NCCCO Rigger Level II common mistakes
NCCCO Rigger Level II · Understand the traps and how to avoid them.
Builds the capacity check from the bare load weight only - e.g., a 9,000 lb valve body - and never adds the shackles, spreader beam, slings, and lifting lugs, nor converts a supplier's weight given in kilograms or tonnes.
Candidates treat 'the load' as the object being lifted, because that is how the question is worded, and they shortcut the arithmetic under time pressure.
What to do instead
Write a weight budget line by line - item, quantity, unit weight, subtotal, rigging hardware, total - before touching the load chart, and do the unit conversion as an explicit written step rather than mentally.
Cannot state what makes a lift 'critical' or list the contents of the lift plan, answering only that a critical lift is 'a big or heavy one' or that the plan is 'the paper the engineer signs'.
The term sounds intuitive, so candidates substitute their own definition for the regulatory/standards definition and never learned the plan's required elements.
What to do instead
Memorize the criteria categories (exceeds a stated percentage of the crane's rated capacity, two or more cranes, personnel aloft, travel over occupied areas or near power lines, non-standard or unproven configuration) and the plan elements (load weight and CG, rigging and capacities, crane position and chart, ground bearing, sequence, signals, contingency/emergency), then rehearse them out loud until they can be listed cold.
Computes sling leg tension by dividing the load by the number of legs, and computes a multi-leg sling's capacity by multiplying one leg's working load limit by the number of legs, with no angle applied.
At 90 degrees to horizontal the short-cut gives the right answer, so candidates generalize it; and an angle factor is easy to confuse with the angle measured from vertical.
What to do instead
Fix the geometry first: define the angle from horizontal, then use tension per leg = load / (number of legs x sin of that angle), and check the result against the two limiting cases (legs vertical: tension equals share; legs near horizontal: tension grows large). For capacity, apply the manufacturer's angle factor (e.g., two legs at 60 degrees from horizontal give 1.732 times a single leg's limit) rather than adding leg limits.
Assembles hardware by what fits and looks strong - pin bearing on the shackle body instead of the bow, two slings pulling a hook at a wide angle or side-loading it, a choker taken directly over a sharp structural corner, or a wire rope sling bent around a pin far smaller than the rope diameter.
Candidates select components by pin diameter and visual size while ignoring orientation, loading direction, and bend radius, because those limits are not printed on the hardware.
What to do instead
Rig hardware the way it was rated to be loaded: shackle bow takes the load and the pin sits in the bearing, hooks are loaded in the saddle and within their side-load limits, a latch is closed and not carrying load, softeners or corner protectors are fitted wherever a sling contacts an edge, and the D/d ratio is checked against the sling manufacturer's efficiency rating before the sling is accepted.
Returns gear to service with defects that meet published removal criteria - a hook whose throat opening has spread, wire rope with broken wires or a worn diameter, a synthetic sling with a deep cut, snag, or ultraviolet/chemical damage, a chain with a stretched link or gouge.
Candidates inspect with the pass/fail question 'does it look bad?' instead of comparing measured condition against a numeric threshold, so borderline but disqualifying damage passes.
What to do instead
Inspect against numbers, not impressions: know the hook throat-opening spread and wear limits, the broken-wire and diameter-reduction criteria for the specific rope construction, and the cut/wear/heat/chemical limits for each sling type, and record the measurement or the specific defect rather than a general description.
Keeps using a sling or sling assembly whose identification tag is missing or illegible, or whose periodic inspection is overdue, reasoning that the gear 'still looks fine.'
Candidates treat the tag as a convenience rather than part of the equipment, and they do not separate pre-use inspection (the user's job, every shift) from periodic inspection (documented, at defined intervals, by a designated person).
What to do instead
Adopt the rule that no tag means no rating and no service, remove the item from service and route it for periodic inspection or destruction, and be able to state who performs pre-use versus periodic inspection and that the interval is set by the manufacturer or a qualified person based on severity of use.
Rigs an asymmetric or unfamiliar load to the lifting points that are convenient, does no test lift, and lifts the full height in one motion - then loses control when the load tips or rotates.
Candidates assume the lifting points were placed at the center of gravity and are reluctant to spend time on a slow, low trial pick.
What to do instead
Establish the center of gravity (symmetry, drawing data, or a trial pick), place the hook over it, and raise the load just a few inches, stop, and confirm level and stable before any further hoisting; if the load will rotate, plan for control of rotation with tag lines or a second line before the lift starts.
Plans a two-crane lift by splitting the load 50/50, sets capacities from that split, and has no written sequence for how the load will be transferred or how drift between the two hoists will be prevented.
Candidates apply the balanced-share assumption because it is the only arithmetic they know for multiple cranes, and the dynamic transfer between hoists is invisible on paper.
What to do instead
Treat load share as a function of the center of gravity position between the pickup points (which is rarely equal), apply the required capacity reduction for the multi-crane configuration, and write out the step-by-step sequence - who hoists when, what is the allowable drift, who directs, what stops the lift - before the pick begins.
Lets the lift proceed on signals from a ground worker who is not the designated signalperson, uses improvised or non-standard hand signals, and does not know who may give a stop signal.
Candidates learn hand signals as a memorized set of arm positions without learning the system around them - one designated signalperson, agreed signals, and universal stop authority.
What to do instead
Set the communication plan in the pre-lift meeting: name the signalperson, confirm the operator can see or hear that person, agree hand or radio signals with a backup method, use only the standard signal set for the task, and state clearly that anyone who sees a hazard may give and must have obeyed the stop signal.
Sends a worker out to handle the load by hand or to hold a tag line while standing under or in the path of the load, or omits tag lines on a long, oddly shaped load that then swings and rotates freely.
Candidates focus on stopping the swing and forget that the person controlling the load must never be in the fall zone, and they treat tag lines as optional extras rather than a planned control.
What to do instead
Plan load control before the lift: use tag lines of adequate length so the handler stands clear and outside the swing radius and can release immediately, keep every part of the body out from under and out of the path of the load and rigging, and if the load cannot be controlled from a safe position, stop and re-plan the pick.