Debunking anchor/climbing myths, Part 2
Here's something to consider when talking about climbing techniques - Consider using the words “never” and “always” with restraint.
Let's have a look at some long-running misunderstandings, myths, and hearsay. Maybe we can put some of these well meaning but perhaps misinformed ideas to rest.
“I saw the DMM video where they broke Dyneema knotted runners in drop tests. So, you should NEVER tie a knot in Dyneema; it weakens the material to a dangerous level.”
Wowzer, this one can really get people riled up on the interwebs! Opinions range from “Yer Gonna Die (YGD)”, to “Generally not best practice, but it’s probably okay”, to “No worries, not a factor in real world climbing.” Might the truth be somewhere in the middle?
Here’s my short answer: Yes, it does weaken the webbing, depending on the knot, let's say 50%. But, a sewn Dyneema runner is rated to about 22 kN, so even if you reduce the strength of that half, you still have a strength of around 11 kN. The maximum force possible in any real world climbing scenario is about 9kN, and that is in the extremely rare scenario of a very harsh factor 2 fall. Even when catching a factor 1 fall, the force on the anchor is only about 2 kN.
The technical documentation on Dyneema slings from Black Diamond and Petzl does not expressly forbid knots in Dyneema. Black Diamond mentions it as a “caution”. But they also mention as a “caution” getting water, ice, or mud on your slings, which we know is hardly the end of the world. (Plus, they also have the same caution warning on a nylon sling, so it's not just a Dyneema thing.)
Thus, the diminished strength that comes from the knot doesn't really matter in real world climbing scenarios. Yes, it can break in a drop test. No, it doesn’t break in real life. Think of it this way: tens of thousands of climbers have tied knots in Dyneema for decades, but have you ever heard of a knotted sling breaking in real life? No.
Here's another way to think about: 11 kN is as strong or stronger than any gear placement, stronger than the force a dynamic rope will create, and more than your body can handle.
Many IFMGA certified guides use and teach this technique regularly.
Having said that, if you don't like it, then don't do it. But, no need to criticize others if they choose to tie knots in Dyneema.
Below: Quad anchor tied with overhand knots in Dyneema webbing (photo and anchor by Dale Remsberg, an IFMGA Certified Guide and Technical Director of the American Mountain Guides Association (AMGA).
“You should NEVER connect your tether/PAS to your belay loop. Todd Skinner did that, his belay loop broke, and he died. So, you shouldn't do it either.”
or maybe:
“You should ALWAYS run soft goods, like rope and slings, through the tie in points, and clip hard goods, like carabiners, to the belay loop.”
When ascending a route, it's usually best practice to use the rope and clove hitch yourself to the anchor. But when it's time to rappel, you're probably going to want a tether. Whether you use a designated tether like a PAS or a Petzl Connect, or make one DIY with a double length sling, you need to choose how to connect it to your harness.
There are some cases when attaching your tether directly to your belay loop is not only acceptable, but the recommended practice. There are some other situations where it's probably not such a great idea.
What activity are you doing?
What does the manufacturer say?
What’s your tether made of?
What kind of knot or hitch connects the tether to your harness?
These are all nuances in technique that need to be considered, rather than a binary “always” or “never.”
Here are some general guidelines:
Regarding Todd Skinner's tragic death, he apparently was rappelling fast on static ropes. The bottom of the rope was tied to the lower anchor (the “J loop”). Todd rapped into the bottom of the loop at speed, and when he hit the bottom of the loop, this large static force caused his harness to fail. It did not happen under a standard body weight rappel. (Source: Andy Kirkpatrick, “Higher Education”, page 182., and private Instagram message from Will Gadd.) Todd's harness was extremely old and worn out. Check your harness regularly and retire it without hesitation if it shows significant wear for any reason.
If you do connect a tether to your belay loop, don’t leave it permanently connected. Doing this can prevent the loop from rotating and may concentrate wear in a single spot. Remove the tether when you're done for the day, or after your rappel.
If you're girth hitching a designated PAS type tether, the usual manufacturer recommendation is to use both tie in points. (Even then it's a bit of a “soft” recommendation.)
If you're girth hitching a “DIY” tether with a skinny Dyneema sling, it’s probably best to use both tie in points. (Plus some people think it’s best not to use a static Dyneema sling as a tether at all.)
If you're girth hitching a tether (or adjustable daisy for aid climbing) with a wider nylon sling, either the tie in points or the belay loop should be fine.
If you're using a rope style lanyard such as the Petzl Connect Adjust, follow Petzl’s recommendation and girth hitch it to your belay loop.
If you’re doing via ferrata, the standard practice is to girth hitch the lanyards to your belay loop.
Many world class climbers and IFMGA Certified Guides prefer to use the belay loop.
And . . . if you're not using a girth hitch and using a double loop bowline tether, it's okay to tie it through your belay loop with any kind of material.
Again, to learn more about this, check out this detailed article.
“You should ALWAYS rappel off of sport climbing anchors. If you lower off, it wears out the anchor hardware.”
Many older climbers were brought up with this ethic. However, the modern approach to getting the last climber down from a sport anchor is to lower through the anchor hardware. Why?
Most modern hardware is designed to be easily replaced
Lowering can reduce communication errors between the climber and the belayer
The climber never goes off belay
There’s less chance of dropping the rope
You don't need any extra gear like a leash or a rappel device
Most of all, it’s the recommended practice from the American Alpine Club. You can see an entire article about it here.
Note, this only applies to the LAST climber. Generally, the first climber should build an anchor with their own gear, and lower of that. This is especially true if you are a top roping with a larger group or doing multiple laps.
And yes, some climbing areas have a local ethic of always rappelling for the last person. If you’re climbing somewhere new, ask about preferred technique. It's up to you to choose between getting a stinkeye from the locals and using modern best practices.
General procedure of what's going on below: 1) Climber pulls a bight of rope and threads it through the anchor chains. 2) Climb a ties a figure 8 loop and clips it to her belay loop with a locker. 3,4) Climber then unties her tie in knot and pulls the tail through the chains. 5,6) After clear communication with the belayer, climber calls for a lower. Note, she stays on belay the entire time. Diagram, Petzl.com
“You should NEVER load a carabiner in 3 or more directions; doing so weakens it dangerously.”
Hopefully you learn early on in your climbing that whenever possible you should load a carabiner along the spine, and always avoid cross loading across the gate, which can reduce the strength of the carabiner by about 2/3. Good advice, always do this when you can.
But, there are some other situations where a carabiner can be loaded in three or even four directions, such as in the photo below. What's the story on that? Is it dangerous?
Turns out, for recreational climbers, this is probably fine. Black Diamond did some break testing on this, and even under extreme loading in four directions (known as quad-axial loading) , the carabiner only lost a maximum of about 25% strength, down to around 15 kN.
Setting up an anchor as shown in the photo below to belay your second, where the maximum force is probably going to be at most 3 kN, is acceptable. Again, you don't have to do it yourself, but if you see someone else rigging it like this, know that it's well within the breaking limit of the equipment. (And, loading in three directions, known as tri-axial loading, showed hardly any reduction in strength in the carabiner.)
We cover this extensively and share the Black Diamond results in this article.
“When you tie into your harness, you should ALWAYS tie a ‘safety knot’ to backup your rewoven figure 8 knot.”
A “backup” knot is unnecessary. This myth is further propagated by many rock gyms (and maybe their overzealous lawyers?) who require this practice. A proper rewoven figure 8 has a good long tail of at least 6 inches, and has been properly “dressed and stressed”, so all the slack is pulled out of it. Once you do these two things, there's no need for a so-called safety knot, backup knot, or anything like that.
Rewoven figure 8, good to go, no backup knot. (Okay nitpickers, the tail could be a few inches shorter . . .)