I want to build a zip line over our pond. I found this thread helpful, where Bob talks about how he built his zip line:
https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=79943 I emailed Bob for a bit of extra info, which he was kind enough to share. He said it was about 120 feet long, with people dropping about 60 feet out. He said that was a lot of fun. He said the anchors held the zip line roughly 12 feet above the water.
For our zip line, because of how the anchor points work out, I’m planning for it to be roughly 245 feet long. From what info I could find it seems people recommend starting with the ideal low point, which happens about 3/4s of the way along the zip line. I thought 5 feet might be a good number for that, so that you’re starting to drag in water by this point, instead of hitting the shore on the other side.
From there they recommend calculating the zip line sag as the total length * 0.02, which in my case equals 4.9 feet. Adding this to the low point gives a lower anchor height of 9.9 feet.
From there they recommend adding a 3% slope, so 7.35 feet in my case. This gives an upper anchor height of 17.25 feet. I was then planning to put a platform 7 feet below this point to launch from, with a small stool step for smaller kids who can’t quite reach the zip line trolley bar. This would put the platform 10.25 feet high off the water. I would put it out over deep water so even if you immediately fall off you’d be fine.
I’m wondering what you all think of this setup. Will it be high enough, or is it perhaps too high? What do you think of setting the launch platform 7’ under the wire? It may be a bit hard kids to reach, hence the stool step, but I think it might be needed to stop adults from being unable to launch with the sag.
