Brook, I can't contribute information at this time as I do not have a bridge crane set up in my shop. It is on my wish list and will be the next major "tool" I add.
It has been discussed on the forum in the past. It took a bit of looking, but it was fun.
http://www.tfguild.org/forums/ubbthreads.php?ubb=showflat&Number=18900&page=1
