Sunday, March 10, 2013

Anchoring Class

I just finished my anchoring class yesterday with Greg and Nick from Outback Adventures and it was a really great class. The class was at Cragmont Park in Berkeley which actually has a wall you can climb on considering it's such a small park. The class was about six hours but most of it was spent practicing different anchors. This is what we went through.

Webbing is strong and lightweight but not as versatile as rope. It looks like a good length to have is 20-30 feet. We were only taught two knots to use with webbing, water knot and overhand on a bight.

Water Knot
This knot is good for making a loop around an object or even a large loop for a girth hitch. It's basically an overhand knot and a retrace with the tail. First you need to determine how large of a loop you want and create the knot there then you use the tail and retrace the knot. The only tricky part is which end to retrace from. If you're making a loop with part of the webbing, retract from side of the tail. If you're making a loop with the entire webbing retrace from the other tail. I don't have a picture of what the bad water knot looks like but it's bad when the tails of the knot are touching. In this picture, the tails are on opposite sides.

Overhand on a bight
I couldn't find a picture of an overhand on a bight knot and I have no webbing to demonstrate. I'll need to get some eventually. A bight is simply just when you fold the rope or webbing in over itself. Then you take the whole thing and just make an overhand knot. Then that creates a loop at the end you can clip into.

It seems like the cordelette is best used by tying it into a loop with two fisherman's knot and then using that loop to make a figure 8 knot as an anchoring point.
I think that was the only thing we learned for the cordelette. This picture shows three anchors but you can also do the same thing with two. They also showed us a quick look at friction knots with a short, small diameter (4mm) cordelette, prussik and autoblock, but we never got a chance to practice those.

Static Rope
The instructors recommended getting a 40-45 feet static rope. It's good for tying around boulders, large trees, and generally any strong anchor points. The knots we learned were the tensionless hitch, double bowline with backup and BHK/BFK (Big Honkin' Knot/Big F***ing Knot).

Tensionless Hitch
This is basically a figure 8 on a bight wrapped around a tree three times and clipped into itself. It depends completely on friction and clipping into itself is just in case it slips. This knot is good to maintain the full strength of the rope because there are no sharp bends in the rope but it requires a lot of rope to use.

Double Bowline
This was the trickiest knot to tie. It makes a nice solid loop and is easy to untie after it's been loaded. Since it's so easy to untie it has a chance to slip so it's usually backed up with a fisherman's knot. The way we were taught was to do two loops around the left hand, up the back up of the hand, around the back of the long end and back down the same hole.

This knot is a nice strong knot for an anchor point. It also has a nice property of setting the carabiner perpendicular to the wall so the rope doesn't rub against the wall. To tie it, you pretty much do a bight twice in the middle of the rope, wherever you want your anchor to be, then tie an overhand in the middle of that last bight. You end up with two loops and an extra loop in the opposite direction that can all be clipped into one spot. This is very good as a top rope anchor with lots of redundancy.

These are usually made of nylon, but there are light weight material called Dyneema or Spectra. They told us that Dyneema and Spectra loses a lot of strength when tied so I'm not sure when those are good to use, I'm guessing when used in a girth hitch. One surprising thing is that these slings are rated for 22kN, which is about 4945 lbs, so one of those little things can hold up a car?

Girth Hitch
A girth hitch is just a loop around itself. Very simple and good around small diameter objects. This photo I found shows a bend though which is not ideal. Ideally you would want to keep it straight since bends weaken the material.

Slings can also be hooked to anchors and tied in a figure 8 just like the cordelette. 

Sliding X or Magic X
One cool thing you can do with slings is to tie a sliding X which is a self equalizing anchor since it lets the master point slide around. The problem with the sliding X is that if an anchor fails, the system will extend which will cause shock loading. This can be minimized by tying limiter knots (just use an overhand knot) near the master point. Another problem is that there is no redundancy in the material. If the sling gets cut the whole anchor fails so using two slings would add some redundancy. The sliding X is super easy to make and requires no tying, but it looks like it can be easily done wrong which can be deadly, so it's probably a good idea to double check that.

Oval Shaped: These are the original carabiners which aren't as strong as D shaped carabiners but has more area for holding gear. 
D Shaped: These are shaped so that it directs the material towards the spine which increases the amount of weight these can hold. One thing the instructor mentioned was that if you hook two carabiners to one D carabiner, they'll kind of fight each other for that corner.
Pear Shaped: I'm not sure what these are good for but it looks like you can hang a lot of gear on the wide side and supposedly it's good for a belay device.

They showed us two ways the gates hook to the carabiner. One way they called it a key hook where the hooks are to the side. They say this is better because the rope doesn't get caught in the hooks like the other type which I think they called a fish hook where the hook faces in toward the carabiner. Other things to keep in mind are straight, bent, and wire gates. Straight gates are for standard applications, bent gates are good for clipping, and wire gates are good for its weight. Then for locking, you have screw locks and twist locks.

Anchoring Principles
A: Angle, make sure the angles between the legs of the anchors are small to reduce the force on each anchor point
S: Sound, Stable, Secure, make sure the anchor points are good
E: Equalized, make sure all the legs are holding equal weight
RE: Redundant, make sure there is redundancy in the system so if one point fails the whole system doesn't fail
NE: No elongation, make sure the system doesn't move when one point fails and cause shock loading to the system

ERNEST is the same thing but they added a T for time.

At the end of the lesson they showed us some trad gear, chocks and cams, and how each works but it was very brief just so we know what they were.

So that's what I learned from anchoring class. There was a lot of other information but these were the important stuff. Greg and Nick were really awesome and I would highly recommend them for a class if you're in the Bay Area. Here's the website for their classes:
I might take the lead climbing and self rescue class some time in the future. But first, I'll need to do some more outdoor rock climbing. I did do some climbing at Cragmont Park after the class but I'll save that for another post.

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