Practice Test GeeksNCCCO (National Commission for the Certification of Crane Operators) Practice Test
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Load Charts and Capacity Calculations Flashcards

7 cards from real NCCCO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

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  1. When using a load chart with a luffing jib attachment, what additional deduction must be applied to the main boom capacity?

    Answer: The weight of the jib and all associated rigging must be subtracted from the rated capacity

    The weight of the luffing jib assembly, including pins, rigging, and the jib hook block, must be subtracted from the main boom's rated capacity because the crane must support this weight before lifting any payload.

  2. A crane's load chart shows a capacity of 40,000 lbs at a 50-foot radius. If the total rigging weight is 800 lbs and the hook block weighs 600 lbs, what is the maximum net payload that can be lifted?

    Answer: 38,600 lbs

    The net payload equals the rated capacity minus all weight below the hook: 40,000 − 800 − 600 = 38,600 lbs.

  3. On a telescoping boom crane load chart, why do capacities typically decrease as boom length increases at the same radius?

    Answer: Longer booms increase structural stress and reduce stability, lowering the rated capacity

    Longer boom sections increase bending moment and reduce structural integrity margins, and the boom's own weight further reduces net lifting capacity at any given radius.

  4. A crawler crane load chart lists two sets of capacities: 'over front' and 'over side.' Which is typically greater and why?

    Answer: Over front, because the carbody and tracks provide greater tipping resistance in the longitudinal direction

    Crawler cranes have greater stability lifting over the front due to the longer longitudinal distance between the tipping fulcrum and the crane's center of gravity.

  5. What does the term 'structural capacity' mean on a load chart as opposed to 'stability capacity'?

    Answer: Structural capacity is limited by the strength of crane components, while stability capacity is limited by the crane's resistance to tipping

    At short radii, cranes are often structurally limited (component strength governs), while at longer radii, stability (tipping resistance) typically becomes the governing factor.

  6. A mobile crane load chart specifies capacities for 'on outriggers, fully extended.' The operator sets outriggers to 75% extension due to site constraints. What must the operator do?

    Answer: Use a manufacturer-provided derated chart or formula for intermediate outrigger positions

    ASME B30.5 requires that operators use manufacturer-provided charts for intermediate outrigger positions; interpolation is not permitted unless specifically authorized by the manufacturer.

  7. When determining working radius for a load chart lookup, from where is the radius measured?

    Answer: From the centerline of rotation to the center of the vertical hoist line with the load freely suspended

    Load chart radius is always measured horizontally from the crane's centerline of rotation to the center of the vertical load line with the load hanging freely.