High Risk Work Licence - Self-Erecting Tower Crane (CS) key terms

A tower crane designed to be assembled, raised and dismantled by its own built-in mechanisms, usually without a separate mobile crane, and typically used for low-rise or residential construction work.

A written document that sets out the high-risk construction work to be done, the hazards involved, the control measures to be applied, and how those controls will be implemented, monitored and reviewed.

Construction tasks listed in work health and safety regulations as requiring a SWMS before starting, including work near energised electrical installations, on scaffolding over four metres, and involving precast concrete.

The legal obligation of a person conducting a business or undertaking, and of workers, to ensure health and safety so far as is reasonably practicable, including for others affected by the work.

A person conducting a business or undertaking, which is the primary duty holder under work health and safety law, whether an individual, company, partnership or other entity, and whether or not for profit.

A test weighing the likelihood and severity of harm against what a reasonable person would know, and the cost, effort and availability of ways to eliminate or reduce the risk.

The ranked order of risk controls, from eliminating the hazard through substitution, engineering controls and administrative controls to personal protective equipment as the least effective option.

A structured process of identifying hazards, judging how likely and how severe the resulting harm could be, and deciding which control measures are needed to reduce risk to an acceptable level.

A marked or barricaded area beneath and around the crane where people are not permitted during lifting, slewing or erection, so that a falling load or dropped object cannot strike them.

A licensed rigger who selects and attaches lifting gear, directs the crane operator by signals, and controls the load during the lift, working closely with the operator throughout the movement.

A person who slings, attaches and balances loads and inspects lifting accessories, holding the appropriate high-risk work licence for the rigging class being performed on site.

Standardised arm and hand movements used to direct a crane operator when radio contact is unavailable or unclear, given by one nominated signaller only at any time.

Short, agreed audible blasts used to warn people, start or stop movement, or attract attention, understood by all site personnel before lifting begins and repeated consistently throughout the work.

Two-way voice contact between the operator and the nominated signaller on a dedicated channel, using clear agreed wording, with a check of signal quality before each lift.

A person positioned to watch a blind area, crane travel path or overhead obstruction and warn the operator or signaller of danger, without giving conflicting movement commands.

The drive system that rotates the crane's upper structure around its vertical axis, controlled by the operator and fitted with brakes and limiters to stop rotation smoothly.

A brake that holds or slows the rotating upper structure, used to stop the crane turning under wind or momentum and to keep the jib from drifting when the machine is parked.

The horizontal or inclined boom of the crane from which the hook and load are suspended, carrying the trolley or fixed lifting point and determining the working radius of the lift.

Mass fitted to the rear of the crane's upper structure to balance the jib and lifted load, reducing overturning moment and helping keep the crane stable during lifting.

The crane's ability to resist overturning from load, wind and dynamic forces, maintained by adequate base support, correctly installed ballast and lifting within the rated capacity for the radius.

The turning effect produced by the load and jib acting about the crane's tipping line, which increases with radius and load and must remain less than the resisting moment of the base and ballast.

The load per unit area that the crane's base or outriggers impose on the ground, which must not exceed the soil's verified capacity or the crane may settle, tilt or overturn.

A rigid spreader plate placed under each outrigger or base foot to distribute load over a larger ground area and reduce bearing pressure on the supporting surface.

An engineering evaluation of soil type, strength and underground conditions at the crane position, used to confirm that the ground can carry the imposed bearing pressures safely.

The designed base, such as a concrete pad, ballast block or rail system, that supports the crane and transfers all loads into the ground without unacceptable settlement or movement.

The planned sequence of assembling, raising or jacking and later removing the crane, carried out to the manufacturer's instructions by competent persons under an engineered procedure and documented risk controls.

The manufacturer's table or graph showing the maximum rated capacity at each working radius and configuration, accounting for jib length, counterweight, reeving and sometimes wind area.

The maximum load the crane is permitted to lift at a given radius and configuration, as stated in the load chart, including the mass of hook block, slings and other lifting gear.

The horizontal distance from the crane's centre of rotation to the centre of gravity of the suspended load, which increases as the load is slewed or the trolley moves outward.

The product of load mass and working radius, used to compare a proposed lift against the crane's rated moment and to check that capacity limits are not exceeded.

A documented check of the crane before each shift or use, covering structures, ropes, brakes, limiters, alarms, controls and base conditions, with defects recorded and reported before work starts.

The process of recording any fault or damage found on the crane or lifting gear, tagging it out of service where necessary, and notifying the responsible person so repairs are made before use.

Attaching a clear warning tag to defective equipment or a crane control to show it must not be used until the fault is repaired and the tag is removed by an authorised person.

The angle between a sling leg and the horizontal, which affects the tension in each leg; flatter angles increase leg tension and reduce the safe working load of the assembly.

A U-shaped metal connector closed by a pin or bolt, used to join slings to loads or to the crane hook, and rated for a stated working load with the pin fully seated.

The maximum mass a sling, shackle or other lifting accessory may carry in a stated configuration, marked on the item and never exceeded during a lift.

A light rope attached to a load so a person outside the fall zone can control its rotation and swing during lifting, without touching the load itself.

Managing the load's movement through smooth starts and stops, correct slinging, tag lines and planned placement, so it does not swing, rotate or strike people or structures.

The maximum wind speed, set by the manufacturer and site procedure, at which lifting, slewing or erection must stop, measured at the crane and allowing for gusting and load wind area.