Crane operation is one of the most important and high-stakes tasks on any construction site. One mistake can be hugely consequential, so clear communication is essential for safe and efficient operation. Crane hand signals are one of the most commonly used and effective ways to communicate with a crane operator. These relatively simple signals are great for providing clear, concise messages quickly. They’re an essential piece of basic safety knowledge for many construction sites, just as much as knowing what safety supplies to bring or how to report an OSHA violation. How do crane hand signals work, and who should use them?
We discuss the basics of crane hand signals, including short descriptions of some of the most common and most important ones.
Why Crane Hand Signals?
Why is it that a low-tech solution like hand signals continues to be so important for crane operation? Here are a few ways that crane hand signals perform better than other options:
- Simple unassisted verbal communication — i.e., shouting at the crane operator — is likely to be almost impossible for an operator to hear. Very few construction sites are quiet enough for unassisted communication of this type.
- Communicating with a crane operator through a radio device, such as a walkie-talkie or headset, is better than unassisted communication, but it can be unreliable. If communication goes down at a critical moment, the lack of guidance for the operator can be dangerous.
- Allowing the crane operator to work based on their vision and perspective is a bad idea. Often, a crane operator will not have the perspective necessary to safely maneuver their load.
Executing Crane Hand Signals
A crane hand signal person takes on a significant responsibility with big consequences for failure. Thus, it’s crucially important that they obey the safety best practices of crane hand signaling:
- Signalers should have special training in crane hand signals and how to use them. Remember that crane signals aren’t interchangeable with other construction vehicle signals.
- Signalers should choose their position carefully. They should remain visible to the crane operator at all times but still have an unobstructed view of the crane load and its path.
- Only one signaler at a time should ever be guiding a crane. Signals from multiple signalers can confuse an operator and cause mistakes. The exception is that a crane operator should always obey a stop signal no matter who it comes from.
- The crane operator should know before they begin operation who the signaler is and where the signaler will stand.
- The area around the signaler should be as free of hazards and distractions as possible.
- Signalers should, whenever possible, refrain from making motions with their hands that are unrelated to guiding the crane, as this might confuse the operator.
- Signalers should always be wearing the right high visibility gear and properly rated hard hats.
Crane Hand Signals: Stopping
- Emergency Stop: Tells the crane operator to stop all movement of the boom and/or load immediately.
- Extend both arms straight out to your sides, palms down. Swing both arms in, all the way to your chest, and then return them to the extended position. Repeat.
- Stop: Tells the crane operator to pause or stop the current action.
- Extend one arm straight out to your side, palm down. Swing your arm in, all the way to your chest, and then return it to the extended position. Repeat.
- Dog Everything: A special crane operator’s term that tells the crane operator to temporarily stop the entire operation. Usually used when weather is about to change, a load won’t fit or plans otherwise need to be adjusted.
- Clasp one hand inside the other and hold both hands on your stomach in front of your navel.
Crane Hand Signals: Boom Movement
- Lower Boom: Tells the crane operator to lower the boom — the arm that extends out to lift the load.
- Extend your arm horizontally, close your fist and give a thumbs-up sign.
- Raise Boom: Tells the crane operator to raise the boom.
- Extend your arm horizontally, close your fist and give a thumbs-down sign.
- Swing Boom: Tells the crane operator to move the boom horizontally.
- Extend your arm horizontally and point your index finger in the direction in which the boom needs to swing.
- Extend Boom: Tells the crane operator to lengthen the boom by telescoping it out.
- Put your hands at your waist level, close your fists and point your thumbs outward.
- Retract Boom: Tells the crane operator to shorten the boom by telescoping it in.
- Put your hands at your waist level, close your fists and point your thumbs inward.
Crane Hand Signals: Load Movement
- Hoist Load: Tells the crane operator to retract the hoist and raise the load into the air.
- Extend your arm vertically into the air, point upward with your index finger and move your finger and hand in small circles.
- Lower Load: Tells the crane operator to let out the hoist and lower the load toward the ground.
- Extend your arm in an L shape away from your body so that your hand is pointing at the ground, point downward with your index finger and move your finger and hand in small circles.
Crane Hand Signals: Miscellaneous
- Slow Down: Tells the crane operator to perform the next operation slowly.
- While performing any other signal, place your hand above the signaling hand.
- Use Main Hoist: Tells the crane operator to use the crane’s primary hoist for the next operation.
- Tap your hand several times on top of your head, and then perform your next signal.
- Use Auxiliary Hoist/Whip Line: Tells the crane operator to use the crane’s whip line or fast line for the next operation.
- Bend your arm at the elbow and keep the forearm vertical. Tap your elbow with the palm of your other hand.
These aren’t the only signals you might need to know when guiding a crane, but they’re a good start. See the full list of OSHA crane hand signals to make sure you know them all.