Wednesday, August 3, 2011

Know Your Materials: Aluminum Rappel Rings

In several past posts I've talked about rappel anchors. Most rappel anchors have some sort of metal rings on them. These rings prevent climbers from having to pull their ropes directly through webbing or bolt hangers. At many traditional climbing areas aluminum rappel rings are found on fixed anchors. These aluminum rappel rings are lightweight, cheap, and easy to add/replace. However, they are not meant for lowering. Let me repeat that - aluminum rappel rings aren't meant for lowering!!

Over the past several months, in several locations I've found aluminum rings placed in areas where people frequently lower down off of climbs. These rings are meant to hold low loads where the loaded rope does not move through the rings. The excessive wear associated with lowering can create sharp edges on these hollow aluminum rings. This sharp edge could potentially cut something like your climbing rope.

Aluminum rappel rings are made from a sheet of aluminum and rolled into a ring. They are hollow on the inside and have an external seam that's easy to see if one looks closely. Unlike carabiners or quick links, which are solid all the way through, aluminum rap rings are hollow and repeated lowering will produce a sharp edge, expose the hollow center, and rob the ring of some of it's strength which comes from it's cylindrical shape.

The only exception to this rule is the Omega Pacific solid aluminum ring. These rings are made of solid aluminum stock. They do tolerate some lowering but wear quickly when climbers repeatedly use them for lowering.
What's the moral of the story? Well, if you're going to be using a tool while climbing be sure to use it properly. In this case, if you're the one placing them make sure you use the right material for the job. Frequently used anchors should have steel, or at the very least a carabiner or two which will tolerate some lowering. If you encounter these aluminum rings on a climb be sure inspect them thoroughly and then rappel off of them, don't lower.