NCCCO Rigger Level II cheat sheet

Load weight data: steel 490 lb/ft³ (plate ≈ 40.8 lb/ft² per inch of thickness), concrete 150 lb/ft³, water 62.4 lb/ft³; add rigging, attachments, and any absorbed water or debris.

Net capacity = manufacturer's rated capacity at the actual radius and boom configuration, minus jib, hook block, slings, spreader beam, and all below-hook device weights.

Sling angle factor = 1 ÷ sin θ, with θ measured from horizontal: 60° = 1.155, 45° = 1.414, 30° = 2.0 times the vertical share.

Tandem lift share: load on crane A = total load × d(B) ÷ (d(A) + d(B)), where d is the horizontal distance from each pick point to the load center of gravity.

Ground bearing pressure = total weight (crane plus load) ÷ effective mat or float area; doubling both mat dimensions quarters the pressure per unit area.

OSHA minimum approach distance to energized lines: 10 ft up to 50 kV; 15 ft for 50–200 kV; 20 ft for 200–350 kV; 25 ft for 350–500 kV; 35 ft for 500–750 kV; 45 ft for 750–1000 kV.

Critical lift triggers: over 75% of rated capacity, more than one crane, travel over personnel or occupied structures, or proximity to energized lines - each requires an engineered lift plan.

Site survey checklist: soil bearing and underground voids or utilities, slope, overhead obstructions and lines, access and swing clearance, landing area, and exclusion zone boundaries.

Sling tension per leg: T = (W ÷ n) × (L ÷ H), where n is the number of load-bearing legs, L the sling leg length, and H the head height from hook to load.

Wire rope sling efficiency: vertical 100%, choker about 75%, basket 200% (D/d ≥ 25 with vertical legs); apply the angle factor to any leg that is not vertical.

Synthetic web sling hitch factors: vertical 1.0, choker 0.8, basket 2.0; never knot a web sling and protect it from cuts, sharp edges, and heat.

Count only 2 load-bearing legs on a 3-leg bridle and only 3 on a 4-leg bridle, because leg loading is never equal.

Keep sling legs 30° or more above horizontal; at 30° the horizontal component equals 0.866 of the vertical share per leg, which can crush or slide the load.

Shackles: pin fully seated, load carried on the bow, and screw-pin shackles avoided where rotation could back the pin out; never substitute a bolt for the pin.

The hook point must be directly above the load center of gravity; an off-center pick tilts the load and shifts weight into fewer sling legs.

A spreader beam carries the horizontal sling component as compression in the beam; verify beam capacity, end fitting capacity, and top sling angles.

Rigging hardware working load limit must equal or exceed the calculated leg tension, accounting for hitch type and angle.

Two inspection levels: a visual pre-use inspection by the user before every lift, and a documented periodic inspection by a designated person at least annually.

Wire rope sling removal: 10 randomly distributed broken wires in one lay, 5 broken wires in one strand in one lay, or any kink, birdcage, core protrusion, or severe corrosion and abrasion.

Chain sling removal: cracks, bent or twisted links, gouges or nicks, wear over 10% of link diameter, stretch beyond the manufacturer's limit, or a missing grade tag.

Web sling removal: holes, cuts, snags, burns, ultraviolet or chemical degradation, broken or worn stitching, knots, or a missing or illegible tag.

Hook removal: throat opening increased more than 15%, wear more than 10% of the original dimension, bend or twist more than 10°, cracks, or a latch that will not close.

Shackle, ring, and link removal: wear over 10% of original diameter, cracks, distortion, or damaged threads.

Any sling or fitting without a legible tag showing rated capacity, reach, material, and manufacturer is removed from service.

Defective gear is tagged DO NOT USE, physically removed from the work area, and the finding is documented in the inspection record.

The pre-lift meeting covers plan, load weight, rigging configuration, roles, signal method, lift sequence, exclusion zone, and emergency stop procedure.

Trial lift: raise the load a few inches and verify balance, rigging, brake holding, and crane stability before hoisting to full height.

Never shock load; start and stop smoothly, keep hoist lines vertical, and do not drag or side-pull a load.

Tag lines control rotation and swing; use at least one, more for long or high sail-area loads, and keep hands clear of wrap and pinch points.

No personnel under a suspended load; use push sticks and tag lines rather than hands to guide the load.

Multi-crane lifts: one lift director, one qualified signal person per crane, and continuous verification that each crane carries its planned share.

Monitor wind and weather continuously; stop when wind exceeds the manufacturer's limit or the load's sail area makes it uncontrollable.

Before release: confirm landing surface capacity, blocking or cribbing, load stability, and that rigging can be removed without pinch-point exposure.

Only one designated, qualified signal person directs the crane at a time; anyone on site may give an emergency stop signal.

Hoist: forearm vertical, forefinger up, hand moved in small horizontal circles. Lower: arm extended downward, forefinger down, small horizontal circles.

Stop: arm extended, palm down, hand moved side to side. Emergency stop: both arms extended horizontally, palms down, moved rapidly side to side.

Radio: dedicated channel tested before the lift; commands are clear, acknowledged, and identify the crane and the signal person transmitting.

Voice signals are permitted only when distance and conditions allow and the operator and signal person have agreed on them in advance.

If a signal is unclear or conflicting signals are received, the operator stops until the designated signal person resumes control.

The signal person positions with an unobstructed view of both operator and load, and uses relay signalers when the sight line is blocked.