What feature is crucial for the safe installation of lifelines?

The safe installation of lifelines is fundamentally linked to their positioning and securing, specifically that they are secured above the point of operation. This feature is vital because it ensures that if a worker falls, the lifeline will effectively catch them and prevent a fall to a lower level. Proper positioning helps distribute the force of a fall more evenly and reduces the risk of injury.

If lifelines are not secured properly, or are positioned at or below the point of operation, they can fail to provide adequate support and protection. Therefore, ensuring that the lifelines are installed correctly is essential for the safety of workers who rely on them in various environments, particularly in construction and maintenance activities where elevation is involved. Other characteristics, such as being made of a certain material, their color, or disposability, while potentially useful for various reasons, do not match the essential safety requirement provided by appropriate securing above the point of operation.