Safe Slinging Practices
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Types of Slings
1) Wire Rope Slings
2) Chain Slings
3) 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: 1084—1969 Manila Rope
IS: 1321—1970 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
ONE
Rope of which
Same as per new
original Fibre strength Rope
is not reduced
TWO
Rope which has been
used and shows
slight external wear
and chafe
THREE
Rope which has fair
NOT TO BE USED
amount of usage,clear FOR HOISTING
indication of internal
and external wear,
loosening of strands
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SWL
80% of the New
Fibre ropes
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
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core.
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 Identification
Rated Load (rated capacity)
•Load test date
•Manufacturer’s 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
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capacity will be reduced
drastically.
Various defects in chain slings
Wear
Twist or
Bend
Cut
Stretched
Links
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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
a. Wear exceeds 15% of a link diameter.
b. Cut,, cracked,, burned, or corrosion pitted
c. Twisted or bent
d. 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 Stopping distance (ft)
speed (ft/ min)
10
5
2
100
0.4
0.7
2.2
150
1.0
1.6
4.9 Increase
in hook
200
1.7
2.9
8.6
load
250
2.7
4.5
13.5
(%)
300
3.9
6.5
19.4
350
5.3
8.8
26.4
450
6.9
11.5 34.5
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
cable’s 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 chain’s 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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