Four cavers were exiting on two caving ropes tied together, with a hard-lay nylon rope for a belay. The third up switched ropes so as not to have to pass a knot on the 170 foot drop. Part way up he had trouble with his Jumars slipping, but made it after a long struggle. Watch out for clogged or worn cam teeth. Jumars in good condition should work on any rope.
NSS News, November 1985 (Part 2) V43N11, Page 366.
Robert Israel Personal Communication December 12, 1984.
No analysis has been done.