High Risk Work Licence - Slewing Mobile Crane C0 (over 100t) flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

Primary duty of care

The PCBU must ensure, so far as is reasonably practicable, the health and safety of workers and others affected by the business, including crane operations and lift planning.

Hierarchy of control

A ranked order of controls from most to least effective: elimination, substitution, isolation, engineering, administrative, and PPE. Higher-order controls are preferred for crane hazards.

Notifiable incident

An incident such as death, serious injury or illness, or a dangerous event like plant collapse or load drop, which must be reported to the regulator as required by WHS law.

Safe work method statement

A written document that sets out the high risk construction work, the hazards, the controls, and how controls will be implemented, monitored and reviewed before work starts.

Risk score formula

Risk is assessed as likelihood multiplied by consequence. Controls are applied in hierarchy order, and residual risk is re-assessed after each control is implemented.

Exclusion zone

A barricaded area around the crane sized to the greater of the swing radius, the load fall zone, or the calculated drop radius, keeping people clear of crush and drop hazards.

Powerline approach limits

Minimum safe distances from energised lines that increase with voltage. The voltage must be identified, the line isolated where possible, and a spotter used.

Wind limit

The maximum wind speed specified by the manufacturer in the load chart. Capacity reductions apply above it, and loads with large sail area increase wind loading.

Radius measurement

The horizontal distance from the crane's slewing centre to the centre of gravity of the load, not to the hook or boom tip. Radius increases with boom deflection.

Rated capacity

The charted capacity for the current configuration and radius, reduced by deductions for hook block, slings, spreader beams, and any jib or fly section attached.

Structural versus stability limit

Two separate limits govern capacity. Structural limits concern boom and component strength; stability limits concern overturning. The chart reflects the lesser of the two.

Configuration-specific chart

A load chart valid only for a specific boom length, counterweight, outrigger spread, and jib setup. A chart for another configuration must not be used.

Sling tension formula

Tension per leg equals load divided by the number of legs multiplied by the cosine of the angle from vertical. Wider included angles increase tension in each leg.

Working load limit

The maximum mass a sling or fitting may lift in a specified configuration. The assembly's WLL is the lowest-rated component in the rigging system.

Centre of gravity

The point through which the load's weight acts. The hook must be directly above it so the load stays level and sling tensions remain equal.

Mass estimation formula

Mass equals volume multiplied by density. Reference densities: steel about 7,850 kg/m³, concrete about 2,400 kg/m³, water 1,000 kg/m³.

Ground bearing pressure

The load on an outrigger divided by the effective pad area. The pad must spread the load to below the verified ground bearing capacity of the soil.

Outrigger load distribution

Outrigger loads are unequal. The outrigger nearest the load carries the greatest load, often several times the average, and governs pad size selection.

Set-up level tolerance

The crane must be level within the manufacturer's tolerance, with outriggers fully extended and pinned and pads bearing on verified stable ground.

Underground voids

Basements, drains, services and backfilled excavations under outrigger pads can collapse under load. They must be identified and assessed before the crane is set up.

Critical lift

A lift with high consequence or complexity, such as a load near capacity, a multi-crane lift, a lift over live plant, or an unusual or unstable load.

Multi-crane load share

Load share between cranes depends on geometry, rigging and relative hook height, not equal division. Each crane must stay within its charted capacity at its radius.

Two-crane capacity rule

In a two-crane lift, the load on each crane must not exceed 75 percent of its charted capacity at the working radius, and the load must be kept level.

Lift director role

The single authority for the lift. All signals and decisions pass through the lift director and the designated signal person, who directs the operator.

Single signal person

Only one signal person directs the operator at a time. Any change of signal person must be communicated to the operator before control passes.

Emergency stop signal

A single sharp movement of the hand or arm across the body, or the word stop by radio. The operator must obey it immediately without question.

Blind lift communication

When the operator cannot see the load, a signal person must be positioned to see both load and operator, or a documented alternative such as cameras or radio relays used.

Load moment indicator test

The load moment indicator and rated capacity limiter must be tested and functional before each lift. A faulty unit puts the crane out of service.

Defect tagging

A defect affecting safe operation must be reported, the crane tagged out and removed from service, and the defect rectified and verified before return to service.

Wire rope discard criteria

Inspection for broken wires, corrosion, kinks, bird-caging and diameter reduction. Discard limits are set by the manufacturer and the applicable standard.

Powerline contact response

The operator stays in the cab and warns others clear. If evacuation is essential, jump clear and shuffle away without touching crane and ground at the same time.

Crane instability response

If the crane becomes unstable or an outrigger sinks, stop the lift, lower the load if possible, evacuate the area, and do not slew or travel.

Smooth control inputs

Gradual starts and stops reduce load swing and dynamic amplification, lowering the effective load on the crane, rigging and ground compared with abrupt movements.