Climbing Tips: Do This, Not That (Part 6)
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In this article:
Boost that low anchor with a pack
Traversing rappel? Pull to that side
Redirects increase anchor load when hauling
Tied webbing on a tree - skip the overhand knot
Grigri lower: Redirect the brake strand
1 - Got a low anchor? “Boost” it with a backpack
Got an anchor that’s pretty much flat on the ground? Ugh, that's not a very ergonomic position to belay from.
(A preposition is a bad thing to end a sentence with. =^)
Quick way to improve it: take a backpack and put it under the master point. This can add a bit of “lift” so you can more comfortably manage the belay.
2 - Traversing rappel? Pull to that side
If the anchor below you is off to one side, say the right, try to rig your rope so the “pull” strand is in that direction.
If you don't, the ropes can cross at the anchor and create a lot of extra friction.
image: From the book “down”, by Andy Kirkpatrick. Used with permission. andy-kirkpatrick.com
3 - Hauling systems: Redirects increase load on the anchor
Sometimes, redirecting your pull through the anchor with a hauling system can be convenient or ergonomic.
However, keep in mind that a redirect increases the force applied to the anchor.
If you have an anchor that you're not very thrilled about, like maybe a vertical picket in snow, this could be important.
In the diagram below, we have a 100 kg load with a 2:1 mechanical advantage haul system.
On the left: no redirect. When hauling, about 0.5x the pulling force goes onto the anchor.
On the right, redirect. When hauling, about 1.5x the pulling force goes onto the anchor. That’s a big difference!
This diagram was made with some cool software called vRigger. Learn more about it at this article.
(In the diagram on the right, you can ignore the green prusik that's randomly attached to the rope. That should be clipped to the red carabiner at the top, sorry about that.)
If you tie a strand of cord or webbing around a tree for an anchor, why can you skip a masterpoint knot?
Why is redirecting the brake strand a critical step if you're lowering someone with Grigri?
