You still get a shock load with a limiter knot. You are just decreasing that force due to acceleration (gravity) by making the path shorter. F=ma (force =mass x acceleration). Acceleration = change in velocity/time. If you limit the time the acceleration is lessened, hence the force is less.
@@timdolinger1352 Shock loads can cause pieces to pull out of cracks or cause rigging to fail especially with static cord like dyneema/spectra runners. DMM did a whole review on this. Bob Gaines and John Long discuss it in their book on climbing anchors too. A well worth read. FYI, th-cam.com/video/Vrgadjo9niY/w-d-xo.html
Up to 50% or more loss in strength actually. After watching these videos my plan is to build sport anchors with 2 slings with sliding X knots (without limiting knots). It's only a little more gear and some peace of mind redundancy. If an anchor blows you'll have a bit more shock load as he mentioned but will have two full strength slings, which should more than make up for it.
Another thing to keep in mind: if your first anchor does fail, it'll still absorb quite a bit of energy, so the second anchor won't have take all of it
That was one of the clearest rock climbing instructional videos I've seen. Thanks.
You guys are brilliant. I watch hundreds of climbing technique videos and yours are so straightforward. Much recommended. Cheers, Cam
Another great tutorial.
Could you possibly do one on anchors using say a tree. Like an improvised anchor. Thanks
Consider it added to the list, it is an area that we want to naturally progress to, but for you Kris, we will speed it up!
You still get a shock load with a limiter knot. You are just decreasing that force due to acceleration (gravity) by making the path shorter. F=ma (force =mass x acceleration). Acceleration = change in velocity/time. If you limit the time the acceleration is lessened, hence the force is less.
Did you do the math or did you test this yourself?
Do shock loads matter? I mean, should they matter in the grand scheme of things?
@@timdolinger1352 Shock loads can cause pieces to pull out of cracks or cause rigging to fail especially with static cord like dyneema/spectra runners. DMM did a whole review on this. Bob Gaines and John Long discuss it in their book on climbing anchors too. A well worth read. FYI, th-cam.com/video/Vrgadjo9niY/w-d-xo.html
Thats help a lot, thanks so much
Excellent explanation
Are there any advantages to using a sliding-X with limiter knots instead of a quad?
My guess would be that the sliding x uses about half the cord? Both perform similarly from what I have seen so mostly preference?
Can you use a figure 8 as a limiter knot in this Sliding X?
yes, and it is easier to undo a figure 8 knot after top roping
So, limiter knots shorten the fall distance by a couple of inches. That's good, but they also drastically weaken the rope
Good thing you're not tied into a single rope/point of failure with a figure 8 knot. Oh wait...
Up to 50% or more loss in strength actually. After watching these videos my plan is to build sport anchors with 2 slings with sliding X knots (without limiting knots). It's only a little more gear and some peace of mind redundancy. If an anchor blows you'll have a bit more shock load as he mentioned but will have two full strength slings, which should more than make up for it.
Another thing to keep in mind: if your first anchor does fail, it'll still absorb quite a bit of energy, so the second anchor won't have take all of it
this can be built with 10000 arms if desired. Why do you say "only 2 arms"?
Just keep in mind everytime you tie a knot it is a potential weak spot.
i just watched a hownot2 video and their tests demonstrated a 50% reduction in strength due to knots.
This anchor seems a little TOO dynamic.