Light Weight Tensioning Systems
Next we’ll discuss how to increase the mechanical advantage of your Ellington/primitive system by using webbing pulleys or additional carabiners. This is a common method used by people who may not be able to bring their lines to tension using the standard primitive method. You’ll need a few extra carabiners but the gains can be worth it.
Once the basic primitive system is built 2 additional carabiners (or webbing pulleys) are needed. One is used as a redirect and the other as a multiplier. Connect the redirect carabiner to the anchor sling in a similar manner as the one used for the primitive (you can also build a separate redirect anchor to increase your throw). The second carabiner is then tied to the tail end of the webbing as close as possible to where it comes out of the front carabiner of the primitive. Tie the carabiner to the webbing using a releasable hitch. You can then thread the tail end of the webbing through the redirect carabiner then through the multiplier carabiner. Once set up your pulling power is multiplied significantly. You can even add a ring grab (discussed in a previous article) to save your hands from pulling on the webbing.
It’s worth noting that the primitive system can be built up by using more carabiners and redirects on the tensioning webbing, let your inner rigging tinkerer run rampant. This method though, is not recommended for high tension slacklines, tricklines or use with very low stretch webbing. Primitives are still limited by the hardware used and bend radius of the webbing at the linelock.
This is a method developed by Thomas Buckingham that builds a mechanical advantage system within the standard banana style weblock. It requires a LineGrip, at least one webbing pulley or carabiner and the loose tail of the webbing. Simply attach the carabiner to the rear attachment hole of the LineGrip then attach the LineGrip to the loose slackline. Use the tail coming out of the weblock and attach it through the carabiner on the LineGrip. That’s all that’s needed. You can pull slack through the weblock and tension you slackline with this simple method. With a small rigging plate and a total of three carabiners (or webbing pulleys) this system can be expanded to a 5:1 MA.
These techniques allow you to go lightweight and play around with gear you might already have. There are many ways to add MA to your system. You could even pull on your primitive with a ratchet if you wanted. As long as you keep the WLL in mind and think about the forces you’re applying, there’s no limit to tinkering. Just be sure to step on the slackline every so often…