What is the signal to shorten the boom or trolley in tower cranes?

The signal to shorten the boom or trolley in tower cranes is represented by the position where one arm is extended outward with the palm open and facing downward. This signal clearly communicates to the crane operator the specific action required, which is to shorten the boom or trolley by moving the load towards the crane.

The open palm indicates a stopping or a directional command, making it easily recognizable. Clarity in hand signals is crucial for safety and efficient communication on job sites, especially in environments where noise may prevent verbal instructions from being heard. Other signals may suggest different actions, thus the open palm facing down distinctly signifies the need to shorten the boom or trolley rather than moving it away or making other adjustments that could lead to misunderstanding and potential safety hazards.