High Risk Work Licence - Portal Boom Crane (CP) common mistakes
High Risk Work Licence - Portal Boom Crane (CP) · Understand the traps and how to avoid them.
Treating the load chart as a single fixed capacity for the crane and quoting one number regardless of boom length, radius, or configuration.
Candidates memorise a headline capacity from training and default to it under time pressure, forgetting that rated capacity is configuration-specific and that the chart's structural and stability limits change with geometry.
What to do instead
Practise reading charts by entering with the actual radius and boom length for the task, then confirming the governing limit (structural, stability, or manual) before quoting a figure. State the radius and configuration alongside any capacity number in answers.
Estimating the load from the item's nominal weight only, ignoring slings, spreader beams, shackles, and rigging hardware, and ignoring the effect of sling angle on tension.
Candidates focus on the visible object and treat rigging as negligible, and they misapply sling-angle factors by dividing by the angle rather than by the sine of the angle to vertical.
What to do instead
Build a habit of summing load plus all rigging and lifting attachments, then applying the sling-angle multiplier (tension equals load divided by the number of legs times sine of angle to vertical). Work several numeric examples until the sine relationship is automatic.
Skipping or rushing the pre-start inspection, signing the checklist without physically checking tyres, outrigger pads, wire rope, hooks and latches, limit switches, and alarms.
Candidates treat inspection as paperwork that must be completed rather than a physical test, and they assume the previous operator's sign-off covers the current shift.
What to do instead
Rehearse a fixed walk-around sequence with a defined order so nothing is omitted, and in written answers list the specific defect classes checked (rope broken wires and kinks, hook throat opening and latch function, fluid leaks, tyre condition, safety device function tests). Emphasise that each shift and each operator requires their own check.
Underestimating ground bearing pressure and setting outrigger pads on uncompacted fill, service pits, or near excavations without checking for voids or underground services.
Candidates judge stability from the crane's footprint alone and do not connect outrigger load to soil bearing capacity, and they overlook nearby excavations that reduce lateral support.
What to do instead
Learn to estimate outrigger load as a share of total weight plus load moment, and match it to pad size and ground type. In answers, always state the need to assess ground conditions, use load-spreading pads sized to the pressure, and keep pads clear of excavations and buried services by a defined margin.
Relying on hand signals alone with an unfamiliar dogman, or continuing a lift when signals become ambiguous or the dogman moves out of sight.
Candidates assume signal conventions are universal and are reluctant to stop a job in progress, so they interpret unclear signals rather than halting.
What to do instead
State the rule that lifting stops when signals are unclear or the dogman is not visible, and that a pre-lift briefing confirms the signal set, the emergency stop signal, and radio channel. In answers, describe agreed communication methods and the authority of any person to stop the lift.
Confusing the roles and legal duties of the person conducting a business or undertaking, the competent person, the crane operator, and the dogman, and attributing the wrong duty to the wrong party.
Candidates learn duties as a general theme rather than as a mapped set of obligations, so they blend responsibilities such as providing a safe system of work, inspecting and maintaining plant, and directing the lift.
What to do instead
Build a role-to-duty table and test yourself on who must do what: the business provides and maintains plant, information, training and supervision; the competent person inspects and assesses; the operator controls the crane and refuses unsafe lifts; the dogman directs the lift and slings the load. Answer duty questions by naming the party explicitly.
Answering hazard questions with generic categories such as 'weather' or 'powerlines' without identifying the specific hazard, its consequence, and a control in the hierarchy order.
Candidates list hazards as labels and jump to a single control, usually administrative or personal protective equipment, rather than eliminating or engineering out the risk.
What to do instead
Structure risk answers as hazard, mechanism of harm, likelihood and consequence, then controls applied in hierarchy order (eliminate, substitute, engineer, administrate, PPE). For powerlines, state the specific approach distance, spotter requirement, and de-energising or isolation as the preferred control.
Describing emergency response as 'call emergency services' without the immediate crane-specific actions: stopping the lift, lowering the load safely, isolating power, and securing the area.
Candidates treat emergency procedure as a generic first-aid answer and do not sequence the machine actions that must precede external help.
What to do instead
Memorise a fixed sequence: stop operations, make the load and crane safe, isolate and lock out, raise the alarm, account for personnel, preserve the scene, then report and record. Practise applying the sequence to scenarios such as contact with powerlines, load drop, or a rigger injury.
Failing to distinguish maintenance that the operator may perform from maintenance requiring a competent person or qualified technician, and not knowing when a defect must ground the crane.
Candidates conflate daily checks with scheduled maintenance and assume any defect can be logged and deferred, missing that safety-critical defects such as brake or limit-switch failure require immediate shutdown.
What to do instead
Categorise defects by severity and state the action for each: safety-critical defects stop work and require isolation and tagging; non-critical defects are recorded and reported for scheduled repair. Learn the record-keeping obligations, including who inspects, how often, and what is documented.
Ignoring or misjudging dynamic and environmental effects: wind on the load's sail area, side loading from slewing or travelling with a suspended load, and shock loading from rapid hoist starts or sudden stops.
Candidates calculate static capacity and treat the crane as a rigid system, forgetting that travelling with a load, rapid slewing, and wind add forces not captured by the static chart.
What to do instead
In answers, always consider the load's wind area and the manufacturer's wind limit, keep travel to the specified configuration with the load lowered and controlled, avoid side pulls, and apply smooth acceleration and deceleration. Explain how each factor increases effective load or reduces stability.