I consider myself pretty handy with engineering type deals but with this I need help. I am putting up a DIY zip line on a family property. Need to calculate the loads on the ends of the line. 1/4" Steel Cable- 44 meter span. 1.1 meters of sag. 2.5% incline. Max weight = 135 KGS So I need the tension for 135KGS suspended from the lowest point, static. I need to know the amount of tension this thing will be exerting on the ends so I can figure out the type of anchors. I have two trees identified for the anchors, one is 2 feet in diameter the other is 1.5 foot eucalyptus. the trees are more than sturdy to hold the cable. I just need to figure out if I need to do a sling wrap on the tree, cable wrap on the tree or a through bolt with a nut and washer. I do not want to wrap the tree if possible but I need the numbers.... I am thinking a 1" threaded rod (used as a throughbolt) with large washers and a locknut should be enough, and a threaded eye on the other end with a locknut securing it in place. that should be plenty strong but since my nieces, daughter, wife, possibly aunts and a whole host of other family members are going to be using it I want to be sure. anybody here knows physics or has experience with zip lines?????