If a signal person extends their arm at shoulder height, makes a fist, and sticks their thumb up, what action are they indicating?

Extending the arm at shoulder height, making a fist, and sticking the thumb up is a widely recognized hand signal for indicating that the boom should move up. This gesture provides a clear visual cue to the crane operator, who can often be at a distance, ensuring they understand the intended action. The position of the arm signifies an upward motion, while the thumb pointing up emphasizes that the operator should elevate the boom or lift.

Understanding these signals is crucial for safety and effective communication on a job site, where miscommunication can lead to dangerous situations. Using standardized signals like this helps maintain a clear and consistent method of conveying instructions.