A group of cavers was doing the 120 foot drop of Grapevine Pit. Al Stubbe got his shirt eaten by his rappel rack but was able to free it and continue.
NSS News, December 1989 (Part 2) V47N12, Page 324.
Sonja Ostrander and George Dasher "WVACS Activities report" The West Virginia Caver, Vol 5, No 5, October 1988, p 17.
No analysis has been done.