A slick way to build an anchor from the rope
There are lots of ways to build an anchor with just the climbing rope. You could use a bowline on a bight, or a “bunny ears” figure 8, as discussed in this post. Either of these gives decent load distribution, but they do require that you learn new knots that some people find a little tricky.
Here’s a slick method to make an anchor with the climbing rope that simply uses clove hitches and a butterfly or overhand knot, which you hopefully already know. (If not, check out the video section.)
One good reason for using the climbing rope as your anchor: if the climbing is tough and run out right off of the anchor, and thus a greater chance for a leader fall to put a large amount of force onto the anchor and belay. Having the entire anchor made out of dynamic rope gives more stretch to the system and will lower the force on all the other components.
There are a few downsides to rope anchors:
It works best if you’re swinging leads on a multipitch climb. If one person is doing all the leading, or if this is the last anchor at the top of a climb and you’re transitioning to rappel, it’s better to craft an anchor from a sling or cordelette so you have both ends of the rope to work with. (Even if you plan on swinging leads, your partner might decide they don't want to take their turn and you might have to go again, so keep that in mind.)
If the next pitch is a real rope stretcher and you might need every bit of it, this may not be the best choice.
When the leader pulls up the rope on the second, the rope pull come tight first onto the anchor and not directly onto the second climber. This can create a few meters of potentially unwanted slack when the second breaks down the anchor. The second can clip in to one bolt or piece of solid gear with a tether before they remove the anchor as a possible solution.
Rope anchors can make any sort of self rescue technique more challenging, because the end of the rope is a component of the anchor. Yes the belayer can can simply untie and they're out of the system, but then they’ll have a harder time using the rope for much of anything useful.
Say you’re leading, and arrive at a two bolt belay anchor. Here’s what you do.
Clove hitch the rope (that’s tied to your harness) to a bolt with a locker. Clip a second locker onto the second bolt.
Maybe 6-8 inches inches on the “backside” of this clove hitch, tie a bight knot. Here I tied a butterfly knot, but it could be an overhand or figure 8 on a bight.
Next, clove hitch the rope to the second bolt. Adjust the clove as needed to center the loop.
Clip a plaquette style belay device to the butterfly, and bring up your partner.
Done! You’re connected to both bolts, and you have an equalized master point. You hopefully set this up in under one minute, and used a minimum amount of gear.
