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HEO Tower Crane NC III study materials
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HEO Tower Crane NC III practice questions

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Question 1Pre-operation inspection, rigging, and site preparation

Before a tower crane is erected on a new site, which document must be reviewed to confirm the crane's rated capacities at the planned jib lengths and radii?

  1. The load chart issued for that specific crane model and configuration Correct answer.
  2. The electrical contractor's cable layout drawing
  3. The site's delivery schedule for concrete trucks
  4. The crane operator's daily time record

Explanation

Rated capacity depends on the specific crane model, jib length, counterweight arrangement, and radius. The manufacturer's load chart for that exact configuration is the only valid basis for planning lifts, and it must be on hand before erection and lifting begin.

Question 2Pre-operation inspection, rigging, and site preparation

A crane is to be founded on compacted fill. Which pre-operation check most directly confirms the foundation can carry the crane's loads?

  1. Checking the geotechnical bearing report and the base loading calculations against the actual ground conditions Correct answer.
  2. Verifying the concrete ballast blocks are painted and free of rust
  3. Confirming the operator has a valid crane certification card
  4. Measuring the height of the surrounding fence

Explanation

Tower cranes impose large concentrated loads and overturning moments on their bases, so the ground bearing capacity must be compared with the calculated base pressures. The geotechnical report and the crane base loading data provide that comparison, and any shortfall requires a designed foundation such as a pile cap or raft.

Question 3Pre-operation inspection, rigging, and site preparation

When selecting wire rope slings for a lift, the rated capacity of the sling assembly must be based on which factor in addition to the rope diameter?

  1. The number of lifts planned for the day
  2. The splice or termination type and the sling configuration angle Correct answer.
  3. The crane's slewing speed
  4. The colour of the sling tag

Explanation

A wire rope sling's capacity is determined by the rope construction and by how the ends are terminated, such as a swaged fitting, hand-spliced eye, or mechanical splice. The configuration also matters because multi-leg slings lose capacity as the leg angle to vertical increases.

Question 4Pre-operation inspection, rigging, and site preparation

Which item of personal protective equipment is mandatory for riggers working at height on a tower crane's jib or tower sections?

  1. A high-visibility vest only
  2. Steel-capped boots only
  3. Cut-resistant gloves only
  4. A full-body harness with twin lanyards attached to an engineered anchor point Correct answer.

Explanation

Work at height on crane structures requires fall arrest or fall restraint, which means a full-body harness connected to a designated anchor point. Twin lanyards allow the worker to remain attached while transferring between anchor points. Other PPE items are required too, but they do not address fall hazards.

Question 5Pre-operation inspection, rigging, and site preparation

During a pre-erection inspection, a tower crane's slewing ring shows visible cracks and grease leakage at the raceway. What is the correct action?

  1. Apply additional grease and proceed with normal lifting
  2. Stop work, tag the component out of service, and refer the defect to a competent person for assessment Correct answer.
  3. Reduce the crane's SWL by ten percent and continue
  4. Continue erection and monitor the ring during the first week of operation

Explanation

Cracks in a slewing ring are a critical structural defect that can lead to catastrophic failure of the crane. The machine must be taken out of service and the defect assessed by a competent engineer before any further assembly or lifting. Greasing or derating does not restore the integrity of a cracked ring.

Question 6Pre-operation inspection, rigging, and site preparation

What is the primary purpose of the pre-operational daily inspection of a tower crane before the first lift of the shift?

  1. To verify that the site canteen is open
  2. To satisfy the client's paperwork requirements
  3. To detect defects and hazards that could cause failure or loss of control during the shift Correct answer.
  4. To record the operator's productivity targets

Explanation

The daily inspection is a functional safety check that looks for defects such as damaged wire rope, faulty limit switches, loose fasteners, and fluid leaks before work starts. Its purpose is to catch conditions that could cause a load to drop or the crane to lose control.

Question 7Pre-operation inspection, rigging, and site preparation

On a tower crane, which safety device prevents the hook block from being pulled into the jib head?

  1. The anemometer
  2. The trolley travel limit switch
  3. The slewing limiter
  4. The hoist over-hoist (upper) limit switch Correct answer.

Explanation

The over-hoist limit switch stops the hoist before the hook block contacts the jib or trolley, preventing rope damage and load drop. It must be tested during the pre-operation check by hoisting slowly without a load.

Question 8Pre-operation inspection, rigging, and site preparation

A site plan shows a tower crane jib that will pass over a public footpath. Which control should be established before lifting begins?

  1. A verbal warning to pedestrians each time a load passes
  2. A sign on the site gate only
  3. A requirement that the operator honk the horn continuously
  4. A designated exclusion zone beneath the jib with physical barriers and signage Correct answer.

Explanation

Where a crane operates over or near public areas, a defined exclusion zone with physical barriers, signage, and where required a protected walkway must be established. This prevents people from being under a suspended load or within the drop zone. Verbal warnings and horns are not reliable controls.

Question 9Pre-operation inspection, rigging, and site preparation

Which condition of a wire rope hoist line requires the rope to be removed from service immediately?

  1. Slight surface discolouration from dust
  2. A light coating of lubricant on the strands
  3. Broken wires exceeding the rejection criteria in the applicable standard, or a kink or birdcage Correct answer.
  4. A manufacturer's tag attached near the drum

Explanation

Wire rope must be withdrawn from service when broken wires, kinks, birdcaging, or other damage exceed the rejection criteria in the applicable standard. These conditions reduce strength and can cause sudden rope failure under load. Lubrication and dust are normal and are not rejection criteria.

Question 10Pre-operation inspection, rigging, and site preparation

When preparing a lift plan, the total load to be lifted must include which of the following?

  1. The load weight divided by the number of sling legs
  2. The load weight plus the weight of slings, shackles, spreader beam, and hook block Correct answer.
  3. Only the weight shown on the load's delivery note
  4. Only the weight of the crane's counterweight

Explanation

The gross load used against the load chart must include the load itself plus all rigging and lifting attachments below the hook, and the hook block where the chart requires it. Omitting rigging weight can push the lift beyond the rated capacity at that radius.

Question 11Pre-operation inspection, rigging, and site preparation

A shackle is being selected to connect a sling to a lifting eye. Which marking must be verified on the shackle body?

  1. The working load limit and manufacturer identification Correct answer.
  2. The paint colour code of the site
  3. The crane operator's name
  4. The date the site was established

Explanation

Lifting shackles must be marked with their working load limit and identifiable manufacturer or traceability information so the rigger can confirm capacity. Site paint codes and personal names are not capacity markings and cannot be relied upon.

Question 12Pre-operation inspection, rigging, and site preparation

During site preparation, the crane's earthing and lightning protection arrangements are being checked. What is the key requirement?

  1. The jib should be painted in a conductive colour
  2. The crane should be isolated from earth to prevent stray currents
  3. Earthing is only needed if the crane has an air-conditioned cab
  4. The crane should be electrically bonded and earthed in accordance with the manufacturer's instructions and local electrical requirements Correct answer.

Explanation

Tower cranes are tall steel structures and must be bonded and earthed as specified by the manufacturer and local electrical codes to protect against lightning and electrical faults. Isolation from earth would increase the risk of dangerous potential differences.

Question 13Pre-operation inspection, rigging, and site preparation

A rigger needs to lift a bundle of steel bars whose centre of gravity is offset toward one end. What is the most appropriate rigging approach?

  1. Use a chain wrapped around one end only
  2. Lift the bundle with the trolley at maximum radius
  3. Attach a single sling at the mid-point of the bundle
  4. Use two or more slings positioned so the bundle hangs level, and verify the balance with a trial lift Correct answer.

Explanation

An offset centre of gravity causes the load to tilt, which changes sling tensions and can cause the load to slide out. Slings must be positioned so the load hangs level, and a short trial lift confirms balance before the full lift.

Question 14Pre-operation inspection, rigging, and site preparation

Which factor most affects the tension in each leg of a two-leg sling as the included angle between the legs increases?

  1. The colour of the sling
  2. The leg tension is unaffected by the angle
  3. The leg tension decreases as the angle between the legs increases
  4. The leg tension increases as the angle between the legs increases Correct answer.

Explanation

As the angle between sling legs widens, each leg must carry a larger share of the vertical load, so leg tension rises sharply. This is why wide sling angles reduce the usable capacity of a multi-leg sling assembly and must be considered during rigging selection.

Question 15Pre-operation inspection, rigging, and site preparation

Before erecting a tower crane adjacent to an overhead power line, what should be confirmed?

  1. That lifts will only occur at night
  2. That the crane's jib and load path can maintain the required safe clearance, or that the line has been de-energised and isolated Correct answer.
  3. That the line is painted yellow
  4. That the operator can see the line from the cab

Explanation

Cranes must maintain the safe approach distance to energised overhead lines at all times, including jib movement and load swing. If that clearance cannot be guaranteed, the line must be de-energised, isolated, and confirmed by the electricity authority before work proceeds.

Question 16Pre-operation inspection, rigging, and site preparation

What does the term 'outrigger' refer to in the context of a tower crane base?

  1. The rope that raises the jib
  2. The structural arms that spread the crane's base loads into the foundation or ballast Correct answer.
  3. The operator's seat belt anchor
  4. The hook block assembly

Explanation

Outriggers or base beams spread the crane's concentrated loads and overturning moments over a wider area so the foundation can carry them safely. Their correct installation and ballast arrangement are verified during site preparation and pre-erection checks.

Question 17Pre-operation inspection, rigging, and site preparation

A pre-operation check finds that the crane's anemometer is not functioning. What is the correct course of action?

  1. Remove the anemometer and rely on the weather forecast
  2. Proceed only if lifts are below half capacity
  3. Proceed with lifting and estimate wind speed by feel
  4. Do not operate the crane until the anemometer is repaired or replaced Correct answer.

Explanation

The anemometer is a safety device that triggers stopping of lifting when wind speed exceeds the manufacturer's limit. Without a working anemometer, the operator cannot know when the limit is reached, so the crane must be taken out of service until it is repaired.

Question 18Pre-operation inspection, rigging, and site preparation

Which document typically records that a tower crane has been inspected and found safe before being put into service after erection?

  1. The concrete pour card
  2. The commissioning or thorough examination report by a competent person Correct answer.
  3. The site induction attendance sheet
  4. The daily delivery docket

Explanation

After erection or major alteration, a competent person must thoroughly examine and test the crane and record the results before it is put into service. This report confirms that the installation and safety devices meet requirements.

Question 19Pre-operation inspection, rigging, and site preparation

A crane's load moment limiter is being tested. What is its function?

  1. To limit the speed of the hoist drum
  2. To lock the slewing brake when the wind rises
  3. To prevent the crane from lifting loads that exceed its rated capacity at the current radius Correct answer.
  4. To measure the fuel level in the crane's generator

Explanation

The load moment limiter continuously compares the actual load and radius against the rated capacity and stops movements that would overload the crane. It is a primary safety device and must be tested and calibrated before lifting.

Question 20Pre-operation inspection, rigging, and site preparation

When planning a lift near a site boundary, the rigger notices that the load will pass over a temporary site office occupied by staff. What is the best control?

  1. Reduce the hoist speed during the pass
  2. Relocate the office or reroute the lift so the load does not pass over occupied areas Correct answer.
  3. Schedule the lift during the staff lunch break
  4. Ask staff to watch for the load and move if necessary

Explanation

Suspended loads should not pass over occupied areas; the preferred control is to eliminate the hazard by relocating the facility or planning a lift path that avoids it. Relying on occupants to dodge a load or on timing is not an acceptable substitute for removing the exposure.

Question 21Pre-operation inspection, rigging, and site preparation

What is the purpose of ballast on a tower crane base?

  1. To provide stability against overturning moments generated by the load and jib Correct answer.
  2. To increase the crane's lifting capacity at all radii
  3. To reduce the noise of the slewing motor
  4. To serve as a counterweight for the operator's cab

Explanation

Ballast provides the counterbalancing moment needed to keep the crane stable against the overturning effect of the load and jib. The correct type, amount, and position of ballast are specified by the manufacturer and must be verified before operation.

Question 22Pre-operation inspection, rigging, and site preparation

A rigger is checking chain slings before a lift. Which condition requires the sling to be taken out of service?

  1. A light film of oil on the links
  2. A worn identification tag that is still legible
  3. Stretched links, cracks, or gouges that reduce the link cross-section Correct answer.
  4. A recent inspection tag attached to the master link

Explanation

Chain slings must be withdrawn when links show stretching, cracks, gouges, or wear beyond the limits set by the applicable standard, because these reduce strength. A legible tag, light oil, and a current inspection tag are normal and acceptable.

Question 23Pre-operation inspection, rigging, and site preparation

When a tower crane is being erected, which area should be cordoned off?

  1. Only the site entrance gate
  2. The entire area beneath the jib and the erection zone, including the crane's slewing radius Correct answer.
  3. Only the area behind the counterweight
  4. Only the operator's cab

Explanation

Erection involves suspended components, assembly at height, and slewing of the jib, so the whole erection zone and the area beneath the jib must be cordoned off. The exclusion zone must cover the full slewing radius and any area where a component could fall.

Question 24Pre-operation inspection, rigging, and site preparation

A load chart shows a capacity of 4.0 tonnes at 30 m radius and 3.2 tonnes at 35 m radius. A 3.5 tonne load must be placed at 33 m radius. What does this indicate?

  1. The lift is acceptable if the hoist speed is reduced
  2. The lift is acceptable because the load is below the 4.0 tonne figure
  3. The lift is acceptable if the wind is below 10 m/s
  4. The lift is not acceptable at that radius and the load or radius must be changed Correct answer.

Explanation

Capacity decreases as radius increases, so at 33 m the rated capacity lies between 3.2 and 4.0 tonnes and is below 4.0 tonnes. A 3.5 tonne load may therefore exceed the rating at that radius, and the plan must be changed rather than relying on the higher figure at a shorter radius.

Question 25Pre-operation inspection, rigging, and site preparation

Which of the following is a required check on the crane's hook before the shift begins?

  1. That the hook has been polished
  2. That the hook has a functioning safety latch and shows no cracks or excessive throat opening Correct answer.
  3. That the hook block has a manufacturer's sticker
  4. That the hook is painted the same colour as the jib

Explanation

The hook must have a working safety latch and must be free from cracks, deformation, and excessive throat opening or wear. These defects can allow the load to slip off or the hook to fail under load. Paint, polish, and stickers are cosmetic.

Question 26Pre-operation inspection, rigging, and site preparation

During pre-operation inspection of a tower crane, a rigger finds that the rated capacity indicator plate on the jib is faded and partly illegible. What is the correct action before lifting?

  1. Estimate the capacities from the load chart kept in the site office
  2. Report it and have the plate replaced or restored before the crane is used Correct answer.
  3. Continue lifting but record the defect in the logbook at the end of the shift
  4. Tape over the faded figures and write the capacities by hand

Explanation

The rated capacity indicator must be legible so the operator and riggers can confirm the permitted load at each radius. An illegible plate is a defect that must be corrected before the crane is put to work, not deferred. Handwritten patches or memory of the chart are not acceptable substitutes for the approved marking.

Question 27Pre-operation inspection, rigging, and site preparation

Before a tower crane is erected on a prepared foundation, the concrete foundation has cured and the holding-down bolts are in place. Which check confirms the base is ready to receive the mast?

  1. The foundation level and bolt projection match the manufacturer's drawing Correct answer.
  2. The concrete surface has been swept clean of loose aggregate
  3. The area around the base has been marked with warning tape
  4. A fresh coat of paint has been applied to the holding-down bolts

Explanation

The manufacturer's foundation drawing specifies level tolerances, bolt positions and projection, and these must be verified before the mast is landed. Cleaning, taping or painting do not confirm the structural interface is correct. Getting the geometry wrong at this stage cannot be corrected easily once the crane is erected.

Question 28Pre-operation inspection, rigging, and site preparation

A rigger is preparing the standing area for a tower crane that will be climbed with a hydraulic climbing frame. Which site preparation measure is most important around the climbing zone?

  1. Barricading the area beneath and around the climbing frame against access Correct answer.
  2. Stacking spare tie bars beside the mast for quick access
  3. Erecting a windbreak screen on the jib side
  4. Placing a fire extinguisher at the base of the mast

Explanation

Climbing operations involve suspended loads and people working at height, so the zone where components could fall must be controlled. Barricades keep unauthorised people out of the drop area. Spare materials stored at the base add trip and falling-object hazards rather than helping.

Question 29Pre-operation inspection, rigging, and site preparation

A rigger must attach a four-leg chain sling to a load with four lifting points that are not symmetrically arranged. Which practice best ensures the load is shared safely?

  1. Use only two legs and ignore the other two lifting points
  2. Assume each leg carries an equal share and size the sling accordingly
  3. Treat the sling as a two-leg assembly and check each leg's tension before lifting Correct answer.
  4. Shorten legs with makeshift knots until the load sits level

Explanation

When lifting points are not symmetric, the load is unlikely to be shared equally between all four legs, so the assembly should be assessed as a two-leg sling for capacity purposes. Tension in each leg must be observed during a trial lift. Assuming equal sharing can overload individual legs.

Question 30Pre-operation inspection, rigging, and site preparation

A tower crane is to be erected close to a site boundary fence. What should be confirmed about the crane's slewing area before erection begins?

  1. That the counter-jib is longer than the jib
  2. That the crane base is positioned at the highest point of the site
  3. That the fence has been painted in a high-visibility colour
  4. That the jib and counter-jib can slew without contacting the fence or adjacent structures Correct answer.

Explanation

The slewing envelope must be clear of obstructions, including boundary fences, buildings and neighbouring property. Contact during slewing can damage the crane or structures and injure people. Colour, jib proportions or base elevation do not establish a clear envelope.

Question 31Pre-operation inspection, rigging, and site preparation

A rigger is checking the condition of a hook before the first lift. Which observation requires the hook to be withdrawn from service?

  1. The safety latch opens freely when pressed by hand
  2. The hook shows a crack at the saddle of the bend Correct answer.
  3. The hook swivels smoothly in its bearing
  4. The hook has a light coating of grease on the shank

Explanation

A crack anywhere in the hook body is a serious defect and the hook must be removed from service immediately. Cracks cannot be repaired by welding in the field and may propagate under load. Free movement of the latch and swivel and normal lubrication are acceptable conditions.

Question 32Pre-operation inspection, rigging, and site preparation

A rigger is selecting wire rope slings for a lift and notices that one sling has several broken outer wires clustered along one strand. What does this indicate and what action is required?

  1. A manufacturing mark; the sling can be used at full capacity
  2. Normal wear; the sling may continue in use until the next monthly inspection
  3. Localised damage that reduces strength; the sling should be quarantined Correct answer.
  4. Surface rust only; the sling can be used if greased before lifting

Explanation

Clustered broken wires in one strand indicate localised deterioration that significantly reduces the rope's strength. The sling must be taken out of service and quarantined so it cannot be reused. Greasing or waiting for a scheduled inspection does not restore capacity.

Question 33Pre-operation inspection, rigging, and site preparation

A tower crane is being set up on a site where the ground beneath the foundation has been recently filled. What should be confirmed before the foundation is constructed?

  1. That the fill has been adequately compacted and its bearing capacity verified Correct answer.
  2. That the crane will only lift light loads
  3. That the fill has been covered with a layer of gravel
  4. That the fill has been in place for at least one week

Explanation

Recently placed fill may settle or have insufficient bearing capacity, which can cause foundation movement and crane collapse. Geotechnical verification of compaction and bearing capacity is required before constructing the foundation. A gravel layer, light loads or elapsed time alone do not provide that assurance.

Question 34Pre-operation inspection, rigging, and site preparation

During site preparation, the rigger must establish the crane's operating radius markings on the ground. Why is this done?

  1. To show the operator where to park the site vehicle
  2. To identify the location of the site canteen
  3. To indicate the boundary beyond which the crane must not handle loads Correct answer.
  4. To mark where the counterweights should be stacked

Explanation

Radius markings show the limit of the crane's rated operating area so that loads are not handled beyond the planned radius. They help the operator and riggers keep lifts within the load chart. They are not parking, storage or welfare markers.

Question 35Pre-operation inspection, rigging, and site preparation

A rigger is preparing to land a load on a roof where operatives are working. Which site preparation control should be in place before the lift proceeds?

  1. A tarpaulin laid over the landing zone
  2. A second crane standing by on the ground
  3. A designated landing area with edge protection and a clear means of access Correct answer.
  4. A warning sign at the site entrance

Explanation

The landing area must be prepared so that the load can be set down safely and accessed without exposing people to falls. Edge protection and a clear access route are the key controls. A tarpaulin, entrance signage or a standby crane do not make the landing area safe.

Question 36Pre-operation inspection, rigging, and site preparation

A rigger is checking the crane's limit switches before the shift. Which test result shows that the hoist limit switch is working correctly?

  1. The hoist continues until the operator releases the control
  2. The hoist stops automatically before the hook block reaches the jib head Correct answer.
  3. The hoist alarm sounds only when the hook is lowered
  4. The hoist slows but does not stop at the upper limit

Explanation

The hoist limit switch must stop the hoist before the hook block can contact the jib head, preventing two-blocking and rope damage. Stopping automatically at the set point is the correct behaviour. Continuing, slowing without stopping, or alarming only on lowering does not demonstrate a functioning limit.

Question 37Pre-operation inspection, rigging, and site preparation

A rigger is inspecting a shackle before use and finds the pin is bent and the threads are damaged. What is the correct action?

  1. Straighten the pin in a vice and reuse it
  2. Use the shackle with the pin replaced by a bolt of the same diameter
  3. Withdraw the shackle from service and tag it as defective Correct answer.
  4. Use the shackle only for light loads

Explanation

A bent pin and damaged threads mean the shackle cannot be relied upon to hold under load. It must be withdrawn and tagged so it is not returned to service. Substituting a bolt or straightening the pin does not restore the manufacturer's rating.

Question 38Pre-operation inspection, rigging, and site preparation

A tower crane is to be erected on a site where the wind speed at jib height is forecast to exceed the manufacturer's erection limit. What should be done?

  1. Postpone the erection until the wind speed is within the permitted limit Correct answer.
  2. Proceed but reduce the load being lifted during erection
  3. Proceed if the ground-level wind speed is below the limit
  4. Erect the crane with the jib pointing downwind

Explanation

Erection limits apply to wind speed at the height of the crane components being handled, not at ground level. If the forecast exceeds the permitted speed, the work must be postponed. Reducing loads or orienting the jib does not make erection within the manufacturer's limit.

Question 39Pre-operation inspection, rigging, and site preparation

A rigger is planning the lifting accessories for a load whose weight is known but whose centre of gravity is not marked. What is the most appropriate preparation step?

  1. Assume the centre of gravity is at the geometric centre
  2. Determine the centre of gravity by calculation or trial lift close to the ground Correct answer.
  3. Lift the load and observe how it tilts before deciding on slinging
  4. Attach slings to the heaviest-looking end

Explanation

The centre of gravity determines how the load will hang and how the sling legs share the load. It should be established by calculation or a controlled trial lift just above the ground. Assuming a geometric centre or guessing from appearance can produce an unbalanced and dangerous lift.

Question 40Pre-operation inspection, rigging, and site preparation

Before the first lift of the shift, the operator and rigger must confirm that the crane's load moment limiter has been tested. What does a successful test demonstrate?

  1. That the crane will stop or restrict operation before the rated load moment is exceeded Correct answer.
  2. That the crane can lift loads beyond its rated capacity in an emergency
  3. That the hoist rope has been correctly reeved
  4. That the crane's slewing brake is holding

Explanation

The load moment limiter monitors the combination of load and radius and intervenes before the rated moment is exceeded. A successful test shows the device will restrict operation at the set point. It is not a means of exceeding capacity and does not test rope reeving or the slewing brake.

Question 41Tower crane setup, erection, and dismantling support

During tower crane erection, what is the primary purpose of the foundation or ballast design check before the mast is installed?

  1. To ensure the base resists overturning and bearing loads under the erection and service conditions Correct answer.
  2. To confirm the crane's rated capacity at maximum radius
  3. To set the slewing brake release torque
  4. To determine the required wire rope diameter for the hoist

Explanation

The foundation and ballast resist the overturning moment and vertical loads generated by the crane structure, jib, and lifted loads. Erection planning must verify bearing pressure and stability before any mast section is placed, because the crane is most vulnerable during assembly when ballast or ties may be incomplete.

Question 42Tower crane setup, erection, and dismantling support

A mobile crane is being used to assist in assembling a tower crane. Which document must be confirmed before lifting mast sections?

  1. The electrical lockout register
  2. The site's waste disposal manifest
  3. The tower crane manufacturer's load chart only
  4. The mobile crane's lift plan including capacity, radius, and ground bearing check Correct answer.

Explanation

The assisting mobile crane needs its own lift plan that verifies capacity at the actual radius, boom configuration, and ground bearing pressure at the outrigger positions. The tower crane chart is irrelevant to the mobile crane's lifting capability during assembly.

Question 43Tower crane setup, erection, and dismantling support

What is the function of the climbing frame (climbing cage) during a tower crane climbing operation?

  1. It acts as the final tie to the building
  2. It provides the counterweight mounting bracket at the turntable
  3. It guides and supports the mast sections as the crane raises itself using its own hydraulic rams Correct answer.
  4. It houses the operator's cabin during normal operation

Explanation

The climbing frame surrounds the mast and carries the upper structure while hydraulic rams push new mast sections into the tower. It transfers loads temporarily during climbing and must be correctly pinned and inspected before each stroke.

Question 44Tower crane setup, erection, and dismantling support

Before dismantling a tower crane, why must the sequence in the manufacturer's manual be followed exactly?

  1. Because the manual is the only legal document required on site
  2. Because it shortens the warranty period
  3. Because removing components out of sequence can create unbalanced loads and instability Correct answer.
  4. Because it reduces the number of workers needed

Explanation

Dismantling reverses the erection logic, and each step assumes the previous component is still in place to carry loads. Removing ties, ballast, or jib sections out of order can produce an unbalanced structure that exceeds the remaining supports' capacity.

Question 45Tower crane setup, erection, and dismantling support

Which component transfers the horizontal forces from the tower crane mast to the building structure?

  1. The wall tie (anchorage) Correct answer.
  2. The trolley
  3. The hoist rope
  4. The hook block

Explanation

Wall ties connect the mast to the building and carry horizontal reactions such as wind and slewing loads. They are installed at specified heights and must be designed and inspected for the actual tie forces.

Question 46Tower crane setup, erection, and dismantling support

What must be verified about the ground before positioning the outriggers of an assisting mobile crane at a tower crane erection site?

  1. That the ground is level and has adequate bearing capacity with properly sized mats Correct answer.
  2. That the ground slopes toward the crane for water runoff
  3. That the ground is asphalt regardless of thickness
  4. That the ground is covered with loose gravel for drainage

Explanation

Outrigger loads are concentrated and can exceed the ground's bearing capacity, causing settlement or tip-over. Mats spread the load, and the surface must be assessed for voids, underground services, and slope before setup.

Question 47Tower crane setup, erection, and dismantling support

What is the purpose of the overload limiter (moment limiter) during tower crane operation after erection?

  1. To limit the slewing speed in high wind
  2. To prevent the crane from exceeding its rated load or load moment for the current configuration Correct answer.
  3. To control the hoist brake release
  4. To measure the mast verticality

Explanation

The overload limiter compares actual load and radius against the configured load chart and stops hoisting or trolleying outward when limits are approached. It must be calibrated for the specific jib length, counterweight, and tie configuration after erection.

Question 48Tower crane setup, erection, and dismantling support

During erection, why are pins and bolts on mast connections checked for full insertion and locking before the next section is added?

  1. To allow the crane to slew faster
  2. To reduce the required counterweight
  3. To ensure the connection can carry the loads and cannot work loose under vibration Correct answer.
  4. To speed up the next lift by reducing weight

Explanation

Mast connections transfer the full vertical and moment loads between sections, so partial pin insertion or missing locking devices can cause joint failure. Vibration and dynamic loads during erection can walk out an unlocked pin.

Question 49Tower crane setup, erection, and dismantling support

A tower crane is to be erected adjacent to a public road. Which control best addresses the risk of falling objects during assembly?

  1. Erecting during peak traffic hours to finish quickly
  2. Increasing the hoist speed to reduce time aloft
  3. Establishing an exclusion zone and, where required, road closure or protected walkway Correct answer.
  4. Removing the anemometer to avoid false alarms

Explanation

Falling tools or components during erection are a primary hazard, so the area beneath and around the crane must be excluded from people and traffic. Where the public cannot be diverted, physical protection or a road closure is required.

Question 50Tower crane setup, erection, and dismantling support

When a tower crane is climbed and tied to a building, what must be confirmed about the tie anchor points before the tie is loaded?

  1. That the anchors are painted to match the building
  2. That the anchors are installed by the crane operator alone
  3. That the embedment or fixing design has been verified and the concrete has reached adequate strength Correct answer.
  4. That the tie is installed at any convenient height

Explanation

Tie anchors transfer large horizontal reactions into the building, so their design, embedment, and the concrete strength at the time of loading must be confirmed. Loading anchors before the concrete matures can pull them out.