Wire Rope Inspection and Replacement Criteria Flashcards
6 cards from real NCCCO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Wire Rope Inspection and Replacement Criteria flashcards as text
What is the discard criterion for wire rope based on broken wires in one lay length?
Answer: Six randomly distributed broken wires in one lay length, or three broken wires in one strand
ASME B30.2 and most standards specify that wire rope must be removed from service when six randomly distributed broken wires appear in one rope lay length, or when three broken wires are found in a single strand.
What amount of diameter reduction from nominal size indicates a wire rope must be removed from service?
Answer: Reduction beyond specified ASME limits based on rope diameter (e.g., 3/64 inch for 9/16 to 3/4 inch rope)
Wire rope must be removed from service when diameter has been reduced beyond specified ASME limits for each rope diameter range, indicating loss of metallic cross-section.
What is the primary purpose of wire rope lubrication during crane operations?
Answer: To reduce internal friction between wires and strands and protect against corrosion
Wire rope lubrication reduces internal friction between individual wires as the rope bends around sheaves and drums, dramatically reducing fatigue wire breaks, while also providing corrosion protection.
Where on a crane wire rope are fatigue breaks most commonly found and why?
Answer: At areas of maximum bending, especially the first sheave from the drum
Fatigue wire breaks concentrate at sheave contact points, especially the first sheave from the drum, because this is where the rope experiences the greatest bending cycle frequency and bending stress concentration.
What is fleet angle in wire rope operations and why must it be controlled?
Answer: Fleet angle is the angle between the rope path and the plane of the drum groove; excessive fleet angle causes uneven winding and rope damage
Fleet angle is the angle between the wire rope and the centerline of the drum groove; excessive fleet angle causes the rope to wind over itself or pile up on one end, damaging the rope and drum groove.
What is a wire rope core and why is it important for rope performance?
Answer: The core provides internal support to maintain strand geometry and carries part of the load; its condition affects rope performance and diameter stability
The wire rope core, whether fiber core (FC) or independent wire rope core (IWRC), supports the outer strands to maintain their geometry, provides lubrication retention, and in the case of IWRC, contributes to the rope's load-carrying capacity.