Crane operators use standard hand signals such as hoist, hoist lower, stop and emergency stop when moving loads. A vertical forearm, forefinger pointing up and moving in a small horizontal circle signals hoist; similarly, but with the arm extended downward, the signal means hoist lower. To signal stop, the arm is extended, palm down, and held still. An extended arm, palm facing downward and hand moving rapidly right and left signals an emergency stop and that the magnet has disconnected.
There is only one designated signaler at a time, but crane operators must obey the stop signals regardless of who is giving the signal. The standard signal for slow hoisting a load involves placing a flat palm over the circling forefinger of the hoist load signal. A critical crane hand signal is "dog everything," when the signaler clasps his hands in front of his body. This signal is appropriate for risky situations such as rain or danger to a person standing nearby and signals the operator to pause.
Other hand signals include raise the boom, lower the boom and swing. An extended arm, fingers closed thumb pointing upward tells the crane operator to raise the boom, thumb pointing downward to lower it and a finger points to the direction of swing. The signal that tells the operator to raise the boom and lower the load involves horizontally extending one arm with closed fingers and thumb pointing upward, while extending the other slightly bent arm downward, pointing the forefinger downward while the hand rotates in horizontal circles.