NCCCO Rigging Fundamentals and Hardware 4

Question 1

When a sling is used in a choker hitch, the rated capacity compared to a straight vertical hitch is:

Accepted Answer

Reduced to approximately 75%

Answer

A choker hitch reduces sling capacity to approximately 75% of the vertical hitch rating due to the bend angle created at the choke point.

Question 2

What is the primary purpose of a shackle's safety pin or bolt?

Accepted Answer

To prevent the pin from unscrewing under load

Answer

The safety pin or cotter pin prevents the shackle pin from unscrewing due to vibration or load rotation during a lift.

Question 3

A spreader beam is used in a rigging configuration primarily to:

Accepted Answer

Keep sling legs vertical and prevent inward compression on the load

Answer

Spreader beams maintain sling legs in a vertical or near-vertical position, preventing compressive forces from being applied to fragile or wide loads.

Question 4

Which of the following conditions requires immediate removal of a wire rope sling from service?

Accepted Answer

Six randomly distributed broken wires in one rope lay

Answer

ASME B30.9 requires wire rope slings to be removed from service if six or more randomly distributed broken wires are found in one rope lay.

Question 5

When two slings are used in a basket hitch with a 60-degree angle from horizontal, the tension in each sling leg compared to the load weight is:

Accepted Answer

Greater than half the load weight

Answer

At 60 degrees from horizontal, the sling tension factor exceeds 0.5, meaning each leg carries more than half the total load weight.

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

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

NCCCO Rigging Fundamentals and Hardware 4