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a
e
60 °
c
b
d
FIGURE 11.3
Illustration for Example 11.3.
therefore,
sin60°= ae
ab
transposing,
ae
ab
=
sin60
°
substituting known values,
1000
0 866
ab =
=
1155
.
The total weight on each leg of the sling at a 60° angle from the load is 1155 lb. Note that the
weight is more than half the load, because the load is made up of two forces—one acting vertically,
the other horizontally. An important point to remember is that the smaller the angle, the greater
the load (force) on the sling. For example, at a 15° angle, the force on each leg of a 2000-lb load
increases to 3864 lb.
Note: Sling angles less than 30° not recommended.
Let's take a look at what the force would be on each leg of a 2000-lb load at various angles that
are common for lifting slings (Figure 11.4), and work a couple of example problems.
2000 lb
1414 lb
2000 lb
1000 lb
45°
2000 lb
30°
2000 lb
2000 lb
2000 lb
(A)
(B)
(C)
(D)
FIGURE 11.4
Sling angle and lead examples.
 
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