I feel like I may be missing something as I read this. If you have your lines all going to the 5/16 mainline, why would anyone need anything else besides a 3 way tee? I am sure I am missing something I just do not know what it is. When you say "belt" are you referring to something like in this video? http://www.youtube.com/watch?v=b3gCxJMzCPs
If so, why not just run the line behind the tree and not put the line in the front to make a loop? It seems like if this is to just keep tension on the line that running it behind the tree should work? Thanks for the help,
-Dave