There has GOT to be a way to engineer a system so he can remain tied off the whole way up, maybe with just a couple of change overs along the way. I'm thinking a series of weighted cables with hooks and breaks, like seat belt breaks. So, you tie off to the hook at the bottom, the hook follows you up for maybe 50 feet, or whatever, and if you fall, the breaking system engages so it stops your fall. Once you get to the top of one cable, you switch over to the next. On the way back down, you use them again, which essentially resets the cables for the next time someone goes up.