NCCCO Mobile Crane key terms

A visual and functional check the operator performs before each shift, covering wire rope, hydraulic leaks, safety devices, controls, and the carrier, with deficiencies corrected before work begins.

Examination of hoist and boom ropes for broken wires, kinks, corrosion, birdcaging, and diameter loss, compared against the manufacturer's removal criteria before the rope is returned to service.

A sensing system that warns the operator, or stops hoist, boom-lower, and telescope-out motion, before the load block or ball contacts the boom tip.

An onboard computer that senses boom angle, boom length, and pressure to show rated capacity, actual load, and radius, warning the operator as capacity is approached.

A control device that automatically stops crane functions when the load or moment exceeds the rated capacity for the current boom and outrigger configuration.

A physical barrier or marked boundary that keeps workers clear of the area swept by the rotating superstructure and counterweight.

Any place where a person's body could be caught between moving crane parts, such as the counterweight and a wall or the boom and the cab.

A spring-loaded gate on the hook that closes the throat so slings, chains, and lines cannot slip off during a lift.

A rigid plate or cribbing placed under an outrigger float to spread the crane's load over a larger area and lower the pressure on the ground.

The force per unit area that a crane's outrigger float or track imposes on the soil, mat, or slab beneath it, which must stay below the ground's capacity.

The condition of the crane being set up within the manufacturer's tolerance for level, since an out-of-level crane loses capacity and may tip.

The distance from the boom pivot to the boom tip with telescoping sections extended, used with boom angle to find capacity on the load chart.

The angle of the boom measured above horizontal, read from the boom angle indicator and used to determine working radius and rated capacity.

An auxiliary boom section mounted at the main boom tip to add height and reach; it adds weight and reduces the crane's rated capacity.

Removable weights mounted at the rear of the upper works that balance the load and improve stability; the amount must match the load chart being used.

The sliding structural member that extends the outrigger float outward from the carrier, widening the crane's support base for lifting.

Contact between the load block or ball and the boom tip, which can break wire rope, damage the boom, or drop the load.

Pulling or dragging a load sideways so the boom is forced out of its designed lifting plane, which can bend the boom or tip the crane.

A sudden application or release of force, such as snatching a load off the ground, that produces stresses much greater than the load's static weight.

A rope tied to the load and held by a worker on the ground to control swinging and rotation while the crane moves the load.

A friction brake that holds or slows rotation of the upper works; it is not intended as a service brake for stopping a swinging load.

The force wind exerts on the boom and load, increased by large, light loads that act like sails, raising radius and side load.

The number of rope falls running between the boom tip and the load block; more parts increase capacity and reduce hoist speed.

The rated capacity read directly from the load chart for a given boom, radius, and configuration, before any deductions are made.

The usable lifting capacity left after the weight of the hook block, slings, and other below-the-tip attachments is subtracted from the gross capacity.

A weight subtracted from the load chart value for items such as the hook block, jib, auxiliary sheave, and rigging, as required by chart notes.

The manufacturer's table or graph giving rated capacities for specific boom lengths, angles, radii, quadrants, and outrigger configurations.

The horizontal distance from the crane's center of rotation to the center of the load, including boom deflection, used to enter the load chart.

The zone around the crane, such as over the front, side, rear, or full 360 degrees, that determines which capacity column applies.

The lifting limit set by the strength of crane components such as the boom, pins, cylinders, and wire rope, as opposed to tipping.

The crane's resistance to overturning about its tipping axis; it usually controls capacity at long radius or over the side.

Standardized arm and hand movements from ASME B30.5 that a signalperson uses to direct the operator when voice communication is not used.

A person trained and evaluated to give crane signals, who knows the crane's motions, the applicable standard, and the hazards of the lift.

A signal that anyone on the site may give at any time, requiring the operator to stop all crane motion immediately and hold position.

The closest a crane, boom, or load may come to an energized line, set by OSHA according to line voltage unless the line is de-energized and grounded.

A lift that meets defined risk criteria, such as exceeding a set percentage of capacity, using multiple cranes, or lifting personnel, and needs a written plan.

The manufacturer's document containing setup, inspection, operation, maintenance, and capacity information that the operator is required to follow.

The consensus standard for mobile and locomotive cranes that covers construction, marking, inspection, testing, and safe operation in the United States.

The federal construction rule for cranes and derricks, covering operator certification, inspections, signalpersons, power line safety, and ground conditions.

The operator's right and duty to stop or refuse a lift they believe is unsafe, even when pressured by a supervisor or customer.