NCCCO Rigger Level I common mistakes
NCCCO Rigger Level I · Understand the traps and how to avoid them.
Approving a sling for use based only on a quick visual glance, without checking the ID tag or the removal-from-service criteria (broken wires, heat damage, tag missing).
Candidates treat inspection as a formality and rely on 'it looks fine,' because they have not memorized the specific rejection thresholds and required tag information.
What to do instead
Practice a fixed inspection sequence for every sling: tag present and legible, then material-specific defects (broken wires in a defined lay length for wire rope, cuts/glazing for synthetic, cracks/wear for alloy chain), then hardware. State the rejection criterion out loud for each defect you find.
Using a sling with a missing or illegible capacity tag because the hardware 'looks heavy enough' to guess a rating.
Candidates want to keep the lift moving and assume similar-looking slings share ratings, but capacity depends on material, size, configuration, and splice/end fitting.
What to do instead
Apply the rule that an unidentifiable sling is out of service. When practicing, cover tags and force yourself to identify the sling type and look up the rating rather than estimating.
Selecting a sling based on the vertical (single-leg) capacity when the actual hitch is a choker or basket.
Candidates memorize one capacity number per sling and forget that the same sling has different ratings for vertical, choker, and basket configurations.
What to do instead
Always state the hitch first, then the configuration-specific capacity, then the applicable efficiency factor. Build a habit of writing 'capacity = vertical rating × configuration factor' before rigging.
Ignoring the sling angle from horizontal when calculating leg tension, treating a two-leg lift as if each leg carries half the load regardless of angle.
Candidates underestimate how quickly tension rises as legs flatten, and they confuse load share with tension.
What to do instead
Work multi-leg problems using the tension formula (leg tension = load share ÷ sin of angle from horizontal) and drill angles of 60, 45, and 30 degrees until the tension multipliers are automatic.
Attaching a choker hitch without confirming the choke is seated and snug, or choking on a sharp corner or fitting without protection.
Candidates focus on getting the hook on the load and skip the seating step, and they do not connect choker efficiency loss with poor choke placement.
What to do instead
Follow a choke checklist: choke point clear of fittings and sharp edges, softener or corner protection in place, choke fully seated before tension, and reduced capacity applied.
Tying or relying on a knot in a sling or tag line where a proper hitch or hardware is required, or using a knot whose strength loss is unknown.
Candidates overestimate knot security and do not know that knots sharply reduce rope strength and can slip under cyclic load.
What to do instead
Learn the small set of knots actually used in rigging (e.g., bowline, clove hitch, timber hitch) and their applications and limitations, and default to hardware or a proper hitch for load-bearing connections.
Standing inside the fall zone or under the load while guiding it, or placing hands on the load instead of using a tag line.
Candidates want control and a good view, and they underestimate how far a load or rigging can swing or drop.
What to do instead
Rehearse position discipline: tag line from outside the fall zone, never under a suspended load, and identify the swing path before the lift starts. State your escape route before signaling.
Missing the hazard of a sharp edge, weld bead, or corner under a sling, or missing abrasion against adjacent structure during the lift.
Candidates look at the load's overall shape rather than the contact points, and they do not visualize the load path during travel.
What to do instead
Walk the entire sling path from hook to attachment and back, checking every contact point for edges, heat, and abrasion, and add softeners or corner protection before tensioning.
Rigging a load without confirming the center of gravity, causing an unbalanced or tilting pick, or attaching legs asymmetrically on an off-center load.
Candidates assume the geometric center equals the center of gravity and do not check for internal weight distribution or attached components.
What to do instead
Identify or estimate the center of gravity before choosing attachment points, use a trial lift to confirm level, and adjust leg lengths or attachment points rather than forcing the load level.
Mismatching hardware-using a hook with too small a throat opening, a shackle pin that can rotate loose, or a hook without a latch/mousing in a load-bearing application.
Candidates match hardware by size impression rather than by rated capacity, fit, and the requirement for latches or mousings to prevent load release.
What to do instead
Check hardware against three criteria every time: rated capacity at least equal to the required load, correct fit (throat and pin seated, no side loading), and secure closure (latch or mousing as required).