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The 1970s through 1980s was a golden era of cave exploration across the U.S. Cavers typically use static kernmantle ropes which are removed after a cave has been explored, but instances exist where rope is left permanently rigged. Today caves across the country have a rope of unknown and potentially questionable histories permanently rigged. In 2023 in West Virginia's Shoveleater Cave a pre-rigged rope broke while a caver was descending a 9m pit. Luckily the fall was minor and the caver was only jarred, but the incident raised curiosity within the caving community about the strength of permanently rigged ropes.
An informal study was conducted on 13 permanently rigged ropes removed from caves in the Southeastern United States at Pigeon Mountain Industry's rope production facility in Lafayette, GA. No history was known about the ropes. Ropes in the study were manufactured from an estimated 1988 to 2018. Damaged and intact ropes were pulled to failure and the failure point noted. Ropes that showed no visible signs of damage broke between 10kN and 20kN. An additional three samples which exhibited signs of severe rope wear also broke at 10kN to 14kN, far below their Minimum Breaking Strength (MBS).
The study shows that old ropes can be strong but visual inspection alone is not enough to gauge a rope's strength. The most important factor that diminishes a rope's strength is use, not age.
Philip Rykwalder
About the Presenter:
Caver for 33 years with a focus on alpine caving in the Western US (including first explorations of Virgil the Turtle's Greathouse Cave and Tears of the Turtle)
Participated in 68 expeditions across 14 countries
Former Southeast Coordinator for the Vertical Training Commission
Chattanooga Hamilton County Rescue Service member (5 years)
Fellow of the NSS
Expedition rigger and author of over 40 articles on expeditions, ropes, and rigging
Resides in Chattanooga, TN