Which load is a light material but can stop lifting in windy conditions?

• A. Concrete block
• B. Steel plate
• C. Plywood
• D. Water tank

Answer: (C)

Wind effects on lifting operations: a light, flat material can catch a lot of wind and have little weight to resist that push. Plywood, being thin and broad, presents a relatively large surface area to the wind, so even modest gusts can generate substantial horizontal force. That makes the load unstable and can drive it sideways or cause it to sway beyond the crane’s controlled envelope. In windy conditions, this sail-like effect can overwhelm the crane’s maneuverability and rigging, leading operators to stop the lift until conditions ease. Heavier loads—such as concrete blocks, steel plates, or a water tank—have far more mass and are much less easily moved by wind, reducing the likelihood that wind alone will terminate a lift.