22 Operations & Operational Aids Practice Questions & Answers

1. 1. A mobile crane is equipped with a load moment indicator (LMI). Which statement correctly describes how the operator should use it?

   • A.The LMI measures the ground bearing pressure under the outriggers and confirms the setup is adequate.
   • B.The LMI replaces the load chart once the crane's configuration has been entered into it.
   • C.The LMI is an operator aid: the operator must still verify the load weight and the radius and work within the load chart.✓ Answer
   • D.The LMI allows the operator to keep lifting until the alarm sounds, because the alarm marks the crane's true limit.

   An LMI compares the load being lifted with the rated capacity for the configuration the operator has entered, so its output is only as good as that entry, its calibration and its sensors. Federal rules classify it as an operational aid, which by definition supplements — never replaces — the operator's own verification of weight and radius and the manufacturer's load chart, and rated capacity must never be reached by deliberately 'running into' the alarm.

   Source: OSHA 29 CFR 1926.1416, Operational aids; ASME B30.5, Mobile and Locomotive CranesReport a problem with this question

2. 2. During a shift the crane's load moment indicator stops working. Under the federal operational-aid rule, what is permitted?

   • A.Work may continue as long as every lift is kept below half of the chart capacity for that configuration.
   • B.Work may continue if the weight of each load is determined from manufacturer or shipping data or by a recognized calculation and given to the operator before the lift, and the device is repaired within the required period.✓ Answer
   • C.Work may continue with no further action, because an experienced operator can judge load weight by feel.
   • D.All crane operations must stop immediately and may not resume until the device is repaired and recalibrated.

   A load weighing device or load moment indicator is an operational aid, not a safety device, so its failure does not automatically take the crane out of service. The rule permits continued work only under the specified temporary alternative measure — the load weight is established from manufacturer or shipping data or a recognized calculation and given to the operator before the lift — with the repair completed inside the prescribed time.

   Source: OSHA 29 CFR 1926.1416, Operational aids (Category II devices and temporary alternative measures)Report a problem with this question

3. 3. Which device is a Category I operational aid — the group that must be repaired within the shortest time after a deficiency occurs?

   • A.Anti two-block device✓ Answer
   • B.Outrigger/stabilizer position sensor
   • C.Boom angle indicator
   • D.Hoist drum rotation indicator

   The federal operational-aid rule places only three devices in Category I — the boom hoist limiting device, the luffing jib limiting device and the anti two-block device — because each one guards against an immediate structural or dropped-load failure; these carry the 7-calendar-day repair deadline. Boom angle/radius indicators, jib angle indicators, boom length indicators, load weighing/LMI devices, outrigger position sensors and drum rotation indicators are Category II, with a 30-calendar-day deadline.

   Source: OSHA 29 CFR 1926.1416, Operational aids (Category I and Category II lists)Report a problem with this question

4. 4. A crane's boom hoist limiting device becomes inoperative and the required temporary alternative measures are put in place. When must the repair be completed?

   • A.No later than 7 calendar days after the deficiency occurs; if parts were ordered within 7 calendar days, no later than 7 calendar days after the parts are received.✓ Answer
   • B.At the next annual comprehensive inspection of the equipment.
   • C.Before the end of the work shift, with no exception.
   • D.Within 30 calendar days, or within 30 calendar days after replacement parts arrive.

   The boom hoist limiting device is a Category I operational aid, and the federal rule sets a 7-calendar-day repair deadline for that category, with a single exception: if parts were ordered within those 7 calendar days, the repair must be finished within 7 calendar days of receiving the parts. The same parts exception applies to Category II aids, whose base deadline is 30 calendar days.

   Source: OSHA 29 CFR 1926.1416, Operational aids (Category I repair deadline)Report a problem with this question

5. 5. The anti two-block device on a telescopic boom crane has failed and parts are on order. Which temporary measure allows work to continue?

   • A.Mark the hoist cable at a point that gives the operator sufficient warning, and/or use a spotter, including while the boom is being extended.✓ Answer
   • B.Reeve additional parts of line so that the load block physically cannot reach the boom tip.
   • C.Rely on the load moment indicator, which will alarm before the block reaches the boom tip.
   • D.Restrict all lifts to no more than 75 percent of the chart value for the configuration.

   The prescribed temporary alternative measure for an inoperative anti two-block device is to mark the hoist cable at a point that gives adequate warning and/or use a spotter, and on a telescopic machine that watch must also be kept while the boom is being extended, because telescoping out draws the block toward the tip. Extra parts of line and the LMI do nothing to prevent two-blocking, and the device is Category I, so it must still be repaired within the short deadline.

   Source: OSHA 29 CFR 1926.1416, Operational aids (anti two-block device, temporary alternative measures)Report a problem with this question

6. 6. What distinguishes an anti two-block warning device from an anti two-block prevention device, and which is required when hoisting personnel?

   • A.The prevention device only lights an indicator lamp while the warning device sounds a horn; neither one is required for hoisting personnel.
   • B.The warning device automatically stops the function while the prevention device only alarms; the warning device is the one required for hoisting personnel.
   • C.They are the same device under two names, and either one may be used when hoisting personnel.
   • D.The warning device only alerts the operator, while the prevention device automatically stops the function that would cause two-blocking; a functioning automatic prevention device is required when hoisting personnel.✓ Answer

   A two-block warning device gives the operator an alarm and leaves the correction to human reaction, whereas a prevention system interrupts the hoist, telescope or boom function itself before contact can occur. Because a two-block failure over a suspended platform would drop the load line on the occupants, the personnel-hoisting rule requires an automatic prevention device that is functioning, not merely a warning.

   Source: OSHA 29 CFR 1926.1431, Hoisting personnel; 29 CFR 1926.1416, Operational aidsReport a problem with this question

7. 7. The hoist drum is not turning and the load hangs stationary below the boom tip. Which operator action can still bring the load block up against the boom tip?

   • A.Swinging the upperworks to the right
   • B.Retracting the boom
   • C.Extending (telescoping) the boom out✓ Answer
   • D.Setting the swing brake

   Two-blocking is contact between the load block, hook or overhaul ball and the boom tip assembly, and it does not require hoisting. Telescoping the boom out moves the tip away from the drum, so rope is drawn out of the hanging portion of the line and the block rises toward the tip; boom hoist movement can close the same gap. The result can shear the rope and drop the load, so an anti two-block device or a marked cable and spotter is essential during these functions.

   Source: OSHA 29 CFR 1926.1416, Operational aids; ASME B30.5, Mobile and Locomotive CranesReport a problem with this question

8. 8. While the operator is telescoping the boom out, the anti two-block alarm sounds. What should the operator do FIRST?

   • A.Continue extending slowly while watching the block, then boom down to finish the move.
   • B.Swing away from the load and set it down in a clear area.
   • C.Stop the function that is closing the gap immediately, then create clearance by paying out the load line or retracting the boom.✓ Answer
   • D.Increase engine speed to complete the extension before the block reaches the tip.

   The alarm means the block is approaching the boom tip, so the only correct first step is to stop the function that is causing the approach; continuing it, or adding another function, keeps closing the gap. Clearance is then restored by reversing the cause — paying out the load line or retracting the boom — because powering through a two-block condition can part the hoist rope and drop the load.

   Source: ASME B30.5, Mobile and Locomotive Cranes; OSHA 29 CFR 1926.1417, OperationReport a problem with this question

9. 9. Before starting work the operator finds that the crane level indicator is not working. What is required?

   • A.Work may continue at reduced capacity until the next scheduled inspection.
   • B.Operations must not begin; the level indicator is a required safety device, and the equipment must be taken out of service until it works properly.✓ Answer
   • C.Work may continue for up to 7 calendar days if a spotter watches the outriggers during each lift.
   • D.Work may continue for up to 30 calendar days as long as the operator checks level with a hand level.

   The crane level indicator is listed as a safety device along with boom stops, jib stops, foot-pedal brake locks, integral holding devices on hydraulic outrigger and stabilizer jacks, rail clamps and the horn. Operations must not begin unless every one of these is in proper working order, and if one fails during operation the operator stops safely and the equipment goes out of service — there are no temporary alternative measures and no repair grace period for safety devices, which is exactly what separates them from operational aids.

   Source: OSHA 29 CFR 1926.1415, Safety devicesReport a problem with this question

10. 10. The boom angle/radius indicator is inoperative. Which temporary measure allows the crane to keep working?

    • A.Determine the radius or boom angle by physically measuring it with a measuring device for each configuration that will be used.✓ Answer
    • B.Estimate the radius by counting the operator's paces from the crane to the load.
    • C.Substitute the boom length indicator reading for the radius.
    • D.Stop all lifting until the indicator is repaired and recalibrated.

    The boom angle or radius indicator is a Category II operational aid, so work may continue only under its specified temporary measure: the radius or angle is physically measured with a measuring device rather than estimated. Pacing is an estimate, and boom length alone does not give radius, since radius depends on boom angle and on deflection under load; the device must still be repaired within the Category II deadline.

    Source: OSHA 29 CFR 1926.1416, Operational aids (boom angle or radius indicator, temporary alternative measures)Report a problem with this question

11. 11. What is the purpose of a hoist drum rotation indicator, and what temporary measure applies if it fails?

    • A.It weighs the load hanging on the line; if it fails, the load weight is taken from shipping papers.
    • B.It counts the parts of line reeved through the load block; if it fails, the operator recounts the parts of line each morning.
    • C.It measures wire rope wear and stretch; if it fails, the rope must be replaced before further use.
    • D.It shows the operator that the drum is turning and in which direction when the drum is not visible from the operator's station; if it fails, the drum can be marked and mirrors or video added as needed.✓ Answer

    A drum rotation indicator exists because on many machines the operator cannot see the hoist drum from the cab and needs positive confirmation that the drum is moving and in which direction, particularly when starting a lift or lowering. It is a Category II operational aid, and the prescribed temporary measure is to mark the drum so rotation is visible, adding mirrors or video if that is what it takes for the operator to see the mark.

    Source: OSHA 29 CFR 1926.1416, Operational aids (hoist drum rotation indicator)Report a problem with this question

12. 12. Why can starting or stopping a load abruptly overload a crane that is lifting less than its chart capacity?

    • A.Because rated capacities are static values; abrupt acceleration or deceleration adds dynamic force, so the load imposes more on the crane than its static weight.✓ Answer
    • B.Because the chart capacities already include a built-in allowance for shock loading, which is then used up.
    • C.Because sudden movement shifts the load's center of gravity into a lighter position.
    • D.Because the hoist rope stretches under sudden movement, which increases the load radius but not the load.

    Load chart values are static ratings; they do not contain an allowance for the extra force created when a mass is accelerated or decelerated. Snatching a stuck load, taking up slack rope suddenly or stopping a descending load quickly all impose a dynamic force on top of the static weight, which is why smooth control movements and reduced speeds are required rather than optional.

    Source: ASME B30.5, Mobile and Locomotive Cranes (operating practices, dynamic loading)Report a problem with this question

13. 13. What happens to a suspended load when the operator swings too fast and then stops the swing abruptly?

    • A.The load becomes effectively lighter because centrifugal force carries part of its weight.
    • B.The load stays directly under the boom tip at all times, so swing speed has no effect on radius.
    • C.The load moves inward toward the crane, shortening the radius and increasing available capacity.
    • D.The load swings outward like a pendulum, increasing the operating radius and reducing capacity, and it side loads the boom as it travels out of the boom's vertical plane.✓ Answer

    A suspended load is a pendulum: swing acceleration throws it outward, and the greater the swing speed the farther out it rides. Because capacity falls as radius grows, the crane can be inside the chart at the pick and outside it in mid-swing, and the out-of-plane position also applies side force to a boom that is designed to carry load vertically. The control is slow, smooth swing starts and stops with the load kept under the boom tip.

    Source: ASME B30.5, Mobile and Locomotive Cranes (operating practices, swinging the load)Report a problem with this question

14. 14. Why is using a mobile crane to drag a load sideways prohibited even when the load weighs far less than the chart capacity?

    • A.Because the drag force invalidates the load moment indicator's calibration until it is reset.
    • B.Because chart capacities assume dragging is done only with the boom fully retracted and at maximum angle.
    • C.Because dragging wears out the tires or track pads faster than normal travel.
    • D.Because booms are designed to carry load vertically, and side loading can buckle or structurally damage a boom at forces far below the rated capacity — a side force that no load chart accounts for.✓ Answer

    Boom structures — lattice and telescopic alike — are engineered for load applied along their vertical plane, and the load chart rates only that condition. Dragging a load laterally, or pulling at an angle, introduces a bending and torsional side force that can buckle a lattice boom or damage a telescopic boom's sections long before the chart weight is reached, so the practice is prohibited outright rather than limited by weight.

    Source: ASME B30.5, Mobile and Locomotive Cranes (side loading and dragging prohibited); OSHA 29 CFR 1926.1417, OperationReport a problem with this question

15. 15. As a load is picked up, what should the operator expect the boom to do, and what is the operational effect?

    • A.The boom deflects downward under load, so the actual loaded radius is greater than the radius measured before the pick, and the radius must be verified with the load applied.✓ Answer
    • B.The boom rises slightly, shortening the radius, so the available capacity increases as the load leaves the ground.
    • C.The boom twists sideways under load, which is normal on modern cranes and requires no action.
    • D.The boom remains perfectly rigid, and any radius measured before the pick stays valid throughout the lift.

    Every boom deflects when load is applied: the tip drops and moves outward, which increases the operating radius beyond whatever was measured with the hook empty. Since capacity decreases as radius increases, a lift planned at the unloaded radius can be over capacity once the load is off the ground, so the radius must be verified in the actual loaded condition.

    Source: ASME B30.5, Mobile and Locomotive Cranes (determining load radius under load)Report a problem with this question

16. 16. How does free fall lowering differ from power-controlled lowering, and when is free fall of the load line prohibited?

    • A.Free fall is the safer method because it removes drive-train forces from the boom, and it is prohibited only in high wind.
    • B.In free fall the drum is released and the load descends under gravity with only the brake to control it, which invites shock loading and loss of control; free fall of the load line is prohibited when hoisting personnel.✓ Answer
    • C.In free fall the engine drives the drum downward, which gives the most precise placement, and it is prohibited only on rubber tires.
    • D.There is no practical difference between the two; the terms describe the same drum function on different crane types.

    In power-controlled lowering the drive train holds and meters the load down, so speed is controlled at all times; in free fall the drum is declutched and only the brake stands between the load and the ground, which makes overspeed, shock loading when the brake is applied and loss of control far more likely. For that reason the personnel-hoisting rule forbids free fall of the load line and requires boom hoist controls at their most controlled setting.

    Source: OSHA 29 CFR 1926.1431, Hoisting personnel; ASME B30.5, Mobile and Locomotive CranesReport a problem with this question

17. 17. Which of the following is required for a multi-crane (tandem) lift?

    • A.Nothing beyond confirming that the combined chart capacities of the two cranes exceed the weight of the load.
    • B.That both cranes be of identical type and boom length, after which the standard single-crane procedures apply unchanged.
    • C.A written lift plan prepared and supervised by a qualified person, an analysis of how the load is shared between the cranes, one designated signal person, reduced (derated) capacities, and slow, synchronized crane movements.✓ Answer
    • D.Each operator working independently at full chart capacity, each taking direction from his own signal person.

    In a tandem lift the share of the load carried by each crane changes as the load tilts, as the cranes swing or travel, and as radii change, so the lift must be planned in writing and directly supervised by a qualified person. Capacities are reduced below chart values to absorb that uncertainty, one signal person coordinates so the machines move together, and function speeds are kept slow and synchronized.

    Source: ASME B30.5, Mobile and Locomotive Cranes (multiple crane lifts); OSHA 29 CFR 1926.1417, OperationReport a problem with this question

18. 18. When a crane is used to hoist employees on a suspended personnel platform, the total load must not exceed what portion of the crane's rated capacity for that radius and configuration?

    • A.100 percent
    • B.50 percent✓ Answer
    • C.25 percent
    • D.75 percent

    The federal personnel-hoisting rule caps the total load — platform, occupants, tools and rigging — at 50 percent of the rated capacity for the radius and configuration in use, building in a large margin because a failure would injure people rather than damage cargo. The same rule adds a functioning automatic anti two-block prevention device, a proof test of the platform and rigging to 125 percent, a trial lift immediately before the shift, no free fall of the load line, and a stop to hoisting personnel when sustained wind at the platform exceeds 20 miles per hour.

    Source: OSHA 29 CFR 1926.1431, Hoisting personnelReport a problem with this question

19. 19. How does the operator determine the wind speed at which a particular lift must be stopped?

    • A.A single limit of 20 miles per hour applies to all crane operations regardless of configuration.
    • B.From the crane manufacturer's operating manual and wind information for the configuration in use, because the limit depends on boom length, attachments and the sail area of the load.✓ Answer
    • C.A single limit of 30 miles per hour is the accepted industry standard for every mobile crane.
    • D.Whenever the wind indicator alarms, since the alarm point is factory set to the safe limit for any crane.

    Allowable wind is configuration-dependent: a long boom, a jib or a large sail-area load can force a reduction long before a shorter, compact configuration would, so the governing limit is the one published by the manufacturer for the machine as it is rigged. The wind indicator is an operator aid that tells the operator what the wind is doing, not what the crane can stand; the one wind figure fixed by federal rule is the 20 mile-per-hour sustained wind limit for hoisting personnel on a suspended platform.

    Source: ASME B30.5, Mobile and Locomotive Cranes (wind and manufacturer's limitations); OSHA 29 CFR 1926.1431, Hoisting personnelReport a problem with this question

20. 20. At the end of the shift the operator is shutting the crane down and leaving it unattended. Which procedure is correct?

    • A.Leave the boom at a high angle with the hook block hanging free so the crane is ready to work in the morning.
    • B.Land the load, place the boom in the position specified by the manufacturer, apply the swing and travel brakes and locks, put the controls in neutral, shut down according to the procedure, and secure the crane against unauthorized use.✓ Answer
    • C.Leave the engine idling with the controls live so the crane can be repositioned by others if the site needs it.
    • D.Leave the load suspended a short distance off the ground so it is in position for the next shift.

    Securing an unattended crane means removing every stored hazard: the load is landed, the boom is placed where the manufacturer specifies for the machine and the expected weather, swing and travel brakes or locks are set so wind cannot move the machine, controls are neutralized and start-up is disabled against unauthorized use. A suspended load may never be left unattended, and an operator may stay away from the controls with a load suspended only under the narrow conditions the standard specifies.

    Source: OSHA 29 CFR 1926.1417, Operation (leaving equipment unattended, shutdown and securing); ASME B30.5, Mobile and Locomotive CranesReport a problem with this question

21. 21. A load must be guided as it is swung into place and landed. Which practice is correct?

    • A.Have a worker place a hand on the load and walk beneath it so the load can be felt and steadied all the way down.
    • B.Leave the load suspended and unattended while workers move into the landing area to prepare it.
    • C.Let the load rotate freely and have workers stand directly under it to catch it as it comes down.
    • D.Use a tagline that is long enough to keep the handler out of the fall zone, held in the hand and never wrapped around the hand, wrist or body.✓ Answer

    A tagline controls rotation and swing from outside the fall zone, which is the whole point of using one: no employee is permitted under a suspended load, and only those hooking, unhooking or guiding a load that is under control may be in the fall zone at all. Wrapping the line around the hand or body removes the worker's ability to let go if the load moves unexpectedly, and a suspended load is never left unattended.

    Source: OSHA 29 CFR 1926.1425, Keeping clear of the load; ASME B30.5, Mobile and Locomotive CranesReport a problem with this question

22. 22. With a load suspended and the crane part-way through a swing, the operator feels the machine go light and the overload alarm sounds. What is the correct immediate response?

    • A.Continue booming out to reach the intended landing point and set the load down.
    • B.Swing quickly to the nearest open area and release the load there.
    • C.Stop, then reduce the load moment by lowering the load straight down at the shortest safe radius, or by booming up or retracting — never by swinging or booming out.✓ Answer
    • D.Increase engine speed and hoist the load higher to regain stability.

    Going light and alarming means the crane is at or beyond its capacity for the current radius, so anything that increases radius or shifts the load over a weaker quadrant makes it worse: swinging can move the load over the least stable part of the machine and booming out lengthens the lever arm. The reflex is to stop, then unload the machine by shortening the radius — boom up or retract — or by lowering the load vertically to the ground at the shortest safe radius, and only then investigate the weight and setup.

    Source: ASME B30.5, Mobile and Locomotive Cranes (operating practices, overload and loss of stability); OSHA 29 CFR 1926.1417, OperationReport 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 →