I85PREP
⌘ K
High Risk Work Licence - Concrete Placing Boom (PB) study materials
High Risk Work Licence - Concrete Placing Boom (PB) study resources

High Risk Work Licence - Concrete Placing Boom (PB) practice questions

One question at a time. Build your High Risk Work Licence - Concrete Placing Boom (PB) understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Legislation, standards and duty of care

Under the model WHS legislation, what is the primary duty of a person conducting a business or undertaking (PCBU) in relation to concrete placing boom operations?

  1. Ensure the health and safety of workers and others affected by the business so far as reasonably practicable Correct answer.
  2. Provide personal protective equipment and nothing further is required
  3. Guarantee that no incident can ever occur on a site where a boom is used
  4. Transfer all safety responsibilities to the principal contractor by written agreement

Explanation

The primary duty holder must eliminate or minimise risks to health and safety so far as is reasonably practicable, which is an objective standard balancing likelihood, degree of harm, and cost. It is non-delegable, so it cannot simply be handed to another party by agreement.

Question 2Legislation, standards and duty of care

A concrete placing boom is being set up beside an excavation. Which duty holder is responsible for ensuring the plant is inspected and maintained in safe condition?

  1. Only the site's principal contractor
  2. Only the manufacturer of the boom
  3. The concrete supplier delivering to site
  4. The PCBU with management or control of the plant, such as the boom operator's employer Correct answer.

Explanation

A PCBU with management or control of plant at a workplace must ensure the plant is without risks to health and safety, which includes inspection, maintenance and repair. This duty sits with the party controlling the plant, commonly the boom operator's employer, though other duty holders may also owe overlapping duties.

Question 3Legislation, standards and duty of care

What is the purpose of a safe work method statement (SWMS) for high risk construction work involving a concrete placing boom?

  1. To replace the need for any site-specific induction
  2. To record the boom operator's daily hours of work
  3. To describe how the high risk work will be carried out safely and how controls will be implemented and monitored Correct answer.
  4. To document the design calculations for the boom's structural capacity

Explanation

A SWMS sets out the work activities, the hazards, the control measures and how those controls will be put in place, monitored and reviewed. It must be prepared before the high risk construction work commences and be kept available for inspection.

Question 4Legislation, standards and duty of care

Which document provides the competency requirement for a person operating a concrete placing boom in Australia?

  1. The manufacturer's operation manual alone
  2. The site's emergency evacuation plan
  3. The national standard for high risk work licensing, which requires a PB class licence Correct answer.
  4. The concrete pumping industry code of conduct

Explanation

Concrete placing boom operation is declared high risk work, so the operator must hold the relevant class of high risk work licence under the national licensing standard. The licence is issued after assessment against the unit of competency for boom operation.

Question 5Legislation, standards and duty of care

What is the hierarchy of control that must be applied when managing risks associated with boom set-up near overhead power lines?

  1. PPE first, then signage, then exclusion zones
  2. Administrative controls first, then PPE, then engineering controls
  3. Eliminate the risk, then substitute, isolate, use engineering controls, then administrative controls, then PPE Correct answer.
  4. Only rely on the operator's experience and judgement

Explanation

The hierarchy ranks controls from most to least reliable: eliminate the hazard, substitute, isolate, engineering controls, administrative controls and finally PPE. Higher-order controls such as maintaining a de-energised or isolated zone should be used before relying on signage or procedures.

Question 6Legislation, standards and duty of care

Why must a concrete placing boom operator hold a current high risk work licence rather than simply being trained on site?

  1. Because insurers prefer licensed operators but the law does not require it
  2. Because site induction is legally sufficient for all plant operation
  3. Because the law requires licensed operators for declared high risk work, verified through national competency assessment Correct answer.
  4. Because the manufacturer's warranty is voided otherwise

Explanation

Declared high risk work may only be performed by a person holding the appropriate licence, which is issued following assessment against a national unit of competency. Site-specific training supplements but does not replace the licence.

Question 7Legislation, standards and duty of care

A boom operator notices that the outrigger pad is sinking into soft ground during set-up. Applying the hierarchy of control, what is the most appropriate first response?

  1. Ask a nearby worker to stand on the pad to stabilise it
  2. Continue operating and monitor the pad closely
  3. Reduce the boom reach and continue at a slower speed
  4. Stop the task and relocate or engineer the ground support so the load is spread adequately Correct answer.

Explanation

Where ground bearing capacity is inadequate, the hazard should be controlled at source by relocating the boom or providing engineered load-spreading such as properly sized mats or a designed pad. Continuing to operate with a sinking pad risks overturning and is not an acceptable control.

Question 8Legislation, standards and duty of care

A principal contractor engages a boom pumping subcontractor. Which statement best describes their respective duties?

  1. Duties are allocated solely by the contract price
  2. Only the subcontractor owes any duty because it directly operates the boom
  3. Both parties may owe concurrent duties, and the principal contractor must consult and coordinate with the subcontractor on WHS matters Correct answer.
  4. The principal contractor's duty ends once the subcontractor is inducted

Explanation

WHS duties are concurrent and overlapping, so multiple duty holders can be responsible for the same activity. Duty holders must consult, cooperate and coordinate activities with each other to the extent reasonably practicable.

Question 9Legislation, standards and duty of care

What must occur before a concrete placing boom is used to place concrete on a multi-storey construction site for the first time?

  1. A pre-operational check and verification of set-up, including stability, exclusion zones and proximity to hazards Correct answer.
  2. Only a visual glance from the operator at the start of the shift
  3. A full structural engineering review of the building by the operator
  4. A meeting with the concrete supplier about delivery times

Explanation

Before use, the plant and its set-up must be verified as safe, including outrigger deployment, ground conditions, clearances from hazards and exclusion zones. This is part of the duty to ensure plant is without risks to health and safety before it is used.

Question 10Legislation, standards and duty of care

A boom is to be set up near an underground car park roof slab. Which control best reflects the duty to manage risk at source?

  1. Obtain engineering advice on the slab's load capacity and use designed load-spreading or relocate the boom Correct answer.
  2. Place warning tape around the area and proceed
  3. Reduce the concrete pour rate and continue
  4. Rely on the operator to feel for slab movement during operation

Explanation

Ground and structural support capacity must be verified before set-up, and engineered load spreading or relocation eliminates or minimises the risk of collapse. Administrative measures alone do not control the potential for catastrophic failure.

Question 11Legislation, standards and duty of care

How often must the boom's safety devices, such as limiters and interlocks, be functionally checked according to general plant management duties?

  1. Only when a fault is reported by the operator
  2. Only after an incident occurs
  3. Once at commissioning and never again
  4. At intervals specified by the manufacturer and the PCBU's inspection schedule, plus before each use as required Correct answer.

Explanation

The PCBU must ensure plant is inspected, maintained and tested in accordance with the manufacturer's recommendations and a documented schedule. Safety devices must be functional before use because they are critical controls against structural overload and instability.

Question 12Legislation, standards and duty of care

An operator is asked to work in winds that exceed the manufacturer's stated operating limit. What is the correct action under WHS duties?

  1. Ask a supervisor to sign a waiver and continue
  2. Cease boom operation and secure the plant in accordance with the manufacturer's procedures Correct answer.
  3. Lower the boom slightly and continue
  4. Proceed if the pour is nearly finished

Explanation

Operating outside the manufacturer's design limits creates an uncontrolled risk of structural failure or loss of stability. The duty to ensure plant is used only within its design parameters requires the task to stop and the plant to be secured.

Question 13Legislation, standards and duty of care

What is the key purpose of consulting workers during the development of controls for boom set-up and operation?

  1. To reduce the cost of the project
  2. To satisfy a paperwork requirement with no effect on safety
  3. To draw on workers' practical knowledge so hazards are identified and controls are workable and effective Correct answer.
  4. To shift legal liability from the PCBU to the workers

Explanation

Consultation is a legal duty and improves risk management by capturing the practical experience of people who do the work. It helps ensure identified hazards are addressed with controls that can actually be implemented.

Question 14Legislation, standards and duty of care

A boom operator holds a current licence but has not operated a particular boom model before. What does the duty to provide information, training and instruction require?

  1. Model-specific familiarisation and instruction before operating the unfamiliar plant Correct answer.
  2. That the operator decline all work on unfamiliar plant permanently
  3. Only a copy of the manual handed over without discussion
  4. Nothing further, because the licence covers all boom models

Explanation

A licence demonstrates broad competency but does not replace the duty to provide plant-specific information, training and instruction. The PCBU must ensure the operator is familiar with the particular controls, limits and set-up requirements of the plant.

Question 15Legislation, standards and duty of care

Which of the following best describes the meaning of 'so far as is reasonably practicable' when applied to boom operations?

  1. Do only what is written in the manufacturer's manual
  2. Do nothing unless an incident has previously occurred
  3. Do what a reasonable person would do, weighing the likelihood and severity of harm against the cost and difficulty of controls Correct answer.
  4. Do whatever is cheapest regardless of risk

Explanation

The test weighs the likelihood of the hazard, the degree of harm, what the duty holder knows or ought to know, and the availability and cost of controls. Cost is relevant but cannot justify leaving a serious risk uncontrolled.

Question 16Legislation, standards and duty of care

A site has two PCBUs whose boom operations overlap in the same area. What does the WHS legislation require of them?

  1. They must consult, cooperate and coordinate activities so far as reasonably practicable Correct answer.
  2. They must merge their safety management systems into one document
  3. The larger company automatically assumes all duties
  4. Each may operate independently without reference to the other

Explanation

Where more than one duty holder has responsibility for the same matter, each must consult, cooperate and coordinate with the others. This prevents gaps and conflicts in control measures in shared work areas.

Question 17Legislation, standards and duty of care

An incident occurs where a boom contacts a power line. Which combination of obligations applies to the PCBU?

  1. Preserve the site, notify the regulator as required for a notifiable incident, and provide first aid and support to affected workers Correct answer.
  2. Repair the boom immediately before any investigation
  3. Continue work to avoid project delays
  4. Only notify the electricity supplier and take no further action

Explanation

A dangerous incident involving contact with energised electrical equipment is generally notifiable, so the regulator must be notified and the site preserved until released. The PCBU must also ensure injured workers receive care and that the scene is not disturbed except to make it safe or assist an injured person.

Question 18Legislation, standards and duty of care

A risk assessment identifies that the exclusion zone beneath a boom's discharge hose is sometimes entered by other trades. Which control strategy best reflects the hierarchy of control?

  1. Instruct the operator to shout warnings when someone approaches
  2. Rely on a warning sign at the gate and continue
  3. Issue high-visibility vests to all workers on site
  4. Physically isolate the zone with rigid barriers and plan pour sequencing to keep other trades clear Correct answer.

Explanation

Physical isolation and planning the work to eliminate the need for people to enter the hazard area are higher-order controls than signage or warnings. Administrative and PPE measures are less reliable because they depend on human behaviour.

Question 19Legislation, standards and duty of care

A PCBU plans to modify a concrete placing boom by fitting an aftermarket pipe extension not approved by the manufacturer. What is the correct compliance position?

  1. Modifications that affect the plant's structural integrity or stability require engineering assessment and must not compromise the plant's compliance Correct answer.
  2. Any modification is acceptable if it is welded by a competent person
  3. Modifications are permitted if they reduce the pour time
  4. Modifications are permitted if the operator agrees to them

Explanation

Altering plant can change loads, stability and compliance status, so it must be assessed by a competent person such as an engineer and authorised appropriately. Plant must remain compliant with its design and any applicable standards after modification.

Question 20Legislation, standards and duty of care

A boom is set up on a suspended slab and the engineer's capacity check states the outrigger loads must be spread over a defined area. During the pour, the operator observes cracking near a pad. What is the appropriate duty-driven response?

  1. Stop the pour, relieve the load, evacuate the area and have the set-up reassessed by a competent person Correct answer.
  2. Continue and record the observation in the log for later review
  3. Add more concrete to the area to fill the cracks
  4. Complete the pour quickly to reduce the duration of loading

Explanation

Cracking may indicate the slab is approaching or exceeding capacity, creating a risk of collapse. The duty to ensure safety requires the load to be removed, the area made safe and the set-up reassessed before any resumption.

Question 21Hazard identification, risk assessment and control

Before a concrete placing boom is set up on a construction site, which document should identify the hazards, the people exposed and the controls to be applied?

  1. The concrete supplier's delivery docket
  2. The truck mixer service record
  3. The boom operator's logbook
  4. A site-specific risk assessment Correct answer.

Explanation

A site-specific risk assessment identifies each hazard associated with the boom task, who could be harmed, and the controls that reduce the risk to an acceptable level. It is prepared before work begins and is reviewed whenever conditions change. Delivery paperwork and machine records do not perform this function.

Question 22Hazard identification, risk assessment and control

What is the primary purpose of a hazard identification and risk assessment process for concrete placing boom work?

  1. To satisfy the client's insurance policy wording
  2. To reduce the number of workers on site
  3. To decide controls before harm occurs Correct answer.
  4. To allocate blame if an incident later occurs

Explanation

The process exists so that hazards are found and controls are decided before anyone is exposed, which prevents injury rather than reacting afterwards. It is a proactive planning tool, not a blame or staffing mechanism. Insurance and client requirements may prompt it but are not its purpose.

Question 23Hazard identification, risk assessment and control

A placing boom must be set up beside an excavation. Which control should be considered first under the hierarchy of control?

  1. Place warning signs along the excavation edge
  2. Eliminate the need to position the boom near the excavation Correct answer.
  3. Require the operator to wear a high-visibility vest
  4. Instruct the dogman to watch the boom base

Explanation

The hierarchy of control ranks elimination of the hazard highest, because removing the exposure removes the risk entirely. Relocating the boom so it is not near the excavation edge eliminates the collapse hazard. Signs, vests and observers are lower-order administrative or personal controls.

Question 24Hazard identification, risk assessment and control

Why must outrigger or stabiliser loads be checked against ground bearing capacity before a placing boom is set up?

  1. To prevent the machine sinking or overturning Correct answer.
  2. To decide the colour of the delivery hose
  3. To confirm the boom can reach the full pour area
  4. To calculate the concrete slump required

Explanation

The boom transfers large point loads through its outriggers, and soft or uncompacted ground can fail under those loads, causing the machine to settle or overturn. Checking bearing capacity and using spreader mats where needed controls that risk. Reach, slump and hose colour are unrelated to ground pressure.

Question 25Hazard identification, risk assessment and control

Which hazard is most directly created by operating a placing boom near overhead power lines?

  1. Noise exposure to the concrete crew
  2. Dust generation from the pour
  3. Slip hazards from spilled slurry
  4. Electric shock or arc flash to workers Correct answer.

Explanation

Contact or near-contact between the boom and energised overhead lines can cause electric shock, arc flash and fire. Exclusion zones and de-energising or isolating the lines are the usual controls. Noise, dust and slurry are real but are not created by proximity to power lines.

Question 26Hazard identification, risk assessment and control

What is the main reason for establishing an exclusion zone under and around the placing boom's working area?

  1. To protect people from falling objects and hose whip Correct answer.
  2. To give the pump operator a quiet workspace
  3. To reduce the amount of water used on site
  4. To keep the concrete surface free of footprints

Explanation

The area beneath the boom can receive dropped tools, concrete spills and uncontrolled hose movement, so people are kept out to prevent struck-by injuries. The zone is a physical control that separates hazards from workers. Surface finish, water use and operator comfort are not the purpose.

Question 27Hazard identification, risk assessment and control

A boom operator reports that the wind has picked up and is gusting strongly. What is the most appropriate immediate action?

  1. Ask the crew to hold the hose steady
  2. Stop the pour and stow the boom per the manufacturer's limits Correct answer.
  3. Continue the pour but reduce boom speed
  4. Increase the concrete flow to finish faster

Explanation

Placing booms have manufacturer-specified wind speed limits, and exceeding them can cause loss of control, structural overload or overturning. Work should stop and the boom stowed in line with those limits. Slowing down or rushing the pour does not remove the wind hazard.

Question 28Hazard identification, risk assessment and control

Which of the following best describes a 'risk score' produced during a placing boom risk assessment?

  1. The purchase price of the boom unit
  2. A combined judgement of likelihood and consequence Correct answer.
  3. The number of workers on the pour
  4. The volume of concrete delivered per hour

Explanation

Risk is assessed by combining how likely a hazardous event is with how severe the outcome would be. That combined judgement lets controls be prioritised. Cost, headcount and pour rate are separate operational measures and do not express risk.

Question 29Hazard identification, risk assessment and control

During a pre-start review, a supervisor finds the ground under one outrigger has been disturbed by other trades. What should happen before the pour continues?

  1. Ask the operator to keep that outrigger lightly loaded
  2. Proceed and monitor the outrigger during the pour
  3. Add more concrete to the disturbed area after the pour
  4. Reassess the ground support and reinstate adequate bearing before use Correct answer.

Explanation

Changed ground conditions invalidate the original assessment, so the support must be reassessed and adequate bearing restored, for example with compacted fill and spreader mats, before the boom is used. Monitoring during the pour leaves people exposed to a collapse. Operators cannot reliably unload a single outrigger.

Question 30Hazard identification, risk assessment and control

What is the key risk when a placing boom is used on a suspended concrete slab?

  1. Slab colour variation
  2. Hose blockage from cold weather
  3. Overloading the slab beyond its design capacity Correct answer.
  4. Reduced concrete strength at the nozzle

Explanation

Suspended slabs are designed for specific loads, and the concentrated outrigger loads of a placing boom can exceed that capacity unless propping or load spreading is engineered. An engineer's assessment is needed before the boom is set up on a slab. Colour, weather and nozzle strength are not the issue.

Question 31Hazard identification, risk assessment and control

A worker is required to guide the hose at the discharge point. Which control most directly reduces their exposure to hose whip if a blockage clears suddenly?

  1. Using a remote-controlled boom with a secured hose end Correct answer.
  2. Standing closer to the boom base
  3. Increasing pump pressure gradually
  4. Wearing hearing protection

Explanation

Remote operation keeps the worker away from the discharge end, and securing the hose end restrains the violent movement when a blockage releases. Together they reduce the chance of being struck. Hearing protection, standing position near the base and pressure changes do not restrain the hose.

Question 32Hazard identification, risk assessment and control

Why should a placing boom be positioned so that the boom does not pass over occupied areas such as site sheds or public footpaths?

  1. To shorten the hose length required
  2. To reduce the noise reaching those areas
  3. To avoid dropping concrete or the boom onto people below Correct answer.
  4. To improve the concrete finish at the pour point

Explanation

Working over occupied areas exposes people to falling concrete, tools or, in a failure, the boom itself. Positioning the machine so the boom travels over closed or unoccupied ground removes that exposure. Noise, finish quality and hose length are secondary considerations.

Question 33Hazard identification, risk assessment and control

Which factor should be considered when assessing the risk of a placing boom task at night?

  1. The brand of the pump truck
  2. The colour of the concrete mix
  3. Reduced visibility and worker fatigue Correct answer.
  4. The number of delivery trucks booked

Explanation

Night work brings poorer visibility for the operator and crew and higher fatigue, both of which increase the chance of error and injury. Adequate task lighting and fatigue management are the typical controls. Mix colour, truck brand and delivery numbers do not drive the safety assessment.

Question 34Hazard identification, risk assessment and control

After a control measure is introduced for a placing boom hazard, what should be done to confirm it is working?

  1. Monitor and review the control's effectiveness Correct answer.
  2. File the paperwork and take no further action
  3. Wait for the next annual audit
  4. Ask the client to sign a disclaimer

Explanation

Controls must be monitored to confirm they remain effective and suitable as conditions change, which is a continuing duty in the risk management process. Filing and waiting for an audit leave gaps where controls may fail unnoticed. A disclaimer does not verify control effectiveness.

Question 35Hazard identification, risk assessment and control

A delivery driver wants to wash out the pump hopper beside a stormwater drain. What is the most appropriate control?

  1. Designate a contained washout area away from drains Correct answer.
  2. Ask the driver to wash out quickly
  3. Use the drain only during dry weather
  4. Allow washout and dilute it with drain water

Explanation

Concrete washout water is highly alkaline and can harm aquatic life and block drains, so a contained washout area away from stormwater is required. Dilution, speed or dry weather do not prevent the discharge reaching the environment. This is an environmental hazard identified in the assessment.

Question 36Hazard identification, risk assessment and control

Which of the following is the best example of a higher-order control for the hazard of workers being struck by the boom?

  1. Physical barriers preventing access to the boom's travel path Correct answer.
  2. A sign warning of boom movement
  3. A rule that workers must look up
  4. A toolbox talk on boom awareness

Explanation

Physical barriers separate people from the hazard and do not depend on human behaviour, so they rank above signs, talks and rules. Engineering separation is a higher-order control. Administrative measures rely on people remembering and complying.

Question 37Hazard identification, risk assessment and control

What specific hazard arises when a placing boom is set up on a slope or near a trench edge without adequate assessment?

  1. Faster hose wear
  2. Reduced pump output
  3. Loss of stability and possible overturning Correct answer.
  4. Increased concrete temperature

Explanation

Sloping or unstable ground allows the machine to slide, settle or tip, and a trench edge can collapse under outrigger loads. Stability assessment, levelling and adequate setback from edges are the controls. Temperature, hose wear and output are unrelated to ground slope.

Question 38Hazard identification, risk assessment and control

During the pour, the operator notices the boom is drifting and will not hold position. What is the safest initial response?

  1. Keep pouring and correct with the remote control
  2. Ask a worker to push the boom back into position
  3. Increase hydraulic pressure to hold the boom
  4. Stop the pour and move people clear of the boom's path Correct answer.

Explanation

Uncontrolled boom movement indicates a possible hydraulic or control failure that could lead to structural collapse or striking people. Stopping the pour and clearing the area removes exposure while the fault is investigated. Manual pushing or forcing pressure risks worsening the failure.

Question 39Hazard identification, risk assessment and control

Why is it important to identify the hazards of concrete placing boom work jointly with the workers who perform the task?

  1. It guarantees the client will approve the method
  2. It captures practical knowledge of how the task is really done Correct answer.
  3. It transfers legal responsibility to the workers
  4. It removes the need for any documented assessment

Explanation

Workers who perform the task know the practical difficulties and near-misses that a desk-based assessment can miss, so consultation improves hazard identification and control design. Consultation does not transfer legal duties or replace documentation. Client approval is a separate process.

Question 40Hazard identification, risk assessment and control

Which hazard is most associated with the concrete itself during a placing boom pour, rather than with the machine?

  1. Wet concrete causing chemical burns and skin irritation Correct answer.
  2. Boom structural overload
  3. Boom contact with power lines
  4. Outrigger ground bearing failure

Explanation

Wet concrete is alkaline and abrasive, and prolonged skin contact can cause serious chemical burns, so gloves, long sleeves and washing facilities are needed. The other options are machine-related hazards rather than properties of the concrete.

Question 41Hazard identification, risk assessment and control

A site has a known underground service corridor crossing the area where the boom will be set up. What should be done before positioning the machine?

  1. Assume the corridor is deep enough to be safe
  2. Obtain service location information and assess the ground above it Correct answer.
  3. Set up quickly before other trades arrive
  4. Place the outriggers directly over the corridor to spread load

Explanation

Underground services and voids reduce the ground's ability to carry outrigger loads and may also be damaged by them. Accurate location information and an assessment, with relocation or load spreading as needed, are required. Assumption and haste are not controls, and loading directly over a corridor worsens the risk.

Question 42Hazard identification, risk assessment and control

What is the purpose of a pre-start check of the placing boom before each shift?

  1. To calculate the concrete volume required
  2. To detect defects that could cause failure during the pour Correct answer.
  3. To confirm the client's payment schedule
  4. To record the operator's hours for payroll

Explanation

Pre-start checks look for hydraulic leaks, damaged hoses, worn pins and other defects that could lead to loss of control or structural failure during work. Defects found are reported and rectified before use. Payroll, volume and payment matters are unrelated.

Question 43Hazard identification, risk assessment and control

When a risk assessment shows that residual risk from a placing boom task remains high even after controls, what is the correct approach?

  1. Proceed because controls have been applied
  2. Shorten the task duration and accept the risk
  3. Rely on worker experience to manage the risk
  4. Do not start the task until the risk is reduced further Correct answer.

Explanation

If residual risk stays high after controls, the task should not proceed until further controls reduce it to an acceptable level. Applying some controls does not automatically make the task safe. Experience and shorter duration do not substitute for adequate risk reduction.

Question 44Hazard identification, risk assessment and control

Which control best addresses the hazard of the placing boom hose contacting overhead structures during operation?

  1. Pouring only when the site is empty
  2. Increasing pump pressure to keep the hose taut
  3. Removing all signage from the area
  4. Planning boom travel paths and using a spotter with defined limits Correct answer.

Explanation

Planning the boom's travel envelope and using a spotter with clear communication limits prevents the hose or boom striking overhead structures and services. Pressure changes do not control contact, and removing signage reduces awareness. Emptying the site is not a practical control.

Question 45Concrete placing boom types, components and terminology

In concrete placing boom terminology, what does the main articulated arm that carries the delivery pipeline and ends at the placing nozzle get called?

  1. The outrigger leg
  2. The slewing ring
  3. The boom section Correct answer.
  4. The hopper grate

Explanation

The boom is the articulated arm assembly that supports and guides the delivery pipeline from the base to the placing point. Its sections fold and unfold hydraulically to position the end hose over the pour area. Outriggers, hopper grates and slewing rings are separate components with different functions.

Question 46Concrete placing boom types, components and terminology

What name is given to the jointed, hydraulically folded pipe that carries concrete along the boom?

  1. The water line
  2. The suction hose
  3. The air bleed line
  4. The delivery pipeline Correct answer.

Explanation

The delivery pipeline is the pipe run mounted along the boom sections that conveys concrete from the pump to the end hose. It is supported by the boom and articulates at each fold point. Suction, bleed and water lines serve other functions on the machine.

Question 47Concrete placing boom types, components and terminology

Which component allows a truck-mounted placing boom to rotate the whole boom assembly about the vertical axis?

  1. The slewing ring Correct answer.
  2. The wear plate
  3. The end hose
  4. The agitator shaft

Explanation

The slewing ring is the large bearing that connects the rotating boom turret to the base and permits full rotation about the vertical axis. Rotation is driven by hydraulic motors acting through gearing on the ring. The end hose, wear plate and agitator serve unrelated functions.

Question 48Concrete placing boom types, components and terminology

What is the purpose of the end hose on a concrete placing boom?

  1. To flexibly direct concrete into the formwork Correct answer.
  2. To support the weight of the boom tip
  3. To measure concrete slump at the pour point
  4. To vent hydraulic pressure from the boom

Explanation

The end hose is the flexible section at the boom tip that lets the operator place concrete precisely into formwork or a skip. It must be restrained and never handled to swing the boom manually. It does not measure slump, carry boom load, or vent hydraulics.

Question 49Concrete placing boom types, components and terminology

Which term describes a placing boom whose base is mounted on a purpose-built truck chassis and travels between sites?

  1. Trailer-mounted pump
  2. Truck-mounted placing boom Correct answer.
  3. Skid-steer boom
  4. Static tower boom

Explanation

A truck-mounted placing boom combines a road-going chassis with a slewing boom and pipeline, so it can travel between jobs and set up quickly. Static booms are fixed to a base or structure and are not road-registered as a unit. Trailer pumps and skid-steer units are different machine classes.

Question 50Concrete placing boom types, components and terminology

What does the term 'boom section' refer to on a multi-section placing boom?

  1. One of the articulated arms joined by fold joints Correct answer.
  2. The base outrigger beam
  3. The concrete pump piston stroke
  4. The hydraulic oil reservoir

Explanation

A boom section is one of the articulated arms connected by fold joints, and the number of sections determines how the boom folds and reaches. Each section carries pipeline and is moved by its own hydraulic ram. Pump strokes, outrigger beams and oil reservoirs are unrelated parts.