Which device is commonly used to create a 3:1 or 5:1 hauling system in rescue operations?

• A. Carabiner
• B. Edge protection
• C. Moving pulley with fixed-line setup
• D. Prusik knot

Answer: (C)

Mechanical advantage in hauling systems is created by distributing the load across multiple rope segments using pulleys. A moving pulley attached to the load, when used with a fixed line anchored at a separate point, changes how many rope segments share the load. As you haul on the free end, the load is supported by more segments than in a simple direct lift, which increases the force you must apply to move the load and reduces the effort required for the same lift. This setup is how you achieve three-to-one or five-to-one advantages in rope rescue scenarios.

The moving pulley is essential because it actively creates those extra supporting rope strands; the fixed-line component provides the anchor point that defines the system’s geometry. Other hardware mentioned, like a carabiner, gives connection points, edge protection prevents rope damage, and a Prusik knot acts as a friction hitch for backup or progress, but none of these alone establishes the multi-segment load-sharing that yields 3:1 or 5:1 hauling systems. Therefore, the device used to create the 3:1 or 5:1 hauling system is a moving pulley with a fixed-line setup.