Crane Operations & Safety Procedures Flashcards

During a multi-crane lift, Crane A is rated at 200 tons and Crane B is rated at 150 tons. The load weighs 280 tons. The lift plan specifies a 60/40 load-sharing split. Which condition would require the lift to be immediately suspended?

Answer: Crane A's actual load reaches 175 tons during the pick

At a 60/40 split, Crane A's share is 168 tons and Crane B's share is 112 tons. If Crane A's actual load reaches 175 tons, it has exceeded its planned share by more than the acceptable tolerance and is approaching an overload condition. The de-rating at this load percentage, combined with dynamic factors, puts the crane outside the lift plan parameters. The other scenarios—minor rotation, a modest wind increase within typical operating limits, and a small rigging angle adjustment—are manageable with communication but do not alone require immediate suspension.

A lattice-boom crawler crane is performing a 78% of chart pick on a firm mat. The operator notices the crane's load moment indicator (LMI) reads 82% but the calculated chart load is 78%. What is the MOST likely cause and correct response?

Answer: The LMI may be detecting a tipping moment from ground settlement; the operator should stop and reassess ground conditions

An LMI reading higher than the chart calculation is a warning sign that real-world conditions—most commonly uneven or settling ground causing the crane to tilt—are introducing additional load moment not captured in the static chart calculation. The correct response is to stop, not override. Bypassing or ignoring the LMI is a OSHA violation and removes a critical safety barrier. Extending the boom would increase—not decrease—load moment. A 4-percentage-point discrepancy exceeds normal calibration tolerance.

Under ASME B30.5, when is it permissible to carry a suspended load over personnel without a written safety plan and employer authorization?

Answer: It is never permissible under any routine operational circumstance without those controls

ASME B30.5 and OSHA 1926.1425 prohibit swinging or traveling with a suspended load over personnel unless specific conditions are met—including a written safety plan, employer authorization, and demonstration that no safer alternative exists. None of the other options (load weight thresholds, communication alone, or netting) constitute the authorization pathway defined in the standard. The question asks about routine operational circumstances, and the answer is that it is never routinely permissible without those formal controls.

A mobile crane's load chart shows a capacity of 42 tons at a 30-foot radius on outriggers fully extended over the rear. The job requires a 38-ton pick at a 30-foot radius, but the lift must be made over the side at 90° from the rear centerline. The side capacity at 30 feet is 28 tons. The operator's BEST course of action is:

Answer: Reposition the crane so the pick falls within the rear quadrant of the load chart

The crane's rated side capacity at 30 feet is 28 tons—the lift at 38 tons would represent a 36% overload in that quadrant, which is extremely dangerous and illegal. Rear chart capacity is irrelevant when the swing position is over the side. Reducing the radius might help, but the question frames the lift requirement as fixed at 30 feet. The correct, conservative answer is to reposition the crane so the 38-ton pick falls within the rear quadrant where the 42-ton rating applies. Load charts are quadrant-specific; operators must never confuse rear capacity with side or front capacity.

A qualified rigger is inspecting a wire rope sling before a critical lift and finds the following: 3 broken wires in one rope lay, a 7% reduction in diameter from the nominal size, and evidence of kinking that has been straightened. Which finding ALONE is sufficient cause to immediately remove the sling from service?

Answer: The straightened kink

Under ASME B30.9, a wire rope sling must be removed from service if it has been kinked—even if the kink has been straightened. Kinking permanently damages the internal wire structure and load-path geometry; straightening restores visual appearance only, not structural integrity. For broken wires, the threshold for a 6-strand rope is 6 or more broken wires in one rope lay, so 3 wires alone does not meet the removal criterion. A diameter reduction of 6% or more (not 7%) for some sling types triggers removal—but 7% exceeds that threshold too; however, the kinking criterion is the clearest standalone disqualifier regardless of degree.

An operator is performing a pick-and-carry operation with a rough-terrain crane rated for this function. The load chart allows travel with a load only with the boom at minimum length and at a specific angle. During travel, the site spotter signals a sudden stop because a soft patch was not flagged on the ground survey. The operator should:

Answer: Brake smoothly and gradually to avoid dynamic load swing amplification

During pick-and-carry operations, sudden or hard braking dramatically amplifies the pendulum effect of the suspended load, creating dynamic load swings that can multiply the effective load moment and cause tipping. The correct technique is smooth, gradual deceleration to allow the load to remain as stable as possible. Lowering the load during travel over soft ground risks uncontrolled contact with the surface. Swinging the boom during an emergency travel stop is dangerous and can shift the center of gravity unpredictably. Firm braking is the wrong choice because of load swing amplification.