What is the maximum grade a crane can operate on if it is not level?

What is the maximum grade a crane can operate on if it is not level?

• A. 2% grade, equal to about 1 inch
• B. 0% grade, level position
• C. 5% grade, equal to about 2 inches
• D. 1% grade, equal to less than 1/2 inches

Answer: (D)

When a crane isn’t on level ground, its stability relies on keeping any slope as small as possible. A crane’s outriggers and base are designed to resist tipping best when the surface is level, and even small inclines can shift the load’s vertical line relative to the base, reducing the tipping margin. The maximum allowed nonlevel grade is a very small slope—about one percent. That means the ground can change by roughly one unit in height for every hundred units of horizontal distance. This tiny tolerance helps keep the crane within its stability limits under typical lifts. Steeper slopes, like two percent or five percent, would push the balance toward tipping and are not considered safe for operating when the crane isn’t level. So, the best choice reflects that a crane may operate on a slight grade, but only up to about one percent. If the ground is steeper than that, you should level the crane or move to level ground before lifting.

When a crane isn’t on level ground, its stability relies on keeping any slope as small as possible. A crane’s outriggers and base are designed to resist tipping best when the surface is level, and even small inclines can shift the load’s vertical line relative to the base, reducing the tipping margin.

The maximum allowed nonlevel grade is a very small slope—about one percent. That means the ground can change by roughly one unit in height for every hundred units of horizontal distance. This tiny tolerance helps keep the crane within its stability limits under typical lifts. Steeper slopes, like two percent or five percent, would push the balance toward tipping and are not considered safe for operating when the crane isn’t level.

So, the best choice reflects that a crane may operate on a slight grade, but only up to about one percent. If the ground is steeper than that, you should level the crane or move to level ground before lifting.