Transcript No Slide Title

Cranes and Slings
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Major Causes of Crane Accidents
Contact with power lines
Overturns
Falls
Mechanical failures
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Crane Hazards
• An unstable load, lack of communication, lack
of training, and inadequate maintenance or
inspection are major contributors to crane
accidents.
• Operators or others working in the area can
be victims to “struck by" and "caught in"
injuries.
• Contact with power lines causes many
accidents.
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Crane Hazards
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Improper loading
Excessive speeds
No hand signals
Inadequate inspection and maintenance
Unguarded parts
Unguarded swing radius
Working too close to power lines
Improper exhaust system
Shattered windows
No steps/guardrails walkways
No boom angle indicator
Not using outriggers
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Crane Parts
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Rated Capacities
• Make sure the crane operator can see the:
– Rated Load Capacities
– Operating Speeds
– Special Hazard Warning or Instruction
• APPLICABLE OSHA STANDARD
– 1926.1501 (a)(2) Rated load capacities, and
recommended operating speeds, special hazard
warnings, or instruction, shall be conspicuously posted
on all equipment. Instructions or warnings shall be
visible to the operator while he is at his control station.
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Competent Person
• The competent person must
inspect all machinery and
equipment prior to each use, and
during use, to make sure it is in
safe operating condition.
• If it needs fixing, take it out of
service and don’t use it until it is
fixed
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Know the Weight of the Load
• Refer to shipping ticket or other documentation
• Ensure lift calculations are correct
• Ensure load is within load chart rating for boom
length and load radius of crane
• Crane is rated by the maximum weight it will lift
at a minimum radius and minimum boom length –
the further from its centerpoint, the less it will lift
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Load Limiting Factors
• Not level
• Wind
• Side loads
• On its wheels
• Lifting over the side
• Use of extensions, jibs and other attachments
• Limits of wire rope, slings and lifting devices
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Load Example –
30 ton crane
• Will lift 60,000 pounds at 10 feet from the center
pin of the crane
• Based on level surface, no wind, and outriggers fully
extended
• At 25 feet from the center pin with an 80 foot
boom, the capacity is only 14,950 pounds
• At 74 feet from the center pin, the capacity is only
4,800 pounds
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Wire Rope Slings
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Alloy Steel Chains
Adapts to shape of the load
Can damage by sudden
shocks
Best choice for hoisting
very hot materials
Must have an affixed tag
stating size, grade, rated
capacity, and sling
manufacturer
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Chain Wear
When a chain
shows excessive
wear, or is
cracked or pitted,
remove it from
service
Non-alloy repair
links can not be
used
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Wire Rope Slings
• Used to hoist materials
Core
• Selection considerations:
 strength
 ability to bend without cracking
 ability to withstand abrasive wear
 ability to withstand abuse
Wire rope
Wire
Center
Strand
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Damaged wire rope
Crushed Rope
Broken Strands
Damaged wire rope must be taken out of service
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Protruding Ends
Cover or blunt protruding ends of strands
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Wire Rope Clips
When using U-bolt
wire rope clips to
form eyes, ensure
the "U" section is in
contact with the
dead end of the
rope
Dead End
This is the correct method
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Wire Rope Slings
Remove From Service
If these happen, remove the wire rope sling from service
Kinking
Bird Caging
Crushing
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Synthetic Web Sling
Markings
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Mark or code to show:
– Name or trademark of
manufacturer
– Rated capacities for the
type of hitch
– Type of material
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Synthetic Web Sling
Stitching
Stitching
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Stitching is the only method allowed to attach end
fittings to webbing, or to form eyes
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Synthetic Web Slings Remove from Service
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Remove from service if any
of these are present:
– Acid or caustic burns
– Melting or charring of any
part
– Snags, punctures, tears or
cuts
– Broken or worn stitches
– Distortion of fittings
Heat Damage
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Sling Tables
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Sling Stress Example
• From the table, a single branch with a 90
degree loading is rated at 3,250 lbs.
• If there is a safety factor of 4, the chain could
lift
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