RAPPEL FAILURE—INADEQUATE KNOT

Utah, Zion National Park, Spaceshot

On May 21, Roeslain Tamin (35) fell 180 feet to his death while rappelling from the popular climbing route Spaceshot in Zion National Park. Evidence and interviews lead to the following sequence of events.

Tamin and his climbing partner Richard Connors (29) had climbed the first four pitches of Spaceshot on May 20, then descended, fixing lines on the way. On May 21, they returned and ascended their fixed lines to the top of the fourth pitch. Due to approaching weather, they decided to retreat and take their ropes down with them. Tamin rappelled to the ledge on top of the second pitch followed by Connors. The two then prepared for the final 60 meter rappel to the ground. Tamin walked a short distance over to their fixed rope at the anchor, out of view of Connors. Tamin took the weight off the end of the fixed rope by clove-hitching it to a carabiner clipped to the anchor webbing. Connors pulled down a rope from the just-completed rappel, then threw the end of it to Tamin. Tamin then presumably tied the two rope ends together. Connors then fed the rest of the rope to Tamin, who in turn put it over the edge. Tamin began his rappel while Connors was coiling rope approximately ten feet away. They were separated by a boulder large enough to partially obstruct Connors’ view of Tamin. Tamin probably fell shortly after going on rappel. He was found with both ropes running properly through his rappel device, with approximately ten feet of each rope above the device. But there was no evidence that the ropes had been tied together.

Analysis

Tamin and Connors had been climbing partners for eight years and tended to tie similar knots. Connors stated that they both commonly tied a figure eight knot with the tails on the same side and with an overhand backup as their primary rappel knot. Both trusted this knot but had not tested its limitations. This knot was used because of its tendency not to get stuck when pulled from below, as happens with many other knots. In this instance Tamin may have tied the knot with tails shorter than usual. But a backup knot was probably not used. These are plausible speculations due to the length of this rappel being the same as their ropes—60 meters. The lower you exit the rappel the easier the terrain becomes, and a notation made on their route description by Tamin to the effect that, “Ropes barely reach, go left of stance.”

It would seem unlikely that Tamin neglected to tie the two ropes together given that the ropes were found threaded properly through his rappel device. Non-scientific tests performed on the knot in question showed several important things. When weighted, this knot will invert; if the knot is not dressed properly, it comes untied significantly more easily than will a properly dressed knot. When tied with short tails and cycled (repeated weighting and unweighting), the tails can be brought into the knot body, causing the knot to unravel.

The ropes used during this accident were sent to Black Diamond’s lab in Salt Lake City, where this knot (as well as a standard overhand rappel knot) was tested using their Satec Universal Testing Machine. Tests showed that the figure eight knot inverted at loads two-thirds that of the overhand, an untightened figure eight inverted at about a 30 percent lower load than one well tightened. Conclusions of Paul Tusting, BD Quality Assurance Manager, were that, “...either the knot was tied incorrectly or it was extremely loose. The testing also demonstrates that if a well dressed figure eight with long tails were used with these ropes, a field failure of the knotis extremely unlikely. Lastly, this testing indicates that the overhand (tails on same side) is superior in strength to the figure eight (tails on same side) when well dressed and tightened.” (Source: Kevin Killlian, SAR Coordinator, Zion National Park)

(Editor’s Note: Fewer rappelling accidents have been reported in the last decade or so. On the other hand, lowering accidents are on the increase. The common reason for both is inattentiveness to the familiar and obvious, even among experienced climbers.)