On September 12, I had a near miss when I was climbing a sport route called Twist and Shout (5.13c) at Coney Island in Boulder Canyon. The route has four fixed quickdraws on the overhanging top half of the route, two of which are regular quickdraws with a nylon dogbone, and two of which are chain-link draws with regular aluminum carabiners on the clipping ends. I briefly looked at the carabiners as I clipped them on my onsight attempt and did not notice any excessive wear or grooving. As I fell above the third fixed draw, which was a chain-link draw with an aluminum carabiner, the biner cut the sheath of the rope, exposing nearly 20 feet of the core.
While Boulder Canyon is an extremely popular place to climb, this particular route is somewhat obscure and does not see a lot of traffic, so the condition of the fixed gear is not well-documented. Instead of going bolt to bolt to inspect the moves and the fixed gear, I was focusing on an onsight attempt and only gave the fixed draws a cursory inspection (the clips were difficult). Most of the danger from fixed draws comes from excessive grooving when the carabiner gets worn down. However, carabiners that come in contact with the bolt hanger can get nicks, abrasions, and small, rough teeth that are hard to see without careful inspection. When these carabiners are then placed on the rope-receiving end of the draw, such as for a replacement carabiner on a fixed draw, such burrs can knife the sheath. These can be very difficult to see, especially if you hang directly on the rope running through fixed draws when going bolt to bolt. If the condition of the gear is unknown, it's a good idea to clip directly into the bolt hanger with an independent draw, then fully inspect the fixed draw's condition before committing to using it. (Source: Jason Haas.)
[Editor’s note: This report also highlights the importance of inspecting and replacing carabiners on fixed quickdraws frequently. Steel carabiners last much longer than aluminum biners in such uses, but even steel biners eventually can develop rope-damaging grooves, nicks, and burrs.]