In rope rescue, what is the role of prusiks or progress-capture devices within a mechanical advantage system?

• A. A friction-based device used to secure rope length and control movement.
• B. Prusiks or progress-capture devices provide friction to control rope movement.
• C. Pulleys alone create mechanical advantage.
• D. Anchors themselves provide mobility.

Answer: (B)

Prusiks or progress-capture devices are used to create a friction-based brake inside a mechanical advantage system. They are wrapped around the standing rope so that when the load is moved, the knot tightens and grips the rope, slowing or stopping further motion. This lets rescuers capture progress and hold a load in place without needing constant manual control, while still allowing controlled movement when the device is reset or released. Pulleys mainly change direction or multiply force, and anchors are fixed points; they don’t provide this built-in friction-based lock to control rope movement.