Safe Slinging Practices

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Safe Slinging Practices
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Types of Slings

• Wire Rope Slings
• Chain Slings
• Synthetic Web Slings

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Ropes, chains, and slings

• Primary hazard is structural failure due to
• Overloading (the weakest link)
• Deterioration and/or wear
• Environmental exposure
• Improper rigging
• Abuse

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Natural fibre ropes
IS 10841969 Manila Rope IS 13211970 Sisal
Rope MANILA Black Yarn Grade-I SPECIAL QUALITY
ALL THE THREE STRANDS
Grade-II STANDARD QUALITY ALL THE TWO
STRANDS Grand-III MERCHANT QUALITY ONE
STRAND SISAL Red or Green YARN in one strand
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SWL of Fibre ropes
Value Condition SWL
ONE Rope of which original Fibre strength is not reduced Same as per new Rope
TWO Rope which has been used and shows slight external wear and chafe 80 of the New
THREE Rope which has fair amount of usage,clear indication of internal and external wear, loosening of strands NOT TO BE USED FOR HOISTING
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Fibre ropes
DANGER
Once a Fibre Rope is condemned it should be cut
with a knife so as to ensure that it should not
be used again.
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Fibre ropes
Causes of Deterioration
ROUGH USE Rubbing against sharp edges Damaged groves of sheaves Dragging from under the load
HARMFUL CONTACT With water, oil, chemicals and heat
BAD STORAGE Heap on wet floor, poorly ventilated godown
Internal wear by Repeated Flexing
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Synthetic Fibre ropes

• IS 4572 1968 Polyamide (Nylon Filament Rope)
• IS 5175 1969 Poly Propylene Rope
• IS 8674 1978 Polyethylene Rope
• Advantages
• Light in Weight
• Higher Strength
• Increased Resistance to Repeated Bending,
  Flexing and Abrasion
• Resistance to water and
• Choice of Selection

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Wire Rope and Wire Rope Slings
Components of Wire Rope
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Left Lay
Right Lay
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Crushing Because of loose winding on drum, rope
was pulled in between underlying wraps and
crushed out of shape.
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Birdcaging The sudden release of a load cause
birdcaging.Here individual strands open away from
each other, displacing the core.
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Locking of strands Premature breakage of wires
resulted from "locking" of strands, which was
caused by insufficient lubrication.
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Abrasion Neglect of periodical inspection left
this rope in service too long, resulting in
considerable abrasion.
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Kinking Kink or "dog leg was caused by improper
handling and/or installation. A kink causes
excessive localized or spot abrasion.
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Reverse bending Running this rope over one
sheave and under another caused fatigue breaks in
wires.
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Pitting Too much exposure combined with surface
wear and loss of lubrication caused corrosion and
pitting. .
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Wear Too long in service. Repeated winding and
overwinding of this rope on a drum while it was
under heavy stress caused the unusually severe
wear.
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Wire Rope

• Wire Rope Sling IdentificationRated Load (rated
  capacity)
• Load test date
• Manufacturers name
• Periodic inspection due date
• Broken wires (10 in one lay or 5 in one strand)
• Severe corrosion
• Localized wear
• Reduction in outer wire
• Damaged end fittings
• Distortion, kinking, etc

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Wire rope Permissible Stretch
6 strand wire rope 6 in. for 100 ft. length
8 strand wire rope 9 to 10 in. for 100 ft. length
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Wire rope
Dia of rope Permissible reduction in dia. (inch)
3/4 3/64
7/8 to 11/8 1/16
11/4 to 11/2 3/32
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Wire Rope Slings
single-rope legs
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Wire Rope Slings
sling with single-rope legs, Torpedo loop-locks
and choker hook
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TWO LEGGED BRIDLE SLINGS
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THREE LEGGED BRIDLE SLINGS
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FOUR LEGGED BRIDLE SLINGS
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Chain and Chain Sling
Parts of Chain Sling
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Chain and Chain Sling
Single Chain Sling
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Chain and Chain Sling
Double Chain Sling
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Chain and Chain Sling
Triple Quadruple Chain Sling
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Chain and Chain Sling
Adjustable Chain Sling
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Chain Sling Identification

• Chain Size
• Manufacturers Grade
• Rated load and angle
• Reach
• Number of legs
• Manufacturers name and trademark
• Next inspection

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What should you avoid while using chain slings?

• impact loading do not jerk the load when
  lifting or lowering the sling. This increases the
  actual stress on the sling.
• Do not drag chains.
• Do not splice a chain by inserting a bolt
  between two links.
• Do not shorten a chain with knots or by
  twisting.
• Do not force a hook over a link.
• Do not use homemade connections. Use only
  attachments designed for the chain.
• Do not heat treat or weld chain links the
  lifting capacity will be reduced drastically.

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Various defects in chain slings
Wear
Cut
Stretched Links
Twist or Bend
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Periodical inspection

• Clean sling before inspection.
• Hang the chain up or stretch the chain out on a
  level floor in a well-lighted area. Remove all
  twists. Measure the sling length. Discard if a
  sling has been stretched.
• Make a link-by-link inspection and discard if
• Wear exceeds 15 of a link diameter.
• Cut,, cracked,, burned, or corrosion pitted
• Twisted or bent
• Stretched-- Links tend to get longer

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Chain Sling Inspection Items

• Cracks, stretches, or deformed master links,
  coupling links, chains or other components. 
• One leg of a double or triple chain sling is
  longer than the others.  
• Hooks have been opened more than 15 of the
  normal throat opening measured at the narrowest
  point or twisted more than 10 degrees from the
  plane of the unbent hook.  
• Chain size at any point of any link is less than
  stated in the chart on the next slide, the sling
  shall be removed.  

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Chain Slings
Only chain slings purchased from the manufacturer
are allowed.No homemade slings allowed!!
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Special Precautions

• It is important to realize that the capacity of a
  sling decreases as the angle at which it is used
  to lift increases.

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Rigging Devices

• Shackles
• Hooks
• Wire Rope Clips
• Wedge Sockets
• Eyebolts
• Spreader Beams
• Slings

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Shackles
Recommended Not Recommended
Recommended
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Proper Use of Shackles
Never replace a shackle pin with a bolt
The load will bend the bolt
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Avoid eccentric loads
Bad Good
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Proper chocking of shackles.
Bad Good
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Shackle Inspection
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Hooks

• Manufacturers identification.
• Never weld on hooks.
• Working safety latch.

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Wire Rope Clips

• The most common use of wire rope clips on cranes
  is at wedge and socket-end fittings.
• The clip does not provide strength to the wedge
  and socket connection.
• It is there to prevent the wedge from
  accidentally being released.

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Installing Wire Rope Clips
Installed properly as to number, direction,
spacing and torque.
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Wedge Sockets

• Most common method of terminating ropes on
  cranes.
• All parts must match in size.
• Measure rope diameter to ensure proper size.

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Wedge Socket - Correct Rope Installation

• Live end of the rope, the straight side of the
  socket and the pinhole all line up.

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WINDING WIRE ROPE
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Rigging
Basic Rules of Rigging

• Know the Weight
• Know the Capacity

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HITCHES
STRAIGHT PULL
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HITCHES
CHOCKER HITCH
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HITCHES
BASKET HITCH
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• Marked with the capacity and proof tested to 125
  percent of that capacity.
• Load should not be left suspended or unattended

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How Horizontal Angle Affects Sling Capacity
Note A good operating practice is to keep
sling angles from going below 60 degrees
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Sling Angle Factor
Sling Angle Factor L/H Where L Length of
the sling. H Height of the connection point
from the horizontal plane of the load.
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Sling Angles
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Hook load increases on brake application during
lowering
Loading lowering speed (ft/ min) Stopping distance (ft) Stopping distance (ft) Stopping distance (ft) Increase in hook load ()
Loading lowering speed (ft/ min) 10 5 2 Increase in hook load ()
100 0.4 0.7 2.2 Increase in hook load ()
150 1.0 1.6 4.9 Increase in hook load ()
200 1.7 2.9 8.6 Increase in hook load ()
250 2.7 4.5 13.5 Increase in hook load ()
300 3.9 6.5 19.4 Increase in hook load ()
350 5.3 8.8 26.4 Increase in hook load ()
450 6.9 11.5 34.5 Increase in hook load ()
Avoid rapid acceeration or deceleration of load
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Hand Signals
An illustration of the signals must be posted at
the job site
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Sheave grooves may become grooved if cables
nominal diameter is reduced, indicating wear.
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Safe Usage Practices

• Slings should be stored off the floor and hung
  on racks whenever possible in a clean, dry
  environment.
•  

• Never drag slings across the floor. 

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Safe Usage Practices (Cont.)

• Never shock load slings.
• Keep loads balanced to prevent overloading
  slings.
• Always lift loads straight up.
•  
• Never rest a load on a sling, or pinch a sling
  between the load and the floor.

• A sling should not be pulled from under a load
  when the load is resting on the sling.
• Make sure the hook is always over the center of
  gravity of the load before lifting it.
• Do not apply a load to a twisted, knotted or
  kinked chain.
• Do not force or hammer hooks or chains into
  position.

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Safe Usage Practices (Cont.)

• Hands and Fingers shall not be placed between the
  sling and the load while the sling is being
  tightened around the load.
• Clean chains regularly as dirt and grit can cause
  excessive wear at the link bearing points.

• Never shorten a sling with knots, bolts or other
  makeshift devices.
•  
• Protect the chains surface from contact with
  sharp corners, which can cause permanent damage
  through gouging or abnormal stress and wear.

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Ropes, chains, and slings

• Factors affecting load capacity
• Hitch type
• Leg angle from vertical
• Other issues
• Hook deformation (maximum 10 twist, 15 throat
  opening)
• Rope wear
• Consider replacement if more than 12 randomly
  distributed broken wires within a single strand
  within a single lay (ANSI B30.2)
• Chain deformation

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Ropes, chains, and slings

• Selected controls
• Proper selection of rigging materials
• Proper use
• Keeping loads within limits
• Regular inspection/testing of rigging components
• Training of riggers
• Other issues
• Hook retainers
• Load capacity charts for field use

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Review

• Select the right sling for the job.
• Inspect slings prior to use, removing from
  service any in question.
• Remember the effect of sling angles on load
  capacities.
• Properly store slings when finished to avoid
  damage.

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Conclude

• Associates in the direction of travel
  should be warned to move and remain
  clear of a lifted load at all times.
• Loads should not be suspended over personnel
  below.
• Under no circumstances may anyone ride the hook
  or load.
• Directional movement should be made smoothly and
  deliberately. Avoid rapid movements in any
  direction.

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Conclude

• Locate the hoist directly above the lifting point
  of the load before lifting.
• Lower loads directly below the hoist.
• Keep hoisting ropes vertical. Do not pull or
  push the load.
• Maintain two full wraps of cable on the hoisting
  drum.
• Never pull a hoist by the
  pendant cable

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Thank you