rcwild
04-03-2009, 11:06 AM
Over the past weekend Rick Green and I removed the piton at the final rappel in Egypt 1. Rick told me it once had a note attached to it asking that it not be removed because it would be needed as an anchor the following weekend. Assuming the person who wrote the note was concerned about his group's safety if the piton was removed. He should have been concerned about his group's safety using it. It was very poorly placed.
Now, we have all encountered "good" bad anchors. Anchors that were poorly placed, but continue to be used and hold. But we need to be careful. A "good" bad anchor will become a bad bad anchor sooner or later.
Wishing I took a before photo so we could use this as a scenario, but I didn't so we'll have to rely on my descriptions.
Pitons come in a variety of types. Two types are pictured in the illustration below. The one we removed was an angle. Angles should be placed so the edges are in opposition to the back. The piton in E1 was placed so the edges were in opposition to each other. This placement can make it easier for the piton to roll out. As the piton is driven, the sides also flex in a bit, making the piton a bit spring loaded.
The piton was also much too long for the crack it was placed in. For a good placement, the piton should slide into the crack on it's own about 75% of its length, then tapped with a hammer to set it. The E1 piton was about six inches long and driven in less than 1.5 inches. The person who placed it should have used a much smaller piton or gone crack shopping -- for a deeper crack suitable for the long piton.
The major issue using a piton that is too long is leverage. See the illustration for two examples. The top placement is textbook; piton driven all the way to the eye. Okay to use the eye. The middle placement couldn't be driven in all the way, so a sling is tied around the piton against the rock to reduce leverage. The E1 piton extended 4-5 inches out from the rock, but had a rapide in the eye with webbing threaded through the rapide. Too much leverage.
The bottom placement does not relate to this situation, but illustrates using a sling to improve the direction of pull on a piton. Pitons should be loaded in sheer (90 degrees), not in tension (straight out).
Removing the E1 piton was fairly effortless. A couple taps with a rock, then a tug with an improvised funkness device.
Our group had no problem getting down the rappel with a human anchor who received a thigh belay from the bottom.
Now, we have all encountered "good" bad anchors. Anchors that were poorly placed, but continue to be used and hold. But we need to be careful. A "good" bad anchor will become a bad bad anchor sooner or later.
Wishing I took a before photo so we could use this as a scenario, but I didn't so we'll have to rely on my descriptions.
Pitons come in a variety of types. Two types are pictured in the illustration below. The one we removed was an angle. Angles should be placed so the edges are in opposition to the back. The piton in E1 was placed so the edges were in opposition to each other. This placement can make it easier for the piton to roll out. As the piton is driven, the sides also flex in a bit, making the piton a bit spring loaded.
The piton was also much too long for the crack it was placed in. For a good placement, the piton should slide into the crack on it's own about 75% of its length, then tapped with a hammer to set it. The E1 piton was about six inches long and driven in less than 1.5 inches. The person who placed it should have used a much smaller piton or gone crack shopping -- for a deeper crack suitable for the long piton.
The major issue using a piton that is too long is leverage. See the illustration for two examples. The top placement is textbook; piton driven all the way to the eye. Okay to use the eye. The middle placement couldn't be driven in all the way, so a sling is tied around the piton against the rock to reduce leverage. The E1 piton extended 4-5 inches out from the rock, but had a rapide in the eye with webbing threaded through the rapide. Too much leverage.
The bottom placement does not relate to this situation, but illustrates using a sling to improve the direction of pull on a piton. Pitons should be loaded in sheer (90 degrees), not in tension (straight out).
Removing the E1 piton was fairly effortless. A couple taps with a rock, then a tug with an improvised funkness device.
Our group had no problem getting down the rappel with a human anchor who received a thigh belay from the bottom.