Rust stains extending into the cross section of natural fiber and nylon yarns can lower the line strength by?

• A. Two
• B. SIX
• C. Nine
• D. Twelve

Answer: (B)

When rust stains extend into the cross section, they create internal flaws that reduce the rope’s effective area and introduce weak points. The load-bearing capacity depends on the intact cross section, so any intrusion by rust inside the fibers cuts into what can carry the load. For natural fiber and nylon yarns, this type of interior damage typically results in a modest but real loss in strength, about six percent. That level of reduction reflects the combination of a limited depth of penetration and the creation of stress concentrators that become the first points of failure under load. The other options imply far smaller or much larger reductions than what is commonly observed for this defect, so six percent is the best match for the scenario.