Rigging and Hoisting Operations Flashcards

What is the minimum safety factor (design factor) required for wire rope slings used in rigging operations per ASME B30.9?

Answer: 5:1

ASME B30.9 requires a minimum design factor of 5:1 for wire rope slings used in rigging.

When a load is suspended from two sling legs with a 120-degree included angle between them, each leg carries approximately what percentage of the total load?

Answer: 100%

At a 120-degree included angle, each sling leg carries 100% of the total load due to the increased tension from the wide angle.

Which type of rigging hardware is used to change the direction of a wire rope without creating a fixed termination?

Answer: Snatch block

A snatch block (also called a redirect block) allows wire rope to change direction while the rope remains free to move through it.

What is the correct procedure when a tag line is used during a crane lift?

Answer: Use it to guide the load without pulling the hook off center

Tag lines are used to guide and control load rotation without pulling the crane hook off-center, which could cause side loading.

A pipefitter is rigging a horizontal pipe using a double-wrap choker hitch. Compared to a single choker, the double-wrap choker increases the rated capacity by approximately:

Answer: 25%

A double-wrap choker hitch increases the rated capacity by approximately 25% compared to a single choker hitch.

What is the maximum allowable D/d ratio recommended for a wire rope running over a sheave to minimize rope wear?

Answer: 20:1

A minimum D/d ratio of 20:1 (sheave diameter to rope diameter) is generally recommended to minimize wire rope fatigue and wear.

Which condition requires immediate removal of a wire rope sling from service?

Answer: Six randomly distributed broken wires in one rope lay

Per ASME B30.9, six randomly distributed broken wires in one rope lay is a criterion for removing a wire rope sling from service.