According to A.S.M.E., when should warning signals be given?

Warning signals are crucial for ensuring the safety of operators and personnel in the vicinity of overhead cranes. The correct answer emphasizes that warning signals should be given when starting and during the movement of the crane. This practice is essential because it alerts everyone in the area that the crane is about to enter a potentially hazardous operation, helping to prevent accidents or injuries.

By announcing the starting and movement phases of the crane, it ensures that those working nearby are aware of the crane's actions, allowing them to stay clear and maintain a safe distance. This protocol minimizes risks during operation and creates a safer working environment.

In contrast, while warning signals could be useful in other scenarios, such as during maintenance checks, load tests, or when shutting down the crane, they are not specifically mandated to occur in those situations the way they are during the actual movement of the crane. Hence, the emphasis on signals during operation serves a more immediate safety purpose.