Wheeled truck crane on outriggers margin of stability is?

• A. 70%
• B. 85%
• C. 90%
• D. 95%

Answer: (B)

The idea being tested is how much safety buffer, or margin of stability, a wheeled truck crane retains when the outriggers are set. Outriggers widen the base and distribute the load more evenly, which increases stability, but you still need a healthy reserve to account for dynamic lifting forces, gusts of wind, uneven ground, and operator inputs. The best choice reflects a standard, practical safety margin used in training and field practice: a solid buffer that isn’t pushed to the limit.

That’s why this option is favored: it represents a balanced, common-sense margin that keeps tipping from occurring while allowing effective lifting. The smaller margins would leave too little room for dynamic effects and errors, increasing tipping risk, while margins that are too large would underutilize the crane’s capability and aren’t typical in standard procedures.