NCCCO Rigging Techniques & Equipment Inspection 2

Question 1

What is the rated capacity of a sling determined by?

Accepted Answer

The sling type, size, configuration (hitch type), and angle of use

Answer

Sling capacity depends on the type (wire rope, chain, synthetic), diameter/grade, hitch configuration (vertical, choker, basket), and the angle relative to vertical. Capacity tags must be attached.

Question 2

How does sling angle affect lifting capacity?

Accepted Answer

As the sling angle decreases from vertical, the tension on each sling leg increases, reducing the effective capacity

Answer

When slings are spread at an angle, each leg must support more than its share of the vertical load due to the horizontal force component. At 30° from horizontal, each leg experiences twice the vertical load.

Question 3

What must be checked during a pre-use inspection of wire rope slings?

Accepted Answer

Broken wires, kinks, crushing, corrosion, heat damage, end fitting condition, and the capacity tag

Answer

Pre-use inspection covers: broken wires (count per rope lay), kinks, crushing, bird-caging, corrosion, heat damage (discoloration), end fitting integrity, and a legible capacity tag.

Question 4

What is a 'choker hitch' and when is it used?

Accepted Answer

A sling configuration where the sling wraps around the load and the eye passes through the other eye, cinching tight on the load

Answer

A choker hitch wraps the sling around the load and cinches tight, gripping the load through friction. It's used when loads need to be gripped tightly, but it reduces sling capacity to approximately 75% of vertical rating.

Question 5

Shackles used in rigging must be inspected for what conditions?

Accepted Answer

Deformation, wear, corrosion, cracks, proper pin installation, and correct working load limit for the application

Answer

Shackle inspection includes checking for deformation (bent or stretched), wear at contact points, corrosion, cracks, proper pin installation (correct pin type, fully threaded), and appropriate WLL rating.

NCCCO (National Commission for the Certification of Crane Operators) Practice Test

NCCCO (National Commission for the Certification of Crane Operators) Practice Test

NCCCO Rigging Techniques & Equipment Inspection 2