Must have one full turn of rope on the drum.

• A. Winding Drums
• B. Obstruction Devices
• C. Manual Unlocking
• D. Force Resistance

Answer: (A)

When the drive uses a winding drum, you need one full turn of rope wrapped on the drum to ensure proper engagement and torque transmission. This wrap provides enough surface contact so the drum can reliably wind and unwind the rope under load without slipping. It also helps distribute wear along the rope and across the drum, giving predictable operation during starting, stopping, and changes in load. If there isn’t a full wrap, the rope can slip off the drum, leading to insufficient drive, jerky motion, or loss of movement. The other options don’t relate to how the rope engages the drum: they refer to different safety features or operations not about rope seating on the drive drum.