Rotation resistant rope used for personnel lifting must have a minimum safety factor of?

• A. 12 minutes
• B. 6
• C. 24
• D. 3

Answer: (A)

In rope lifting, the safety factor is the margin between what the rope can safely hold (its breaking strength) and the maximum load it must carry, including any dynamic or shock loads that can occur during ascent, descent, or arrest of a fall. For personnel lifting, this margin needs to be large because dynamic forces can momentarily exceed the static weight of the person and gear, and because rope condition can change with wear, age, dirt, and knots.

Rotation‑resistant rope used for lifting people is specified to have a minimum safety factor of 12. This means the rope’s breaking strength should be at least 12 times the maximum expected load, giving ample room to absorb shock loads and instrument wear over time. The option shown as “12 minutes” is a misprint in units; the requirement is a dimensionless factor of 12, not a time value.

So, the needed margin is 12, reflecting the high reliability needed when human life is involved and the unpredictable forces that can occur during rope operations.