Wire Rope Inspection and Replacement Criteria Flashcards

During inspection of a 6x19 classification running wire rope, an inspector finds 2 broken wires in the valleys between strands within a single rope lay. What is the correct action, and why are valley breaks treated differently than crown breaks?

Answer: Remove the rope from service immediately; valley breaks indicate internal wear that is likely more advanced than visible surface damage suggests

Valley breaks occur at the contact point between strands rather than on the exposed crown of wires. Because they form at an internal contact zone, valley breaks signal that internal wear and fatigue are likely far more advanced than what is visible externally. ASME B30.5 and industry guidance treat any valley break as a serious indicator warranting removal from service, regardless of the total broken-wire count, because the inspector cannot assess the true extent of internal degradation.

A rotation-resistant wire rope (35x7 construction) is being inspected on a lattice-boom crane. The inspector finds 3 broken wires distributed across a 20-rope-diameter length of rope. Per ASME B30.5, what is the correct determination?

Answer: The rope must be removed from service; rotation-resistant ropes have a stricter criterion of 2 broken wires in 6 rope diameters or 4 in 30 rope diameters

Rotation-resistant wire ropes have significantly stricter discard criteria than standard ropes because their multi-layer construction means external broken wires are a disproportionately severe signal of overall rope degradation. Per ASME B30.5, rotation-resistant ropes must be removed when 2 broken wires are found in any 6-rope-diameter length, or 4 broken wires in any 30-rope-diameter length. With 3 broken wires found in 20 rope diameters, the 30-diameter window criterion (4 wires) has not been exceeded, but the 6-diameter window must also be checked — however, the critical takeaway is that the standard 6-broken-wire rule does NOT apply to rotation-resistant ropes.

When measuring wire rope diameter to assess wear-related diameter reduction, which measurement technique produces a valid reading?

Answer: Measure across opposite strands at the widest point of the rope cross-section using calipers

Wire rope diameter must be measured across the full circle of strands — from the crown of one strand to the crown of the diametrically opposite strand — using calipers. This captures the true load-bearing diameter. Measuring into the valley between strands gives an artificially small reading that overstates wear. ASME and manufacturer guidance specify this crown-to-crown measurement technique. A reduction exceeding the standard's allowable amount (which varies by rope diameter class) is cause for removal, independent of visible broken wires.

A crane's pendant (standing) wire rope shows 3 broken wires distributed across a 10-rope-diameter length near an end termination. Under ASME B30.5 criteria for standing ropes, what action is required?

Answer: Remove from service; standing ropes have a stricter criterion and 2 broken wires in 6 rope diameters is the removal threshold

Standing ropes (pendants, gantry ropes, back hitch ropes) experience primarily static tension and do not cycle over sheaves, but they are subject to stricter broken-wire removal criteria than running ropes precisely because fatigue breaks in a static rope are unexpected and signal a more severe condition. ASME B30.5 specifies removal of standing rope when 2 or more broken wires are found within 6 rope diameters of an end connection, or 4 or more broken wires in any 30-rope-diameter length. Three breaks within 10 rope diameters triggers the 30-diameter criterion, requiring removal.

A wire rope suspected of having been subjected to a shock load shows no visible broken wires, no kinks, and no measurable diameter reduction. What is the correct inspection and service decision?

Answer: Remove the rope from service pending a thorough hands-on inspection of the full length; shock loads can cause internal wire fractures and core damage not visible externally

A shock load — caused by a sudden release of tension, a load drop, or a snapped sling — can cause severe internal wire fatigue fractures, core crushing, and inter-wire nicking that produce no visible external symptoms immediately after the event. ASME B30.5 and OSHA 1926.1413 require that ropes subjected to a shock load be removed from service and given a thorough inspection before returning to use. The inspector must manually flex and examine the full rope length because internal damage will not be apparent without tactile inspection and may not produce measurable external changes.

An inspector observes that a wire rope has developed a 'birdcage' deformation where the outer strands have flared outward and the core is protruding. The operator states the rope can still carry load because no wires are broken. What is the correct response?

Answer: Remove the rope from service immediately; birdcaging is an irreversible structural deformation that permanently destroys the rope's ability to distribute load evenly

Birdcaging occurs when torsional shock or rebound forces cause the outer strands to unlay and separate from the core, flaring outward. Even if no individual wires are broken at the time of inspection, the rope's helical geometry has been permanently altered — the strands and core no longer share load proportionally, creating extreme stress concentrations whenever the rope is tensioned. Attempting to proof-load or re-tension a birdcaged rope is dangerous because it can cause catastrophic failure. ASME B30.5 lists birdcaging as an absolute removal-from-service condition, regardless of broken wire count or rope length affected.