mechanical knot

ward

ward

Participating member
Location
Unincorporated Clackamas, OR
SRT techniques rely strongly upon a fixed rope. This presents problems: the basal anchor limits the ability of a single climber to reposition and there are a host of other concerns (competent ground crew, etc) that make the basal tie off in many cases sub par. A retrievable system is desirable and there are a plethora of them.

From what I can tell, almost all of these retrievable systems incorporate a big fat knot somewhere along the chain. This is undesirable because, upon removal of the system, the knot might get stuck in a crotch! There is therefore a need for a mechanical knot that can work with existing ring on ring friction saver design. I am astounded that such a product doesn't already exist.

I have attached a sketch of my own "Eichel", an instance of the kind. Please weigh in. Why doesn't this device exist already? Am I missing something?
 

Attachments

  • 360323-eichel.webp
    360323-eichel.webp
    36.7 KB · Views: 348
Thanks Bonner. Yeah, kind of like that, but what I'm thinking of would need to be installed easily midline in tree without tools, just by hand. And it would need to be load rated...difficult, but not insurmountable requirements to implement.
 
Its not the attachment thats the issue, its the 'holding' process. Are you pinching, camming, bunching the line? Whats the effect on the cordage, what type of rope will work on, etc...
 
This is where I sense my limits. I don't know what would work best--or safest--or even at all. A lot of r and d would be needed--the kind of thing that a big manufacturer could offer.

I think some kind of camming mechanism would have to be incorporated--like in an ascender. Probably have to be strictly limited to certain kinds of rope, e.g. 16 or 24 strand.
 
What you list as shortcomings or limitations of srt are, to me, nothing more than part of the solution.

If you're setting up a choked psp part of the solution is retrievability or haul back. Using a looped knot shouldn't lead to jamming during haul back unless the climber doesn't have good awareness of their setup. If jams happen too often then maybe the awareness of the climber needs to be considered not srt. This would tell me that the climber is spacing out and not paying attention. What else aren't they paying attention to?

Please don't take this as a critique or confrontation.

I am so impressed with the new thinking that's going into advancing srt. Since so many climbers are adding/converting to srt more minds are working.

I'm looking at your sketch on my phone and I can't quite figure out what you're thinking. When I get my laptop up I'll look closer.

It seems like you're trying to find a streamlined/tapered device to make an eye in the rope. Rather than a cam take a look at how the biner slides in the angled slots of the cheek plates of the Hitch Hiker. Another mechanism that comes to mind is the wire bale that the phone company uses to hand the line from the soffitt, go out and look at the double taper device.
 
Your comments are much appreciated, Tom. Thank you for them. Yes, the picture is hand-drawn and merely suggestive--it does not qualify as having solved this problem. I originally envisioned this as working by the piece being split in two and brought together on the rope by a binding ring. On the drawing those 2 funky rings are the meant to show the friction saver in cross section, with the piece wedged in there and the backward facing teeth.

As for the desirability of a small mechanical stopper knot as a way to go, I can only point out how difficult some situations are to retrieve your line even from a ddrt on a friction saver! It would seem that with the large butterfly knots, etc., that people are most often using, that they may wish to "do better" for themselves.

I wanted to start the thread so that others could contribute their critique, ideas, etc. Keep it coming!

Tuttle, as for the Shunt idea, yes, but remember the head has to be like a bullet and can't have spare parts jangling about (like a shunt): but that kind of camming mechanism is what might work. Would you feel comfortable single lining off of a shunt?


I can't believe RopeShield hasn't been down this corridor before or Kevin B.?
 
I use a shunt and a grillon, the shunt has a pulley on it for a rads techinque.

I'll try and get my head around what your trying to do, need a bit more info on using a cambium saver on srt, i just choke mine and attach a throwline for retrieval (if needed), that said...its never needed as I only ever do dismantles.
 
I believe a custom made collet may work,as long as the clamping force was spread over a rather long portion of the rope.
 
I am having a little trouble understanding what the advantage would be. Currently I choke almost every PSP that I use and when I pull my rope the knot is always coming down a clean line, I have never laid my retrieval end over a crotch. Also if you are concerned about the knot pulling through a crotch on the retrieval, then what about the friction saver that is going to be dragging behind it?
 
The Pinto cinch works brilliantly and had no knot running through a crouch at all, there I nothing to get stuck. I wouldn't use a shunt.
 
[ QUOTE ]
The Pinto cinch works brilliantly and had no knot running through a crouch at all, there I nothing to get stuck. I wouldn't use a shunt.

[/ QUOTE ]

my shunt is only to hold the pulley for rads, my grillon is whats holding me.

shunt on its own would be risky, but its a great add on and easy on the rope unlike hand ascenders.
 
I've never had an issue with my double fig8 setup getting stuck, Like Tom said climbing SRT you have to be more aware of what you are doing and plan your climb much more than Ddrt
 
I use the ring/ring FS jammed with a knot. I'm usually installing it by hand once I ascend anyways, so it's as simple as making sure the retrieval end has a clear path. I usually retrieve with a throwline anyway. I'm after simplicity anyways.
 
You must log in or register to reply here.

New threads New posts

Back
Top Bottom