What caused the increase in load radius when tension is applied to a load directly under the hook?

When tension is applied to a load directly under the hook, boom deflection occurs due to the weight of the load and the forces acting upon the crane's boom. As tension is applied, it changes the angle and position of the boom slightly, which can effectively increase the load radius. This is because any upward force from the load can create a bending moment in the boom, causing it to bow or deflect.

In this context, the load radius is defined as the horizontal distance from the center of the rotation of the crane to the center of the load being lifted. When the boom deflects under the weight of the load, this distance increases, thereby increasing the load radius even when the load is directly beneath the hook.

Understanding boom deflection is crucial for safe crane operation, as it can affect stability and lifting capacity. Operators must be aware of how the load and the corresponding tension impact the boom structure to ensure that safe lifting practices are maintained.