Canyoneering Rope Shrinkage Tests
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?
I will list and update the data collected here, with generally the latest data on top.
Rope #2 - Imlay Canyon Fire Rope, 120 foot nominal length. Put in service 6/2/2017
122 feet 0 inches - original carefully measured length.
6/3/2017 - Full Imlay with 4 people/4 ropes, this being one of them. Wet and dry.
118 feet 10 inches - first canyon loss of 2.6 %
117 feet 8 inches - second usage overall loss of 3.55% (still a slight bit wet)
Rope #1 - Imlay Canyon Fire Rope, 120 foot nominal length, Put in service 6/20/2016
121 feet 0 inches - original carefully measured length
6/21/2016 - Imlay Sneak route w 3 ropes, 5 people. Wet and dry.
118 feet 8 inches - first canyon loss of 1.9 %.
unfortunately, this rope was coreshot in the canyon, and reduced in length, and I stopped using it to measure shrinkage...