Rigging a Two-Bolt Anchor
Perhaps the most common rigging set-up in high-traffic canyons, such as you'll find in the Zion area, the following is the "Standard Rigging" for a two-bolt anchor. EQUALIZED, TIED OFF RIGGING FOR TWO BOLTS
Equalizing Two Bolts, A
This rigging, as shown, requires about 8 feet of webbing (2-1/2 meters).
[A]. Pass one end through one bolt hanger, through the ring, then through the other bolt hanger.
Equalizing Two Bolts, B
[B]. Pass the other end through the ring, and join with the first end using a Water Knot. Tighten.
Equalizing Two Bolts, C
[C]. Pull down on the Ring while feeding webbing through the bolt hangers.
(In this example, I have placed the tail of the knot on the inside of one of the bolt hangers, where it will protect the primary webbing from cutting across the sharp edge of the bolt hanger).
Equalizing Two Bolts, D
[D]. Point the ring in the direction of the rappel. With careful pointing, the load on the anchor will be equalized between the two bolts, each having pretty close to half the weight.
Equalizing Two Bolts, E
[E]. Taking the four strands neatly, tie an Overhand in the doubled Bight. Tighten neatly.
This is the TIED OFF part. By Tying Off, we prevent EXTENSION should one of the anchors fail.
Uses:
A standard tie-off for two-bolt anchors.
Comments:
- When tied neatly, this form looks so "finished" that even the most diligent of beginners are likely to leave it alone.
- Webbing can cut on the sharp edges of bolt hangers. Be sure to inspect the webbing where it passes through the hangers. For high-traffic canyons, it is best to use a Rapide between the sharp bolt hanger and the webbing.
- Glue-in Bolt Hangers tend to have a rounded surface that is webbing-friendly.
Equalizing Two Bolts, Finished
EQUALIZED, TIED OFF RIGGING FOR TWO BOLTS, USING LESS WEBBING.
Two Bolt Rigging with Less Webbing, A
The standard rigging above is good, but it does require quite a bit of webbing. Here is a method to achieve much the same result, but using only 5 feet of webbing (1-1/2 meters).
[A]. Tie one end of the webbing to one bolt hanger, using an Overhand on a Bight via Rethread.
Two Bolt Rigging with Less Webbing, B
[B]. Thread the ring on the "other" end, and tie the "other" end to the other bolt hanger, using an Overhand on a Bight via Rethread.
Two Bolt Rigging with Less Webbing, Finished
[C]. Point the bottom and ring in the direction of the rappel, and tie off with an Overhand on a Bight.
Uses: Similar to the Standard Two-Bolt Tie-Off, but uses less webbing - OR, extends the rappel point further using the same webbing.