Rigging and Hoisting Flashcards

What does WLL stand for when marked on rigging equipment?

Answer: Working Load Limit

WLL stands for Working Load Limit, the maximum load a piece of rigging equipment is rated to lift under normal service conditions.

Which hitch configuration provides the highest effective WLL when using a single-leg sling?

Answer: Basket hitch

A basket hitch supports the load on both sides of the sling, effectively doubling the rated capacity compared to a vertical (straight) hitch.

When two sling legs form a 120° included angle, what is the approximate tension in each leg relative to the total load weight?

Answer: Equal to the total load weight

At a 120° included angle each leg is 60° from vertical, so tension per leg = W/(2 × cos 60°) = W/(2 × 0.5) = W, equalling the full load weight.

What is the minimum number of wire rope clips (Crosby-type) required when forming an eye in 1/2" (13 mm) diameter wire rope?

Answer: 3

CSA and manufacturer standards require a minimum of 3 wire rope clips for 1/2" rope to achieve the required connection efficiency.

A synthetic web sling whose red warning core is visible through the outer jacket should be:

Answer: Removed from service immediately

An exposed red warning core indicates the sling outer jacket is critically worn; the sling must be removed from service immediately per CSA Z150 requirements.

What is the primary purpose of attaching a tagline to a suspended load?

Answer: To control the load's rotation and prevent uncontrolled swinging

A tagline allows workers to guide and stabilise a suspended load from a safe distance without being in the load's fall zone.

According to CSA standards, what is the maximum recommended included angle between two sling legs for most rigging lifts?

Answer: 120°

CSA and ASME B30 standards recommend a maximum included angle of 120° between sling legs; beyond this the leg tension increases to dangerous levels.