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NCCER Signal Person study materials
NCCER Signal Person study resources

NCCER Signal Person: Voice and Radio Communications

NCCER Signal Person · Work through your exam, one topic at a time.

All guide sections

Voice and Radio Communications

What the exam tests

The Voice and Radio Communications domain tests whether you can set up and use radio or voice signals so the operator receives clear, timely commands, and whether you know what to do when communication fails. OSHA 1926.1420 covers radio, telephone, and other electronic transmission; 1926.1421 covers voice signals. The signal person must be qualified and must use signals the operator understands.

Core rules

  • Test the radio or electronic communication before each shift. Confirm that the signal person, operator, and any relay are on the same channel and can hear each other.
  • Identify the crane and the signal person before giving a command. A command such as “Crane 2, Signal 2, hoist” prevents the wrong operator from acting.
  • Use standard, concise voice commands: STOP, EMERGENCY STOP, HOIST, LOWER, BOOM UP, BOOM DOWN, SWING LEFT, SWING RIGHT, TRAVEL FORWARD, TRAVEL REVERSE. Avoid vague phrases such as “take it up a little” or “bring it over.”
  • Have the operator repeat or acknowledge critical commands when the lift plan or site rules require it.
  • If radio transmission is interrupted, the operator must stop until communication is restored. Do not keep operating on assumed commands.
  • Keep the channel clear. Casual conversation can block a stop command.
  • Use a dedicated channel when one is available. If multiple cranes share a channel, use distinct call signs and direct each command to one crane.

Worked example

Two cranes are working on one channel. The signal person says “Swing left” without identifying the crane. Both operators may begin to swing, creating a collision risk. The correct transmission is: “Crane 2, this is Signal 2, swing left.” The operator replies, “Crane 2, swing left, copy.” The command is now addressed, acknowledged, and limited to one machine.

Traps

Saying “up” instead of HOIST; failing to test the radio; giving a command without a crane identifier; continuing after a radio cuts out; using “stop” casually when EMERGENCY STOP is meant; allowing non-signal personnel to give commands on the channel.