NCCCO Service Truck Crane key terms

A crane mounted on a commercial truck chassis, typically behind or between the cab and body, used to lift and place loads at jobsites and on service calls. It is usually operated from a remote or deck-mounted control station.

A truck with a telescoping or articulating boom used to lift loads, often with the boom mounted at the rear of the bed. It travels between sites and lifts without a separate carrier.

A crane whose boom consists of two or more jointed sections that fold at hydraulic knuckle joints. It is common on service trucks because it stows compactly and can reach over and around obstacles.

A boom made of nested sections that extend and retract hydraulically to change length. Extending the boom increases radius and reduces capacity, so the load chart must be read at the actual boom length and radius.

The jointed section of an articulating crane that folds at a hinge, allowing the boom to reach over walls or into openings. The knuckle geometry changes capacity, so charts are specific to boom configuration.

The maximum load a crane may lift at a given configuration, as published by the manufacturer after applying all reductions. It is the value read from the load chart, never a field estimate or an operator's judgment.

The load value shown in the manufacturer's load chart before deductions for lifting attachments. It includes the weight of the hook, slings, spreader bars, and other rigging that travels with the load.

The load that may actually be lifted after subtracting the weight of all lifting attachments from the gross capacity. It is the figure used to judge whether a planned lift is within the chart.

The weight subtracted from gross capacity for items such as the hook block, slings, shackles, spreader bars, and any attached lifting device. Failing to deduct rigging weight is a common cause of overload.

The horizontal distance from the crane's rotation center to the center of gravity of the load, measured with the boom at the working position. Capacity decreases as radius increases.

The extended length of the boom from its pivot to the tip, measured in the configuration being used. Load charts are tabulated by boom length and radius together, so both must be known.

The angle of the boom above horizontal, usually measured in degrees. On many charts it is used with boom length to determine radius, and it affects stability and structural loading.

The manufacturer's document listing rated capacities for each boom length, radius, and configuration, plus notes on outriggers, quadrants, and deductions. It is the controlling authority for every lift.

A placard on the crane or in the cab showing rated capacities and operating limits for the machine. It must be legible and match the machine's configuration; missing or damaged plates require correction before use.

The footnotes and warnings printed with a load chart that modify how capacities apply, such as outrigger extension, quadrant limits, or wind restrictions. They are part of the chart and must be followed.

The arc or sector around the crane in which lifting is permitted, often limited to the rear or side for truck-mounted cranes. Lifting outside the approved quadrant can exceed capacity or stability.

The crane's resistance to tipping under load, determined by the machine's weight, outrigger spread, and load moment. Stability limits, not just structural strength, often set capacity on truck cranes.

The product of load weight and radius, expressed in weight-distance units. It measures the overturning effect of a lift and is the basis for many capacity and stability calculations.

A hydraulically or manually extended stabilizer leg that widens the crane's support base and transfers load to the ground. Capacity charts usually assume full outrigger extension and proper float support.

The pad or float attached to the bottom of an outrigger that spreads load over a larger ground area. Floats must be properly pinned and supported to prevent sinking or punch-through.

Blocks, mats, or pads placed under outrigger floats to spread load and level the crane on soft or uneven ground. Adequate cribbing is required to prevent settling and loss of stability.

The load per unit area that a crane imposes on the soil through its outriggers or tires. It must be compared with soil capacity; soft or disturbed ground may require mats, cribbing, or relocation.

The soil, slope, and subsurface conditions at the setup location, including fill, voids, and buried utilities. They must be assessed before outriggers are set because poor ground can cause tipping.

A pre-lift inspection of the work area to identify hazards, obstructions, power lines, ground conditions, and access routes. It informs the lift plan and the crane's setup position.

The area around the crane and load kept clear of unauthorized personnel during lifting. Barriers or spotters maintain separation so people are not struck by the load or swing radius.

The distance from the crane's rotation center to the farthest point reached by the boom, load, or counterweight as the crane swings. The area inside it must be kept clear of people and obstructions.

Rotation of the crane's upper structure about its vertical axis. Swing must be controlled smoothly, and the load should be kept close to the ground and within the working quadrant.

Weight added to the rear of the rotating upper structure to offset load moment and improve stability. Its swing path must be kept clear, and it must never be removed or modified without manufacturer approval.

The bending and sag of a loaded boom, which increases actual radius beyond the geometric value. Operators must account for it, especially at long boom lengths and high capacities.

A safety device that stops hoisting or lowering when the hook block approaches the boom tip too closely. It prevents two-blocking, which can snap lines and drop the load.

Contact between the hook block and the boom tip or between upper and lower blocks. It can break wire rope, damage sheaves, and drop the load, and is prevented by the anti-two-block device.

An instrument that senses boom length, angle, and load to display radius, capacity, and percent of capacity, and that warns or stops operation when limits are approached. It supplements but does not replace the load chart.

The check of the crane before each shift, covering fluids, leaks, tires, outriggers, wire rope, hook, safety devices, and controls. Defects found must be corrected or reported before lifting begins.

The stranded steel cable that hoists and supports the load through the sheaves and hook block. It must be inspected for broken wires, kinks, corrosion, and wear against rejection criteria.

A grooved pulley that guides wire rope and changes its direction. Worn or cracked sheaves damage rope and must be replaced; rope must seat properly in the groove.

The assembly of hook, sheaves, and housing that carries the load and reeves the wire rope. Its weight is deducted from gross capacity and it must have a functioning latch.

A spring-loaded gate on the hook that keeps slings and fittings from slipping off. A missing or damaged latch is a defect that must be corrected before lifting.

The combined weight of slings, shackles, hooks, spreader bars, and other below-the-hook devices. It must be subtracted from gross capacity to determine the allowable load.

A written description of a lift covering load weight, rigging, crane position, radius, capacity, hazards, and personnel responsibilities. It is required for complex or critical lifts and guides safe execution.

A lift that is unusually hazardous, such as one over people, near power lines, at high capacity, or involving unusual loads. It typically requires a documented plan and additional supervision.

The minimum distance kept between any part of the crane, load, or rigging and energized lines. Required distances vary by voltage, and a spotter or utility coordination is often needed.

The manufacturer's document describing operation, setup, maintenance, and safety procedures for the specific crane. It must be available to the operator and followed along with the load chart.

The folded or retracted position in which the boom rests for travel. The crane must be returned to it, with outriggers retracted, before the truck is moved.

The approved condition for moving the truck with the boom stowed, outriggers up, and any travel restrictions observed. Lifting while traveling is limited or prohibited by the manufacturer.

A person positioned to watch the load, swing path, and surroundings and to signal the operator when the view is obstructed. The spotter must stay in visual or radio contact with the operator.

Standardized arm and hand movements used to direct crane operations when radios are unavailable or as a backup. Only one designated signal person should direct the operator at a time.

The outermost end of the boom where the sheave and load line exit. The tip's height and position determine headroom, two-blocking risk, and the actual radius of the load.