Radio & Voice Signals for Crane Lifts

When the operator can’t see the signal person, as on blind lifts, tall buildings and tower cranes, radios carry the signals. Clear, agreed-upon voice commands on a dedicated channel keep loads under control. Garbled or crossed radio traffic causes accidents.

• Signal persons
• Crane operators
• Riggers

Radio requirements

• Test the radios on site before the lift begins
• Use a dedicated channel for crane signals, except when several cranes must coordinate on one
• The operator receives signals hands-free (headset or speaker)
• Spare batteries on hand

Before the lift: agree on the signals

The operator, the signal person and the lift supervisor must meet before the lift and agree on the voice signals they’ll use. Use the same words every time.

How to give a voice command

Each voice signal should contain these parts, in this order:

1. Function: what to move (hoist, boom, swing, travel)
2. Direction: up, down, left, right, in, out
3. Distance and/or speed: “10 feet,” “slow”
4. Function stop

Example: “Crane 2, swing left… 20 feet… 10… 5… 2… swing stop.”

Good radio practice

• Identify the crane at the start of each signal when more than one crane is on the job.
• Talk constantly while the load is moving, so the operator knows you’re still there; some crews count down distance.
• Only one signal person talks to the operator during a lift, except for stop.
• Keep chatter off the channel.

Back-up plan

• Have hand signals as a backup when the operator can see the signal person.
• Plan what happens if the radio dies with the load in the air: stop, hold, and re-establish communication.

Last updated: October 2, 2026