Which hand signal describes the OSHA method to lower the boom?

The OSHA method for signaling to lower the boom uses a specific hand signal to ensure clarity and safety in crane operations. The correct signal involves extending the arm horizontally to the side, with the thumb pointing down and the other fingers closed. This signal is particularly effective as it provides a clear indication to the crane operator that the boom should be lowered. The horizontal arm position is easily visible from a distance, which helps prevent misunderstandings and ensures that the operator can respond quickly and appropriately.

In this context, the position of the thumb down signifies the action of lowering, while the closed fingers indicate no other movement or action is taking place at that time. This standardized method reduces the risk of accidents by making sure everyone involved in the operation understands what is being communicated.

The other signaling methods do not align with OSHA guidelines for this specific action. For example, an arm extended vertically or both arms moving downward could be misinterpreted or not clearly convey the exact intention. Similarly, a raised fist is not a recognized method for signaling the lowering of the boom, which is crucial for maintaining safety and avoiding confusion on the job site.