Which statement about crane operation on uneven ground is correct?

Which statement about crane operation on uneven ground is correct?

• A. It should not operate on any grade
• B. It can operate on a 5% grade
• C. It can operate on a 2% grade
• D. It can operate on a 1% grade, equal to less than 1/2 inches

Answer: (D)

Crane stability depends on staying level on the support surface, and uneven ground is a direct tipping risk. You may operate on a small grade only if the crane can be leveled within its designed tolerance. The statement that it can operate on a 1% grade with less than a half‑inch difference between the heights under the outriggers captures that limit: a 1% grade means the ground rises 1 inch for every 100 inches of horizontal distance, and what matters in practice is the height difference across the outrigger pads. If that differential is kept under 1/2 inch, the crane’s leveling system can bring the structure within safe, level operation. If the grade is steeper, or the height difference between supports exceeds the permitted tolerance, you should not operate until the ground is leveled or proper cribbing/mats are used. The other options imply no grade or larger slopes, which exceed safe operating limits.

Crane stability depends on staying level on the support surface, and uneven ground is a direct tipping risk. You may operate on a small grade only if the crane can be leveled within its designed tolerance. The statement that it can operate on a 1% grade with less than a half‑inch difference between the heights under the outriggers captures that limit: a 1% grade means the ground rises 1 inch for every 100 inches of horizontal distance, and what matters in practice is the height difference across the outrigger pads. If that differential is kept under 1/2 inch, the crane’s leveling system can bring the structure within safe, level operation. If the grade is steeper, or the height difference between supports exceeds the permitted tolerance, you should not operate until the ground is leveled or proper cribbing/mats are used. The other options imply no grade or larger slopes, which exceed safe operating limits.