HEO Tower Crane NC III key terms

The product of a lifted load and its horizontal distance from the crane's slewing centre, used to compare actual loading against the rated capacity curve for a given configuration.

Manufacturer-issued table or curve showing the maximum permitted load at each radius for a specific jib length, counterweight arrangement, and hoist rope fall configuration.

The maximum load a crane configuration may lift at a stated radius under the manufacturer's chart, before any deductions for lifting attachments or site-specific derating.

The horizontal distance from the crane's slewing centre to the centre of gravity of the suspended load, measured with the jib positioned as it will be during the lift.

The total suspended mass comprising the payload plus hook block, slings, spreaders, and any other rigging below the rope, all of which must be deducted from chart capacity.

The mass of the actual material or component being lifted, excluding hooks, slings, and other below-the-hook equipment that count toward gross load.

The number of rope falls supporting the load between the hook block and the trolley or jib head, which determines the hoist capacity and line speed available.

A documented method statement that defines the load, crane position, radii, rigging, personnel roles, sequence of operations, exclusion zones, and contingency measures for a specific lift.

A lift that exceeds a defined threshold such as a percentage of chart capacity, involves multiple cranes, lifts personnel, or carries unusual risk, requiring a higher level of planning and approval.

A coordinated lift using two or more cranes on the same load, requiring a shared plan, defined load share per crane, and continuous communication between operators and the lift supervisor.

A multiplier applied to a load's weight to account for the increased tension in sling legs as the angle between the legs and the horizontal decreases.

A flexible assembly of wire rope, chain, or synthetic webbing used to connect the load to the hook, selected for its working load limit and the hitch used.

A U-shaped connector closed by a pin or bolt, used to join slings to hooks, eyes, or lifting points; the pin must be fully seated and moused where required.

The maximum mass or force a rigging component is rated to withstand in a specified configuration, marked on the item and never exceeded during a lift.

The collective term for shackles, hooks, swivels, turnbuckles, and master links used to assemble a lifting arrangement, each requiring inspection before use.

The point at which the total weight of an object acts; if it is not directly below the hook, the load will tilt, so lifting points must be chosen to keep it controlled.

The condition in which a suspended load hangs level because the lifting points and sling lengths are arranged symmetrically about the load's centre of gravity.

A rope attached to a load and controlled by a person on the ground to restrain rotation and sway, keeping the load clear of structures and personnel during the lift.

The assembly of sheaves, frame, and hook that travels on the hoist rope; its weight forms part of the gross load and it must be inspected for sheave and latch condition.

A safety device that detects when the hook block approaches the trolley or jib head too closely and stops the hoist motion to prevent rope and component damage.

A configured restriction on the crane's slewing arc, used to keep the jib and load clear of adjacent structures, power lines, or other cranes on site.

The rotating motion of the crane's upper structure about its vertical axis, controlled by the operator and subject to braking and free-slew considerations when handling loads.

A marked ground area beneath and around the lifting operation where unauthorised people are prohibited, sized to account for the load, its swing, and foreseeable failure.

The horizontal reach of the jib from the slewing centre at a given trolley position, which together with the load determines the load moment the crane must resist.

A retractable or fixed beam that extends a crane's support base to the ground, increasing stability and reducing ground bearing pressure during lifting.

The load per unit area transmitted through crane supports to the ground, which must be checked against soil capacity and reduced using mats or pads where needed.

The engineered base, such as a reinforced concrete footing or ballasted raft, that supports a tower crane and transfers its loads safely into the ground.

A threaded steel fastener embedded in the crane foundation or mast base to secure the structure against uplift and overturning forces, tightened to a specified torque.

A prefabricated lattice or tubular segment of the tower crane's vertical mast, bolted or pinned together to build the crane to its required freestanding or tied height.

The process of raising a tower crane's working height by adding mast sections or using a climbing frame, carried out under a documented procedure with wind limits.

A structural connection between the crane mast and a building or other support that provides lateral restraint at defined heights, installed to the manufacturer's specification.

Ballast mounted at the rear of the jib to balance the load moment; its quantity and position must match the load chart used for the lift.

The documented check of crane structure, ropes, brakes, limit devices, and safety systems carried out before the first lift of a shift or after any significant event.

A device that automatically stops a crane motion at a preset travel point, such as maximum hoist height or trolley travel, and must be tested before work begins.

The maximum wind speed at which lifting, climbing, or erecting may proceed, defined by the manufacturer and monitored on site with an anemometer.

The practice of tracking wind speed and direction, lightning, and visibility during operations, with defined actions to suspend work when conditions exceed limits.

A qualified worker who directs the crane operator using standard hand, voice, or radio signals and who has authority to stop the lift when conditions become unsafe.

A standardised arm and hand movement used to command crane motions such as hoist, lower, slew, and trolley, understood identically by operator and signalperson.

A single emergency command, given by anyone on site regardless of role, that requires the operator to halt all crane motion immediately and hold position.

The competent person responsible for planning and controlling a lifting operation, confirming rigging, briefing the team, and authorising the lift to proceed.

A short pre-task briefing covering the method, hazards, roles, and emergency arrangements for the day's work, recorded and attended by all involved personnel.

The procedure of isolating energy sources, applying a personal lock and tag, and verifying zero energy before maintenance or repair work on crane systems.

The defined sequence for parking the crane, lowering and securing the hook, applying brakes and storm locks, and recording the machine's condition at the end of a shift.

A mechanical device that pins the slewing mechanism in the parked position to prevent uncontrolled rotation in high winds when the crane is left unattended.

The examination of hoist and pendant ropes for broken wires, corrosion, kinks, and diameter reduction against rejection criteria before and during use.

A test load applied to lifting equipment or a crane structure to verify strength and integrity, typically exceeding the rated capacity by a defined factor.

A drawing or calculation showing sling lengths, angles, hardware, and lifting points for a specific load, used to confirm the arrangement is within component limits.

Mandatory safety gear such as a hard hat, safety footwear, high-visibility clothing, gloves, and fall protection worn by everyone in the crane operating area.

A formal written authorisation that defines the scope, hazards, controls, and validity period for higher-risk activities such as crane erection, climbing, or maintenance.

A person who has the training, experience, and authority to identify hazards and take corrective action in the task assigned, as required by workplace safety regulations.

A structured evaluation of hazards and their likelihood and severity, used to select controls before lifting, erection, or maintenance work begins.

The documented notification of near misses, equipment damage, or injuries to the responsible person, enabling investigation and correction of the underlying cause.