A crane accident occurs when any element of the crane operating envelope fails during operations, maintenance, or testing. Which of the following would be the exception?

• A. Over rigging the load
• B. Electrical fault
• C. Worn wire rope
• D. Failed limit switch

Answer: (A)

Crane safety hinges on the operating envelope—the safe range of motion, loads, speeds, and conditions under which the crane can operate. An accident is typically tied to a failure of one of those envelope elements, because such failures push the system outside its safe boundaries. A worn wire rope is a direct degradation of the lifting element, compromising strength and reliability. A failed limit switch removes the automatic boundary that keeps movements within safe limits. An electrical fault can cause loss of control or unpredictable movement, violating safe operation. Over rigging the load, however, is exceeding the crane’s rated capacity rather than a failure of any envelope component, so it represents an unsafe operating condition at the process level rather than a failure of the envelope itself.