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Basket hitch: The chain sling is passed through or under the load, the lower terminals are connected directly to the master link or to the hook of
the lifting machine. Generally, this method requires two or more chain sling legs and should
not be used for lifting loads which are not held together. Where the load geometry permits,
a single leg chain sling can be used provided that the chain sling passes through the load
directly above the center of gravity of the load.
Wrap and choke or wrap and basket hitch: These methods are adaptations of choke hitch
and basket hitch, designed to provide extra security of loose bundles and involve taking an
extra loop of chain completely around the load.
If two or more chain sling legs are used in a choke hitch or a wrap and choke hitch care
should be taken:
a) if it is important to avoid imparting a torque to the load, to align the chokes; or
b) if it is important to avoid the load rolling or moving laterally when first lifted, to ensure that
Basket hitch
at least one leg passes either side of the load.
Symmetry of loading: Working load limits (WLL) for chains slings of different dimensions
and configurations have been determined on the basis that the loading of the chain sling
is symmetrical. This means that when the load is lifted the chain sling legs are symmetri-
cally disposed in plan and subtend the same angles to the vertical. In the case of three leg
chain slings, if the legs are not symmetrically disposed in plan the greatest tension will be
in the leg where the sum of the plan angles to the adjacent legs is greatest. The same ef-
fect will occur in 4 leg chain slings except that the rigidity of the load should also be taken
into account, with a rigid load the majority of the mass may be taken by only three or even
two legs with the remaining leg or legs serving only to balance the load.
In the case of 2-, 3- and 4- leg chain slings, if the legs subtend different angles to the
vertical the greatest tension will be in the leg with the smallest angle to the vertical. In the
extreme case, if one leg is vertical, it will carry the entire load.
If there is both a lack of symmetry in plan and unequal angles to the vertical the two effects
will combine and may either be cumulative or tend to negate each other. The loading can be
assumed to be symmetric if all of the following conditions are satisfied and the load is less
than 80% of marked WLL:
Symmetry of loading
a) chain sling leg angles to the vertical are all not less than 15°; and
b) chain sling leg angles to the vertical are all within 15° to each other; and
c) in the case of three- and four-leg chain slings, the plan angles are within 15° of each other.
If all of the above parameters are not satisfied, then the loading should be considered as asymmetric and the lift referred to a competent person
to establish the safe rating for the chain sling. Alternatively, in the case of asymmetric loading, the chain sling should be rated at half the marked
WLL.
If the load tends to tilt, it should be lowered, and the attachments changed. This can be accomplished by re-positioning, the attachment points or
by using compatible shortening devices in one or more of the legs. Such shortening devices should be used in accordance with the distributor's
instructions.
Center of gravity: It is assumed that the attachment point of the hook is directly above the
center of gravity of the load.
The position of the center of gravity of the load in relation to all attachment points for the
chain sling should be established. To lift the load without rotation or overturning following
conditions should be met:
a) For single-leg and single endless slings the attachment point should be vertically above the
center of gravity.
b) For 2-leg slings the attachment points should either side of and above the center of gravity.
For 3- and 4-leg slings the attachment points distributed in plan around the center of gravity. It
is preferable that the distribution should
be equal and that the attachment points are above the center of gravity.
When using 2-, 3- and 4-leg slings the attachment points and sling configuration should be
1. Centre of gravity
selected to achieve angle between the sling's legs and the vertical within the range marked
2. High tension in this leg
on the sling. Preferably all angle to the vertical angle (angle β) should be equal. Angles to the
3. Load P
vertical of less than 15° should be avoided if possible as they present a significantly greater
risk of load imbalance.
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