I recently had a conversation with a highliner about anchors and he mentioned they are starting to reverse the "P" shaped glue in bolts (Bolt products, wave bolts) in their anchors so the force is pulling off of the spine instead of the eye of the "P". The theory being that a change of load has the potential to use the eye of "P" to apply torque to the rock/glue interface. Whereas the spine allows the direction of force to rotate something like 180 degrees with very little change in pull on the bolt.
For a climbing application I do not see it making much of difference as the most common load is going to be a sport fall and top rope anchors see so little force. That being said is there any reason not to be orienting the eye up?
If you install the eye facing up there is a danger that the karabiner or the rope can go over the top of the bolt and jam in the vee-shape between the bolt and the rock with disastrous results. There are warnings about this on both the Fixe (Spain) and the Raumer website as they both make bolts with symetrical eyes. Install bolts with the eye facing down, potential twisting is anyway covered by the standard (there is a torque test).
Thanks Jim, that makes sense. I always appreciate your knowledge and experience. So any potential benefit in a sport climbing context has the rope and carabiner snag potential downside. What about a highline anchor or an anchor used in a rope rescue scenario where you could reasonably expect to see some change of pull direction in the case of a redirect?