When using two sling legs with an included angle of 60 degrees, what load factor do we apply?

When using two sling legs with an included angle of 60 degrees, the load factor you would apply is 1.73. This value is derived from the relationship between the angle between the slings and how the load is distributed between them.

In rigging, when the angle between sling legs increases from vertical, the tension in each sling leg increases as the angle widens. Specifically, for two slings forming an angle, the load factor can be calculated using the formula:

Load Factor = 1 / cos(θ/2)

In this scenario, θ is the included angle, which is 60 degrees. Thus, θ/2 equals 30 degrees. The cosine of 30 degrees is √3/2, which is approximately 0.866. Therefore:

Load Factor = 1 / 0.866 ≈ 1.1547.

However, when both sling legs are taken into account, you multiply this factor by 2 (assuming equal load distribution) to determine the overall load on each leg, resulting in approximately 2.0. But the direct reference to the load factor corresponding to the angle of 60 degrees gives you the figure of 1.73 based on typical rigging tables and guidelines.