Limbwalking: RADS-Petzl Rig and Shunt (video)

[Ron]

First this is not an accomplished limb walk like you guys do. The whole purpose was to illustrate how well a RADS will work on a limbwalk.

This was an experimental setup with the Shunt. Tom Dunlap came up with the idea to use the Shunt in a RADS years ago. I modified his configuration to use a pulley and attach footloops.

I was not impressed with the way the Shunt performed ascending, but I had to go through a small tree and that complicated the ascent and may be part of the reason I wasn't impressed with the Shunt on the way up.

The Shunt was outstanding on the limbwalk and descending. I was amazed at how well the tether tended the Shunt, even when I had some down pressure on the cam.

I'm not recommending anything here, well maybe the Rig, it really performed well in the tedious limb walk and in a controlled rapid rappel.

The ground view comes first then the view from my helmet cam - both perspectives reveal unique details. I was about 60+ feet from the ground camera; I'm surprised it picked up my voice at all with all the background noise.

There is narration in the helmet cam section. You may want to skip the openning disclaimers, but right after them is a bit of detail about the limbwalk.

And, the video is a bit long - 10 minutes; I apologize for that. I just didn't want to cut anything else out.

http://www.youtube.com/watch?v=9FXmVrQKG_M

 

[Tom Dunlap]

Nice illustration of the variation!

Jim and I threw a couple of ideas back and forth about fabricating a handle for the Shunt. It seems like it would be easy to attach without changing the through-bolt on the bottom of the Shunt. Since the S isn't there for life support the modification wouldn't be a compromise.

 

[DSMc]

Nice. The Rig will be added to my climbing gear soon. Seeing the Shunt in action was very interesting. Did the lack of a normal handle make the foot strap preferred to a hands only setup? I use a RADS in tight small trees where smooth movement is more important then covering lots of area so generally prefer a hands only type setup also.

Dave

 

[Ron]

[ QUOTE ]
Nice. The Rig will be added to my climbing gear soon. Seeing the Shunt in action was very interesting. Did the lack of a normal handle make the foot strap preferred to a hands only setup? I use a RADS in tight small trees where smooth movement is more important then covering lots of area so generally prefer a hands only type setup also.

Dave

[/ QUOTE ]
I just got back in from another Shunt-Rig RADS climb. You can actually pull the Rig lever wide open and very smoothly control your descent via hand braking on the down rope. And you can essentially release the braking on the down rope and control the descent with the Rig. Either way the Shunt auto-tends.

For the specific situation you described, more manueveuring than long entry climbs, this set up is just about perfect. You can go up, and come right back down without changing or removing or adding anything. Then when you get in position, just pull the Rig's handle into the lock position and go to work.

As far as descending per se, the Shunt will trail right down with you just as smooth as you please!

I'm still workin' on the foot loop climbing. It's not bad, but I want to compare the Shunt-Rig RADS to a handled ascender with the Rig and see just how much difference, if any, there is.

 

[xman]

I still think using the RIG for positioning and when calculated limb walk come into play you throw in the hand ascender with a pulley knowing that you will come back to it. Certainly, this method is way more efficient than the video I just saw... Easy on, easy off, and you are using one of the two hand ascenders that are needed for ascent! I prefer a two inch sealed bearing pulley, fot the MA. This seems a little bit cumbersome, however I like the intial concept, I prefer to streamline my systems as much as possible(OCD). The Shunt lacks the handle to wrench on in ascent situations. Now having the shunt tethered in a big tree that you have blown two single lines in, one on each side is pro for fall arrest.

Single line X-maniac

 

[Ron]

[ QUOTE ]
I still think using the RIG for positioning and when calculated limb walk come into play you throw in the hand ascender with a pulley knowing that you will come back to it. Certainly, this method is way more efficient than the video I just saw... Easy on, easy off...

[/ QUOTE ]

”…way more efficient…” is a pretty broad statement. How is it “…way more efficient…”? The only thing in the video that wasn’t about as efficient as it can get was the ascent. I’d go so far as to say the self-tending Shunt-Rig based RADS is about as efficient and effective as it can get for up and downs, in and outs, esp. limb walks.

You may have mistaken a difficult to negotiate limb and my hard lean on my rope as the self-tending Shunt-Rig RADS being inefficient. On the way out the limb the Shunt self-tends and goes with you with no effort or attention from the climber. I don’t see how any other setup could be any more efficient on a limb walk. In fact, the self-tending Shunt-Rig based RADS just might be the most efficient method out there for limb walking. Here’s why I say that:

In the video, I am on a small, bouncy limb – hence it was very important that I minimize weight and force on the limb. That requires a ‘hard’ lean on the rope at all times and theoretically, just enough force on the limb to maintain balance, hold position, and move out the limb.

A DdRT, Rig only SRT, and a self-tending Shunt-Rig based RADS would be essentially equal (well, in a DdRT you would have two ropes to manage instead of one) as far as moving out on the limb goes. Coming back is a different story.

In both a DdRT and Rig only SRT, the climber has to tend the tail by pulling the tail outward from him, i.e. we are pulling rope away from our body, and that’s not that bad unless you are trying to really put some lean on your rope(s) to minimize force on the limb. When you do that, now your arm has to pull opposite of your lean and on a 1:1 basis – that’s a little more complicated.

With the self-tending Shunt-Rig based RADS, you are pulling the tail towards you which pulls you in the direction you want to go and it does so with a 3:1 MA on your arm! So you can really put some lean in the rope and still overcome it with one arm.

[ QUOTE ]
..and you are using one of the two hand ascenders that are needed for ascent! I prefer a two inch sealed bearing pulley, for the MA. This seems a little bit cumbersome, however I like the intial concept, I prefer to streamline my systems as much as possible(OCD)…

[/ QUOTE ]

“…one of the two hand ascenders…” – There aren’t two, handled ascenders in a RADS. I guess I don't understand how carrying two, handled ascenders plus a descending device is more streamlined than the Shunt and a descender???

[ QUOTE ]
…The Shunt lacks the handle to wrench on in ascent situations…

[/ QUOTE ]
That’s true if one needed to do that. But the handled ascender does not allow instant up-down reversals and must be removed and reattached in many operations. Plus it makes for a far more complicated emergency descent.

It is true that a handled ascender is a little more efficient on the way up. I use to ascend on a customized Texas setup and it was efficient, but then one day I had the thought, if I were up about 40' or so and still climbing and I had to descend immediately, say the proverbial bee attack, how would I do it? The changeover from a two, handled ascender climb, be it Frog or Texas style takes a lot of time and effort.

Every system has pros and cons. The self-tending Shunt-Rig based RADS has one con – it doesn’t ascend as well as desired in its present configuration, but I’ve already made some progress with that and am continuing to look at ways to improve the ascent phase. Other than that, I think it makes an almost ideal climbing system. You can make ascents with only hands – easier than DdRT I might add, you can use foot loops, you can do instant up-down reversals with absolutely no gear changes or cam disengaging. The same thing that gets you into the tree can get you out a limb and back without any gear addition, gear adjustment, cam release and the thing is always self-tending.

But these are just my impressions after using various forms of RADS and two handled ascender systems. Somebody else may put the same time and effort into the same systems and decide something else.

 

[Tom Dunlap]

When I've used the Shunt I always find a comfortable place to push even without a handle. It is only marginally less 'easy' than using a handled ascender. Offset that tiny bit with all that there is to gain and the issue is moot.

When I look at climbing systems I try to look at how many calories it would take to use in an application. Giving up a few calories in one part that will be gained in another makes it better for me.

Adding the Fixe/biner makes for a slick foot loop attachment point.

 

[DSMc]

[ QUOTE ]
For the specific situation you described, more manueveuring than long entry climbs, this set up is just about perfect.

[/ QUOTE ]

Thank you so much, for that quoted phrase has allowed me to place my order for not only the Rig but the Shunt. I was able to show this to my wife and say, "but Ron said".

Worked like a champ.

Dave

 

[Ron]

Congrats on the new toys.....err, tools - that's it - tools, they are tools!

I think you'll like them. Just give yourself some time to adapt to configuration. It does manuevers and descending incredibly well - especially since you do a lot of arms climbing - I do too.

I'm gonna continue to work on the ascending, i.e. longer ascents. Based on some things Tom said, I think it'll wind up being good at that too.