Which equipment is designed to lift or lower heavy loads?

A hoist is specifically designed to lift or lower heavy loads using a pulley system or similar mechanisms. Hoists can be either manual or powered and are commonly used in construction, manufacturing, and shipping to move heavy materials safely and efficiently. They can handle substantial weight, making them essential for tasks that involve lifting objects that would otherwise be too heavy or cumbersome for manual handling.

The other options, while related to material handling and equipment, do not serve the primary function of lifting or lowering heavy loads. Rollers facilitate the movement of loads across surfaces, allowing for easier transportation rather than vertical lifting. A drum handler is typically used to manipulate drums or barrels but is not inherently designed for vertical lifting like a hoist. Unit loads refer to a method of consolidating items into a single unit for easy handling and transport but does not directly involve lifting mechanisms. Hence, the choice of a hoist is aligned with the requirement for equipment that can effectively lift and lower heavy loads.