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Red Seal Mobile Crane Operator study materials
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Red Seal Mobile Crane Operator practice questions

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Question 1Occupational health and safety, legislation, and regulatory compliance

Under Canadian mobile crane practice, who holds the primary legal duty to ensure a lift plan is prepared and followed before a tandem lift begins?

  1. The site's first-aid attendant on shift
  2. The rigger with the most seniority on the crew
  3. The employer, who must ensure the work is planned, supervised and performed safely Correct answer.
  4. The crane rental company's dispatcher, who schedules both cranes

Explanation

Occupational health and safety legislation across Canadian jurisdictions places the general duty on the employer to plan, organize, supervise and monitor the work, including lift planning for multi-crane operations. Supervisors and workers have supporting duties, but the overarching obligation to establish and enforce the plan rests with the employer.

Question 2Occupational health and safety, legislation, and regulatory compliance

A crane operator notices a defect in the load moment indicator during the pre-shift inspection. What is the required course of action under typical provincial OHS rules?

  1. Continue lifting at reduced capacity while logging the defect
  2. Ask the rigger to watch the boom angle manually instead
  3. Take the crane out of service until the defect is corrected and documented Correct answer.
  4. Report the defect at the end of the shift and keep working

Explanation

Safety devices and limiting indicators must be functional before a crane is used; a defective load moment indicator removes a critical safeguard. The equipment must be removed from service, repaired and the repair verified and recorded before work resumes.

Question 3Occupational health and safety, legislation, and regulatory compliance

What does the term 'competent person' mean when applied to a crane operator or rigger in Canadian OHS legislation?

  1. A person who is qualified by training and experience and familiar with the relevant hazards and controls Correct answer.
  2. A person designated in writing by the prime contractor regardless of training
  3. A person with at least ten years of documented crane experience
  4. A person holding a Red Seal certificate in any trade

Explanation

The statutory definition of a competent person combines qualification through training, experience and knowledge with practical familiarity with the work and its hazards. Certification alone, or designation alone, does not satisfy the definition unless the person is genuinely qualified.

Question 4Occupational health and safety, legislation, and regulatory compliance

Which document must a crane operator be able to produce on request to demonstrate the crane has been inspected and maintained as required?

  1. The crane's inspection and maintenance records Correct answer.
  2. The bill of lading for the last load
  3. The operator's personal logbook of hours worked
  4. The site orientation sign-off sheet

Explanation

Regulations require that inspection, testing and maintenance records for the equipment be kept and made available to the operator and to an officer on request. These records demonstrate that required inspections were performed and defects corrected.

Question 5Occupational health and safety, legislation, and regulatory compliance

A worker on the crew refuses to operate a crane because the outrigger pad is sinking into soft ground. Under OHS legislation, what protection applies to that worker?

  1. The worker is protected from reprisal for refusing unsafe work Correct answer.
  2. The worker may be disciplined for delaying the schedule
  3. The worker must continue and file a complaint afterwards
  4. The worker loses pay for the remainder of the shift automatically

Explanation

OHS statutes provide a right to refuse work that the worker has reasonable cause to believe is dangerous, and prohibit reprisal against a worker for exercising that right. The refusal must be reported and the hazard investigated through the prescribed process.

Question 6Occupational health and safety, legislation, and regulatory compliance

Before a crane is erected or climbed on a project, what must the employer ensure regarding the manufacturer's instructions?

  1. The instructions are filed on site but need not be followed
  2. The crew may improvise if the manufacturer's manual is unavailable
  3. The erection is performed in accordance with the manufacturer's specifications by qualified persons Correct answer.
  4. Only the crane owner must review the instructions

Explanation

Erection, climbing and dismantling must follow the manufacturer's instructions and be carried out by qualified persons under competent supervision. Deviating from the manufacturer's procedures can compromise structural integrity and void the equipment's design assumptions.

Question 7Occupational health and safety, legislation, and regulatory compliance

A crane is set up beside an energized overhead power line. The operator cannot confirm the line's voltage and the utility has not been contacted. What is the correct regulatory approach?

  1. Lower the boom and lift only when the line appears quiet
  2. Proceed if a spotter stands near the line and watches the boom
  3. Maintain the legislated minimum approach distance for the known or assumed voltage and arrange a utility disconnect if the distance cannot be kept Correct answer.
  4. Wrap the conductor with tape and continue lifting

Explanation

OHS rules set minimum approach distances based on line voltage, and where those distances cannot be maintained the line must be de-energized and grounded or otherwise controlled by the utility. A spotter does not substitute for the required clearance or isolation.

Question 8Occupational health and safety, legislation, and regulatory compliance

During a lift, the operator must leave the controls briefly. What does safe practice and typical regulation require?

  1. Lower the load, set the brake, and shut down or secure the machine per the manufacturer before leaving Correct answer.
  2. Ask a nearby worker to hold the boom control lever
  3. Leave the engine running and the controls unlocked for a quick return
  4. Leave the load suspended and post a warning sign

Explanation

An operator must not leave the controls with a load suspended or the machine in an unsafe state. The load is landed, brakes set and the machine secured according to the manufacturer before the operator leaves the station.

Question 9Occupational health and safety, legislation, and regulatory compliance

Which statement best describes the employer's obligation regarding a suspended load over a walkway used by other trades?

  1. Only persons wearing high-visibility vests may pass beneath
  2. A warning horn sounded before each lift is sufficient
  3. Workers may pass beneath if the load is slung with two slings
  4. The area beneath the load must be cleared of workers and barricaded against entry Correct answer.

Explanation

No worker may stand or pass under a suspended load; the employer must establish an exclusion zone and barricade it so that access is prevented. Horn warnings and PPE do not replace physical exclusion.

Question 10Occupational health and safety, legislation, and regulatory compliance

A mobile crane is being operated on a public road to travel between two work areas. Which regulatory requirement typically applies?

  1. The crane may travel without lights if escorted
  2. Only the crane's load chart must be carried in the cab
  3. The crane and operator must meet road traffic licensing and the crane must be in safe operating condition Correct answer.
  4. No requirements apply because the crane is not lifting

Explanation

When a crane travels on a public highway it becomes a vehicle subject to traffic law, including licensing, registration and equipment condition, in addition to OHS requirements. The operator must hold the appropriate licence and the machine must be roadworthy.

Question 11Occupational health and safety, legislation, and regulatory compliance

What is the purpose of a notice of project or project registration filed with the OHS regulator for certain crane operations?

  1. To transfer liability for the lift from the employer to the regulator
  2. To obtain permission to exceed the load chart
  3. To notify the regulator of higher-hazard work so that it can be tracked or inspected Correct answer.
  4. To certify that the crane operator is competent

Explanation

Many jurisdictions require notification or registration for specified high-hazard activities, allowing the regulator to identify and monitor the work. It does not shift legal duties, certify individuals or authorize load chart exceedance.

Question 12Occupational health and safety, legislation, and regulatory compliance

A rigger is asked to use a sling that has a frayed section and an illegible capacity tag. What does the regulation require?

  1. Remove the sling from service and tag it as defective Correct answer.
  2. Use the sling only for light loads under 500 kg
  3. Use the sling at half its estimated capacity
  4. Cover the frayed area with tape and proceed

Explanation

Rigging hardware with damage or missing capacity identification must be withdrawn from service and clearly tagged so it cannot be returned to use accidentally. Capacity cannot be assumed when the tag is illegible.

Question 13Occupational health and safety, legislation, and regulatory compliance

Which of the following best describes a supervisor's duty during a critical lift on a construction site?

  1. To ensure the work is carried out safely and in accordance with the lift plan and procedures Correct answer.
  2. To personally operate the crane if the operator is delayed
  3. To approve changes to the lift plan without consulting the operator
  4. To sign the payroll for the crew performing the lift

Explanation

A supervisor must ensure that workers are supervised and that work follows established plans and safe procedures, including the lift plan. The supervisor does not take over operator functions or unilaterally alter the plan without proper review.

Question 14Occupational health and safety, legislation, and regulatory compliance

What must be verified about a crane's annual or periodic inspection before the machine is placed into service on a new project?

  1. That the inspection report is kept only in the owner's office
  2. That the inspection was completed at any time in the crane's life
  3. That the inspection was performed within the interval required by regulation and defects were corrected Correct answer.
  4. That the inspection was done by the operator's co-worker

Explanation

Periodic inspections must be performed at the intervals set by regulation or the manufacturer, and any defects found must be corrected before the crane is used. Records must be available to those who need them, not stored away from the site.

Question 15Occupational health and safety, legislation, and regulatory compliance

A crew plans to lift a load whose weight is unknown and whose rigging geometry has not been confirmed. Which action complies with lift planning requirements?

  1. Estimate the weight from the load's appearance and proceed
  2. Lift a few centimetres and judge by the crane's response
  3. Proceed using the crane's maximum capacity as a safety margin
  4. Stop and determine the load weight and rigging configuration before lifting Correct answer.

Explanation

A lift cannot be planned without knowing the load weight, the rigging arrangement and the resulting forces on the crane. The weight must be determined by calculation, documentation or weighing before the lift proceeds.

Question 16Occupational health and safety, legislation, and regulatory compliance

Under OHS legislation, what is the worker's duty when a hazard is identified during crane operations?

  1. Report the hazard to the supervisor and, where authorized, take action to control it Correct answer.
  2. Document the hazard only at the end of the project
  3. Fix the hazard without informing anyone
  4. Ignore the hazard if it is outside the worker's trade

Explanation

Workers must report hazards and unsafe conditions to their supervisor and cooperate with controls, and may take action within their authority to prevent injury. Silence or unilateral undocumented fixes undermine the internal responsibility system.

Question 17Occupational health and safety, legislation, and regulatory compliance

A crane with a lattice boom is being assembled near a live electrical substation. Which control hierarchy element must be considered first?

  1. Eliminating the hazard by arranging a utility de-energization or relocation Correct answer.
  2. Providing rubber gloves to the assembly crew
  3. Scheduling assembly for a windy day
  4. Posting warning signs at the site entrance

Explanation

The hierarchy of controls calls for eliminating the hazard first, which in this case means having the utility de-energize, ground or relocate the conductors. PPE, signage and scheduling are lower-order measures used when elimination is not reasonably possible.

Question 18Occupational health and safety, legislation, and regulatory compliance

Two employers share a project site where one employer's crane will lift loads over the other's work area. What does the internal responsibility system require?

  1. The crane owner assumes all duties for the other employer's workers
  2. The regulator must supervise every lift
  3. Each employer works independently with no coordination
  4. The parties coordinate to identify and control hazards that affect each other's workers Correct answer.

Explanation

Where multiple employers work at the same site, they must coordinate their activities so that hazards created by one are communicated and controlled for the others. This shared coordination duty is a core feature of the internal responsibility system.

Question 19Occupational health and safety, legislation, and regulatory compliance

An operator is directed to make a lift that would exceed the load chart for the configured boom length and radius. Which response is correct under OHS law and crane practice?

  1. Comply because a supervisor gave a direct instruction
  2. Reduce the boom angle to gain capacity beyond the chart
  3. Refuse the lift and report the unsafe direction through the established process Correct answer.
  4. Make the lift but record the overload in the log

Explanation

A load chart limit is a manufacturer's design limit, and an instruction to exceed it is an unsafe work direction that the operator must not follow. The operator should refuse, report the matter and have the lift re-planned within rated capacity.

Question 20Occupational health and safety, legislation, and regulatory compliance

After a crane contacts an energized line and the operator is uninjured, what sequence best reflects regulatory and safe practice?

  1. The operator climbs down immediately and inspects the boom
  2. The operator remains in the cab, warns others away, and has the line de-energized before exiting Correct answer.
  3. The operator restarts the lift once the boom stops sparking
  4. The crew approaches and pulls the operator from the cab

Explanation

Contact with an energized line can energize the entire crane, so the operator should stay in the cab and keep others clear until the utility confirms de-energization. Leaving the machine or being touched by rescuers can complete a circuit and cause fatal shock.

Question 21Rigging, load calculation, and lift planning

A two-leg sling bridle has legs at 60 degrees to the horizontal, each leg carrying 5 tonnes of tension. What is the approximate vertical load being supported?

  1. About 4.3 tonnes
  2. About 5.0 tonnes
  3. About 8.7 tonnes Correct answer.
  4. About 10.0 tonnes

Explanation

The vertical component of each leg is tension times the sine of the angle to horizontal, so 5 x sin 60 degrees equals about 4.33 tonnes per leg. Two legs give roughly 8.66 tonnes of vertical load.

Question 22Rigging, load calculation, and lift planning

When is a lift plan required for a mobile crane operation?

  1. Only when two cranes perform a tandem lift
  2. Only when personnel will be suspended under the load
  3. Whenever the lift is complex, critical, or exceeds routine criteria set by the employer Correct answer.
  4. Only when the load exceeds 90 percent of the chart capacity

Explanation

A documented lift plan is required for non-routine or critical lifts as defined by the employer's lift classification, which typically includes heavy loads, blind lifts, or proximity to hazards. Routine lifts within pre-defined limits may proceed under standard procedures.

Question 23Rigging, load calculation, and lift planning

What does the load moment of a mobile crane represent?

  1. The total counterweight installed on the crane
  2. The weight of the load divided by the boom length
  3. The angle between the boom and the horizontal
  4. The product of the load weight and the radius from the crane's rotation axis Correct answer.

Explanation

Load moment is the turning effect of the load about the crane's tipping axis, calculated as load weight multiplied by working radius. It is the basis for the capacity charts, which reduce allowable load as radius increases.

Question 24Rigging, load calculation, and lift planning

A load weighs 12 tonnes and the crane's working radius is 10 metres. The capacity chart shows 14 tonnes at 10 metres. What is the net capacity utilization?

  1. About 120 percent
  2. About 86 percent Correct answer.
  3. About 117 percent
  4. About 71 percent

Explanation

Utilization is load divided by rated capacity, so 12 divided by 14 equals approximately 0.857, or about 86 percent. The lift remains within chart capacity but is close enough to warrant careful planning.

Question 25Rigging, load calculation, and lift planning

What is the primary purpose of using a load chart's deduction for the lifting attachment?

  1. To account for wind loading on the boom
  2. To convert the boom length into a working radius
  3. To increase the allowable load by the weight of the hook block
  4. To ensure the gross load including rigging does not exceed the rated capacity Correct answer.

Explanation

Rated capacities are gross loads, so the weight of the hook block, slings, spreader bars, and other attachments must be subtracted from the chart value to determine the net load that can be lifted. Ignoring these deductions can overload the crane.

Question 26Rigging, load calculation, and lift planning

A wire rope sling is choked around a bundle. Compared to the same sling used in a vertical hitch, what happens to its rated capacity?

  1. It decreases because of the bend and the choke angle Correct answer.
  2. It increases because the bundle is gripped more tightly
  3. It remains identical because the rope is the same
  4. It is unaffected as long as the load is balanced

Explanation

A choker hitch derates the sling because the rope bends sharply around itself and the choke angle reduces the effective strength. Manufacturers publish choker capacity factors, commonly around 75 to 80 percent of vertical capacity.

Question 27Rigging, load calculation, and lift planning

What is the effect of a larger included angle between sling legs on the tension in each leg?

  1. Tension decreases as the angle widens
  2. Tension becomes equal to the load weight at any angle
  3. Tension increases as the angle widens Correct answer.
  4. Tension stays the same regardless of angle

Explanation

As the included angle between legs increases, each leg must carry a larger share of the load along a steeper direction, so tension rises. At 120 degrees the tension in each leg equals the full load weight.

Question 28Rigging, load calculation, and lift planning

What is the minimum required capacity marking on a synthetic web sling used in lifting?

  1. Only the sling length
  2. The manufacturer's rated capacity for each hitch type Correct answer.
  3. The color of the sling only
  4. Only the date of manufacture

Explanation

Synthetic web slings must carry a legible tag showing the manufacturer's rated capacity for the hitch configurations used. Without this information the sling cannot be safely selected for a lift.

Question 29Rigging, load calculation, and lift planning

A four-leg sling assembly lifts a rigid load that shares weight evenly. What conservative assumption do rigging standards typically use for capacity?

  1. Only three legs are assumed to carry the load Correct answer.
  2. The load is assumed to be carried by one leg
  3. Only two legs are assumed to carry the load
  4. All four legs share the load equally

Explanation

Because a rigid load may not seat evenly on all four legs, standard practice assumes only three legs share the load when the load distribution is indeterminate. This provides a margin for uneven seating.

Question 30Rigging, load calculation, and lift planning

What does the term 'center of gravity' mean in relation to rigging a load?

  1. The point of maximum stress in the sling
  2. The geometric center of the load's largest face
  3. The attachment point of the crane hook
  4. The point where the load's weight is considered to act Correct answer.

Explanation

The center of gravity is the point through which the total weight of the load acts. The hook must be positioned above the center of gravity so the load hangs level and does not tilt.

Question 31Rigging, load calculation, and lift planning

A load is asymmetric, with its center of gravity offset to one side. What is the most appropriate rigging approach?

  1. Use multiple pick points positioned so the hook is above the center of gravity Correct answer.
  2. Use only a choker hitch at the heaviest end
  3. Reduce the load weight by 50 percent
  4. Attach a single vertical sling at the geometric center

Explanation

When the center of gravity is offset, pick points must be arranged so the hook sits directly above it, keeping the load level and preventing uncontrolled tilt. This may require unequal sling lengths or a spreader.

Question 32Rigging, load calculation, and lift planning

What is the primary reason for using a spreader beam in a lift?

  1. To reduce the weight of the load being lifted
  2. To eliminate the need for a load chart
  3. To increase the crane's working radius
  4. To keep sling legs vertical and avoid horizontal compressive forces on the load Correct answer.

Explanation

A spreader beam holds the sling legs apart so they remain more vertical, reducing horizontal compression on the load and lowering leg tension. It also protects loads that cannot tolerate side pressure.

Question 33Rigging, load calculation, and lift planning

Before a lift, the rigger notices a wire rope sling with several broken outer wires and a kink. What is the correct action?

  1. Shorten it with a knot to bypass the damage
  2. Remove it from service and tag it out Correct answer.
  3. Use it if the broken wires are on the outside only
  4. Use it only for loads under one tonne

Explanation

Broken wires, kinks, and other structural damage reduce a sling's strength and are grounds for removal from service. The sling should be tagged and set aside for inspection or disposal.

Question 34Rigging, load calculation, and lift planning

What is the standard hand signal for 'stop' in mobile crane operations?

  1. Arm extended, palm down, moving the hand back and forth Correct answer.
  2. Both arms raised with palms open
  3. Arm extended horizontally and pointing at the load
  4. Arm extended upward with a clenched fist

Explanation

The recognized stop signal is the arm extended with the palm down, moved back and forth horizontally. Clear standardized signals prevent miscommunication between the signal person and the operator.

Question 35Rigging, load calculation, and lift planning

A crane is set up on a firm, level surface but the outrigger pad rests on compacted fill adjacent to an excavation. What is the main concern?

  1. The boom may become too short
  2. The crane's counterweight becomes too heavy
  3. The load chart becomes invalid because of the fill
  4. The outrigger may punch through or the ground may fail under load Correct answer.

Explanation

Outrigger loads are concentrated over small areas, and ground near an excavation may have reduced bearing capacity or a failure plane. The crane could settle or tip if the support fails, so matting and setback from the edge are required.

Question 36Rigging, load calculation, and lift planning

What is the purpose of a load test or proof test on lifting accessories?

  1. To calibrate the crane's load moment indicator
  2. To verify that the accessory can withstand a specified test load above its rated capacity Correct answer.
  3. To determine the exact weight of the load to be lifted
  4. To measure the wind speed at the lift site

Explanation

Proof testing applies a specified test load, typically a multiple of the rated capacity, to confirm the accessory's integrity and strength. It is not a substitute for routine visual inspection.

Question 37Rigging, load calculation, and lift planning

A two-leg bridle supports a 10-tonne load with each leg at 45 degrees to the horizontal. What is the approximate tension in each leg?

  1. About 10.0 tonnes
  2. About 14.1 tonnes
  3. About 5.0 tonnes
  4. About 7.1 tonnes Correct answer.

Explanation

Each leg carries half the vertical load, 5 tonnes, divided by the sine of 45 degrees. Since sin 45 degrees is about 0.707, tension is approximately 7.1 tonnes per leg.

Question 38Rigging, load calculation, and lift planning

When planning a tandem lift with two cranes, what is a critical planning requirement?

  1. The load must be shared according to a defined plan with one designated leader Correct answer.
  2. Each crane must be able to carry the entire load alone
  3. Only one crane's load chart needs to be reviewed
  4. The lift may proceed without communication between operators

Explanation

Tandem lifts require a written plan that defines load share, crane positions, and a single designated leader coordinating both operators. Communication and defined responsibilities prevent uncontrolled load transfer.

Question 39Rigging, load calculation, and lift planning

What does the term 'gross load' include in a lift calculation?

  1. The payload minus the counterweight
  2. Only the weight of the payload
  3. The payload plus all rigging, hook block, and attachments Correct answer.
  4. Only the rigging weight

Explanation

Gross load is the total weight the crane must support, including the payload, slings, shackles, spreader beams, and the hook block. Capacity charts are based on gross load, so all components must be counted.

Question 40Rigging, load calculation, and lift planning

A crane's capacity chart shows 20 tonnes at 8 metres radius and 16 tonnes at 10 metres. A load of 17 tonnes including rigging must be placed at 10 metres. What does this indicate?

  1. The lift exceeds capacity at that radius and must be replanned Correct answer.
  2. The lift is within capacity and may proceed
  3. The lift is acceptable if wind is calm
  4. The lift is acceptable if the boom is shortened

Explanation

At 10 metres the chart allows 16 tonnes, but the gross load is 17 tonnes, so the lift exceeds rated capacity. The plan must change, for example by reducing radius or using a larger crane.

Question 41Rigging, load calculation, and lift planning

Why must the hook be positioned directly above the center of gravity when lifting a load?

  1. To minimize the load's tendency to tilt or swing Correct answer.
  2. To reduce the weight of the load
  3. To shorten the sling legs
  4. To increase the crane's lifting capacity

Explanation

If the hook is not above the center of gravity, the load will tilt until the center of gravity lies below the hook, causing uncontrolled movement. Proper hook placement keeps the load level and stable.

Question 42Rigging, load calculation, and lift planning

What is the significance of the 'boom deflection' when estimating radius for a capacity check?

  1. Boom deflection has no effect on capacity
  2. Boom deflection only affects the hook height
  3. The boom bends under load, which can increase the actual working radius Correct answer.
  4. The boom shortens under load, reducing the radius

Explanation

Under load the boom deflects downward, which can increase the actual radius beyond the unloaded geometry. Capacity checks must account for this so the chart value used matches the real working radius.

Question 43Rigging, load calculation, and lift planning

What is the correct way to store synthetic web slings between lifts?

  1. In a sealed container exposed to direct sunlight
  2. In a damp area to keep the fibers flexible
  3. Coiled tightly around sharp metal hooks
  4. In a dry, ventilated area away from sunlight and chemicals Correct answer.

Explanation

Synthetic slings degrade with UV exposure, moisture, and chemical contact, so they should be stored clean and dry away from sunlight and contaminants. Proper storage preserves strength and extends service life.

Question 44Rigging, load calculation, and lift planning

A load is rigged with a single sling that passes under it and both ends attach to the hook, forming a basket hitch. How does capacity compare to a vertical hitch of the same sling?

  1. It is equal to the vertical capacity
  2. It is unrelated to the vertical capacity
  3. It is half the vertical capacity
  4. It is roughly double the vertical capacity when legs are vertical Correct answer.

Explanation

A basket hitch uses two parts of the sling to support the load, so with vertical legs it can carry about twice the vertical rated capacity. The angle between the legs reduces this as it widens.

Question 45Rigging, load calculation, and lift planning

During a lift plan review, a rigger identifies that the load will pass over an energized power line. What is the most appropriate control?

  1. Maintain the required minimum clearance and use a signal person or spotter Correct answer.
  2. Rely on the crane's insulated boom
  3. Lower the load closer to the line to reduce swing
  4. Proceed quickly to minimize exposure time

Explanation

Power line hazards require maintaining the mandated minimum approach distance and using spotters or barriers to prevent contact. Speed or proximity does not eliminate the electrocution hazard.

Question 46Rigging, load calculation, and lift planning

A load weighing 8 tonnes is lifted with a two-leg sling whose legs each make a 30-degree angle with the vertical. Assuming the load is symmetric and each leg shares the load equally, what is the approximate tension in each leg?

  1. About 6.9 tonnes
  2. About 4.6 tonnes Correct answer.
  3. About 8.0 tonnes
  4. About 4.0 tonnes

Explanation

For a symmetric two-leg lift, the tension per leg equals half the load divided by the cosine of the angle from vertical. Half of 8 tonnes is 4 tonnes, and 4 divided by cos 30 degrees (0.866) gives approximately 4.6 tonnes. The sharper the angle from vertical, the greater the leg tension for the same load.

Question 47Rigging, load calculation, and lift planning

What does the rated capacity of a lifting accessory represent?

  1. The load at which the accessory's safety factor reaches 1.0
  2. The load at which the accessory begins to yield permanently
  3. The maximum load the manufacturer allows in a specified configuration Correct answer.
  4. The average load the accessory has carried in service

Explanation

Rated capacity is the maximum load the manufacturer permits for a defined configuration, such as a particular hitch type and sling angle. It already includes an appropriate design safety factor and is not the point of permanent deformation. Working within the rated capacity keeps the accessory in its intended safe range.

Question 48Rigging, load calculation, and lift planning

A load has its center of gravity offset from the geometric center of the pick points. How does this affect the tension in the sling legs?

  1. Tension stays equal because the hook shares the load evenly
  2. The leg nearer the center of gravity carries more tension Correct answer.
  3. Tension depends only on the total load, not the offset
  4. The leg farther from the center of gravity carries more tension

Explanation

When the center of gravity is offset, the load is shared unequally, and the sling leg closer to the center of gravity carries a greater share. This is why an offset load must be rigged so the hook is over the center of gravity and capacities are checked for the most heavily loaded leg. Ignoring the offset can overload one leg even when the total load is within capacity.

Question 49Rigging, load calculation, and lift planning

In a lift plan, what is the purpose of calculating the 'gross load' rather than only the load weight?

  1. To account for the weight of the load plus rigging and any attached lifting gear
  2. To estimate the fuel consumption of the crane during the lift Correct answer.
  3. To set the maximum travel speed of the crane
  4. To determine the wind area of the load for the capacity check

Explanation

Gross load is the total weight the crane must support, including the load, slings, shackles, spreader beams, and any attached gear. Capacity charts are based on gross load, so using only the load weight underestimates the demand on the crane. Accurate gross load is fundamental to a safe capacity check.

Question 50Rigging, load calculation, and lift planning

A wire rope sling shows a broken core strand and a pronounced kink. What is the correct action?

  1. Straighten the kink and return it to service
  2. Use it only for light loads below half its rating
  3. Remove it from service and tag it as defective Correct answer.
  4. Shorten the sling by tying a knot to bypass the damage

Explanation

A broken core strand and a kink are both grounds for removal from service because they reduce strength and indicate abuse. The sling should be tagged defective and removed so it cannot be used inadvertently. Knots are never tied in wire rope slings, and no light-load exception applies to damaged gear.