Date of Event: 6/14/2020
Canyon involved: Parkett Creek
Region: Oregon
Country: United States
Submitted by: Jason Bowman
Source: Self-Report
Injury: Near Miss
Cause: Anchor error Unknown
Description of Event: Team of two canyoneers, experience level from Advanced/Intermediate to Expert. Both active mountain rescue technicians. Leader completed this canyon six times in the preceding year, partner completed this canyon three times in the same time frame. On this day water flow was very high, a6 in the French rating system. The team had received beta from another team of four experienced canyoneers who completed the canyon on the previous day.
Upon reaching the anchor station for R1 (~5 meter vertical plunge), both team members inspected the fixed anchor, a single loop of 1″ tubular webbing tied with a water knot around a 5″ diameter tree. The tree was smooth, lacking any bark, though it had a few broken branch stubs which were at least 6″ vertically above and below the webbing location. A standard 6mm maillon rapide was in place on the webbing. The webbing was identified as being the same sling placed by this same team of canyoneers on 16 June 2019, almost exactly one year prior. A minor nick in the edge of the webbing about 1″ from the knot was observed, but otherwise the webbing appeared in excellent condition. The knot appeared tight, and had tails approximately 2″ long on each side. The webbing was wet from heavy rain a few hours earlier, but showed no evidence of ever having been submerged by flood waters. It is estimated that at least 60 people have rappelled on this anchor since the webbing was placed one year ago.
A standard figure-8 block was constructed on the fixed sling and rapide. As the first canyoneer transitioned over the edge, he lost his footing and fell approximately 1 meter into the main force of the current. The second canyoneer, who was standing at the anchor prepared to to lower on the contingency anchor if needed, observed significant stretch in the webbing and the entire tree shaking from the force of the fall. The canyoneer on rappel struggled to regain footing, resulting in cyclical high loading of the anchor from the force of the water acting on the rappeller’s body. The canyoneer at the anchor observed cyclical stretching of the webbing that seemed abnormally severe. Suddenly the anchor catastrophically failed resulting in the rappeller falling approximately 1.5m into a pool of water below and was not injured. The canyoneer at the anchor was nearly struck in the face by the flying anchor hardwear. The second canyoneer grabbed the tail end of the rappel rope and pulled it entirely back up. The rope was undamaged and the figure-8 block was intact. He then constructed a new webbing anchor on the same tree (which did not appear damaged in any way) to descend.
The failed webbing and maillon rapide were located in the pool below. The rapide was undamaged, tightly closed. Both ends of the webbing appeared to be the original knife cuts. A loose overhand knot was present in one end of the webbing with approximately 3″ of tail.
Analysis: It appears that one end of the webbing slipped through the knot. The involved canyoneers hypothesize that the high force during the fall followed by severe cyclical loading under continued heavy force may have contributed. It is also possible the wetness of the soft webbing may have contributed.
It is also possible the mallion rapide may have been in contact with the knot, possibly contributing.