NCCCO Rigger Level I cheat sheet

Inspection frequency rule: rigging is inspected before each use and at the start of each shift, plus a documented periodic inspection at intervals not exceeding 12 months.

Sling removal criteria: remove from service for broken wires, severe corrosion, kinks, birdcaging, crushed or deformed fittings, or missing/t illegible ID tags.

Wire rope rejection benchmarks: 12 randomly distributed broken wires in one lay, 4 broken wires in one strand in one lay, or any valley corrosion.

Chain sling rejection: any crack, nick, gouge, bent or twisted link, stretch exceeding 5% of original length, or wear exceeding 10% of link thickness.

Web sling rejection: cuts, snags, holes, burns/charring, ultraviolet degradation, broken stitching, or missing load tag; shock-load or acid damage requires removal.

Synthetic round sling rejection: cover damage exposing core, core yarn breakage, or any label that is missing or unreadable.

Hardware inspection: hooks with throat opening increased more than 5% (or 15% for some standards) or wear exceeding 10% of original dimension are removed from service.

Shackle and eye inspection: reject for cracks, bent pins, distorted bows, or threads that will not fully engage; pins must be the correct type and fully seated.

Vertical hitch capacity equals the sling's single-leg rated capacity; choker hitch reduces capacity to about 75-80% of vertical; basket hitch can reach up to 200% of vertical when legs are vertical.

Sling tension formula: T = (Load x Load Factor) / number of legs, where load factor increases as the horizontal angle decreases.

Sling angle factor: at 60 degrees from horizontal, tension multiplier is about 1.155; at 45 degrees about 1.414; at 30 degrees about 2.0.

D/d ratio rule: capacity of a wire rope sling in a basket or choker hitch decreases as the ratio of bend diameter to rope diameter decreases; ratios below 25 reduce capacity.

Choker hitch angle effect: a choker with a large angle between the choked leg and the standing part loses capacity; the tighter the choke around the load, the closer to full choker rating.

Bridle hitch: with two or more legs, the included angle between legs should not exceed 90 degrees; capacity drops as the angle widens.

Knot rule: knots reduce rope strength by roughly 40-60%; a bowline retains about 60-70% of rope strength, a square knot much less.

Never tie knots in wire rope or chain slings; knots are only appropriate in fiber rope where the application permits and the reduced capacity is accounted for.

Shock loading: sudden application of load can multiply forces several times over static weight; avoid jerking, dropping, or swinging loads.

Center of gravity: an unbalanced load will tilt; the hook must be directly above the center of gravity or the load will shift when lifted.

Sling angle hazard: as the horizontal angle decreases below 45 degrees, leg tension rises sharply and horizontal force on the load increases.

Pinch and crush points: hands and feet must stay clear of slings, hook throats, and load contact points; never place body parts under a suspended load.

Electrical hazard: maintain the required minimum approach distance from energized lines; wet conditions and conductive rigging increase risk.

Environmental hazards: wind, ice, rain, and heat affect load stability and rigging capacity; tag lines control rotation and swing.

Rigging failure modes: overloading, worn or damaged gear, improper hitch, edge contact, and load shift are the primary causes of rigging accidents.

Load edge protection: sharp corners cut slings; use softeners, corner protectors, or edge rollers to prevent abrasion and cutting.

Wire rope slings: suited to abrasive and hot environments; inspect for broken wires, kinks, and corrosion; use with thimbles and proper fittings.

Chain slings: strong and durable for abrasive and high-temperature service; grade 80 or 100 chain only; never use proof coil or transport chain for overhead lifting.

Synthetic web and round slings: lightweight and non-marring but vulnerable to cuts, UV, chemicals, and heat; protect from sharp edges.

Shackles: screw pin for temporary or repeated connections; bolt-type for permanent or long-term connections; never side-load a shackle beyond its rated capacity.

Hooks: use hooks with a functioning latch or moused hook; never tip-load a hook; load must seat in the bowl of the hook.

Spreader and equalizer beams: spreader beams convert compressive load into beam bending; equalizer beams distribute load between pick points without a bending moment.

Tag lines: control load rotation and swing; keep personnel clear of the load path and never wrap a tag line around a body part.

Rigging hardware identification: verify rated capacity markings on slings and hardware; unmarked or unrated gear must not be used for overhead lifting.