of the sling shifting on the hook. Rigging 21

Sling Angle • The preferred method when two sling leg are used, is to use two slings that terminate at the hook, providing the best possible load control and stability. • When additional sling legs are needed, a master link and shackle may needed to prevent sling bunching on the hook and to even out sling load distribution. Rigging 22

Sling Angle DO NOT Wrap the sling around the hook in any manner Rigging 23

D/d Ratio • D/d – Is the ratio between the curvature of the part being rigged D and the diameter of the sling being used d • This ratio is important in because it effects both the load carrying capacity of the sling and its ability to resist damage – An excessively small D/d ratio with wire rope and chain sling will be permanently damaged the sling. • The D/d ratio for wire 6 x 19 rope is 25/1. • Other sling type have different D/d ratings, such as 6/1 for chain slings or 5/1 for grommet slings OCHPP 24

D/d? Flat Web Slings • Flat web slings have no diameter and therefore no D/d ratio. • All web sling manufacturers recommend some form of edge protection be used between web slings and load edges to protect the sling against damage, such as cutting. • Some manufacturers suggests that at minimum the edge radius of the load contact point should be at least the thickness of the sling at the point of contact. • If the sling is 3/16” thick webbing, the contact radius should be 3/16” or greater. • If the sling is 2 or more ply’s in thickness, it is the total thickness of all the ply's at the contact point of the sling and load that constitutes the sling thickness. • A chamfered edge is not the same as a radius, it still has sharp edges. OCHPP 25

Sling Protection • All slings types must be protected from sharp edges of a load, and any other damaging forces. • Many types of protection are available and can be improvised, below are some examples OCHPP 26

Sling Strength Loss • Shown here are test results from two different sling manufacturers, showing the loss of ultimate strength of the sling do the various sizes of edge cut in a 2 inch wide single ply sling. Rigging 27

Sling Strength Loss • To help put things in perspective: • The red wire represent 12 randomly spaced wire on a wire rope sling, this equates to about 10 -1/2 % of the wires in the sling. • The image below represents the cross section of a 1 inch wide by. 147 inch thick web sling, the blue area is about 10 -1/2 of the sling fabric a cut of about . . 015” deep, this is about the thickness of two business cards. The image below is about what the sling cross section would look like in your hand. Rigging 28