I concur with some of your stuff, and not other. I've seen deadman > anchors blow up pretty quickly. And, doesn't matter the speed of > disintigration if you're mid rappel...only need to take long enough to > dump you. > Deadman anchors can be very good if properly made. If I recall the picture well it was loaded in a vertical plane ? That's not good at all, but in this situation more then offset by the friction on the lip of the pothole as said in previous posts. Best is to load such an anchor in an as horizontal plane as possible or even a slight downward direction. Check out mountaineering/alpine sites or handbooks for good deadman anchors, I've rappeled on a bunch of them buried in... snow, and on objects far less bulky and less heavy then a pack filled with sand (piolets, skis, branches, plastic trash bag filled with snow...). Koen