Pick and Carry Operations Flashcards

A crane rated for pick and carry has a static load chart showing 20 tons at 20-foot radius and a separate traveling load chart showing 14 tons at 20-foot radius. Why is the traveling capacity lower?

Answer: Dynamic forces during travel (acceleration, deceleration, surface irregularities) create additional loading that reduces the safe traveling capacity compared to a static, stationary lift

Dynamic forces during crane travel — inertia from speed changes, vibration from surface, load swing — add to the static load, reducing the net capacity available. The traveling chart accounts for these additional forces.

During a pick and carry operation, the operator notices the load has begun to swing. What is the FIRST action the operator should take?

Answer: Stop all travel motion immediately and allow the load to come to a natural rest, using tag lines to assist if available

When a load swings during pick and carry, the first action is to stop travel motion. Continued movement amplifies the swing. The load should be allowed to dampen to rest, with tag lines helping stabilize the load before travel resumes.

What does OSHA 29 CFR 1926.1424 specify regarding the crane operator's responsibilities when traveling with a load near workers?

Answer: The employer must ensure workers are not in the travel path, and the operator must travel only when assured that the path is clear of personnel

OSHA 1926.1424 requires the employer to ensure the travel path is clear of all workers, and the operator must verify clearance before beginning or continuing travel with a suspended load.

When a rough terrain crane's outriggers are retracted for a pick and carry operation after a static lift, what change must be made to the load?

Answer: The load must be reduced to comply with the crane's on-rubber (tires only) pick and carry load chart, which is significantly less than the on-outrigger static lift capacity

When outriggers are retracted, the crane's stability reverts to its on-rubber condition. Pick and carry load charts are based on on-rubber configuration and are significantly lower than static on-outrigger capacities.

What is center of gravity shift in the context of pick and carry operations, and why is it a hazard?

Answer: The change in the effective position of the combined center of gravity (crane plus load) as the crane accelerates, decelerates, or traverses slopes during travel, which can move the total center of gravity toward the tipping axis

During travel, inertial forces shift the effective center of gravity of the crane-load system. Acceleration moves it backward (toward the rear tipping axis), deceleration moves it forward, and slopes tilt the CG downhill — all of which can bring the CG toward the tipping fulcrum.

What is the maximum permissible operating slope for most mobile cranes when performing a pick and carry operation, and how is this typically specified?

Answer: Maximum permissible slope is specified in the crane manufacturer's operational manual and load chart, varying by crane model — typically between 1% and 3% (0.6 to 1.7 degrees) for pick and carry

Maximum operating slopes for pick and carry are specified by the manufacturer and are typically very small — 1 to 3 percent (fractions of a degree) — because slope tilts the crane, effectively increasing the working radius on the downhill side and reducing stability.