G
gadgetgeek
,
I salute your knowledge and your openness to get into this kind of details with me here. This is actually the main purpose why I posted this onto the forum here: trying to see if other people, potentially more knowledgeable than me in some areas, can bring in additional ideas.
I fully got the thing with the prussics now.
I guess by "VTs" you mean Valdotain Tresse hitches. You are probably specialised as a rock climber (please correct me if I'm wrong). The VT is a controversial hitch even since François Dussenne introduced it during the early 90's. It is more popular within the tree climbing community, than in rock climbing. There are a few variants (including one with a pulley in its setup, designed to reduce the risk of locking). It's not a hitch for everyday use, being more complicated than prussics. Its biggest downside is that sometimes it locks so hard, that you need to completely release pressure out of it and work with two hands to unlock it. That's why some people called it "the suicide hitch". But this hitch is that magic thing that saves your day if you ever have to do with slippery cord (e.g. teared too much, with frozen ice on it, wet or accidentally soaked in oils, etc.).
If by
"Klamheist style knots" you mean the Klemheist hitch described at
this link, yes, I have tried that cord with this hitch, as well as with all the other friction hitches that have ever reached onto the internet somewhere (Distel, Purcel, Icicle, Blake's, etc., etc., etc.). They all slipped under my weight, onto that paracord. Even the Rat Tail Stopper slides, when you try to attach yourself to a paracord strand using 2 mm dyneema as secondary cord. And once the slide starts, the paracord outer sheath melts after just 3 cm of slippage. The Valdotain Tresse is the only one that works - and it works in this setup only if crossed around 7 times or more. That is why I cross it 9 times (7 as the minimum + 2 for extra safety). If I go more than 9 times it becomes exponentially harder to unlock when I want to move it up or down on the main cord.
My legs loop uses a Dropper Loop Knot to join the two ends. You are right that it is a type of knot best suites for monofilament line. Actually that's the context in which I learned it many years back. It is more difficult to taighten it with a braided or abrasive cord. There is not much need for a special knot on the legs loop. A Double Fisherman's, or a Figure 8 bend would work as well, and probably also the Zeppelim Bend. I had choosen the Dropper Loop because it is less prominent onto the cord, and thus less prone to dig deep into my flesh if touching my leg when under tension.
I think you are correct with everything about the soft shackle. The point is that it is easy to do, easy to untie when you want, and in this application it doesn't untie accidentally, even though the tension is temporarily released repeatedly. And for strength, it is still stronger that the main cord (which is a single strand from the same type of cord), so connector is not the weak spot of the setup.
You notice correctly that the ratio between the main cord and the secondary is 1:2 here and it is less than ideal, but it is 1:2 just in theory. Paracord is advertised as 4 mm thick, but its inner strands are lose on the sheath and it is deformable when pressed. When under tension, it is less than 4 mm in diameter (I think it's just 3 or 3.5). So the ratio is even worse than it seems.
Yeah, there is no margin for mistakes. You need to be focused and careful when doing it.
You are asking why would one make climbing more dangerous than it already is. And why had I put this video into the public space. These are both valid questions. Let's start with the simpler one: I made this video and published it for 3 reasons:
1. To give a solution that works, for free, to other people who might be interested in this type of capability.
2. To gather feedback and ideas from the community, that could potentially improve my setup further.
3. To prove that it is possible. It is similar to the reason why olympic champions in sports like weight lifting still strive to achieve new records (even though it is already too difficult). It is a sort of useful for mankind to know where are the limits of the "impossible".
And now let's end with the other question: what is the usability or the value of this application (i.e. climbing on paracord):
1. Burglary and intrusion. When talking these two words, most people think of illegal activities. But it is not always the case. Imagine that you need to go ultralight into a mission where you have constraints to carry less than 5 Kg including the water and food, and you have to carry specific devices that already take most of that weight. What if part of your route to the target area requires a small elevation gap which needs cordage to be passed? Of course, you would normally prefer to carry a thin kevlar, spectra, or dyneema cord (dyneema being the favorite), instead of paracord. But that may raise suspicions, compared with some paracord, when carried in an area where paracors is typically carried and used for other purposes by everyone. Also, if your plan at the extraction point doesn't include cord, you may simply dispose the paracord immediately after using it to climb, and reuse it for other purposes. Talking about weight and volume constraints, imagine situations when I needed to travel to the insertion point with a public line airplane, carrying no more than a hand luggage in the typical 22 x 14 x 9 inches, which needed to include a lot of exchange clothes and gear, from which the cordage was just a little piece. Sometimes I needed to run up a mountain route, in a specific time window, and then abseil or climb up a portion of that route, which could not be passed otherwise. In such situations, carrying the standard 11 mm thick professional static cord was practically impossible, or could compromise other aspects of the mission if carried.
2. Disaster evasion. Remember those people at World Trade Center, who were jumping off the windows, looking for an easier death than being burned? What if you get caught like that in a building, or in a context where abseiling 2 or 3 floors lower brings you out of danger? And what if you only have some paracord at hand (because that is the most popular type of cord - which everyone carries for preparedness, even when they think they won't need a cord)?