I’ve come up with a technique for using a Rap Ring as a line locker. I am not sure if this is an original idea, but I thought of it on my own, and I don’t recall seeing this on any other Slackline pages. That doesn’t mean it is my idea, of course!
[EDIT: browsing Adam’s website a second time revealed his method for making the fixed-end anchor with one carabiner and two rap rings.]
Basically, my method is what I call a double line locker, or a double-bight line locker. Not sure how it should correctly be called. I came up with this method to save myself a carabiner when anchoring the “fixed” end of a primitive Slackline. I wanted to anchor a second line, and wondered if I had enough equipment to do so without buying more carabiners. The trick was to prevent tri-loading, without using a carabiner (see my post on eliminating tri-loading here). Below is a picture of the final rigged line with the new technique. Further down the page I describe how to create this anchor point.
In the picture above, we see the yellow Slackline, and a purple anchor coming from around a tree. This solution uses two Rap Rings and one carabiner, whereas my previous posts and videos use two Rap Rings and two carabiners at the fixed end of the line. This is a somewhat significant cost savings – mostly because I buy the $11 carabiners, while Rap Rings are under $5. The purple anchor line is wrapped around the tree/tree-protection. There are no other carabiners or equipment. Only the requisite water knot.
[Edit: after reading this post, you may be interested in a similar method that eliminates the water knot in the anchor.]
The next few pictures show the steps to assemble the Rap Ring to the anchor once the anchor has been passed around the tree (or other stationary object).
Start with an anchor.
Now, we basically have a bight. Of course this is really two bights, one inside the other, but the principle works the same now as when installing a line locker in the usual fashion. Slip the ends through a Rap Ring.
One thing I have figured out is that as the line wraps around the tree, it is vertical. Once it comes to the dual-bight line locker, it needs to go back to horizontal (because we want the Slackline to be horizontal). I have noticed the line stays very flat, and the one-quarter turn twist resulting from the mismatch in horizontal and vertical is not a big deal. You can reduce it by carefully determining the best way to route the anchor pieces before sending them into the Rap Ring. If you eliminate all twists, the line will lay quite flat when everything is tightened.
I’ve used this setup successfully on my 50′ primitive line.
Another place I’ve found this useful is on my wife’s 50′ line that has loops sewn at the ends. On her line, we use a slip-knot around a tree. This makes it quite difficult to get the Slackline flat because of the way the slip knot works. I’ve been using an anchor at the fixed end instead of the slip-knot setup. This helps keep her line very flat.
Here is a picture:
Have you seen or used this setup before?
What are your thoughts on it?