What is the purpose of a "friction device" in a rescue operation?

In a rescue operation, the primary purpose of a friction device is to control the descent of a person or load by creating friction against the rope. This is crucial in scenarios where precise control is needed to manage the speed of descent safely. Friction devices allow rescuers to have a manageable and stable system when lowering or raising loads, effectively preventing uncontrolled falls and ensuring the safety of both the rescuer and the person being rescued.

These devices work by applying friction to the rope, which slows down the movement and enhances the user's ability to manipulate the descent speed. This capability is vital in rescue scenarios where the conditions might be precarious, and the safety of individuals involved could be at risk if descent rates are too rapid. Hence, the ability to control descent is a fundamental aspect of effective rope rescue operations.