Technique to release trunk anchored SRT line remot

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15 years 7 months ago #132317 by moss
This is a theoretical design to release a trunk anchor in a super tall tree so that the climber can advance the rope from a trunk anchor to a limb cinch higher up. There is no danger of accidentally releasing the anchor during ascent.

To release the anchor the climber uses the throw line to pull the entire length of the rope back through the hitch. The upper end of the rope needs to be controlled going down (with a throwline) so it doesn't fall into a heap and tangle or snag a branch. There are many pitfalls, the rope could get hung during the \"switch\", the climber will be stuck in the tree. I'm hoping this post will spark some innovation to solve this tricky problem.

I'm showing it with a hitch, theoretically it could be done with an appropriate rated rope grab device that allows the rope to move easily back through the device.



-moss

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15 years 7 months ago #132318 by Davej
Ok, I'm a newbie so let me cautiously ask -- why do you need the friction hitch?

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15 years 7 months ago #132319 by treeman
Moss,
I would think you would need a loose friction hitch to pull out the rope. I don't know. One way to find out however.

I have used a fifi hook for this same purpose. The concept is a bit scary, with an open hook, but it is method that works under load. Rock climbers are familiar with it. I use a taped double fifi hook to give myself peace of mind when I am traveling up a long pitch. The anchor is a double wrap of nylon webbing. The load is placed on the un-knotted section of webbing (wrap 2, pull 1 on large wood). This system can be used aloft too, with cleaning of webbing by following climber or on the way down. The trick is to keep the rope on load.

Waving from a treetop,
Peter Treeman Jenkins

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15 years 7 months ago - 15 years 7 months ago #132320 by moss
treeman wrote:

Moss,
I would think you would need a loose friction hitch to pull out the rope. I don't know. One way to find out however.


If Tenex or something like that was used for the closed split tail and the optimal hitch was selected it would collapse and open nicely when the rope was pulled in the opposite direction. It is a lot of rope to pull back through the hitch and the end of the rope would have to be very clean (no tape) to completely exit the hitch.

Actually, an idea! Damn I'm trying to work right now! A hard plastic/nylon sleeve on the rope just above the hitch would keep the rope fair going back through the hitch and it would also encourage the hitch to collapse nicely.

But a mechanical device (rope grab) would be better, only allows the rope to go one way and would flow easily for the pull out.

Yep, I was trying to come up with a new paradigm to get away from the finickyness of the Fifi hook. It's too much to have to think about while you're working through branches on ascent (remember, don't slack the rope!) The ideal SRT ascent system allows you to focus on climbing and not think about the anchor.

The system I'm suggesting allows the rope to be slacked and reloaded with no loss of integrity.
-moss
Last edit: 15 years 7 months ago by moss.

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15 years 7 months ago - 15 years 7 months ago #132321 by moss
Davej wrote:

Ok, I'm a newbie so let me cautiously ask -- why do you need the friction hitch?


The hitch is holding your life as you climb (it is the anchor), and allows you to pull the rope out the other side of the hitch if you want to free a trunk anchored rope to reset your SRT anchor up higher. This is for a super tall tree where a 200 or 300 ft. static rope only gets you to the first pitch (\"lower\" branch on the tree).
-moss
Last edit: 15 years 7 months ago by moss.

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15 years 7 months ago #132322 by Davej
moss wrote:

The hitch is holding your life as you climb (it is the anchor)



Ok, but a good big stopper knot would not go through a good pulley, would it? The other idea you seem to suggest is something like the following?

http://www.newtribe.com/catalog/product_info.php?cPath=21&products_id=35

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15 years 7 months ago - 15 years 7 months ago #132323 by Baker
When you pull the rope UP you pull the throw line. The knot, I assume, is for safety when climbing. There will be no knot at the other end of the rope, allowing the climber to pull it up to him/her, through the hitch and the pulley. Interesting option. The only change I would make would be to use a hitch tending pulley (PMP). It will tend the hitch better without allowing it to roll. As far as the hitch itself - maybe a klemheist?
Last edit: 15 years 7 months ago by Baker.

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15 years 7 months ago - 15 years 7 months ago #132324 by moss
Davej wrote:

Ok, but a good big stopper knot would not go through a good pulley, would it? The other idea you seem to suggest is something like the following?

http://www.newtribe.com/catalog/product_info.php?cPath=21&products_id=35


That's true, I guess I like the way a hitch or a device grips the rope in a more distributed way (a rope grab less so) but just putting a stopper behind a pulley could do it. But what you suggest gives ideas for a easily attachable and removable rope clamp, maybe milled from a small block of aluminum that would substitute for the stopper knot and then a custom pulley that would have a flat surface on one side for the rope clamp to rest against. Simple is definitely better, if the hitch can be taken out of the equation and replaced with small sturdy chunks of hardware with no wearable or moving parts (except the wheel in the pulley), all the better.

Yep, the Microcender is the sort thing I'm talking about.

This is pretty esoteric functionality to achieve for an SRT anchor but worth thinking about.
-moss
Last edit: 15 years 7 months ago by moss.

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15 years 7 months ago - 15 years 7 months ago #132325 by moss
Baker wrote:

When you pull the rope UP you pull the throw line. The knot, I assume, is for safety when climbing. There will be no knot at the other end of the rope, allowing the climber to pull it up to him/her, through the hitch and the pulley. Interesting option. The only change I would make would be to use a hitch tending pulley (PMP). It will tend the hitch better without allowing it to roll. As far as the hitch itself - maybe a klemheist?


There is a hitch tending pulley in the drawing, it's labeled as \"slack tender\". Yep, a Klemheist would be worth testing. Whatever the hitch is, it should collapse and open well and regrab the rope just as well when the rope is reloaded (if the climber slacks and reloads the rope during ascent).
-moss
Last edit: 15 years 7 months ago by moss.

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15 years 7 months ago - 15 years 7 months ago #132326 by Davej
moss wrote:

But what you suggest gives ideas for a easily attachable and removable rope clamp, maybe milled from a small block of aluminum that would substitute for the stopper knot and then a custom pulley that would have a flat surface on one side for the rope clamp to rest against. Simple is definitely better, if the hitch can be taken out of the equation and replaced with small sturdy chunks of hardware with no wearable or moving parts (except the wheel in the pulley), all the better.



Well, here's simple... a sturdy pulley, a small stack of hefty steel fender washers with 1/2\" holes, and a triple overhand stopper with a three foot tail.

Edit: to prevent the chance of snags you'd probably need to lower the end of the rope on throwline as the opposite end is being pulled up.
Last edit: 15 years 7 months ago by Davej.

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15 years 7 months ago #132327 by michaeljspraggon
Replied by michaeljspraggon on topic Re:Technique to release trunk anchored SRT line remot
Moss, you mentioned the possibility of the end of the rope getting snagged around something as it drops from the climber to the ground before being pulled through the friction hitch.

Thinking laterally for a moment, couldn't you leave the other end of the rope tied around thre base of the tree and advance the other end? I mean, if you're doing short pitches once in the branches then a 100m rope should suffice for trees of up to, say 85m. The problem is how to ensure that the rope doesn't drop to the ground by accident after you've taken the other end up, leaving you stranded. I would secure the rope to the branch it is slung over before taking it up then use the other end to pull over the target branch on each new pitch, securing it to the previous branch as before to avoid getting stranded if there is a large gap between branches.

To descend, simply do it in reverse, rappeling instead of jugging up. The disadvantage, I suppose, is that you need to remove attachment to the branches while rappeling out from the top in one pitch.

Michael

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15 years 7 months ago #132328 by michaeljspraggon
Replied by michaeljspraggon on topic Re:Technique to release trunk anchored SRT line remot
... to secure the rope to the branch at each pitch you could use a 1-2m long prusik cord tied around the rope in a friction hitch locking if the running end tries to slip towards it. This length of prusik cord allows it to be adjusted so that the load on the main rope is on the tie in around the base of the trunk, not the smaller branch higher up, (which may be weaker with a load pulling upwards on it instead of downwards).

I hope this is clear. I don't have a scanner to attach a sketch!

Michael

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15 years 7 months ago - 15 years 7 months ago #132331 by moss
michaeljspraggon wrote:

Moss, you mentioned the possibility of the end of the rope getting snagged around something as it drops from the climber to the ground before being pulled through the friction hitch.


Yep, getting the rope hung is a hazard. Remember this is all speculation and theoretical to work towards a possible way to do this. The rope end going down should be controlled by attaching a throwline.

michaeljspraggon wrote:

Thinking laterally for a moment, couldn't you leave the other end of the rope tied around the base of the tree and advance the other end? I mean, if you're doing short pitches once in the branches then a 100m rope should suffice for trees of up to, say 85m. The problem is how to ensure that the rope doesn't drop to the ground by accident after you've taken the other end up,


That's the standard way to do it, leave the \"foot\" of the rope anchored and advance the other end. Apparently in very tall trees climbers are looking for a way to release the anchor at the trunk from up in the tree. Treeman is not the first climber I've heard mention using a Fifi hook for a ground release system.

Dropping ropes is always a hazard, experienced climbers internalize this risk and have a variety of strategies. All you have to do is drop a rope once and you'll likely never do it again. The bottom line is always secure your rope, preferably to your harness before going to the next step. Holding a rope with your hand while performing another task is not a good idea. I usually make a slip knot in my rope (in the correct direction to hold) and clip it to my harness when I need a \"third hand\".

I really like the direction that DaveJ has suggested, I think it will lead to the next iteration.
-moss
Last edit: 15 years 7 months ago by moss.

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15 years 7 months ago - 15 years 7 months ago #132332 by moss
Davej wrote:

moss wrote:

But what you suggest gives ideas for a easily attachable and removable rope clamp, maybe milled from a small block of aluminum that would substitute for the stopper knot and then a custom pulley that would have a flat surface on one side for the rope clamp to rest against. Simple is definitely better, if the hitch can be taken out of the equation and replaced with small sturdy chunks of hardware with no wearable or moving parts (except the wheel in the pulley), all the better.



Well, here's simple... a sturdy pulley, a small stack of hefty steel fender washers with 1/2\" holes, and a triple overhand stopper with a three foot tail.

Edit: to prevent the chance of snags you'd probably need to lower the end of the rope on throwline as the opposite end is being pulled up.


That's the direction I'm thinking now (the stack of washers concept except mill it from aluminum round stock to keep it light). I think I mentioned the throwline for dropping the top end of the rope in my original post, total agreement here. It could be the other end of the same throwline that's pulling the lower end of the rope up.

This is fun, good ideas coming out. I woke up at 5 this morning and the idea popped into my head, have no idea why, it's not a problem for my climbing, east coast trees aren't big enough. I figured turning it loose would be a good way to move it towards something that actually works. Thanks for the responses.
-moss
Last edit: 15 years 7 months ago by moss.

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15 years 7 months ago - 15 years 7 months ago #132336 by Davej
moss wrote:

That's the direction I'm thinking now (the stack of washers concept except mill it from aluminum round stock to keep it light). I think I mentioned the throwline for dropping the top end of the rope in my original post


Oops, you did mention that in the original post. I don't know about round stock... seems like any nice chunk would be fine. Drill the hole and then round off all the edges. I guess you could drill several holes if you use several rope sizes.

Edit: Had another idea if you want to get weird. You could make a thing that sort of has the shape of a bicycle pedal. The rope would enter through a hole in the \"front\" then make two round turns around the \"middle\" and exit through another hole in the \"back\" where you would then tie your stopper. This might keep the stopper knot from getting really tight.
Last edit: 15 years 7 months ago by Davej.

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