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NCCCO Boom Truck practice questions

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Question 1Site and Lift Planning

Before a boom truck lift begins, the site supervisor asks for the load chart applicable to the specific crane. Which document must the operator confirm is in the cab and matches the crane's configuration?

  1. The project's fall protection plan
  2. The delivery truck weight tickets
  3. The manufacturer's load rating chart for that crane model and boom configuration Correct answer.
  4. The concrete pour schedule

Explanation

The load rating chart issued by the manufacturer for the specific crane and boom configuration is the controlling document for capacity. It must be available to the operator and reflect the actual boom length, jib, and outrigger setup. Other site documents do not establish lifting capacity.

Question 2Site and Lift Planning

A boom truck is set up on a slope where the bubble level shows the carrier is out of level. What is the correct planning response before making a lift?

  1. Reposition or re-block the truck until it is level within the manufacturer's tolerance Correct answer.
  2. Reduce line speed to compensate for the slope
  3. Proceed if the load is under half of the chart capacity
  4. Add counterweight to the rear of the carrier

Explanation

Load charts assume the crane is level within the manufacturer's stated tolerance, and side loading or tipping can result from an out-of-level condition. The truck must be repositioned or re-blocked until level before lifting. Capacity reductions or speed changes do not correct the underlying stability problem.

Question 3Site and Lift Planning

Which factor most directly determines the required outrigger spread and blocking for a boom truck lift?

  1. The color coding of the slings
  2. The number of workers on the signal crew
  3. The ground bearing pressure and the manufacturer's outrigger configuration Correct answer.
  4. The wind direction forecast for the following day

Explanation

Outrigger spread must match a configuration covered by the load chart, and the blocking or matting must spread pressure so the ground can support the imposed loads. Ground bearing capacity and manufacturer requirements are the controlling inputs. Sling color and crew size do not govern outrigger setup.

Question 4Site and Lift Planning

During planning, the lift director identifies a power line near the swing path. Which practice best reflects standard planning for this hazard?

  1. Have the operator swing quickly through the area to reduce exposure time
  2. Maintain the required minimum approach distance and consider a spotter or de-energization Correct answer.
  3. Assume the lines are de-energized if no sparks are visible
  4. Rely on the load being non-conductive to protect the crew

Explanation

Planning for electrical hazards requires maintaining the applicable minimum approach distance for the voltage involved and controlling the hazard through options such as de-energization, grounding, or an observer. Quick movement and assumptions about the lines increase risk. Non-conductive loads do not protect against contact with the boom or rigging.

Question 5Site and Lift Planning

What is the primary purpose of a pre-lift meeting on a boom truck job?

  1. To assign blame if the lift fails
  2. To decide which crew member operates the crane that day
  3. To satisfy payroll documentation requirements
  4. To confirm roles, signals, sequence, and hazard controls with everyone involved before the lift Correct answer.

Explanation

A pre-lift meeting aligns the operator, riggers, signal persons, and lift director on the plan, including roles, communication, lift sequence, and hazard controls. It is a planning and coordination tool, not a disciplinary or administrative exercise. Operator assignment should already be determined by qualification.

Question 6Site and Lift Planning

A boom truck must lift a load whose weight is close to the chart capacity at the planned radius. Which planning action is most appropriate?

  1. Verify the actual load weight and account for all rigging and hook-block weight in the total Correct answer.
  2. Proceed because the chart already includes a safety factor
  3. Use a longer boom to increase capacity
  4. Ignore the radius because the load is light

Explanation

Chart capacity must be compared against the total load, which includes the load, rigging, and any attached hardware. When the margin is small, confirming actual weight rather than estimating is essential. Boom length and radius are chart inputs, not workarounds for a marginal lift.

Question 7Site and Lift Planning

Which item belongs in a written lift plan for a critical boom truck lift?

  1. The home addresses of the rigging crew
  2. The history of prior projects by the contractor
  3. The fuel receipts for the carrier
  4. The crane's planned position, load weight, radius, boom configuration, and ground conditions Correct answer.

Explanation

A lift plan documents the technical basis for the lift: crane location, load weight, working radius, boom and rigging configuration, and ground support conditions. Personal information, fuel records, and company history are not part of the lift plan. The plan should be specific enough for the crew to execute and verify.

Question 8Site and Lift Planning

When planning a lift near the edge of an excavation, what ground condition must be evaluated for the outrigger nearest the edge?

  1. The stability of the slope and the bearing capacity of the ground beneath the blocking Correct answer.
  2. The depth of the excavation only
  3. The color of the soil at the surface
  4. The number of workers standing near the edge

Explanation

Outriggers near an excavation edge load the soil close to a slope, so the planner must evaluate slope stability and bearing capacity to prevent collapse or tipping. Surface color and excavation depth alone do not establish support capacity. Worker positions are a separate safety concern.

Question 9Site and Lift Planning

What does the term 'working radius' mean when planning a boom truck lift?

  1. The length of the boom from foot pin to tip
  2. The distance the truck traveled to reach the site
  3. The height of the load above the ground
  4. The horizontal distance from the crane's rotation center to the center of the load Correct answer.

Explanation

Working radius is the horizontal distance from the axis of rotation to the center of the load, and it is a primary input to the load chart. Boom length and load height are separate parameters. Travel distance to the site has no bearing on capacity.

Question 10Site and Lift Planning

A planner is comparing two crane positions for the same lift. Position A requires a longer boom at the same radius; Position B uses a shorter boom at the same radius. How does boom length generally affect capacity?

  1. Capacity depends only on the load weight
  2. Longer boom always increases capacity at a given radius
  3. Capacity generally decreases as boom length increases at a given radius Correct answer.
  4. Boom length has no effect on capacity at a given radius

Explanation

At a fixed radius, a longer boom raises the boom's center of gravity and increases the moment acting on the crane, so chart capacity generally decreases. The load chart reflects this relationship. Boom length is therefore a meaningful planning variable, not a neutral one.

Question 11Site and Lift Planning

Which of the following is a required consideration when planning a lift where the load will be set on a roof?

  1. The color of the roof membrane
  2. The number of windows on the building
  3. The age of the building's elevator
  4. The roof's structural capacity to support the load and any crane loads imposed on it Correct answer.

Explanation

When a load is set on a roof or the crane imposes loads on a structure, the structural capacity of that surface must be evaluated. Roof membrane color, window count, and elevator age do not relate to load-bearing capability. Structural verification protects both the crew and the building.

Question 12Site and Lift Planning

A boom truck will pick a load from a truck parked on soft ground. What planning measure best addresses the risk of outrigger settlement?

  1. Increase the boom angle to reduce reach
  2. Use larger mats or cribbing to distribute the outrigger load over a greater area Correct answer.
  3. Lower the load faster to reduce time on the outriggers
  4. Remove the outriggers and lift on rubber

Explanation

Soft ground requires load spreading so the outrigger pressure stays within the soil's bearing capacity; mats or cribbing increase the contact area. Lifting on rubber is only permitted where the manufacturer's chart allows it and does not solve soft-ground settlement. Speed and boom angle do not correct bearing failure.

Question 13Site and Lift Planning

Why must the planner account for the weight of the hook block, slings, and shackles in the lift plan?

  1. They add to the total load that the load chart capacity must support Correct answer.
  2. They are only relevant when lifting personnel
  3. They are deducted from the crane's gross vehicle weight
  4. They reduce the effective radius of the lift

Explanation

The load chart capacity must be compared to the total suspended load, which includes the load plus all rigging and the hook block. These items are not deducted from vehicle weight and do not change the radius. Ignoring them can push a lift over capacity.

Question 14Site and Lift Planning

A lift plan calls for the boom to pass over a building. Which additional hazard should the planner evaluate?

  1. The type of landscaping around the building
  2. The possibility of the load or boom striking the structure or dropping a load onto it Correct answer.
  3. The number of parking spaces near the building
  4. The building's paint color

Explanation

Swinging over a structure introduces hazards of contact with the structure and of a dropped load landing on it or on people below. The planner should consider clearance, controlled load paths, and exclusion zones. Cosmetic and site-amenity details are not relevant to the lift hazard analysis.

Question 15Site and Lift Planning

Which condition would require the planner to obtain a new or revised lift plan before proceeding?

  1. A change in the number of hard hats on site
  2. A change in the color of the tag lines
  3. A change in the lunch break schedule
  4. A change in wind speed that exceeds the manufacturer's limit for the lift Correct answer.

Explanation

Wind speed above the manufacturer's limit affects the crane's capacity and stability and requires the lift to stop or the plan to be revised. Tag line color, break schedules, and PPE counts do not alter the technical basis of the lift. Any change to the plan's controlling assumptions should trigger review.

Question 16Site and Lift Planning

When planning a lift, what is the purpose of establishing an exclusion zone under and around the load path?

  1. To define the boundary of the construction site
  2. To mark where the crane will be stored overnight
  3. To keep unnecessary personnel out of the area where a dropped load or swinging load could strike them Correct answer.
  4. To reserve parking for the crane crew

Explanation

An exclusion zone keeps people who are not essential to the lift away from the area beneath and around the load path, reducing exposure to dropped or swinging loads. It is not a parking or storage designation. Site boundaries are separate from lift-specific exclusion zones.

Question 17Site and Lift Planning

A planner must choose between a single-crane lift and a two-crane (tandem) lift. Which factor most strongly favors a tandem lift?

  1. The load is light and easily handled by one crane
  2. The load exceeds the capacity of any single available crane at the required radius Correct answer.
  3. The crew prefers tandem lifts for practice
  4. The site has plenty of room for a single crane

Explanation

A tandem lift is typically considered when the load cannot be safely handled by one crane at the required radius, or when the load's geometry requires two pick points. Tandem lifts introduce additional complexity and require a detailed plan with load sharing. Light loads and ample space favor a single crane.

Question 18Site and Lift Planning

What information should the planner use to determine the crane's capacity at the planned configuration?

  1. The weight of the delivery truck
  2. A rule of thumb from a previous job
  3. The crane's maximum rated capacity only
  4. The applicable load rating chart for the boom length, radius, and outrigger configuration Correct answer.

Explanation

Capacity must be read from the manufacturer's load rating chart for the specific boom length, radius, and outrigger configuration. Maximum rated capacity applies only at the most favorable geometry and is not valid at longer radii. Rules of thumb and truck weights are not substitutes for the chart.

Question 19Site and Lift Planning

Which of the following best describes the role of the lift director in boom truck operations?

  1. To manage the project budget
  2. To perform rigging inspections only
  3. To operate the crane whenever the operator is on break
  4. To oversee the lift plan, coordinate the crew, and ensure the lift proceeds as planned Correct answer.

Explanation

The lift director oversees the lift, coordinates the crew, and ensures the plan is followed and hazards are controlled. Operating the crane is the operator's role, and rigging inspection is typically assigned to a qualified rigger. Budget management is outside the lift director's scope.

Question 20Site and Lift Planning

A planner is evaluating whether a lift can proceed in gusty conditions. Which approach is most consistent with safe planning?

  1. Proceed if the load is heavy enough to resist wind
  2. Proceed if the operator feels comfortable
  3. Compare measured wind speed against the manufacturer's limit and account for the load's sail area Correct answer.
  4. Proceed if the lift will take less than ten minutes

Explanation

Wind limits are established by the manufacturer, and the load's sail area affects how much wind force is imposed on the crane and load. The planner should compare measured conditions to those limits and stop or revise the plan if exceeded. Operator comfort, load weight, and short duration are not valid substitutes.

Question 21Site and Lift Planning

What is the purpose of verifying that the load's center of gravity is known before the lift?

  1. To determine the crane's fuel consumption
  2. To select the color of the tag lines
  3. To ensure the load will hang level and that the rigging arrangement is appropriate Correct answer.
  4. To decide the operator's break schedule

Explanation

Knowing the center of gravity allows the rigger to place slings so the load hangs level and loads are shared as intended, reducing the risk of shifting or uncontrolled rotation. It does not determine fuel use or tag line color. Break scheduling is unrelated to load geometry.

Question 22Site and Lift Planning

Which of the following is a key planning consideration when the boom truck must travel with a load suspended?

  1. Whether the road is paved or gravel only
  2. Whether the load is wrapped in plastic
  3. Whether the manufacturer permits travel with a suspended load and what capacity applies Correct answer.
  4. Whether the operator has a commercial driver's license

Explanation

Traveling with a suspended load is permitted only where the manufacturer's instructions and load charts allow it, and capacity may be reduced for travel configurations. Road surface may be a secondary consideration, but it does not establish permission. Licensing and packaging do not determine whether suspended-load travel is allowed.

Question 23Site and Lift Planning

Why should the planner identify the crane's swing clearance before setup?

  1. To select the site's landscaping
  2. To calculate the operator's overtime
  3. To determine the crane's paint scheme
  4. To ensure the counterweight and boom will not strike structures, equipment, or personnel during rotation Correct answer.

Explanation

Swing clearance planning ensures the rotating counterweight and boom have unobstructed paths, preventing contact with structures, equipment, or people. Paint, overtime, and landscaping are unrelated to rotation geometry. Clearance must be verified for the full swing arc.

Question 24Site and Lift Planning

A planner is reviewing a lift where the load will be picked from the ground and placed on a trailer. Which sequence detail is most important to plan?

  1. The color of the trailer
  2. The order of rigging attachment, lift, swing, and set-down, including signal communication at each step Correct answer.
  3. The trailer's registration date
  4. The number of tires on the trailer

Explanation

The lift sequence defines how the load moves from pick to set-down, including when rigging is attached, how signals are given, and how the load is controlled at each stage. Trailer color, registration, and tire count do not affect the lift sequence. A clear sequence reduces confusion and hazard exposure.

Question 25Site and Lift Planning

What is the purpose of a site visit or walk-down during lift planning?

  1. To identify actual site conditions such as obstructions, ground conditions, and access that may not appear on drawings Correct answer.
  2. To interview job applicants
  3. To finalize the project's financing
  4. To order office supplies

Explanation

A site walk-down reveals real conditions-obstructions, soft spots, overhead lines, and access limits-that drawings may omit or misrepresent. Financing, hiring, and supplies are unrelated to lift planning. The walk-down should be documented and used to refine the lift plan.

Question 26Site and Lift Planning

When planning a boom truck lift, what does the term 'boom deflection' describe?

  1. The retraction of outrigger beams before travel
  2. The hydraulic extension speed of the telescoping boom sections
  3. The downward bending of the boom under the weight of the load and boom Correct answer.
  4. The sideways rotation of the upper works during a swing

Explanation

Boom deflection is the elastic bending of the boom caused by the load and the boom's own weight, and it increases the effective radius and can change load height. The planner must account for it because it affects both the radius used to read capacity and the clearance under the load.

Question 27Site and Lift Planning

A planner reads a load chart and finds the boom truck's capacity is listed for a specific boom length and radius. Which additional chart condition must be matched before the rated capacity applies?

  1. The number of workers on the ground
  2. The type of trailer the load arrived on
  3. The quadrant or swing area the boom will operate in Correct answer.
  4. The color of the load being lifted

Explanation

Load charts are rated for particular operating conditions, including the swing quadrant (over the front, side, or rear) and whether the crane is on outriggers or tires. If the planned lift occurs in a quadrant or configuration not covered by the chart, the listed capacity does not apply.

Question 28Site and Lift Planning

A planner is preparing a lift plan for a boom truck operating on a slope. What is the most appropriate planning action regarding the load chart?

  1. Use the chart capacity without adjustment because the machine is level
  2. Apply the manufacturer's slope or leveling requirements and verify the machine can be leveled before reading capacity Correct answer.
  3. Reduce the radius by the slope angle and read the chart at that shorter radius
  4. Increase the counterweight to offset the slope

Explanation

Load charts assume the crane is level, so operating on a slope without proper leveling invalidates the rated capacity. The planner should confirm the manufacturer's leveling or slope limits and ensure the machine can be made level (for example with cribbing) before using chart values.

Question 29Site and Lift Planning

A planner is determining the total load for a boom truck lift. The load weighs 4,000 lb, the rigging weighs 300 lb, and the hook block and other lifting attachments weigh 500 lb. Which value should be compared to the chart capacity?

  1. 4,800 lb Correct answer.
  2. 4,300 lb
  3. 4,000 lb
  4. 5,300 lb

Explanation

The load used against chart capacity includes the load, all rigging, and the hook block and other lifting attachments. Adding 4,000 + 300 + 500 gives 4,800 lb, which is the value to compare to the rated capacity at the planned radius.

Question 30Site and Lift Planning

A planner is evaluating whether a boom truck can set a load onto a structure while the boom passes near an energized overhead line. The utility owner states the line cannot be de-energized. Which planning approach is most consistent with safe practice?

  1. Establish the required minimum approach distance, and if it cannot be maintained, stop and revise the plan with the utility owner before proceeding Correct answer.
  2. Lower the boom quickly if it approaches the line
  3. Maintain the required minimum clearance, and if it cannot be maintained, use a spotter and proceed
  4. Rely on the operator's judgment to keep the boom clear of the line

Explanation

When a line cannot be de-energized, the planner must identify the applicable minimum approach distance and design the lift so that distance is maintained for the boom, load, and rigging. If the distance cannot be maintained, the plan must be revised with the utility owner rather than relying on proximity judgment or spotters alone.

Question 31Load Charts and Capacity Determination

On a boom truck load chart, what does the load radius represent?

  1. The horizontal distance from the center of rotation to the center of gravity of the load Correct answer.
  2. The length of boom extended from the boom pivot
  3. The straight-line distance from the boom pivot to the boom tip
  4. The vertical height of the boom tip above the ground

Explanation

Load radius is measured horizontally from the crane's center of rotation to the vertical line through the load's center of gravity. It is not the boom length or the boom-tip height, so it must be read from the horizontal plane, not the boom itself.

Question 32Load Charts and Capacity Determination

A boom truck chart lists a capacity for a 30 ft radius. The actual measured radius is 32 ft. How should the operator determine capacity?

  1. Use the capacity listed for the next longer radius on the chart Correct answer.
  2. Use the 30 ft capacity because the difference is small
  3. Average the 30 ft and 35 ft capacities
  4. Interpolate between the 30 ft and next listed radius values

Explanation

When the actual radius falls between chart values, the operator must use the capacity for the next longer (greater) radius listed. Interpolating upward overstates capacity and is not permitted on most charts.

Question 33Load Charts and Capacity Determination

Which item is normally included in the gross load that must be compared to the chart's rated capacity?

  1. The load minus the weight of the hook block
  2. The load plus the operator's body weight
  3. Only the weight of the material being lifted
  4. The load plus the rigging and any attached lifting devices Correct answer.

Explanation

Gross load includes the weight of the load, rigging, slings, shackles, and any attached lifting devices below the boom tip. The hook block and other boom-attached components are handled through the chart's deductions.

Question 34Load Charts and Capacity Determination

A chart's capacity is 12,000 lb at the working radius. The hook block weighs 800 lb, and the rigging and load weigh 10,500 lb. What is the total gross load?

  1. 12,000 lb
  2. 10,500 lb
  3. 9,700 lb
  4. 11,300 lb Correct answer.

Explanation

Gross load equals the load plus rigging plus the hook block (and other deductions) when the chart requires those deductions. Adding 10,500 lb and 800 lb gives 11,300 lb, which is below the 12,000 lb rating and therefore acceptable.

Question 35Load Charts and Capacity Determination

What is the purpose of the boom deflection or boom-tip height note on some boom truck charts?

  1. To indicate the hydraulic pressure limit of the boom cylinder
  2. To list the outrigger spread required for the lift
  3. To show that radius increases as the boom deflects under load Correct answer.
  4. To specify the maximum wind speed for the lift

Explanation

Under load, the boom deflects downward, which increases the actual radius beyond the geometric value. Charts with deflection notes require the operator to account for this added radius when determining capacity.

Question 36Load Charts and Capacity Determination

A boom truck is set up on outriggers fully extended on firm, level ground. Which chart section applies?

  1. The outrigger-extended capacity section Correct answer.
  2. The travel-speed capacity section
  3. The on-rubber (truck crane) capacity section
  4. The pick-and-carry capacity section

Explanation

Charts are divided by configuration, so a fully extended outrigger setup on firm level ground uses the outrigger-extended ratings. On-rubber ratings apply only when the truck is working from its tires without outriggers.

Question 37Load Charts and Capacity Determination

Which factor most directly reduces the rated capacity shown on a boom truck chart?

  1. Lowering the hook block to the ground
  2. Increasing the load radius Correct answer.
  3. Shortening the boom length
  4. Reducing the wind speed

Explanation

Rated capacity decreases as the load radius increases because the load moment on the boom and structure grows. Boom length, configuration, and setup also affect capacity, but radius is the primary driver.

Question 38Load Charts and Capacity Determination

A boom truck chart shows two capacities at a given radius: one for a 360-degree working area and one for an over-the-front area. Why do these differ?

  1. The carrier and outrigger structure provide more support in some directions than others Correct answer.
  2. The engine provides more power in the front position
  3. The boom is stronger when pointed forward
  4. The hook block is heavier in the front position

Explanation

Structural strength of the carrier, outriggers, and frame varies by direction, so charts often publish higher ratings in stronger quadrants. The operator must use the rating that matches the actual working area.

Question 39Load Charts and Capacity Determination

What does a shaded or bold line on a boom truck load chart often indicate?

  1. The area where the boom must be fully retracted
  2. The area where outriggers must be removed
  3. The area where the chart is invalid
  4. The area where capacity is limited by structural strength rather than stability Correct answer.

Explanation

Charts often separate structural limits from stability limits, and shaded regions typically show where one governs. The operator must apply the lower governing limit for the actual configuration.

Question 40Load Charts and Capacity Determination

A boom truck is working at a 25 ft radius with a 60 ft boom. The chart gives 9,000 lb at 25 ft and 8,000 lb at 30 ft. What capacity applies at 25 ft?

  1. It cannot be determined
  2. 8,000 lb
  3. 8,500 lb
  4. 9,000 lb Correct answer.

Explanation

When the actual radius exactly matches a listed radius, the capacity listed for that radius applies. The 25 ft value of 9,000 lb is used without interpolation or rounding.

Question 41Load Charts and Capacity Determination

Which load chart deduction is commonly subtracted from the rated capacity to determine the net allowable load?

  1. Weight of the operator
  2. Weight of the fuel in the tank
  3. Weight of the counterweight only
  4. Weight of the hook block and any attached boom-head equipment Correct answer.

Explanation

Many charts require deducting the weight of the hook block, headache ball, and other boom-head attachments from the rated capacity. The remaining value is the net load available for rigging and material.

Question 42Load Charts and Capacity Determination

The chart allows 7,500 lb at the working radius. The hook block weighs 500 lb and the rigging weighs 300 lb. What is the maximum material weight that can be lifted?

  1. 7,500 lb
  2. 7,000 lb
  3. 7,200 lb
  4. 6,700 lb Correct answer.

Explanation

Subtract both the hook block and the rigging from the rated capacity to find the allowable material weight. 7,500 minus 500 minus 300 equals 6,700 lb.

Question 43Load Charts and Capacity Determination

What is the effect of operating a boom truck without fully extending the outriggers when the chart requires full extension?

  1. The chart capacity remains the same
  2. The rated capacity for the reduced outrigger configuration must be used, which is lower Correct answer.
  3. The capacity increases because the load is closer
  4. The chart becomes invalid and no lift is allowed

Explanation

If outriggers are not fully extended, the crane is in a different configuration than the chart assumes. The operator must use the chart section for the actual outrigger condition, which typically gives lower capacity.

Question 44Load Charts and Capacity Determination

Which condition would require the operator to reduce capacity below the chart value even when radius and configuration match?

  1. Using a lighter hook block
  2. Operating on a slope or soft ground that may not support the outriggers Correct answer.
  3. Lifting a load with a known weight
  4. Using a slightly shorter boom

Explanation

Charts assume firm, level supporting ground. Soft or sloped ground can cause outrigger settlement or tipping, so capacity must be reduced or the lift stopped.

Question 45Load Charts and Capacity Determination

On a boom truck chart, capacity at a 10 ft radius is 15,000 lb and at 20 ft radius is 9,000 lb. Which statement best explains the change?

  1. Capacity decreases because the wind speed increases
  2. Capacity decreases as radius increases because the load moment increases Correct answer.
  3. Capacity decreases because the boom gets shorter
  4. Capacity decreases because the hook block gets heavier

Explanation

As radius grows, the same load creates a larger moment about the boom pivot and tipping line. The chart reduces capacity to keep the moment within structural and stability limits.

Question 46Load Charts and Capacity Determination

A boom truck is rated 6,000 lb at the working radius. The total gross load is 6,200 lb. What is the correct action?

  1. Proceed if the outriggers are fully extended
  2. Reduce the radius or load until gross load is within the rating Correct answer.
  3. Proceed because the difference is within 10 percent
  4. Proceed if the wind is calm

Explanation

The gross load must never exceed the rated capacity for the actual configuration and radius. The operator must reduce the load or change the setup until the gross load is at or below the rating.

Question 47Load Charts and Capacity Determination

What does the term 'load moment' refer to in boom truck capacity determination?

  1. The weight of the load multiplied by its horizontal distance from the tipping line Correct answer.
  2. The time required to lift the load
  3. The angle of the boom above horizontal
  4. The vertical height of the boom tip

Explanation

Load moment is the product of the load and its horizontal distance from the pivot or tipping line. Charts are built around allowable moments, which is why capacity falls as radius grows.

Question 48Load Charts and Capacity Determination

A boom truck chart lists a capacity of 4,000 lb at a 40 ft radius with the boom at 70 ft. The operator plans to use a 50 ft boom at the same radius. What capacity applies?

  1. The capacity listed for the 50 ft boom at 40 ft radius Correct answer.
  2. 4,000 lb, because radius is unchanged
  3. 4,000 lb plus a 10 percent allowance for the shorter boom
  4. The capacity for the longest boom at that radius

Explanation

Capacity depends on both radius and boom length, so the operator must read the row or column for the actual boom length. A shorter boom may have a different rating than the 70 ft boom.

Question 49Load Charts and Capacity Determination

Which statement about the 'range diagram' on a boom truck chart is accurate?

  1. It shows boom angle and radius combinations for given boom lengths Correct answer.
  2. It specifies the hydraulic oil capacity
  3. It shows the truck's highway speed limits
  4. It lists the maximum wind speed for lifting

Explanation

The range diagram graphically relates boom length, boom angle, radius, and tip height. Operators use it to confirm that the planned boom configuration can reach the required radius and height.

Question 50Load Charts and Capacity Determination

A boom truck is set up with outriggers on a steel deck over a basement. The chart shows adequate capacity. What should the operator do before lifting?

  1. Verify the deck can support the outrigger loads, and use load-spreading mats if needed Correct answer.
  2. Reduce boom length to increase capacity
  3. Proceed because the chart capacity is adequate
  4. Increase the load radius to improve stability

Explanation

Chart capacity assumes the ground or structure can carry the outrigger reactions. A suspended deck may not support those loads, so the operator must verify support and use mats or cribbing.