Stop (A)
Extend one arm and hold palm of hand vertical.

Stop (B)
(Specifically for high operations)
Arm extended palm down, fist clenched, move hand right and left.

Hold Everything
Clasp hands in front of body.

Hoist
With forearm vertical, forefinger pointing up, move hand in small horizontal circles.

Lower
With arm extended downwards, forefinger pointing down, move arm in horizontal circles.

Move Slowly
Use one hand to give any motion signal and place other hand motionless in front of hand giving the motion signal.

Raise Boom
(Luff Up)
Arm extended, fingers closed, thumb pointing upwards.

Lower Boom
(Luff Down)
Arm extended, fingers closed, thumb pointing downwards.

Slew
Arm extended, point with finger in direction of boom swing. (For overhead gantry crane move in direction indicated.)

Raise Boom
Lower Load
Right arm extended, thumb pointing upward, left arm extended downward swinging in horizontal circles.

Lower Boom
Raise Load
Right arm extended, thumb pointing downward and left forearm and forefinger vertical, left hand in small horizontal circles.

Extend Boom or Trolley Out
(Telescoping booms)
Both fists in front of body with thumbs pointing outwards.

Retract Boom or Trolley In
(Telescoping booms)
Both fists in front of body with thumbs pointing towards each other.

Use Main Hoist
Tap fist on head, then use regular signals.

Use Auxiliary Hoist
Tap elbow with one hand, then use regular signals.

Finished With Crane
Place arms above head and cross hands.

Travel Machine
(Point Direction)
(Crawler Cranes Only)
Arms bent at elbow, fists clenched, rotate both forearms around each other.

Travel One Track 
(Crawler Cranes Only)
Lock the track on one side indicated by raised fist. Travel opposite track in direction indicated by circular motion of other fist rotated vertically in front of body.