High Risk Work Licence - Slewing Mobile Crane C6 (60t) key terms

A legal framework placing duties on everyone in the supply chain, including crane operators, schedulers and consignors, to ensure load transport and lifting tasks are safe. It targets actions, inactions and demands that could cause unsafe practices.

A person's legal and moral obligation to take reasonable steps to protect their own health and safety and that of others affected by their work. For crane operators this includes refusing unsafe lifts and controlling hazards.

A written document that identifies high-risk construction work, the hazards involved, the control measures to be applied, and how those controls will be implemented, monitored and reviewed. It must be understood by the crane crew before work begins.

A ranked order of risk controls, from most to least reliable: eliminate the hazard, substitute it, apply engineering controls, use administrative controls, then rely on personal protective equipment. Higher-ranked controls are preferred wherever reasonably practicable.

A structured process of identifying hazards, evaluating the likelihood and severity of harm, and deciding which controls are needed. For lifting, it considers the load, crane, ground, environment and people before the lift plan is finalised.

The periodic re-evaluation of existing controls to confirm they remain effective after changes to the site, crane configuration, load or weather. It prevents controls from becoming outdated or ignored over the life of a job.

The rotation of the crane's upper structure about its vertical axis, moving the load in a horizontal arc. Slewing motion creates centrifugal forces and side load on the boom, so it must be smooth and controlled.

The horizontal distance from the crane's centre of rotation to the vertical line through the load's centre of gravity. It is measured with the boom at the working angle and directly determines the crane's rated capacity.

The maximum load a crane may lift at a given configuration, as stated in the manufacturer's load chart, after deductions for attachments and lifting gear. It is not the same as the crane's tipping or structural limit.

The manufacturer's table or graph showing the maximum permitted load for each boom length, radius and counterweight configuration. It also lists deductions for jib, hook block, lifting gear and reeving, and must be the chart issued for that crane.

The load a crane can actually lift after deducting the mass of the hook block, slings, shackles, spreader beams and other lifting gear from the gross chart capacity. It is the figure used to compare against the true load mass.

The rotational effect of a load about the crane's tipping point, calculated as load mass multiplied by radius. Load moment increases rapidly as the radius grows, so even a small load at long reach can exceed capacity.

A force applied sideways to the boom or jib, such as by dragging a load, slewing too fast or a load swinging on its slings. Booms are designed mainly for axial compression, so side load can cause structural failure.

The downward bending of a loaded boom, which increases the working radius beyond the value set before the lift. Operators must allow for this by setting out at a slightly shorter radius than the limit.

A multiplier applied to a load's mass to find the tension in each leg of a multi-leg sling, based on the angle between the legs. As the angle from vertical increases, tension rises sharply, reducing effective capacity.

The maximum mass a sling, shackle or other item of lifting gear is rated to support in a particular configuration. It is marked on the item and must never be exceeded, even briefly.

The point at which the whole mass of an object is considered to act. Knowing it allows the load to be balanced and slung so that it hangs level and does not tilt, rotate or shift during the lift.

The process of determining a load's mass and dimensions from markings, drawings, weighbridge tickets or calculation using volume and material density. Guessing is not acceptable; uncertain loads must be verified before lifting.

A test load applied to lifting gear or a crane to verify strength, usually above the working load limit but below the breaking load. Passing a proof load test does not authorise use beyond the marked working load limit.

A retractable beam extending from the crane's chassis, fitted with a vertical jack or float, that widens the support base and transfers load to the ground. It must be fully extended and pinned as specified in the load chart.

The pressure exerted through an outrigger float or track onto the ground, calculated from the load carried and the contact area. It must be compared with the ground's assessed capacity to prevent settlement or punch-through.

A timber, steel or composite pad placed under an outrigger float to spread load over a larger area and reduce ground bearing pressure. Mats must be sized for the calculated pressure and be sound and correctly positioned.

A documented check of the crane before each shift, covering tyres, outriggers, ropes, hooks, safety devices, fluids and alarms. Defects found must be recorded and the crane taken out of service until repaired.

The formal process of recording any fault or damage found on a crane or lifting gear and notifying the responsible person. The equipment must be tagged out or isolated until the defect is assessed and repaired.

Attaching a clearly marked label to equipment indicating it is defective or isolated and must not be used. It prevents inadvertent operation until the fault has been corrected and the tag removed by an authorised person.

Isolating and securing a machine's energy sources with a personal lock so it cannot be started while maintenance or inspection is underway. It protects personnel from unexpected movement or release of stored energy.

A written document describing the load, its mass and rigging, the crane position and configuration, the path of the lift, the personnel involved and the controls for identified hazards. It is reviewed and agreed before the lift begins.

A lift in which two or more cranes share the load, requiring a detailed plan, matched hoist speeds and a nominated supervisor. Load sharing changes constantly, so each crane must be rated for its worst-case share.

The route the boom and load travel through the horizontal arc during slewing, including any obstacles, personnel or powerlines in that arc. It is checked and cleared before the lift and kept clear throughout.

A trained person who prepares, attaches and directs loads using slings, shackles and other gear, and who communicates with the crane operator. The rigger confirms the load's mass, balance and security before signalling the lift.

A person licensed to sling loads and direct a crane by signals, working under the crane operator's control. The dogger checks the rigging, controls the load's movement and has authority to stop an unsafe lift.

A standardised set of arm and hand movements used to direct crane movements when radios are unavailable or fail. Only one nominated signaller should signal at a time, and the operator must stop if a signal is unclear.

A communication device used between the operator, riggers and supervisor, ideally on a dedicated channel. Radios must be tested before the lift, and a clear stop protocol agreed in case of interference or battery failure.

A defined area around the crane and load path from which unauthorised people are kept out, often marked with barricades or tape. It protects against falling loads, slewing counterweights and crush hazards.

A person positioned to watch for hazards the operator cannot see, such as obstructions, pedestrians or powerlines, and to warn or direct the operator. The spotter must remain in communication and in a safe position.

The minimum safe distance that must be kept between any part of the crane, load or rigging and an energised overhead line. Distances vary with voltage and must be confirmed before work near lines begins.

A sudden release of electrical energy through the air when a crane or load approaches an energised conductor too closely. It can cause severe burns, blast and fire without direct contact.

The exposed surface area of a load that catches the wind, which increases the force on the crane and can cause the load to swing or the boom to deflect. Lifts of large, light or sheeted loads need wind assessment.

The controlled stopping of crane operations and isolation of power when a dangerous situation arises, such as a failed control, fire or contact with a powerline. The operator then secures the load and follows the site emergency plan.