Your personal SRT work setup

For clarification, do you use the Pantin with the RADS also or just footlock?

*It all depends on the height of the climb. For long climbs I use my Gleasy bars, Pantin for mid-range and FL for short ascents.

You use the RADS only for longer climbs?

*Now I don’t use the RADS too much. In my progression through SRT, I got that tweaked and now it’s on to finding the perfect hitch for SRT. The Unicender fits the bill for most SRT climbs when I want to use a tool.

Why do you use the Shunt instead of a Microcender?--is there a difference? Are both springloaded?

*The S will release when the yellow leash cord is pulled. They are both spring loaded. The guys from Petzl gave me the Shunt a while ago but I couldn't find a good use for the tool. A friend of mine from MN, actually Pierce Wasmund who is the MNTCC champ this year [and TB lurker  ] got me thinking about using the Shunt in this application. As I’m typing I got an idea for a way to set the MC up to work with a leash. Let me check this out…

How does the small cord release the Shunt to descend?

*Yes, is it clear how this works? If not, let me know and I'll get some pics up. Pierce was very clever in figuring out how to use the leash as a, sort of, vertical slack tender.

Do you tie-in the shunt to your saddle or only the Petzl ID?

*It depends, it can make a bit of a mess with all of the connections and cordage on the saddle. The cord needs to be kept away from the I’d mechanism and handle.

I assume the Shunt is above your hands and that you just push it up as you climb?

*The S is kept just inside arm’s-length. When I sit in the saddle I like to have it right at hand with just a little stretch.

The 2:1 you refer to would only be for your legs, right?

*Right, by using the tail for ascent it is a 2:1 If the system is setup like in the article, it is 1:1. My goal was to make a compact RADS, using a handled ascender added to the bulk. It also eliminated any yo-yo climbing unless I went all of the way back up to retrieve the upper ascender.

Where did you get the buckles for your Pantin?

 That’s a funny question  I went into my sewing scraps. The little slider on the stirrup came off of a camera neckstrap that I took apart. The other buckle came from a compression strap. When I can make things like this out of “nothing” it really justifies being a pack rat. But that’s another thread 

Do you think that setup would work well with a hitch (Knut) instead of a Gri-Gri?

*Sure, no difference. Actually I use the I’d instead of the GG because I like the panic and positive lock-off features of the I’d. The GG hits about the 80th percentile though.

I’ve attached a picture of another SRT setup you posted on the ‘buzz. Which do you normally use?

*The blue strap setup is in the pouch on my saddle all of the time unless I were using the RADS. Most of the time I use the blue strap setup.

The system I’m trying to put together for just plain exercise is a bit strange at present. I'll post a picture for everyone’s amusement and comments when I get it close to final.

*In the book ON ROPE they have pictures of a rope treadmill. A rope is spliced into an endless loop. A pulley is hung from the tree. At the anchor a friction device is used, a rack is probably the best. A bungee is used to hold the rack vertical. With some experimentation the friction in the rack can be balanced against the climber’s weight so that the climber doesn’t move too far off the ground. As I was typing this I just realized that this is the anchor system that I use for my SRT work. I read the first edition of ON ROPE close to 15 years ago and I remember seeing that setup. I wonder if that virus was planted in my head and just came to life a couple of years ago when I was developing my anchor system??? Strange how the brain works…
 
Tom, thanks very much. I know it took a lot of time to respond to all our questions, and it’s greatly appreciated.

Just a couple more, please?

[ QUOTE ]
*The S is kept just inside arm’s-length. When I sit in the saddle I like to have it right at hand with just a little stretch.

[/ QUOTE ]
Does that mean your hands are below the Shunt as you ascend?


[ QUOTE ]
*Now I don’t use the RADS too much. In my progression through SRT, I got that tweaked and now it’s on to finding the perfect hitch for SRT. The Unicender fits the bill for most SRT climbs when I want to use a tool.


[/ QUOTE ]
[ QUOTE ]
*The blue strap setup is in the pouch on my saddle all of the time unless I were using the RADS. Most of the time I use the blue strap setup.

[/ QUOTE ]
I guess you are trying to replace the Rocker with a hitch?

How are you liking the Knut?

I’ll have to look for that rope treadmill; sounds like a good idea.

Thanks again for all your help,
Jim
 
In order for me to get my hand above the S I have to make a stretch. That makes for a safer system. The climber is less likely to release the tool. I realize that in this setup the I'd takes the slack though. Another thing to consider when adjusting your setup is where the hardware is going to slap you in case of a stumble. My first choice is to keep the I'd low so that I don't get hit in the ribs. Then, keep the upper well away from my face. I've had nightmares about getting hit in the face and spitting teeth like popcorn...nasty dream. The further the upper is the longer the climber can move up the rope in one ratchet.

The blue strap setup hasn't been changed for a couple of years. It works really well togther. No, I'm not trying to replace the Rocker in this setup. I'm trying to find the SRT Grail, a hitch or tool to move up and down the rope.

On Sat. I used the Knut tied with HRC on 7/16" KMIII. The first tie-in used three wraps. Too tight, tried four, still a bit snug. The next time out I'll add another wrap and then go to try the TK. TK uses a marl as the last turn, the Knut uses a half hitch.

You don't need to apologize for the questions. I hope to see SRT become a viable system for arbos. Unless the SRT-virus infects more people it'll take too long to work the bugs out.
 
[ QUOTE ]
On Sat. I used the Knut tied with HRC on 7/16" KMIII. The first tie-in used three wraps. Too tight, tried four, still a bit snug.

[/ QUOTE ]

Tom, as you probably know by now, I'm using the same setup, except maybe for my climbing line, which is the KM III Max, but I doubt there is much difference between the two ropes. I use the same equipment for both SRT and DdRT. Actually, both a classmate of mine in the Advanced Arborist class at ACRT and I thought this was a great hitch for DdRT.

With 3 wraps, I found that the Knut really bound up tight on descent. Like, how do I get down off this line tight! 4 wraps still bound up too much, but, at least, I could pull the hitch with both hands to get myself moving down my line.

As of late, I've been using an actual 5-wrap coil plus the final wrap to make the marl (I think that's what it's called) at the bottom, so 6 in total. I find that I can now use just one hand on the hitch, keeping my other hand on my line, where it should be. I also find that the hitch moves up the line better during ascent. Maybe so many coils keep it from getting sloppy... I don't know. I may even try another wrap and see how that works out.

I think I’ve finished my ‘exercise' setup. I’ll try to post a picture tonight for comments and suggestions. I tried it this morning in the early dawns light, and it worked just as I hoped it would.

Jim
 
[ QUOTE ]
On Sat. I used the Knut tied with HRC on 7/16" KMIII.

[/ QUOTE ]

Have you tried the Knut with other cords? I'm having a hahd time finding the right length from eye to eye to make the HRC work fluidly. I'm still working with it, but right now I favor the Sta-Set.

Jim:

What cord do you use?

You both mentioned that the hitch moves more easily when you add wraps, but this seems counter-intuitive . I would think that adding wraps would create more friction and create more grab. Do you keep the cord the same length for the three, four, and five wrap variations?
 
When I add wraps I lengthen the cord but keep the tails the same length.

My take on the hitches is that the wraps divide the load in a decreasing cascade. Let's see if I can explain how I'm thinking about the way the hitches function.

If the amount of friction needed to hold the weight of the climber is equal to X then both of us have figured out that three wraps will hold. But, we want the hitch to move so that means we need to divide X into smaller pieces. Adding wraps is the divider in a way. I think that the lowest wrap has most of the load and a reduced proportion going to the upper wraps. With four wraps the proportioned share may be something like 45%, 30%, 15% and 10% for the top wrap. With a five wrap in might be 35%, 30%, 20%, 10% and 5%. In a way you could think of this like a wedge or cutting edge. Four wraps is blunt, it is hard to cut fine pieces but with a sharper edge, you could shave. Look at the ratios. With less wraps the hitch seems to lock and grab tight. With more, it still generates enough internal friction but it release smoother.

What we're building in the hitch is a Frictionless Anchor.

Something else that's going on is the attempt to balance the load on both legs of the hitch. Otherwise we're just going back to the performance of an open hitch.

One day when Pete Donzelli and I were skiing he talked about wanting to come up with a way of inserting load cells into ropes so that we could tell how much load is held by each section. We know theoretically that if the stretch of a rope were plotted on a graph it wouldn't be straight. the end with the load stretches more so that the anchor point doesn't have the same load as the loaded end. The same goes for the way that I think about the elusive SRT Grail, the perfect hitch.

Does any of this make sense? If I'm off base, let me know.
 
Mahk, I use HRC also. I used Sta-Set twice. One time, during a descent (and not a fast one), the Sta-Set covering melted, and I had trouble getting down. Then I tried the UltraTech eye-and-eye cord, and it wasn’t much better. After I couple of descents, I started to see glazing. My climbing line, at the time, was ½ inch ArborMaster.

I’ve been very happy since I switched to HRC for my hitch cord; and it has worked great. The covering has a high melting point. I’ve been using the same piece for about 3-4 months now.

When I said “that the hitch moves up the line better during ascent”, I was referring to the hitch holding its form. Sorry, if there was confusion. The legs of the Knut, in conjunction with the micro pulley, tend the hitch upward as you ascend. The legs tend to loosen the coils, and, for me at least, I see no detectable increase in friction with more coils. What I have found is that, within reason, the greater the number of wraps, the better the hitch keeps its form. Also, the Knut seems to have less resistance to movement during descent with increased wraps. Someone hypothesized that that may be due to the fact that friction is spread across more coils, so that it takes less force on top of the hitch to break it free.

As far as length goes, my original length was 48 inches but I use double Fisherman’s knots and not spliced eyes. (Hope Nick isn’t reading this!). My legs are typically 3-4 inches long. I’ve been using the same cord as I increased my coil count, so the length hasn’t change, except maybe for some stretch. The hitch just seemed to perform better as I added the wraps.

Jim
 
Just to get consistent terminology--by 'tail' I mean the part of the cord indicated by the red arrow in the attachment. By 'legs' I mean the part of the cord indicated by the blue arrows. This hitch is <u>not</u> tied the way that I would use it. The legs are much longer than I would use for climbing.

For me, about four, sometimes five wraps is best. Whenever I go to six wraps there is more friction and the cord doesn't advance as easily when I ascend.

The hitch seems to respond better (going both up and down) with legs that are about two inches. If the legs are much shorter, they don't allow enough slack in the coils for the hitch to loosen as I ascend. If the legs are much longer, there is so much slack that (again wgen ascending) the legs just flex and don't apply enough pressure to the coils to cause the hitch to loosen up quickly. But, once the hitch does loosen, the long legs add so much slack in the coils that the hitch doesn't reliably and consistently grab the climbing line when I reach my next position and want to put weight on the climbing line.

The length of the tail(-s of the double fishermen's)doesn't/don't affect the performance of the hitch at all (although if they are way too long then they make it difficult to tie the climbing hitch).

Part of the problem for me is that I sometimes switch between different types and diameters of climbing lines.

There are so many variables and they seem to affect different climbers in so many different ways.
 

Attachments

  • 27501-knutwitharrowsresized.webp
    27501-knutwitharrowsresized.webp
    8.8 KB · Views: 166
Tom, yesterday I tried an SRT setup similar to yours. I had a Petzl Shunt on top and the Yates rocker below and tied into the Shunt. I only got about 10 feet up when I came back down and took the Rocker off, replacing it with a Microcender.

The problem I had was when trying to push the Shunt ahead to advance the system. Standing on my Pantin caused my line to become taut, and, as a result, the rocker wouldn't budge. Have you experienced that?
 
Do you have a Rocker with the flipper tab that goes over the outboard hole? It would have serrated teeth to catch the "rocker" bar that grabs the rope. You would need to flip that open to allow the rope to slide.

How do you attach the Rocker to your saddle?
 
That's it, Tom. I had the tab down for more resistance. It slid with slightly more resistance than the Shunt until I put weight on my line. With the tab up, it slid so easily I was concerned about it grabbing properly.

The Rocker was attached to my saddle with a carabiner. Then, a cord from the carabiner at the Rocker to the small hole in the cam of the Shunt, just to keep the Rocker moving up as I climbed.

Jim
 
You must log in or register to reply here.

New threads New posts

Back
Top Bottom