For giving commands and communication between the crane operator, slinger and other engineering personnel, special sign signals are adopted. With the help of which, the engineering and technical personnel promptly and accurately inform the crane operator how and where to move the cargo.

Signs to the crane operator can be either one slinger or several employees. This method of communication is necessary in cases where the crane operator does not see the area served by the truck crane.

The image below shows schematically the signs:

• raise and lower a load or hook;
• move the crane;
• move the cart;
• turn the boom;
• raise and lower the boom;
• stop (stop moving the load);
• caution (apply before any signal is given if slight movement is needed).