What is the primary role of 'small stuff' lines?

The primary role of 'small stuff' lines is to assist in hand working tasks and small lifting. These lines are typically used for activities that require precision and control, allowing workers to manipulate lighter loads with ease. Their design allows for flexibility and adaptability in various scenarios, such as rigging and securing smaller items or tools during operations.

In contrast, the other options focus on different applications that are not aligned with the specific function of 'small stuff' lines. For instance, securing large payloads typically involves heavier, sturdier rigging systems, while creating barriers around heavy equipment is more about safety and marking zones than handling small items. Measuring large distances is a task that requires other tools and equipment, such as tapes or lasers, rather than the role of 'small stuff' lines. This makes the chosen answer the most appropriate understanding of the function and importance of these lines in practical applications.