NCCCO Wire Rope Inspection and Replacement 5

Question 1

What is the correct procedure for determining a wire rope's 'lay length' during inspection?

Accepted Answer

Measure the axial distance for one strand to make one complete helical revolution around the rope

Answer

One rope lay is the axial distance along the rope in which one strand completes a full 360-degree revolution around the rope core.

Question 2

When replacing wire rope, what is the primary purpose of 'pre-forming' a new rope before installation?

Accepted Answer

To permanently shape each wire and strand into its helical position, reducing rotation tendency and improving fatigue life

Answer

Pre-forming shapes the wires and strands into their final helical positions during manufacture, reducing residual stress and the tendency to rotate or unlay under load.

Question 3

According to OSHA 29 CFR 1926.1413, who is qualified to perform the monthly wire rope inspection on a crane?

Accepted Answer

A qualified person as defined by the standard

Answer

OSHA 1926.1413 requires that monthly wire rope inspections be performed by a qualified person who has specific training, knowledge, and experience in wire rope inspection.

Question 4

What type of wire rope damage results from the rope repeatedly rubbing against a fixed object or the drum flange?

Accepted Answer

Abrasion causing flat spots and reduced wire diameter on the outer wires

Answer

Repeated contact with a hard surface causes abrasive wear, creating flat spots on the outer wire crowns and reducing cross-sectional area.

Question 5

A wire rope shows 'fatigue fractures' with transverse breaks at the wire crowns. What operating condition most commonly causes this?

Accepted Answer

Repeated bending over sheaves or drums with inadequate D/d ratio

Answer

Fatigue fractures at wire crowns are caused by repeated cyclic bending stress from running over sheaves or drums, especially when the D/d ratio is too small.

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 5