Stretch in STATIC kernmantle?

Stretch in STATIC kernmantle?

• A. 5%
• B. 10%
• C. 15%
• D. 20%

Answer: (D)

Stretch in a static kernmantle rope refers to how much the rope length increases when it’s under load, accounting for both immediate elastic elongation and longer-term creep under sustained tension. Static rope is designed to stretch far less than dynamic rope, but it isn’t zero. When a static line is loaded, it lengthens a little right away, and if the load is kept, the fibers creep and the rope continues to elongate over time. In practical rescue settings, that creeping can add up, especially over longer spans or with older or heavily used rope. Because of that time-dependent elongation, the total stretch a static line can experience under sustained load can be quite substantial—up to about 20% of its original length in many situations. That’s why the best answer among the options is 20%. The smaller percentages would underrepresent how much the rope can lengthen with creep, and dynamic rope would exhibit much greater elongation during a fall, which isn’t the scenario described here.

Stretch in a static kernmantle rope refers to how much the rope length increases when it’s under load, accounting for both immediate elastic elongation and longer-term creep under sustained tension. Static rope is designed to stretch far less than dynamic rope, but it isn’t zero. When a static line is loaded, it lengthens a little right away, and if the load is kept, the fibers creep and the rope continues to elongate over time. In practical rescue settings, that creeping can add up, especially over longer spans or with older or heavily used rope.

Because of that time-dependent elongation, the total stretch a static line can experience under sustained load can be quite substantial—up to about 20% of its original length in many situations. That’s why the best answer among the options is 20%. The smaller percentages would underrepresent how much the rope can lengthen with creep, and dynamic rope would exhibit much greater elongation during a fall, which isn’t the scenario described here.