Working on SRT system

Tod,
I don't think I mentioned anything about it affecting the cam action? I was just stating that I thought that clipping your system into the bottom of the handle puts a lot of stress on the handle. The way we are tying into the ascender, a small slip while limb walking or such could load that handle beyond it's WLL.

The way I suggested means that you clip in through the top hole but anchor that krab to the hitch above as well. This way most of the load while working would be in the hitch rather than the handle. Does this sound clear? It's harder to explain without the items in front of us.
 
That's clear, I have noticed that I must be carefull as I start to go to work as I have side loaded the handled cam as it came in contact with a limb.
 
Poster: RockyJSquirrel
Subject: Re: Working on SRT system

"As I thought. Thanks for confirming that you have no suggestions.

Are you climbing trees yet, or just telephone poles still?
Funny how much you know and the authority with which you claim my setup will fail, yet you have little to no practical knowledge............."


REAL NICE !!

You know this COULD be a good topic and a very good place to share info ............ but as always ego's have come into play ........ the penis envy ,mine is bigger than yours just must be ingrained in some climbers ...so........rather than a big pissing in the wind contest why don't you use this place to learn and share and be constructive instead of using the "look at me I AM DA MAN" attitudes
 
Is anyone still trying to work off SRT? I bought an ID back at the end of last year and have used it for a few months. I like working off SRT very much. Much fuss was made about settiing up SRT systems, but really it is no more complicated than DdRT.

The basic setup is as follows. Tie an alpine butterfly or similar knot in the middle of your rope. Pass the rope over the branch so that both sides are even. Pass one leg of the rope through the alpine butterfly, thus noosing the rope around the branch. Now one leg of the rope is for hanging from and the other leg is for retrieval. This is merely a basic retrievable single rope rappel as used by rock climbers and canyoners. Of course when initially climbing the tree, the rope can be placed with a throwline or thrown over a branch and then just noosed with a bowline or similar knot. Retrieval is often not a concern at this point. A carabiner can be used to speed up set up. However this will be side loading the biner and causing the gate to come into contact with the branch. Perhaps two opposite carabiners could be used for extra security.

When working the tree, simply make sure that when you want to come down and stay down, the retrieval tail is adjacent to the working tail. When moving to another stem and installing a new TIP, this can be done by moving to the new TIP,tying a midline loop e.g. a butterfly,and clipping it to a sling at the new TIP. Forget about the rope trailing off towards the old TIP. That is no longer important. When it is time to go back to the first stem, unclip the new TIP, remove the midline knot and you have your old TIP back. If planning to move to a new TIP, with no reason to go back to the old TIP, then before setting off to the new TIP clip a krab around the retrieval end of the rope and clip it to the harness. This will give you the retrieval end of the rope and allow you to retrieve the entire rope and move it to the new stem.

When doing something such as dismantling, where you will finish off at the TIP before logging the stem, rope retrieval will not be an issue. For the TIP, simply use a running bowline.

Any slight extra complication in set-up is offset, in my opinion, by the fact that a cambium saver isn't necessary.

This may all sound complicated, but is easy when you try it.

As for 1:1 systems versus 2:1 systems, there is little to worry about. Much of the time spent climbing, it is easy to work on a one to one system, taking up slack and rappelling. When in a low angle situation where the rope is taking much of the body weight the RADS system provides an ample 3:1 MA. A handled ascender kept on the harness can be quickly placed on the rope and the tail end of the rope clipped into the ascender carabiner. This will allow one handed body thrusting. When you are in from the limbwalk, unclip the ascender and return it to the harness. For getting up branchless sections of tree, the RADS can again be used, or simply place a handled ascender and footloop above the I'D and step up, while taking the slack trough the I'D with one hand.

Andy P
 
I use the I'D and cammed handled ascender from Petzl since 3 years in a SRT configuration. Climbing distances max. 30 meter, I use the Big Shot to set the line. A fast flexible and safe system for tree work. The I'D is a great tool for this type of work, mine is used a lot but still rockin'. In the past I've used it with dynamic line, but the I'D performs better with static line.
Regards, Dick
The Netherlands
 
Husky Racer, as you say it is a fast system to use, the main advantage in my view being the efficiency with which you can ascend long distances not only at the start of the climb but also midway through, for example to work from the top on the other side of the tree or on an adjacent stem. If you are prepared to carry a chest ascender, e.g. a petzl croll, then you can quickly convert to a full-on ascending system using the chest ascender with the handled ascender. No resetting of the rope is required to do this, as would be the case if you wanted to go from DdRT to SRT or to footlocking.

The other major increase in efficiency comes about from having no friction in the system due to the rope being static. Everytime I try to go back to DdRT I get annoyed by the constant rubbing of the rope on branches, and by the inefficiency of redirects.

But of course, I do have some problems as well. The I'D is essentially a two handed device. One hand operates the lever while the other controls the tail of the rope. Limb walking is quite possible without a hand to balance, but it is probably a little slower.

For a while, I was using the I'D one handed, holding both the handle and the rope with the same hand. This works, but doesn't allow the device to be locked off without first removing the hand from the device. I have recently done an IRATA rope access course, and they frown on you letting go of the rope end if the device is not locked off. Having checked the user instructions, I can see that they concur with this view.

Another technicality is that the only place that the instructions show slack rope being pulled through the device is when the device is used for rope climbing in conjunction with an ascender. In this case they specify that the handled ascender must be attached to the harness with a lanyard, presumably as a backup. I don't fully understand the reason for this. If someone could enlighten me I'd be grateful. I suspect that the I'D is designed essentially as a descender and not as a general purpose rope adjuster as we would like it to be. Perhaps by pulling slack through the device the braking hand is not in a good position for braking and so the ascender is needed for backup. Petzl seems reluctant to say that the autolock will definitely work and so I think they want you to be in such a position that if it doesn't work you won't just hit the floor. Of course, in practice, the autolock most probably will work.

The grigri was designed for rockclimbers and so the instructions for rapelling seem less rigorous, with no talk of locking the device off (I think this would be achieved by passing a bight of rope thrugh the attachment carabiner and over the end of the device, as is done with a Petzl Stop). I know that Grigris are used in rope access work, but as the instructions don't specify this kind of activity I am not sure in what ways they are used.

If anyone wants to check all this out before investing their money, they would do well to look at www.petzl.com. The instructions which accompany many of the petzl devices are viewable as pdfs on the website. Petzl will also send you a catalogue if you request one. They do both a sport catalogue and a work solutions catalogue. Both are free and contain quite extensive instructional guides to a range of sport and work activities They are two of the best resources I own.

Andy P
 
I like to try almost anything with regards to climbing. Tried a couple SRT techniques in a 25' Birch the other day. I was safe, I was secure, but I was never smooth. How can SRT be made smooth?
 
[ QUOTE ]
I was safe, I was secure, but I was never smooth. How can SRT be made smooth?

[/ QUOTE ]

If you're asking about SRT descent, that depends on the kind and size and condition of the rope, the type of descent device, and on how it's managed. Simply takes practice to descend smoothly.

If you're asking about ascent, it's all in the rhythm. Using a very static rope helps, too, to eliminate the bouncing. But sometimes you can actually use the rope bounce to gain a little momentum if you time it right. It's also dependent upon the equipment and the technique used, and of course on practicing until you get comfortable.

If you really want to learn SRT, hang out with vertical cavers - they invented SRT and are the masters of it. The deepest single underground drop was just discovered in Croatia - 1700'. Imagine what it would take to descend and ascend that! /forum/images/graemlins/ahhhhh.gif

- Robert
 
I don't have any digital imaging capabilities at the moment, but there is a picture of the system on the rescueresponse website, where it is referred to as a RADS (rope ascending and descending) system. The picture was originally posted by Tom D. Essentially it is just a grigri or I'D attached to the harness and loaded on the rope, and a handled ascender that can be attached to the rope above this. a footloop can be attached to the ascender, or the tail of the rope can be looped up through a carabiner clipped onto the ascender. I think the link is

www.rescueresponse.com/html/news02-02/highlight.html

Someone also posted a picture of the system set up in a tree, using an I'D, some time ago. Now I come to think about it, I think someone might have posted a link just a few posts ago. Anyway, searching previous SRT posts should get you somewhere.
 
A friend of mine shared a really cagey slack tender addition to the RADS. My digi camera is dead so no pics.

Put a Shunt on the rope above your I'D or friction hitch. Clip a biner through the big ring on the Shunt. You could use a pulley too but I haven't found a need for the friction reduction. The tail of the climbing rope, below the friction device/hithc goes back up and through the biner/pulley combo.

Now the slack tender! Take a piece of small cord, throwline or shoe lace works fine. Tie it to the small loop on the back of the Shunt. Tie the other end of the cord to a biner. I use a key chain biner. Clip this to your saddle somewhere. Generally I clip it just below my saddle bridge. With the BFII I clip into the aluminum ring. Adjust the length of the cord to keep the Shunt at the end of your arm reach. That keeps it from bonking your noggin. As you move down the rope, the cord releases the Shunt and it slides along. When you need to take up slack you pull down on the rope that comes back from the Shunt. To ascend you push the Shunt up ahead similar to climbing a doubled rope.

Since none of the Shunt slack tender really supports the climber I don't see a reason to have heavy duty, and heavier/bulky, pieces. What do you think?
 
Tom, I'm guessing you must have been on vacation or something, not like you to join an SRT discussion so late. /forum/images/graemlins/grin.gif That sounds like a nice system you describe. Of course the same could be done with a friction hitch. Just place a micro pulley above the hith and attach it to the harness with a length of cord. This will pull the hitch down when you descend. Of course, your system is much neater and probably works more smoothly.

It's funny you should mention the Shunt. I've been thinking about getting one to incorporate into my system. The IRATA rope access course that I recently did highlighted the versatility of the device. IRATA technicians use the shunt primarily as a rope grab to slide up and down their back-up line. It can also be used as a spare ascender, and any other time that a rope grab is needed.

Interestingly, it is considered a full point of attachment, unlike the toothed ascenders, which must be used as a pair to constitute a full point.

This got me thinking of a slight variation on the working SRT system. The primary attachment point could be a shunt, connected to the harness at arms length. This would allow for easy ascending, in conjunction with a pantin, or a chest ascender and footloop. For free climbing, the shunt could just be moved along the line as necessary. It would also be possible to self-line when using gaffs. It would be easy to limbwalk, letting out slack by pulling the shunt along.

Obviously, this system would not work all of the time. For a start, you couldn't rappel. At this point you would need the I'D. The I'D would also be used when limbwalking on thinner limbs, where your weight must be kept on the rope. To return from such limbwalks, the tail of the rope would be looped up to the shunt to allow body thrusting.

The essence of this system would just to be to remove those awkward situations where it is difficult to let slack through the I'D. It would also overcome the technical problem with the I'D that I mentioned in a previous post. That being that the I'D is a descender,and the manual does not show it being used as a rope adjuster i.e. they don't show the user taking up slack, except when ascending with an ascender and footloop. In this case they clearly state that the ascender must be attached to the harness, as a backup I presume. Maybe I'm reading too much into it, I don't know. With all these things, it is hard to get a balance between being progressive, and sticking to what you know is safe.

Today, I have been testing this system, using a prussic instead of a shunt, and I think it would have potential. The only question in my mind is how safe it would be to be attached only by a shunt. I haven't seen the manual for the shunt, and so I am not fully familiar with it's safety limitations.

I'll be interested to hear everybody's thoughts here. I'm sure many of you will think it's too complicated, but in my view it's worth it. And besides, it does have a certain elegance. Once you've worked a tree SRT style, you don't want to go back /forum/images/graemlins/wink.gif
 
Once you've worked a tree SRT style, you don't want to go back :)

Andy,

I've been saying that for a while too. The people who have seen SRT and have open minds see the value and ease. Since arbos are the only rope workers that use a dynamic [moving] rope it dawned on me a while ago to see if SRT could be adopted to trees.

The cord that I'm using now is made with a Nomex sheath and Technora core. It might be the best rope combo for me. Using all of the tools works but I'm trying to make it smooth and sleek.

Tom
 
I see where you're coming from now, Tom. If you're using a hitch instead of the I'D then that sounds like an ideal system - very sleek and efficient. I'm still trying to get the I'D to work as I would like it to, but at the end of the day you can't beat the one-handed ease of use of a hitch. The fact that the rope isn't deviated at all by the hitch is also a bonus.

I'm a little surprised that no one manufactures a mechanical equivalent of a prussic that can be released under load. Or at least as far as I know nobody does. You wouldn't think it would be too difficult to come up with something.

How are you finding using a hitch on a single rope? What hitch are you using? Do you consider there to be any safety concerns with this method?

Andy
 
How are you finding using a hitch on a single rope?

Right now I don't do production climbing so my testing time is pretty limited. Finding the perfect hitch takes time. Since the dynamics change in the system and the load on the hitch is doubled it is a bit more difficult.

The action isn't as smooth with the Distel. I tried it with different cords and wrap combos.


What hitch are you using?

Lately Ive been using the Knut and this seems to have good promise.

Do you consider there to be any safety concerns with this method?

No more than on DdRT. When I'm working with a new hitch combo I tie overhand on a bite stopper knots below my hitch. I've had some slippage and I don't want to take a grounder.
 
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