NCCCO Rigger cheat sheet

Inspect all rigging before each use and after any incident, shock load, or severe service; remove defective gear from service immediately.

Frequent inspection occurs before each shift or use; periodic inspection is performed at least annually and documented by a qualified person.

Wire rope sling removal criteria include 10 randomly distributed broken wires in one lay, 5 broken wires in one strand in one lay, kinking, bird-caging, crushing, or severe corrosion.

Chain sling removal criteria include cracks, nicks, gouges, weld spatter, stretch, or wear exceeding 10% of the original link diameter.

Synthetic web sling removal criteria include holes, cuts, tears, snags, severe abrasion, broken stitching, chemical discoloration, or a missing or illegible tag.

A sling with no legible identification tag showing capacity, length, and manufacturer is removed from service because its working load limit cannot be verified.

Hook removal criteria include a throat opening increased more than 15% or twist more than 10 degrees; a missing latch on a latch-equipped hook also removes it from service.

Shackle removal criteria include cracks, a bent or worn pin, damaged threads, or wear exceeding 10% of the pin or body dimension.

Never weld, heat, or modify rigging hardware; do not use homemade or unmarked components for overhead lifting.

Vertical hitch: one leg carries its full working load limit; multiple legs share load equally only when symmetrical and the center of gravity is centered.

Choker hitch capacity is typically 75% to 80% of the vertical rating, depending on sling type and manufacturer.

Basket hitch with two vertical legs: capacity is 2 x single-leg working load limit when balanced and both legs carry equal tension.

Sling tension per leg in a symmetric two-leg lift = load / (2 x sin theta), where theta is the angle each leg makes with horizontal.

At 60 degrees from horizontal each leg carries 0.577 x load; at 45 degrees each carries 0.707 x load; at 30 degrees each carries the full load.

An included angle of 90 degrees between legs equals 45 degrees from horizontal for each leg; larger included angles increase leg tension.

D/d ratio = diameter of curvature / sling diameter; small D/d reduces basket and choker capacity, and ratings commonly assume about 25:1.

Knotted slings are not permitted for overhead lifting; a knot can reduce rope strength by 50% or more.

Basic knots: bowline forms a fixed loop; clove hitch makes a quick attachable hitch; half hitch secures a line; timber hitch grips a log.

Maintain OSHA minimum approach distance from energized power lines; the required distance increases with voltage, and de-energizing with lockout/tagout is the preferred control.

Keep the load center of gravity below the lifting point to prevent tipping, flipping, and shock loading.

Shock loading from jerking or sudden stops can exceed the static load several times; lifts must be smooth and controlled.

Sharp edges cut wire rope and synthetic slings; edge protectors or softeners are required, and slings must not be dragged over corners.

No personnel under a suspended load; barricade the drop zone and use tag lines to control rotation from a safe distance.

Side loading of hooks, shackles, and eyebolts reduces capacity and can cause bending or opening; load axially unless the component is rated otherwise.

Synthetic slings are damaged by heat, chemicals, and ultraviolet light; chain is attacked by acids; wire rope fails from corrosion and broken wires.

Ground condition affects stability: soft or sloping ground can let outriggers settle, so bearing capacity and mats must be evaluated.

Wind and weather increase load swing and effective load area; stop lifts when conditions exceed the lift plan or manufacturer limits.

Load hooks in the saddle, not the tip, and keep the latch closed; never tip-load a hook.

Fully seat shackle pins; orient the pin so the load cannot roll it loose, and never substitute a lower-strength bolt.

Shoulder eyebolts must be seated flush and loaded along the bolt axis; angular loading reduces capacity unless the eyebolt is rated for it.

Use a spreader beam to keep sling legs vertical on wide loads, avoiding compression on the load and sling-angle capacity loss.

Tag lines control swing and rotation from a safe distance and are never used to lift or to pull a load beyond the crane's rating.

Synthetic web slings suit polished or finished loads; chain suits abrasive, hot, or rough loads; wire rope suits heavy general service.

A two-leg bridle hitch capacity depends on the angle between legs and the center of gravity; unequal leg lengths cause load shift.

Equalizing slings or a spreader beam distribute load between lifting points; verify each point's capacity before lifting.

For a basket hitch around a load, both legs must be vertical and the load balanced; otherwise capacity is reduced by the sling angle.