I've been slacklining since about April of 2006, and I've been wanting to get into highlining ever since then. Hopefully I'll have the time and the opportunity in the near future. While pondering the physics involved in highline rigging, I started to work out some equations for the forces that a slackline places on its anchors, first in simple cases, then in more complicated ones. One thing led to another, and before I knew it, I had written a 22-page paper on the subject. It's probably wildly inaccurate, but I can at least be pretty certain that the mathematics is correct. Some of the formulas that I derived in the end were surprisingly elegant (that's the only reason that I went so far with it), and a few of the conclusions that I came to were a bit surprising.

Based on the results of that paper, I have written a little slackline calculator script to allow people to estimate the tensions in a slackline and the various forces that might arise in a leash fall on a highline. This is a rewrite of the original calculator script that I made a few years ago. It uses javascript for a more friendly user interface (and hence does all the calculations on your browser, rather than on my server). If it doesn't work for you (probably because my knowledge of non-mozilla-friendly javascript is quite lacking) then you can use this version instead, which uses a server-side script instead of javascript. Or you can use the old calculator, the original one I wrote in 2006.

**DISCLAIMER: I do not claim that the results of this paper or this
calculator are accurate or relevant to any real-world scenario. They are based
on an assumption that may very well be flagrantly incorrect. If you use these
calculations for anything, you do so at your own risk.**