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As
the horizontal angle between the legs of a sling and the load
decreases, the load on each leg increases. The effect
is the same whether a single sling is used as a basket, or
two slings are used with each in a straight pull, as with
a 2-legged bridle.
Anytime pull is exerted at an angle on a leg--or legs--of
a sling, the load per leg can be determined by using the data
in the table below. Proceed as follows to calculate
this load--and determine the rated capacity required of the
sling, or slings, needed for a lift.
1. First, divide load to belifted by number of
legs to be used. This provides load per leg if the lift were
being made with all legs lifting vertically.
2. Determine angle between legs of sling
and the horizontal.
3. Then MULTIPLY load per leg (as computed
in No. 1 above) by the Load Factor for leg angle being
used (from the table below) --to compute the ACTUAL load on
each leg for this lift and angle. THE ACTUAL LOAD MUST
NOT EXCEED THE RATED SLING CAPACITY.
Thus, in drawing three (sling angle at 60°): 1000 ÷ 2 = 500
(load Per Leg if a vertical lift) 500 x 1.154 = ACTUAL LOAD
on each leg at the 60º included angle being used.
In drawing four (sling angle of 45º): 1000 ÷ 2 = 500 (Load
Per Leg if a vertical lift) 500 ÷ 1.414 = 707 lbs. =
ACTUAL LOAD on each leg at the 45º horizontal angle being
used.
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