Shrinkage of Ropes with use
How much do ropes shrink as we use them? There is no standard test for this, so it becomes very hard to say. I think/guess/observe/no-really-it-is-a-guess about 5% in the first few trips, and not much past that. For my Imlay Canyon Gear ropes that are 100% polyester, sheath and core, thus perhaps more resistant to shrinkage than other ropes. But what is really true? Could we actually collect some data and find out?
OK, let's do that.
June 22, 2016 - pulled a brand new 120' Canyon Fire off the shelf. Actual length = 121 feet (1452 inches)
June 21, 2016 - Imlay Sneak route with 3 ropes used randomly. 5 people. 27 rappels or so total, so used on approximately 9 rappel, mostly single strand. Wet.
June 22, 2016 - Rope mostly dry. Measured length = 118 feet, 8 inches (1424 inches) ==> measured shrinkage = 1.93%
Unfortunately, this rope sustained a core shot 20 feet from one end, and is now a 98 foot rope. (sigh)
Alas - next time for sure... I will work on it with a new rope, and probably track this shortened rope too.