What is the maximum included angle allowed when using a shackle on the hook?

The maximum included angle allowed when using a shackle on the hook is 120 degrees. This angle is important because it ensures that the load is distributed evenly across the shackle and minimizes the risk of failure. Angles greater than this can increase the load on the shackle and the lifting equipment beyond their safe working limits.

When the angle exceeds 120 degrees, the stress on the shackle can lead to significant reductions in the safe working load, as the forces become less predictable and can lead to bending or other forms of damage. Maintaining this safe angle helps to ensure safe and effective lifting operations, protecting both the equipment and personnel involved.

It is essential for riggers to understand the importance of this limit to prevent accidents and ensure that lifting operations are conducted safely.