Safe operating procedures, signals, and communication
Domain 4 tests communication and operating discipline. The exam asks who may signal, what a signal means, and what to do when communication breaks down.
Signals and roles
- Only a qualified signal person should direct a lift; the operator must understand the signals used.
- One signal caller at a time; anyone may give an emergency stop.
- Hand signals must follow the recognized standard; voice or radio signals need a dedicated channel and clear words, not slang.
- For a blind lift, plan relay signal persons, test radios, agree on lost-communication behavior, and keep the load path barricaded.
Operating rules
Keep the load low and controlled; use tag lines where needed; avoid side pulls; travel only as the manufacturer allows; sound the horn before moving; never carry riders except in an approved personnel platform. The operator stops when the view, signal, or load control is lost.
Worked example
A load must be set behind a wall where the operator cannot see the landing. The rigger and signal person test radios, agree that "stop" means hold immediately, and station a relay signal person at the corner. The operator lifts a few inches, checks rigging and brake, then follows the signal. If the radio fails, the operator stops and holds the load; the load is not moved until communication is restored and confirmed.
Traps
Using an unqualified coworker as signal person; multiple people signaling; assuming a radio works without a test; moving after a stop signal; using nonstandard hand signals; letting the load swing while watching the wrong spot; not agreeing on lost-communication procedure.