Free NCCCO Mobile Crane Exam Flashcards

The ability of the supporting surface to bear crane and load forces. Before setup, the operator must confirm firm, drained, properly graded ground and identify voids, fill, or excavations that could cause a tip-over.

Material placed under outrigger floats or crawler tracks to spread the load over a larger area. It is sized so ground bearing pressure stays below the soil's safe capacity; inadequate blocking is a leading cause of tip-overs.

Required minimum distance between any part of the crane or load and energized lines. The operator must assume lines are energized; the safest approach is de-energizing and grounding, or using clearance distances based on voltage.

When work near lines cannot maintain the basic clearance, OSHA requires a planning meeting and added safeguards such as a dedicated spotter, range-limiting devices, insulating barriers, or proximity alarms before lifting begins.

Buried utilities, septic tanks, vaults, and old foundations that can collapse under outrigger or track loads. Locating utilities before setup prevents both ground failure and damage to gas, electric, or water lines.

The area within the crane's rotating superstructure (counterweight) tail swing. It must be barricaded so personnel cannot be crushed between the rotating crane and a fixed object.

A barricaded area under and around the lift where only essential workers may enter. It protects personnel from a dropped load, dropped rigging, or crane failure during the lift path.

Mobile crane charts assume the crane is set up level (commonly within about 1% of level). Operating out of level dramatically reduces capacity because radius increases as the boom tilts, even without moving the load.

Near a radio or communication tower, induced electrical charge can build on the crane. If the transmitter is not de-energized, the crane should be grounded or bonded so a worker is not shocked when touching it.

Mapping the route the load travels from pick to set, checking obstructions, personnel, and the shortest safe radius. The plan minimizes time over people and avoids unexpected radius increases.

A documented daily/shift check of the crane before use—wire rope, hooks, controls, safety devices, fluid levels, and tires/tracks. Defects affecting safe operation must be corrected before the crane is used.

A defined set of signals the operator must recognize and obey. With an unfamiliar signal person, the operator and signaler should review signals before the lift; the operator stops if a signal is unclear.

The operator must obey a STOP signal from anyone, not only the designated signal person. Anyone observing a hazard can call a stop, but only the designated signal person directs the rest of the lift.

Lifting the load a few inches to verify the crane is stable, brakes hold, the load is balanced, and rigging is secure before continuing. It confirms the configuration before the load is carried higher.

Applying horizontal force to the boom by dragging a load or swinging too fast. Booms are designed for vertical loading; side loading can buckle the boom and is prohibited unless the manufacturer specifically allows it.

The hook block contacting the boom tip, which can shear the hoist line and drop the load. Anti-two-block devices warn or stop the function before contact occurs; the device must be functional before lifting.

Lowering the boom (smaller angle) increases the operating radius and reduces capacity. Operators control the load by managing radius, because capacity changes with radius more than with weight alone.

Free-fall releases the hoist drum so the load descends by gravity, with limited control. Power-controlled (controlled) lowering uses the drive system for precise descent and is required when personnel or precision are involved.

Extending outriggers per the chart configuration (fully extended, intermediate, or on rubber) and lifting the tires off the ground when required. Capacity charts are specific to each outrigger configuration.

Setting parking brakes, swing locks, and travel restraints, lowering the load or boom as directed, and securing per the manufacturer. This prevents unintended movement, drift, or wind-driven travel when unattended.

A rope handled by a worker to control load rotation and positioning from a safe distance. It keeps the load from spinning into structures or people without putting hands directly on the load.

The number of hoist-line parts supporting the hook block. More parts of line raise the hook's load capacity but slow line speed; reeving must be verified before lifting heavy loads.

A device that compares actual load and radius against the chart and warns the operator as limits are approached. It is an aid, not a substitute for reading the chart and planning the lift.

A structural limit is set by component strength (boom, hoist) and is fixed regardless of position. A stability limit is set by tip-over resistance and changes with radius, outriggers, and ground. Charts may be governed by either.

The line about which a crane would tip, typically the outrigger or track on the load side. The load's distance from this axis (radius) determines the overturning moment the counterweight must resist.

Mass added to the rear of the superstructure to balance the load moment. Charts are valid only for the counterweight configuration listed; using the wrong counterweight invalidates the chart.

The point where a load's weight is concentrated. The hook should be positioned directly over the load's center of gravity so the load lifts level and does not shift or swing when raised.

As the angle between a sling leg and the load decreases, tension in the sling increases sharply. A wider, more horizontal sling spread can multiply leg tension far beyond the load's actual weight.

Vertical hitch carries full rated capacity; choker hitch reduces capacity (about 25%) because it cinches the load; basket hitch can roughly double capacity if the angle is steep and the load is balanced.

Wire rope must be removed for conditions such as broken wires exceeding the allowable count, kinking, birdcaging, corrosion, heat damage, or diameter reduction. Damaged rope is taken out of service, not repaired.

Hooks are removed from service for cracks, throat opening beyond the manufacturer's limit, more than allowed bend or twist, or a damaged safety latch. A spread throat indicates the hook has been overloaded.

The maximum load rigging hardware may safely carry, set by the manufacturer with a built-in design factor. The WLL must never be exceeded, and hardware is rated independently of the crane's chart capacity.

A sudden dynamic force from jerking, dropping, or snatching a load. It can momentarily multiply the effective load far above its static weight, overstressing rope, rigging, and crane structure.

The bending of the boom under load, which increases the actual radius beyond the no-load radius. Operators must account for deflection because the real radius (and lower capacity) is what governs the lift.

OSHA and ASME require frequent (daily to monthly) and periodic (annual, documented) inspections by a qualified person. Records must be kept; deficiencies affecting safety remove the crane from service until repaired.

OSHA 29 CFR 1926.1427 (Subpart CC) requires crane operators to be trained, certified, and evaluated by the employer for the specific equipment before operating in construction work.

Gross capacity is the chart value before deductions. Net capacity is what remains for the load after subtracting the weight of the block, ball, rigging, jib, and other attachments. Lifts are planned on net capacity.

The horizontal distance from the crane's center of rotation to the center of the hook/load. It is the primary input to the chart—capacity drops as radius increases, even with the same load.

Weights subtracted from gross chart capacity: hook block, headache ball, slings, spreader bars, auxiliary heads, and stowed or erected jibs. Omitting a deduction can cause an unintended overload.

The conditions and footnotes that make a chart valid—outrigger position, counterweight, levelness, and whether values are stability- or structure-limited. A capacity number is only valid with its accompanying notes.

A dividing line (often bold) on the chart separating capacities limited by stability from those limited by structural strength. Operating below it means tip-over governs; above it, structural failure governs.

For a given radius, extending a telescopic boom generally reduces capacity because of added boom weight and deflection. Operators select the shortest boom that safely reaches the load.

When an exact value is not listed, use the next lower (more conservative) chart capacity and never interpolate upward. Choosing the least favorable applicable value prevents accidental overload.

Separate chart columns exist for fully extended, intermediate, and on-tires (on-rubber) setups. The operator must use the column matching the actual setup; on-tires capacities are much lower.

On a rough-terrain or truck crane, capacity is lowest over the side and higher over the rear because of the outrigger footprint and chassis. Charts give different values by quadrant of rotation.

A jib has its own capacity chart based on jib length and offset angle. An erected (and even a stowed) jib also reduces main boom capacity and must be entered as a deduction.

The reeved hoist line must support the planned load. Even if the chart allows the weight, insufficient parts of line limits the actual liftable load to the line's capacity—the lower value governs.

The radius after boom deflection under load, which is larger than the unloaded radius. Capacity must be read at the loaded radius, so the operator plans using the more conservative larger radius.

Add total load plus all deductions, find the lift radius and configuration, then compare to the matching chart cell. If the total meets or exceeds the chart value, the lift is not permitted as configured.

Total load divided by the chart capacity for the configuration, expressed as a percent. As lifts approach the chart limit, the margin against tip-over or structural failure shrinks and extra caution is required.