On 13 March Robin Wales (16) and a group of six boys and three girls with little or no previous climbing experience spent the day learning basic climbing techniques on practice climbs.
In the afternoon, Wales and three other members of the party climbed to the top via a trail in order to set up a 100-foot free rappel. Upon reaching the top they tied two 11 mm perlon ropes together and anchored them around a tree making sure that both ropes reached the bottom.
After checking the rope for any rock interference, one member of the party clipped in with a rappel sling and brake bar assembly and proceeded to make a free rappel to the ground.
Next the victim (Wales) donned a nylon webbing rappel sling and brake bar assembly, put on leather gloves, and proceeded to lean back to start his rappel. At this moment his sling came apart—the knot having come undone. Fortunately, he was able to grab the rope and to slide 100 feet to the ground with his hands and legs wrapped around the rope. He suffered no injuries and walked away.
Source: Robin Wales.
Analysis: (Wales and G. Sargent Janes) Had Wales tied the knot in his rappel sling properly and checked it as was suggested by another member of the party, he probably would not have fallen. Wales believed he tied a water knot in his rappel sling; however, this cannot be checked. This knot has been known to “fail” before and should always be set up tightly, particularly when used with nylon webbing. Most rappel accidents are fatal and many are due to errors in setting up the system. This incident clearly points up the need for the use of belays or at least a prussik sling attached to a swami belt. This may not always be feasible on a big mountain, but on practice climbs where beginners are involved, it is clearly essential.