Damage to natural fibers occurs when line under a strain exceeds what percent of its breaking strength?

• A. 60%
• B. 75%
• C. 85%
• D. 90%

Answer: (B)

Natural fiber ropes are especially prone to damage when they’re loaded heavily because their fibers can strain, slip, crush, and heat up under high tension. Once you push the load into a large fraction of the rope’s breaking strength, these micro-weakening processes accumulate and the rope loses its ability to carry load safely. For natural fibers, the damage threshold is reached when the line is strained to about three-quarters of its breaking strength, so pushing beyond that line increases the risk of permanent weakening. That’s why the correct choice reflects that relatively high fraction of strength: staying below this level helps preserve the rope’s integrity. Loads well below this point are generally safe, while approaching or exceeding it makes damage likely and can lead to sudden failure under later use.