Rigging Fundamentals & Material Handling Flashcards

Which type of sling provides the best resistance to damage from sharp edges and high temperatures?

Answer: Chain sling

Chain slings are the most resistant to heat and sharp edges because they are made of metal links that are not subject to cutting or melting like synthetic materials or wire rope.

A wire rope sling should be removed from service if it has how many randomly distributed broken wires in one rope lay?

Answer: 6 or more

ASME B30.9 standards require removing a wire rope sling from service if 6 or more broken wires are found in one rope lay length.

What is the purpose of a spreader bar in a rigging operation?

Answer: To keep sling legs from squeezing inward and damaging the load

Spreader bars maintain the correct distance between sling attachment points, preventing the inward compression forces that could damage or crush the load.

A synthetic web sling must be removed from service if it shows:

Answer: Acid or caustic burns

Acid or caustic burns compromise the structural integrity of synthetic fibers and require the sling to be immediately removed from service and destroyed.

What is a 'basket hitch' in rigging?

Answer: A hitch where the sling is wrapped around a beam and both ends hook to the crane

A basket hitch passes the sling under the load with both ends attached to the lifting hook, supporting the load from below like a basket.

What does 'D/d ratio' refer to in wire rope rigging?

Answer: The ratio of the sheave or pin diameter to the wire rope diameter

The D/d ratio compares the diameter of the sheave, drum, or pin (D) to the wire rope diameter (d), and a higher ratio reduces bending stress and extends rope life.

Before a lift, rigging personnel should determine the load's center of gravity in order to:

Answer: Ensure the load will hang level and stable

Identifying the center of gravity ensures rigging attachment points are positioned correctly so the load hangs level, preventing uncontrolled tilting during the lift.