22 Load Charts & Capacity Practice Questions & Answers

1. 1. A load chart line for the crane's exact configuration shows a gross rated capacity of 24,000 lb at the working radius. Hanging on the crane are a 1,100 lb hook block, a 360 lb overhaul ball that is reeved but not in use, and 340 lb of slings and shackles. What is the maximum weight of load that may be hooked?

   • A.22,560 lb
   • B.24,000 lb
   • C.22,200 lb✓ Answer
   • D.22,900 lb

   Chart ratings are gross values that already include the weight of every load-handling device, so each device must be subtracted to get net capacity: 24,000 - 1,100 - 360 - 340 = 22,200 lb. An overhaul ball that is reeved but not in use is still hanging on the crane and still counts.

   Source: ASME B30.5, Mobile and Locomotive Cranes — rated capacity charts include the weight of load-handling devicesReport a problem with this question

2. 2. The gross rated capacity at the configuration is 20,000 lb and the load-handling equipment deducts total 1,400 lb. The load together with its rigging weighs 16,740 lb. What percentage of the crane's capacity does this lift use?

   • A.83.7 percent
   • B.93 percent
   • C.90 percent✓ Answer
   • D.112 percent

   Percent of capacity is always figured against NET capacity, not gross: 20,000 - 1,400 = 18,600 lb net, and 16,740 / 18,600 = 0.90, or 90 percent. Comparing to the gross value flatters the number and hides how close the lift really is to the limit; a lift at this percentage demands a verified load weight, a measured radius, and smooth control to avoid dynamic loading.

   Source: NCCCO Mobile Crane Operator exam content outline — Manufacturers' Load Charts, determining net capacityReport a problem with this question

3. 3. For the boom length in use, the chart lists 15,600 lb at a 30 ft load radius and 12,900 lb at a 35 ft load radius. The measured load radius is 32 ft. A chart note states that for radii not listed, the rating at the next larger radius shall be used. What gross capacity applies?

   • A.12,900 lb✓ Answer
   • B.14,520 lb
   • C.15,600 lb
   • D.14,250 lb

   Load chart values are never averaged or interpolated upward. For a radius that falls between listed rows the chart note sends the operator to the next LARGER radius, which is always the more conservative value, so 12,900 lb governs. Both 14,250 lb (a straight average) and 14,520 lb (a proportional interpolation) would overstate what the crane may lift.

   Source: Manufacturer load chart operation notes — ratings for load radii not listedReport a problem with this question

4. 4. At the 40 ft load radius in use, the chart lists 9,800 lb for a 70 ft boom and 10,400 lb for an 80 ft boom. The boom is at 74 ft. A chart note states that for boom lengths not listed, the rating for the next longer or the next shorter boom length, whichever is smaller, shall be used. What gross capacity applies?

   • A.No lift is permitted at an unlisted boom length
   • B.10,400 lb
   • C.9,800 lb✓ Answer
   • D.10,100 lb

   The chart note governs, and it says to take whichever of the two adjacent boom lengths yields the SMALLER rating - here the 70 ft column at 9,800 lb. The popular shortcut of always going to the longer boom length fails on this line, because at this radius the longer boom is rated higher. Averaging the two cells is never permitted.

   Source: Manufacturer load chart operation notes — ratings for boom lengths not listedReport a problem with this question

5. 5. A boom extension (fly) capacity chart is entered by main boom angle and lists 8,200 lb at 70 degrees and 7,100 lb at 65 degrees. The boom angle is 68 degrees, and a chart note states that for angles not shown the next lower angle shall be used. What capacity applies?

   • A.8,200 lb
   • B.7,980 lb
   • C.7,650 lb
   • D.7,100 lb✓ Answer

   Fly and jib charts are read by boom angle, and a lower boom angle means a longer radius and therefore less capacity. For an angle between listed values the note directs the operator to the next LOWER angle, the conservative direction, so 7,100 lb applies. Interpolating between the two angles would credit the crane with capacity it does not have.

   Source: Manufacturer boom extension capacity chart notes — capacities read by boom angleReport a problem with this question

6. 6. The main boom chart shows a gross capacity of 26,000 lb at the working configuration. The chart's deduction list shows the boom extension at 900 lb when stowed on the boom base section and 4,400 lb when erected but not used. The extension is erected and offset, the lift is being made off the main boom head, and a 1,100 lb hook block and 500 lb of rigging are in use. What is the net capacity?

   • A.24,400 lb
   • B.23,500 lb
   • C.25,100 lb
   • D.20,000 lb✓ Answer

   An erected extension sits far out on the boom and costs far more capacity than the same extension stowed against the base section, which is why the chart lists two very different deducts. Because it is erected but not used, the larger figure applies: 26,000 - 4,400 - 1,100 - 500 = 20,000 lb. Using the 900 lb stowed deduct here would overstate net capacity by 3,500 lb.

   Source: Manufacturer load chart deduction notes — stowed versus erected boom extension deductionsReport a problem with this question

7. 7. For the boom length and radius the operator wants to use, the rated capacity chart shows no value at all - the cell is blank. What does a blank cell mean?

   • A.Operation at that boom length and radius is not intended or approved; the crane could overturn even with nothing on the hook, so the configuration must not be used✓ Answer
   • B.The capacity is the same as the value shown at the next shorter radius
   • C.The operator may use the smallest value printed anywhere on that chart page
   • D.Capacity there is limited only by available line pull, so the rope rating governs

   A blank cell is not a missing number to be filled in by judgment; it means the manufacturer never rated that combination. Beyond the no-load stability limit the boom and its load-handling equipment alone can overturn the machine, so the operator must change the configuration - shorten the radius, change boom length, or reconfigure the crane - rather than borrow a value from an adjacent cell.

   Source: ASME B30.5, Mobile and Locomotive Cranes — operation only within the rated capacity chartReport a problem with this question

8. 8. On a rated capacity chart, some capacities appear above a heavy (bold) line, or are marked with an asterisk. What does that indicate about those ratings?

   • A.They may be exceeded slightly because a safety margin is already built into them
   • B.They apply only when the crane is working on rubber
   • C.They are the only ratings based on 85 percent of the tipping load
   • D.They are limited by structural strength or hydraulic capability rather than by stability, so the crane can be overloaded to failure without ever giving a tipping warning✓ Answer

   Charts distinguish capacity limited by stability from capacity limited by other factors. Below the line the machine will start to tip before it breaks, which is a warning the operator can feel; above the line the boom, cylinders or structure is the limiting element, and it can fail suddenly with all four outriggers still firmly planted. That is why working in the structural range carries extra restrictions on the chart.

   Source: ASME B30.5 — capacities limited by structural competence versus capacities limited by stabilityReport a problem with this question

9. 9. Under the mobile crane standard, stability-based ratings are held to a stated percentage of the load that would tip the machine. Which pairing is correct?

   • A.85 percent of tipping on fully extended outriggers; 75 percent of tipping on rubber or on crawlers✓ Answer
   • B.100 percent of tipping on outriggers; 85 percent of tipping on rubber or on crawlers
   • C.90 percent of tipping on outriggers; 80 percent of tipping on rubber or on crawlers
   • D.75 percent of tipping on fully extended outriggers; 85 percent of tipping on rubber or on crawlers

   The mobile crane standard (ASME B30.5) sets stability-based ratings as a fraction of the tipping load determined by the crane stability test procedure. Outrigger ratings are held to 85 percent of tipping, while on tires or on crawlers the margin is widened to 75 percent because the support base is narrower and deflects under load. Neither figure is a licence to approach tipping - it is the built-in margin that already exists inside every chart number.

   Source: ASME B30.5, Mobile and Locomotive Cranes — stability-based rating percentagesReport a problem with this question

10. 10. The boom angle indicator suggests the load is at a 30 ft radius, but the radius measured on the ground from the centerline of rotation to the center of gravity of the load is 34 ft. Which value should be used to enter the load chart, and why?

    • A.30 ft, because the angle indicator is calibrated against the same chart
    • B.34 ft, the measured radius, because rated capacity is governed by the actual operating radius and boom angle only indicates radius✓ Answer
    • C.32 ft, the average of the two, since one reading is high and the other low
    • D.30 ft, because chart values already contain a margin that covers a few feet of error

    On a load chart, operating radius governs capacity; boom angle is shown only as an indication of radius and is a reference value once the load is applied. Indicators drift, the machine may be slightly out of level, and the boom deflects, so the measured horizontal distance from the axis of rotation to the load is the number that must be used - and 34 ft will also send the operator to a lower row of the chart.

    Source: ASME B30.5 — operating radius governs rated capacity; boom angle indicates radiusReport a problem with this question

11. 11. An operator booms out until the unloaded radius is exactly the charted radius for the intended load, then picks the load. What happens to the radius?

    • A.The radius stays the same, because the load hangs straight down from the boom tip
    • B.The radius decreases, because the boom angle rises when weight comes onto the hoist rope
    • C.The radius increases but capacity is unaffected, because the chart already assumes maximum deflection
    • D.The boom deflects under load and the load swings out to a larger radius, so the actual radius exceeds the chart radius and the available capacity is lower than planned✓ Answer

    Every boom deflects when loaded: the tip drops and moves outward, and the freely suspended load follows it to a longer radius. Because capacity falls as radius grows, the operator must set the unloaded boom at a higher angle and shorter radius than the chart line requires, then verify the radius again with the load just off the ground.

    Source: ASME B30.5 — boom deflection and operating radius under loadReport a problem with this question

12. 12. How is load radius defined for the purpose of reading a mobile crane load chart?

    • A.The horizontal distance from the axis of rotation to the center of the vertical hoist line or tackle with the load applied✓ Answer
    • B.The distance along the boom from the boom foot pin to the boom point
    • C.The horizontal distance from the boom point to the load's center of gravity
    • D.The distance from the outrigger float to the load on the ground

    Radius is measured horizontally from a projection of the axis of rotation to the center of the vertical hoist line with the load applied - not along the boom and not from any part of the carrier. It is measured with the load on, precisely because deflection moves the load outward from where the unloaded boom pointed.

    Source: ASME B30.5 — definition of load (operating) radiusReport a problem with this question

13. 13. A crane is set on outriggers and its chart identifies rated working areas. Which working area is generally the least stable, and what does that mean for a swing?

    • A.All areas are identical whenever the crane is on outriggers, so the working area diagram may be ignored
    • B.Over the rear; but once a load is picked anywhere it may be swung 360 degrees at that value
    • C.Over the front; the side and rear areas are always rated identically on outriggers
    • D.Over the side; the rating for the area the load will be swung into governs, so a load picked in a more favorable area may not be swung into the side area without re-checking the chart✓ Answer

    The bold lines on a working area diagram fix the limiting position of the load for each rated area, and over the side is the least stable because the horizontal distance from the axis of rotation to the tipping line between adjacent outriggers is shortest there. Swinging a load rated for one area into an area with a lower rating is a classic overturn scenario, so the lowest rating in the arc the load will travel through must govern the lift.

    Source: Manufacturer working area diagram notes; ASME B30.5 rated working areasReport a problem with this question

14. 14. Why are the on-rubber (on-tires) capacities on a crane's chart so much lower than the same crane's capacities on outriggers?

    • A.The counterweight must be removed before working on tires, which halves every rating
    • B.The hoist has less line pull when the crane is not on outriggers
    • C.The tires and suspension form a narrower support base that deflects under load, and on-rubber ratings are held to a lower percentage of the tipping load, so an entirely separate and lower chart applies✓ Answer
    • D.The boom cannot be fully extended when the crane is on tires, so the chart is shorter

    Outriggers push the tipping lines out to a wide, rigid footprint clear of the tires; on rubber the tipping lines close in and the sprung, deflecting tires let the load shift. The standard therefore rates on-rubber work to a wider stability margin, and the on-tires pages carry their own conditions - correct tire pressure, boom centered over the front, and limits on travel with a load.

    Source: ASME B30.5 — ratings for cranes operating on tiresReport a problem with this question

15. 15. An operator extends two outrigger beams fully and leaves the other two at an intermediate position. Which outrigger capacity chart may be used?

    • A.The intermediate chart, since it is the more conservative of the two
    • B.The fully extended chart, provided the load stays over the fully extended side
    • C.None; every beam must be set to the same listed position - fully retracted, intermediate, or fully extended - before any outrigger chart applies✓ Answer
    • D.The on-rubber chart, since the setup does not match any outrigger page

    Outrigger charts are published for specific, uniform spreads and are validated only for that footprint, with the beam pins engaged at the listed position and the tires free of the supporting surface. A mixed setup produces a tipping-line geometry the manufacturer never rated, and because the crane can swing, the short side will eventually carry the load - so the configuration must be corrected before the chart can be read at all.

    Source: ASME B30.5 and manufacturer outrigger chart notes — outrigger position requirementsReport a problem with this question

16. 16. A cell on the load chart carries a footnote stating that the rating applies only when the stated minimum counterweight is installed. The crane is rigged with less counterweight than the footnote requires. What may the operator do?

    • A.Use the rating as long as the load is kept at a short radius
    • B.Use the rating, since counterweight affects only backward stability with no load
    • C.Use the rating and simply subtract the weight of the missing counterweight from it
    • D.Not use that rating; the chart for the counterweight actually installed must be used, and if no capacity is listed there the lift cannot be made as planned✓ Answer

    Counterweight configuration is one of the things that selects which chart is valid, alongside outrigger spread, boom mode and attachment. A footnoted cell is gated: with less counterweight the machine's tipping behavior is different from the one the rating was derived from, and there is no arithmetic that converts one configuration's number into another's. The operator reads the chart that matches the machine as it actually stands.

    Source: Manufacturer load chart footnotes — minimum counterweight requirementsReport a problem with this question

17. 17. A total load of 27,000 lb - load plus all rigging and load-handling devices - is to be hoisted with wire rope whose permissible line pull is 8,500 lb per part. What is the minimum number of parts of line?

    • A.2 parts
    • B.5 parts
    • C.4 parts✓ Answer
    • D.3 parts

    Minimum parts of line is the total load divided by the permissible pull per part, always rounded UP to the next whole part: 27,000 / 8,500 = 3.18, so 4 parts are required. Three parts would give only 25,500 lb of permissible pull, which is less than the load, and a fraction of a part does not exist.

    Source: ASME B30.5 and ASME B30.30 — running rope design factors and parts of lineReport a problem with this question

18. 18. The net chart capacity at the working configuration is 30,000 lb. The hoist is reeved with 3 parts of line and the permissible line pull is 8,500 lb per part. What is the heaviest load that may actually be hoisted?

    • A.25,500 lb✓ Answer
    • B.30,000 lb
    • C.34,000 lb
    • D.55,500 lb

    Two separate limits apply and the smaller one always controls. The rope can lift 3 x 8,500 = 25,500 lb, which is less than the 30,000 lb the chart allows, so the reeving governs and 25,500 lb is the ceiling. The operator either accepts that figure or adds a part of line; the two limits are never added together.

    Source: ASME B30.5 — rope capability versus rated crane capacityReport a problem with this question

19. 19. An operator wants more capacity for a lift and adds two more parts of line to the reeving. What does that accomplish?

    • A.It raises the chart capacity only when the crane is on fully extended outriggers
    • B.It raises what the hoist rope may safely pull, but it does not raise the crane's rated chart capacity, which is set by stability and structural limits✓ Answer
    • C.It has no effect on either limit, since line pull is independent of reeving
    • D.It raises both the rope's capability and the chart capacity in the same proportion

    Parts of line divide the load among more falls of rope, so the rope side of the problem improves in direct proportion. The chart side does not move at all: the crane still tips or breaks at the same load and radius. Extra reeving also adds rope weight and slows the hoist, and reeving beyond what is needed must itself be accounted for as part of the load.

    Source: ASME B30.5 — parts of line and rated capacity are separate limitsReport a problem with this question

20. 20. A chart note states that when a clamshell bucket is used, the weight of the attachment plus its contents must not exceed 80 percent of the rated capacity. The rated capacity at the working configuration is 9,000 lb and the empty bucket with its rigging weighs 2,200 lb. What is the maximum weight of material the bucket may carry?

    • A.6,800 lb
    • B.5,000 lb✓ Answer
    • C.4,000 lb
    • D.7,200 lb

    Duty-cycle work is derated because digging, grabbing and dumping impose shock and side loads that a freely suspended lift does not. Apply the note first, then deduct the attachment: 80 percent of 9,000 = 7,200 lb allowed for attachment plus contents, minus the 2,200 lb bucket = 5,000 lb of material. Charts often add further limits on duty-cycle work, such as a maximum boom length or a minimum boom angle, and those apply as well.

    Source: Manufacturer load chart duty cycle note — clamshell and bucket operationReport a problem with this question

21. 21. A chart note requires that wire rope reeved in excess of the minimum required be accounted for as part of the load, at 1 lb for every extra foot of rope. The crane is reeved with one more part than the lift needs, which adds about 180 ft of rope. How does that enter the capacity calculation?

    • A.Ignore it, because rope weight is already included in the chart rating
    • B.Add 180 lb to the total load before comparing it with the net capacity✓ Answer
    • C.Deduct 180 lb from the parts-of-line capacity but not from the chart capacity
    • D.Subtract 180 lb from the load, because the extra part shares the weight

    Rope hanging between the boom head and the block is weight the crane is carrying at the working radius, exactly like the block itself. The chart rating assumes only the reeving the configuration requires, so every extra foot is added to the load side of the comparison - 180 extra feet at 1 lb per foot means 180 lb more load, not less.

    Source: Manufacturer load chart note — wire rope reeved in excess of the requirementReport a problem with this question

22. 22. A lift is made over the erected boom extension, whose chart capacity at the boom angle in use is 4,000 lb. A 1,100 lb main hook block remains reeved and hanging over the main boom head, and the rigging on the extension weighs 200 lb. What load may be hooked on the extension?

    • A.2,900 lb
    • B.4,000 lb
    • C.2,700 lb✓ Answer
    • D.3,800 lb

    When the lift is made over the extension, every load-handling device reeved over the main boom head is still hanging on the crane and is deducted directly from the extension's capacity, along with the rigging on the extension itself: 4,000 - 1,100 - 200 = 2,700 lb. Leaving the main block reeved is convenient but expensive, and forgetting it is one of the most common calculation errors.

    Source: Manufacturer boom extension capacity chart notes — deduction of devices reeved over the main boom headReport a problem with this question

Practice questions based on the published NCCCO mobile crane operator exam outlines and the consensus safety practices the trade runs on. CCO and NCCCO are marks of the National Commission for the Certification of Crane Operators; this site is not affiliated with or endorsed by NCCCO. Capacity always comes from the load chart for the machine and configuration in front of you, and wind, ground-bearing and permit limits are set by the manufacturer's manual and the authority having jurisdiction — never from a practice question. Confirm current exam requirements before testing. About CCO certification →