NCCCO Wire Rope Inspection and Replacement

Question 1

When inspecting wire rope on a crane, what are 'valley breaks' and why are they particularly serious?

Accepted Answer

Wire breaks occurring in the valleys between strands — they are hidden from easy view and indicate advanced fatigue requiring immediate removal from service

Answer

Valley breaks occur in the contact zones between strands (valleys), hidden from easy view. They indicate internal fatigue and typically occur before crown breaks, making them a critical condition requiring removal from service.

Question 2

Wire rope has a measured diameter of 0.94 inches but its nominal (rated) diameter is 1 inch. Should this rope be removed from service?

Accepted Answer

Yes — a reduction greater than 1/16 inch below nominal for 7/8-inch to 1-1/8-inch ropes requires removal per ASME B30.5

Answer

ASME B30.5 requires wire rope removal when the diameter is reduced more than 1/16 inch below nominal for ropes in the 7/8-inch to 1-1/8-inch range. A 0.06-inch reduction on a 1-inch rope meets this removal threshold.

Question 3

What does 'bird-caging' in a wire rope indicate, and what action is required?

Accepted Answer

The outer strands have expanded outward from the core due to shock loading or severe reverse bending — the rope must be removed from service immediately

Answer

Bird-caging occurs when outer wire strands splay outward from the rope's core, resembling a bird cage. It results from sudden shock loading, kinking, or running over a too-small sheave. The rope has lost its structural integrity and must be removed from service.

Question 4

Which end termination is typically used for permanent attachment of wire rope to a crane drum or dead end anchor to achieve full rated breaking strength?

Accepted Answer

Swaged (pressed) or spelter socket terminations, which achieve 100% of the wire rope's rated breaking strength

Answer

Swaged sockets and spelter (zinc-poured) sockets achieve 100% efficiency — the full rated breaking strength of the wire rope — making them the preferred permanent terminations for crane applications where safety is critical.

Question 5

When installing wire rope clips (clamps) on a wire rope, what is the correct clip orientation rule?

Accepted Answer

Never saddle a dead horse — the clip saddle bears on the live (loaded) rope end and the U-bolt bears on the dead (short) end

Answer

The mnemonic 'never saddle a dead horse' means the saddle (flat bearing surface) of the clip always bears on the live (load-carrying) rope end, never on the dead end. Reversing this reduces clip efficiency by up to 40%.

NCCCO (National Commission for the Certification of Crane Operators) Practice Test

NCCCO (National Commission for the Certification of Crane Operators) Practice Test

NCCCO Wire Rope Inspection and Replacement