Final answer:
Each worker on a swing stage requires two safety lines: one attached to their harness and connected to the swing stage, and another attached directly to the swing stage.
Step-by-step explanation:
In swing stage operations, each worker must have two safety lines.
The first safety line is attached to their harness and connected to a lanyard which is secured to the swing stage. This safety line provides fall protection in case the worker loses his or her balance.
The second safety line is attached to the swing stage and acts as a backup line. In the event of a failure in the primary line or swing stage system, the worker is still protected by the backup line.