Self tending climbing system

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The friction knot is sliding at will. They way we ended up setting up the single bridge was by splicing a plastic thimble roughly 5" from the top of the single bridge. This way you could anchor in and then attach your friction knot via the thimble to the single bridge. In doing this the friction knot and anchor knot were too close to function seperately and the the friction knot often would slide down whenever it wanted to. (usually not when you wanted it to) Because these experiments weren't proving fruitful we pretty much abandoned the idea.

If you have an idea on how this could work better (single bridge) let me know. I will do my best to splice up something for ya to match your description.

thanks again for the input Whitinsville.

rich
 
Rich,

Sorry to beat the dead horse, but I think you misunderstood my question. Did you see my attachment?

I'm not questioning why you have two bridges, but rather, why the two bridges are also two separate pieces of line? If my illustration were more accurate, it would have a very small "eye" at the end, formed by the spliced-in piece of line. That eye would be just large enough for the two pieces of line to go through. This way, you would girth hitch one long piece of line to one attachment point on your harness. You would still have two bridges, but they would be one piece of line. The only purpose served by the spliced-in section is to keep the bridges from shifting from one side to the other (lengthening one while shortening the other).

In the end, I suppose there would be little gain over this approach; I just though it might be simpler (fewer "pieces") and quicker to attach (one girth hitch vice two).

Again, I appologize if I'm beating our collective head against the wall. Thanks for your gracious responses!

Shayne
 
Shayne,

Sorry man, I misunderstood what you where getting at. I see what you are saying now and in response I would say that I am not sure why you couldn't just use one piece to save on multiple girth hitches.

I will give it a try and get back to you.
Thanks again for the input.

Rich
 
I don't know about the single cord method. It seems the girth hitch maintains as much of its strength as it does by distributing the load over both of its "legs". If you were to use both ends of the proposed single hitch, I'd think that not only would it want to variably shift (I know that aspect was addressed) but that it would also provide a measurable loss of strength within the whole system. Probably not enough to make it questionable in and of itself, but why take chances? The two separate girth hitches shouldn't take twice as long to form as the more complicated single one, and what are we talking about, maybe 30 seconds?

As for creative input on my part, I was kicking around the thought of doing away with the longer cord entirely by replacing it with a short piece of throw line and affixing the static end of the climbing line directly to the saddle as usual. Try to follow along:

Form a short loop of throw line which contains the ring you've otherwise got spliced into the longer cord. Make the loop just long enough to easily form a prussic around the static end of the climbing line at your desired position. The smaller the ring, the tidier the hitch (I realize you're trying to minimize "floppiness" in the system or you would have merely clipped the leash clip to the 'biner instead of splicing the ring into the cord).

You could stow the short loop attached to the leash clip.
 
Glens,

That is not a bad idea and would certainly be a less exensive way to achieve similar results. I guess the idea of the longer bridge was mainly an attempt to relieve some of the clutter at the connections points on your harness.

As well, the longer bridge would reduce the chance of you knicking the section of your climbing line that usually takes the most abuse. (nick arayas idea there)
The thought being that it is cheaper to replace the longer anchor bridge than it would be to replace the splice on your climbing line. (not that any of us ever knick our ropes 3 inches above the splice the first time we climb on a new line)
Another feature could be to make the bridges out of Amsteel or something that may hold up better to hand saw cuts and if possible chain saw cuts. (ok I am dreaming now lol)

I am pretty dang sure your system will work great Glens. May be a good way for everyone to try this out as home as well. You can always substitute some Nylon webbing for the short bridge. This will give you a good feel for what the system can achieve.
 
Crerative thinking Rich. In addition to the benefits that you listed, the climber can also self belay when spurring a pole or when climbing branch to branch up the tree.

I think that Todd had a good description--this is basically an extendable bridge. Tom D. has likened it to a quick draw used in rock climbing.

Replacing the longer bridge with a small loop of cord as glens describes works well. Rather than the brass ring, however, use a key chain carabiner. The brass snap on the micro pulley can be eliminated, and the micro pulley can be attached directly to the carabiner as it would be for normal use.

In the 'long' (extended) mode, the key chain 'biner is clipped to the small Prusik loop and under the micro pulley (I haven't tried clipping it to the 'biner as glens suggested). This advances the micro pulley and thus the climbing hitch. The prusik loop allows infinite adjustability for different split tails and bridges.

In the 'short' mode the key chain 'biner is unclipped from under the micro pulley and clipped to the static side of the climbing line. This will keep the Prusik loop from coming off of the line. When the climbing carabiner on the end of the short bridge (the extended bridge/quick draw) is clipped to the saddle, the micro pulley and climbing hitch will function as they normally do.

--ONE WORD OF CAUTION--

A high maintenance hitch--one that does not always and consistently regrab the climbing line after the hitch has been advanced--should NOT be used. Rich mentioned this before, but I think it should be emphasized that the hitch needs to grab the climbing line consistently and securely each and every time that it is advanced.
 
Thanks Mahk, Glens, Shayne and everyone else who has put some good thought into perfecting this thing. My guess is that within a month we will all have a dependable system that can help make our lives a bit easier. Another side benefit to leaving the static side alone would be in being able to tie in normally throught a friction saver at the top of a tree. (instead of having to clip the long bridge in short)

Either way you use it another benefit is the fact that you can use this to self belay while you are practicing for the belayed speed climb. Once you get to the top you can just bring the hitch low and descend.

I think the idea of using a prusik with ring ( or keychain biner) to tend the climbing knot was actually brought up a long time ago but not with the use of an extension on the knot side.

I think I will try both systems (long bridge vs. prusik on static side) for a bit and try to see if there is any difference in performance.

Thanks again for all the input everyone.

Rich
 
[ QUOTE ]
I think the idea of using a prusik with ring ( or keychain biner) to tend the climbing knot was actually brought up a long time ago but not with the use of an extension on the knot side.


[/ QUOTE ]

I don't mean to dampen your creative thinking, but I also think that other people's creative thinking should be credited as well.

The system of an extendable bridge (or quick draw as Tom has called it) with an adjustable Prusik for the slack tender has been around for some time and in many variations. Throw line, starter cord, and shoe laces have all been used for the Prusik, and Bishop company even sold a 'kit' that basically consisted of a loop of string, a small carabiner, and a micro pulley.

One extendable bridge system uses an open climbing hitch that is tied with a long bridge (and which has to be retied to shorten the bridge). In another variation the climber ties the eye end of the climbing line to the 'biner with a Buntline, and leaves a long tail which serves as the extension/quickdraw, and a third variation uses an eye and eye split tail with two small eyes (instead of the girth hitch that you use).

There are also various types of sliding bridges that have been published and/or discussed in these forums.

Again, I don't want to discourage invention and new ideas; I'm just adding some of the things that have appeared in the past.
 
Mahk,

Have you climbed on any of those other systems? And if so what where some of the benefits/disadvantages associated with them? I seem to recall trying the sliding bridge system for awhile but eventually giving it up due to some reason or another. Might not be a bad idea to go back through some of those ideas to see if a little mix and match would provide the best solution.

Pretty sure I have the last 12 years worth of TCI magazine somewhere, but in the event that I can't find some of them a little help would be nice.
 
Greg,

[ QUOTE ]
I guess I'm not quite getting this either. how far is your Vt from you when extended ? and if extended can you move up and down so to speak or just up ?

Greg

[/ QUOTE ]


The basic idea is that you would extend the system if you want to ascend the line. (whether hip thrust or foot lock) Once you are done ascent (next limb, or 50' up doesnt matter) you would shorten the system to have precise control of knot.

When extended your short bridge is basically at a length allows you to just barely get your hand over the knot. This is done so that in an emergency you could come down in extended mode. But it is better to stand on a limb, safety in, and shorten the system to descend or work the tree.
 
ok , thats what I thought. This is a sytem I have used for self belay for quiet some years , just set up a tad different.

I'll try and take a pic of it some time and put it on your thread. it's a little less complicated but , maybe not as fool proof as yours. As a matter of fact , I used it today to enter a tree for practice on a areial rescue.

Thanks
Greg
 
I would first like to compliment you on this climbing idea. I set up the system, and it worked great, especially for a few girls on our crew who have more lower body strength than upper. In reference to connecting the knot portion to the harness, I found that leather corner straps do a great job of holding the bridge in the carabiner. It makes the whole process of shortening the bridge a lot less scary. I also found that the bridge with the brass ring falls slack and all to weight in on the one bridge. Should both bridges have to be just the right length? Again...when the tie in point was reached I found it was best to take the longer bridge with the ring and attach it to the saddle as well. This worked fine, but it seemed that if you were really crawlin' around up there, your knees might get caught in one of the bridges. All in all though... I thought it worked great, and we didn't have any trouble with the knot not catching.
 
wwcttreecrew,

Thanks a ton for the input. When the system is extended there should not be any body weight on the brass ring. Both bridges should be holding all of the weight. If your long one is slack there is a good shot the either the dog leash snap you are using is too short or you may have a different connection to your harness as I do. Either way it can be fixed by making a custom piece to the length you want. If you want email or pm me the dimensions you need and I will be glad to make some up for you.

I agree with the awkwardness of lowering the long bring when you are up by your tie in point. Usually you aren't in that position for too long , but if you have a way to fix that let me know.

Thanks again for the input.

rich
 
Hi Rich , I read about your idea and I'm getting ready to try it!Instructions and pics are clear. I'm impatient to climb with and give you my impressions! Tank you for sharing! /forum/images/graemlins/grin.gif /forum/images/graemlins/applaudit.gif

A presto!
 
Was my pleasure Krapa. Let me know if you have any questions or improvements on it. Good luck.
 
I thought this thread needed an update.

I just got this setup from Rich.

Haven't used it yet on the job, but will post some comments when I do!
 
Sorry to everyone for the thoroughly confusing set of slides to describe this thing. I am currently working with someone who actually has some talent with a camera to get more pics that will hopefully shed a better light on how the anchor bridge works and is set up. I should have that finished this week.

Thanks go to everyone out there who is trying this system out and adding their feedback on how to make it better. There has already been a rather large change in design that helps alleviate the problems with your hitch accidentally opening and staying open. The new pictures will explain it all.

There has also been a lot of interest in the modified version of the anchor bridge by which the climber is using only one bridge attachment and not two. I will post some pics of the versions that I know of so far. I know there are more modifications that can be and have been made to this system to make it fit for each climber. If you have come up with a mod, I would love to see your pictures too.

Anyone interested in the new set of splicing instructions for the changed design can email or pm me and I will get them to you after I post the new pictures.

rich
 
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