Shunt Revisited

[rcwild]

14 March 2009 NOTE: Merged several threads about the Petzl Shunt into one thread. Original post is from 2004. Course equipment list has changed since then.


The equipment list for ACA courses specifies the top preference on ascenders as a Petzl Tibloc and Shunt. I have been looking at handled ascenders and wonder how these would work for a beginner such as myself?

Handled ascenders are actually more efficient to use than Shunts and Tiblocs. If you are going caving or climbing a big wall, knowing that you will definitely be doing some ascending, take handled ascenders.

But in canyoneering, we carry them just in case we need them, but actually use them infrequently. Handled ascenders are too bulky and heavy to carry around, not knowing if you will even need them.

Tiblocs take up very little space and weigh virtually nothing. The Shunt can be used as a self-belay device while on rappel and can be used to ascend double ropes (of equal diameter).

[rcwild]

Over the years, I've managed to get the gear I carry down to a bare minimum. Always prefer multi-purpose gear. When a new idea comes my way, I might carry an extra piece or two for a while to determine how functional and multi-purpose it is. It has become very rare for me to make any permanent changes in what I carry, but I did make a change recently.

Gear carried on my harness in most technical canyons.

Old list:

Petzl Spelegyca with Petzl Attache carabiners
Petzl Huit (figure eight)
Locking HMS carabiner for figure eight
Canyon Quickdraw
3 Petzl Attache (HMS) carabiners
Petzl Shunt on locking oval carabiner
Petzl Tibloc on locking oval carabiner
12" tied prusik
48" nylon runner
48" nylon/Spectra runner
Valdy (valdotain, valdostano)

What I changed:

No longer carrying 12" tied prusik, 48" nylon runner and 48" nylon/Spectra runner. Replaced with 8 feet of untied 6mm cord, 48" Spectra (white) runner, 24" Spectra (white) runner.

Reasons:

Untied 6mm cord provides more versatility than pre-tied prusik. I can rig a friction hitch on the rope with the cord, then tie an overhand knot in the two strands to create a prusik of various lengths on the fly. I can also use it to tie a short version of a purcell prusik if needed. I used to carry untied cord when I was guiding. Switched back now, in part, after seeing a few new uses demonstrated by Joe Storms, Jasper National Park Ranger.

Recent tests conducted by Sonny Lawrence and Paul Stoval revealed that the new Spectra runners create very little friction when they're run over carabiners used as pulleys. They're lighter and less bulky than nylon runners of same strength and don't absorb water. During my recent visit to California, I watched Paul rig a simple and very quick 4:1 haul system using one 48" and one 24" sling. Sweet.

I had a concern about the slippery Spectra runners holding on the rope when using friction hitches, but they've proven to work quite well. The slipperiness makes it easier to remove overhand knots that I tie in the runner to adjust length.

Also considered switching from Petzl Spelegyca to purcell prusik based on recent test results. Decided against it because I get so much more versatility from the Spelegyca.

[sonnylawrence]

I suggest reconsideration of the carabiners. Every now and then I come across someone with a fat rope. A smaller diameter carabiner is easier to use with the Tibloc. I carry one Black Diamond Positron screwgate.

[rcwild]

I suggest reconsideration of the carabiners. Every now and then I come across someone with a fat rope. A smaller diameter carabiner is easier to use with the Tibloc. I carry one Black Diamond Positron screwgate.

Got that covered with the locking oval I use to carry my Tibloc. It is made of thinner stock and works with the Tibloc on thick ropes. On thin ropes I switch to an Attache.

[koentje]

On my gear belt I only allow things that:
- I need very often
- I might need in a hurry/ermergency

In the first category:
- a spelegyca and a fig of 8 with their carabiners. The spelegyca attached to the belt with a large alu D-ring, this provides a nice big clip-in point that's always there.
- 4 or 5 assorted carabiners, most of them HMS screw types (the most versatile). That's it.

The things I might need in a hurry:
- a knife in a sheat (on one of the leg loops)
- a spectra piece of webbing, tightly looped as to not snag on things
That's it.

In addition to that I carry my vadotain around my waist (can't snag on things there and is very readily available, not knotted) and I hold the shoulder straps of my backpack together with a quickdraw which also holds a gigi.

With this "meagre" setup I can do everything: descend and ascend rope in every imaginable way, under tension or not and single or double. I can cut and lower, you name it. I can also haul somebody up in a hurry if need be. But I don't consider hauling somebody up an emergency - if it's an emergency better to have gravity aid you and lower the problem :D.

Rich, I know 'tis the season ;) but you must look like a christmas tree carrying (mechanical) doubles of everything and way too much loose ends that can get caught on things above and under water - lighten up :p

[rcwild]

Count again, Koen. I'm only carrying a couple pieces more than you. No loose ends hanging anywhere ... except that damn long extension cord for all my Christmas lights.

[koentje]

Count again, Koen. I'm only carrying a couple pieces more than you. No loose ends hanging anywhere ... except that damn long extension cord for all my Christmas lights.

I was just pulling your leg :D, but it remains a fact that you're carrying one lbs of expensive gear on your belt - where it's either easily lost and/or can snag on things (14 ft of cord and webbing on your belt without counting your valdy, the spelegyca and the little loop of cord on your shunt :-) - even rolled up that still makes a bundle).
I too carry a few of those comfortable "extra's" (a jumar and a mini-traxion pulley), but tucked away in my backpack. Not for fast emergency use and not easily lost.

Koen

[rcwild]

I was just pulling your leg :D, but it remains a fact that you're carrying one lbs of expensive gear on your belt - where it's either easily lost and/or can snag on things (14 ft of cord and webbing on your belt without counting your valdy, the spelegyca and the little loop of cord on your shunt :-) - even rolled up that still makes a bundle).
I too carry a few of those comfortable "extra's" (a jumar and a mini-traxion pulley), but tucked away in my backpack. Not for fast emergency use and not easily lost.

All good points, but it hasn't been a problem for me. By American canyoneering standards, I travel very light.

I think having a runner or two handy is more important when relying primarily on natural anchors. Very quick to throw a sling around a tree or chockstone for clipping.

[koentje]

All good points, but it hasn't been a problem for me. By American canyoneering standards, I travel very light.

I think having a runner or two handy is more important when relying primarily on natural anchors. Very quick to throw a sling around a tree or chockstone for clipping.

Wow ;-) !

Consider this: if you have to rig a rappel on a natural anchor, what needs to be opened ? Right, your backpack to take out the rope - what are those runners dangling at your belt for then ?

I keep a few runners and about 20 ft of sling-by-the-meter in the top pocket of my backpack along with my whistle, gloves and diving mask. I arrive at a rappel, swing off my pack, unzip the pocket and take out what I need. And if it's just for clipping in I can use my valdotain.

If somebody else would be with me he/she would already have the rope ready for me by the time I'm finished. If not I'd take out the rope myself.
And since I'd have to take off my backpack anyhow, no gain in having slings on my belt, that's only dangerous in a highflow canyon.

If speed is important and in a canyon where there are no or almost no anchors we've got another setup: two take front with the drill and sling. The first (drill guy) goes down and chooses the rap point. When the second (sling guy) has arrived and the anchor spot is chosen.
If it's a natural one the sling-guy installs it following the directions of the drill guy who has had time to study the situation, the drill guy keeps a rap ring ready when the sling is put.

If it's a bolt the drill-guy drills the hole(s), puts in the anchor(s) and steps back to let the sling guy finish the anchor with sling or rap ring.

By the time that's done the drill is packed and the ropes are there - the guys behind do nothing else then recuperating rope and playing them through.
This system is so fast the rope guys can't keep up most of the time :-).

But still no runners or slings on the belts...

If it's just one canyon we draw straws to see who calls the moves and who rides shotgun :-). If it's a whole week we just take turns !

[rcwild]

This falls under "whatever works for you" and "whatever is appropriate for the situation". I understand all of your points, Koen, and you know I have a lot of respect for your experience and skill. People reading this should consider the pros and cons of both approaches and decide what works best for them.

I think it's important to emphasize your comments about gear getting snagged. A couple incidents involving people getting trapped under the water because a sling or daisy chain on their harness got caught on a rock was the motivation for my Racking Gear post.

Many canyons around here that get so narrow you can't get through with any gear on your harness.

Didn't you used to carry a Shunt? Thought I saw one on your harness when we did canyons together.

Did I ever tell you what Gi Gi means in Apache?

[koentje]

This falls under "whatever works for you" and "whatever is appropriate for the situation". I understand all of your points, Koen, and you know I have a lot of respect for your experience and skill. People reading this should consider the pros and cons of both approaches and decide what works best for them.

Didn't you used to carry a Shunt? Thought I saw one on your harness when we did canyons together.

Did I ever tell you what Gi Gi means in Apache?

That's the whole idea of all this, that people weigh pro's and contra's and come up with their own style.

My harness "style" has gone mostly unchanged for the last 8 years or so. I moved my valdotain from my belt to my waist after I saw somebody else carry it like that and I found a good knife for wearing on the leg loop. That must be about it. Works for me so far.

And I must have carried a shunt the whole of two months :-): I bought one in the early days because it was compulsory equipment for the exam, decided I didn't like it so I shelved it right afterwards.
I dug it up again in a bid to prolong rope life, by using the shunt as a rope clamp for the rappeling rope: after each person down I'd slip the rope through a foot or so to shift the rubbing spots.
Maybe that's when you spotted it, but it didn't last very long (max 2 months, certainly not a whole season), I replaced it by a gigi which is in my opinion more dependable, versatile, cheaper, less weight & bulk then a shunt in about every aspect.

I re-dug up my old shunt last year in Norway for use as a self-belay device on that big 1500 ft rappel... just in case ;-). I installed it about halfway down ditched it again after maybe 70 ft, haven't touched it since.

Do tell me, what's a gigi in Apache ? Take care because children might be reading this ;) !

[DJ Meding]

Gigi ?????

[rcwild]

... decided I didn't like it so I shelved it right afterwards.

I'm not quite ready to shelve my Shunt, but ... I've been having trouble with it on newer canyon ropes, including the BlueWater 9.2mm. It seems to be flattening the rope a bit. Just enough that it doesn't hold as reliably.


I dug it up again in a bid to prolong rope life, by using the shunt as a rope clamp for the rappeling rope: after each person down I'd slip the rope through a foot or so to shift the rubbing spots.

This use is one of the reasons I carry a Shunt. But can do the same thing with a GiGi or a munter/mule on two strands. I also carry it in case I want an auto-belay on rappel, but I have to admit that's very very rare. I carry it to ascend on two ropes, but I can do that with a sling or prusik. Hmmm. Maybe I'll dig up my GiGi and start playing around with it more. I used it a lot when I was guiding climbs.


I replaced it by a gigi which is in my opinion more dependable, versatile, cheaper, less weight & bulk then a shunt in about every aspect.

Enter Kong GiGi in Google and you'll come up with movies.


Do tell me, what's a gigi in Apache ? Take care because children might be reading this ;) !

For the children's sake, I'll tell you in a private email.

[koentje]

I'm not quite ready to shelve my Shunt, but ... I've been having trouble with it on newer canyon ropes, including the BlueWater 9.2mm. It seems to be flattening the rope a bit. Just enough that it doesn't hold as reliably.

This use is one of the reasons I carry a Shunt. But can do the same thing with a GiGi or a munter/mule on two strands. I also carry it in case I want an auto-belay on rappel, but I have to admit that's very very rare. I carry it to ascend on two ropes, but I can do that with a sling or prusik. Hmmm. Maybe I'll dig up my GiGi and start playing around with it more. I used it a lot when I was guiding climbs.


I saw the same last week during a training exercise (going up a guided rappel), the shunt wouldn't "bite" a single 10,5 mm rope (handheld). The guy had to change it.

The advantage a gigi has over a shunt in the rope-protection role are multiple, apart from bulk, weight and price:
- no lever which can be pushed open against rock
- works with different ropes and diameters together
- you can use the two strands separately, if one strand is still loaded you can feed rope on the other strand

And you can use a gigi to climb a single or double rope as well, on your harness a bit in the way you would use your fig of 8. And by putting your pedal into the top hole you can "twist" it around to make the ascent/descent conversion in the blink of an eye.
Or as a backup descender... or as a conversation starter "what is that" or "do you know what it means in Apache" ;-) ?

Basically the big technical disadvantage of a shunt is that you have to use it on identical double ropes. Put in a 10 mm Bluewater and a 10 mm Beal and one will slip.
It's a kind of love/hate thing, I know a lot of people who swear by it but as many who can't stand one :-).

[rcwild]

Okay, I'm almost convinced. For anyone following this who wants more information about the GiGi, here are some links:

Kong GiGi (http://www.kong.it/doc412.htm)

Storrick: Kong GiGi (http://storrick.cnchost.com/VerticalDevicesPage/Belay/StichtBelayPages/Sticht689.html)

For a while I was using a Trango Magic as my primary rappel device. I liked it because I could use it as a figure eight, as a carabiner brake bar, and as a GiGi. I stopped carrying it in sandstone canyons because it's thin and I worried about it wearing through too quickly. I might start carrying it again instead of a GiGi, but not as my primary rappel device.

Trango Magic (http://www.trango.com/prod.php?id=41)

Storrick: Trango Magic (http://storrick.cnchost.com/VerticalDevicesPage/Belay/MiscBelayPages/MiscBelay759.html)

[Turtle]

While practicing ascending yesterday, using a Petzl Shunt for the upper grab (connected to my harness) and a Petzl Tibloc for the lower grab (connected to a leg loop), the lay of the rope required that I pass over a prolonged, rounded transition from vertical to horizontal. Through several iterations of the ascending gait, it was all but impossible to avoid contact between the Shunt and the rock as the tensioned rope wrapped the rounded transition.

This has me wondering...

How crucial is it to monitor/manipulate the orientation of the Shunt as it contacts the rock? Is it possible that Shunt/rock interaction could release the Shunt?

NOTE ON TERMINOLOGY: I use "belly" to refer to the surface of the Shunt through which the lever passes when released and clipped. I refer to the opposite surface as the "back". I refer to the other two surfaces are "sides".

When I weighted the Shunt while clearing the rounded edge, on some occasions it would lay nicely on its back. This appeared very secure. On other occasions it very much wanted to roll onto one side or the other. This bothered me a bit, as the biner/lever engagement was seeing slight pressure from the rock face in this orientation.

Which orientation the Shunt would seek seemed to depend on the lay of the rope relative to the fall line, my foot placements, etc. It wasn't clear to me that the Shunt really could be rolled onto its belly, but presumably that configuration is very undesirable.

Is it possible to roll a Shunt onto its belly? Would it really release? Is resting a Shunt on its side safe? Is it generally safe to use a Shunt when clearing such a transition?

[rcwild]

Hi Mark,

I've been a fan of the Shunt for quite a while. Based on another discussion I'm having with Koen, I MIGHT switch over to using a GiGi, but in the meantime ...

There are some nuances to using a Shunt. First, if I was looking for a device to only function as an ascender, it wouldn't be a Shunt. I like it because it has several other uses. As an ascender, it is great for ascending two strands of rope, as long as it is two strands of the same rope. Even a slight difference in diameters can cause problems. If I'm already on the ground, I can rig my double strands so I only have to climb one strand, in which case I'd use a different ascender.

If I know there is a lip to pass at the top, I'd rather use my Shunt for my foot loop and something else, like a Tibloc, on top. It's hard to pass a Shunt over the lip because it is so bulky. There are some other good reasons to use your Shunt for your footloop and not as your primary contact point. In some applications, the Shunt's lack of teeth are ideal. When ascending -- with your Shunt as your primary contact -- the lack of teeth is a disadvantage because it can slip down the rope. Possible even when free-hanging. Even greater possibility when passing a lip as you described.

If you opt to use your Shunt as your upper (harness) ascender and encounter a tough lip. One solution I've used is to stop and rig my figure eight in ascending mode. It will be positioned lower than your foot loop ascender, much like a Croll. This setup makes passing lips much much easier anyway. Once past the lip you can continue with this ascending setup or switch back to using your shunt.

[rcwild]

In a private email about Resurgence canyoning packs, Koen described an optional feature called "cloison verticale", which he described as:

" ... a kind of flat, open-ended sleeve on the inside. Like all good backpacks those packs have a gear hanger on the inside, at the top of the back panel. The sleeve is basically a double lining just below that gear hanger, open at top and bottom. It's purpose is to protect/cover the gear that's dangling from the hanger (jumar, shunt, pulley, whatever) so that the rest of the backpack contents don't catch up on them, especially rope ... "

Sounds like a nifty feature. Wish my Resurgence pack had it. Would make a big difference to me in how much gear I carry in my pack vs how much I carry on my harness. Gear I clip to the "gear hanger" tends to get tangled with the rope.

[sonnylawrence]

One problem is what to do with bat hooks, especially the Talon variety. A few years ago I poked a hole through my Thermarest pad and the pack while carrying one. Now I keep them in a Petzl bolt pouch. It would be nice to have a compartment in a pack that could handle them.

[gioffri]

....Wish my Resurgence pack had it. Would make a big difference to me in how much gear I carry in my pack vs how much I carry on my harness....

give a look at the webbag: http://www.wildwater.it :eek:

big pocket on the back panel and many gear hangers

ciao.
Gianfranco

www.x-gatt.com

[sethjandersen]

Question:
In canyoneering it seems that most if not all of your rope ascents would involve climbing two strands of rope at the same time that have been set up for bottom retrieval. Is there special techniques/equipment for ascending two strands of rope at the same time? Sorry if this is a very obvious question but I'm very new to the sport and am practicing as many raps/ascents as I can in a controlled environ. I have purchased a pair of Tiblocs to be carried for emergencies but am wondering if I need something futher. Thanks for the help!

[MIQ_WRX]

The Petzl Shunt will work on two ropes. I like the Bachmann knot for two ropes too. Some rope systems used for canyoneering will allow ascending on a single rope (biner or knot blocked and contingency anchors for example). I think there are some techniques to stabilize a "toss and go" double strand system to allow single rope ascending too. It's probably good to know how to ascend single and double strand safely.

-MIQ

[ratagonia]

Question:
In canyoneering it seems that most if not all of your rope ascents would involve climbing two strands of rope at the same time that have been set up for bottom retrieval. Is there special techniques/equipment for ascending two strands of rope at the same time? Sorry if this is a very obvious question but I'm very new to the sport and am practicing as many raps/ascents as I can in a controlled environ. I have purchased a pair of Tiblocs to be carried for emergencies but am wondering if I need something futher. Thanks for the help!

In canyoneering, we often set the rope up single strand - meaning that the actual rappelling (and subsequent ascending, if required) takes place on a single strand of rope. The pull down is achieved using a seperate piece of rope (or the other side) that is not actually rappelled on. So - YES, one should know how to climb a doubled non-blocked rope, but the techniques championed by the ACA emphasize use of a single rope.

In addition to a shunt, the various ascending knots - Prusik, Bachman, 'that third one' - can work well on double ropes.

Tom

[sethjandersen]

Thanks for the help guys!

[koentje]

In canyoneering, we often set the rope up single strand - meaning that the actual rappelling (and subsequent ascending, if required) takes place on a single strand of rope. The pull down is achieved using a seperate piece of rope (or the other side) that is not actually rappelled on. So - YES, one should know how to climb a doubled non-blocked rope, but the techniques championed by the ACA emphasize use of a single rope.


In a typical canyon scenario the rope will rub somewhere along the line of descent. It's not a good idea to jug up a single rope that rubs over an edge...
Unless it's completely free of rub, prefer going up double if you can.

And be careful with a shunt: to suppose it always works on rope with the same diameter can be dangerous. It only works dependably on double identical rope, since hardly any rope is the same diameter.

A given 10.5 mm caving rope from brand X will have a different diameter than 10.5 mm by brand Y. Even different rope types of the same brand have enough difference to have the thinner rope slip under load.
Maybe the friction of the anchor on top will prevent this from happening when jugging up a double rope. But it should be clear that the safety of a shunt on double rope is not a thing to be taken for granted.

[bigtoeski]

Is the third one mentioned above known as the klemheist?

[ratagonia]

Is the third one mentioned above known as the klemheist?

Yes, it is.....

[sonnylawrence]

Recently I witnessed an experienced canyoneer using a Petzl Shunt on a single strand 9 mm rope. The person was one foot from the edge of a vertical cliff. The Shunt is only able to use single strand on 10 mm or greater diameter rope. Consequently I thought I would re-visit the load a Shunt can handle before it begins to slip. Paul Stovall and I rigged a dynamometer and mechanical haul device to load the Shunt. New and old ropes were tested. Each one was loaded with a single strand or double strand going through the Shunt. Forces in kilo-newtons are reported when the Shunt started to slip. The sheath bunched up on the Canyon Pro and Ez-bend. For some of the doubled ropes, the test was stopped at around 5 kN when there was still no slippage.

For practical purposes, one can view a person as weighing one kN. She or he could easily double the weight the rope sees by slipping while there is slack or before the stretch in the rope is removed. Consequently any of the values in the table of less than 2 kN could indicate that in that scenario the Shunt would slip and the person could get injured. This is a static test. The values likely will be much different for a dynamic test.

[hank_moon]

Good reminder, Sonny. The SHUNT is designed for use on 1 or 2 ropes, but when used on single rope, the minimum recommended diameter is 10 mm. On doubled rope, the min. is 8 mm. I used a Shunt on single 9 mm to recover a rope last Sunday w/o problem, but YMMV depending on the usual variables.

[Turtle]

Sonny, any thoughts on how to reconcile the results with what you observed in your earlier test (http://www.canyoneering.net/forums/showthread.php?t=643)? In that test, you had a Shunt on a single strand 8mm holding well over 2kN. Only one or two of the six 8mm single strand tests came close to that value this time around...

[sonnylawrence]

Sonny, any thoughts on how to reconcile the results with what you observed in your earlier test (http://www.canyoneering.net/forums/showthread.php?t=643)? In that test, you had a Shunt on a single strand 8mm holding well over 2kN. Only one or two of the six 8mm single strand tests came close to that value this time around...

I think the Shunt on small diameter rope is very dependent on the condition and design of the rope. For example the Canyon Pro vs. Canyon Pro DS were different. The original Canyon Pro had the sheath obviously bunch up. That was not the case with the DS. Old (hence dirty) vs. new rope acted differently. It leaves me in general not trusting the Shunt on 8 and 9 mm ropes unless they are doubled. It is now very rare that I use the same rope doubled. (Keep in mind the Shunt needs in essence for the two strands to be the same to work properly. For example it doesn't work to use 8 and 9 mm ropes simultaneously in a Shunt.) So I don't carry a Shunt. It is not worth the weight and bulk. It would be nice if it were redesigned to fit 8 mm rope single stranded. Paul Stovall came up with a prototype for a device that could be used to ascend and descend. It could be made out of stainless steel. However I hit the deck pretty fast when I tried it! Back to the drawing board.

[crankin]

I would refer those interested to this site (.pdf):

http://www.ropeworks.com/site/pdf/RA%20Testing%20Paper.pdf

It has been documented that the shunt will slip from x-factor falls. In this way the shunt actually acts as a fall-arrest, which can be nice, considering that most of us are using static ropes - i.e., if you were using it as a back-up while descending and lost control of your rappel, you're not going to stop as soon as the shunt starts taking tension.

In general, there will/should be little to no fall factor created in most uses of the shunt when it applies to canyoneering. The times I think it most likely would be when using as part of a personal tie-in point on a loaded rope or if your foot slipped out of a stirrup during transitions/ascending/knot-passing. (Of course those unfamiliar with the shunt can easily release it before it is completely loaded. But that's not part of this discussion.)

Having said that, there are certainly some concerns and questions:

1. The various ropes used in the testing by Ropeworks/BLM were all around 7/16" (~11mm). You can certainly expect more slippage for smaller diameter ropes. But how much? (Sonny? ;) )

2. A direct follow-up to #1. If passing a knot, or during any point in ascension, you could develop an x/x-factor fall if you screwed up. If the shunt slips x-amount along the rope and hits the knot or lower ascender, you might get to take the big drop (if not second-tied to another ascender).

3. How would your lower ascender react?

I'm not nearly at the point of saying that the shunt should not be used on single-strand 9mm rope. It can be damned useful. But with 8mm I take another rope-grab. My opinions are subject to change as well. When it comes down to it, We're not trying to be OSHA or ANSI compliant whilst recreating. I'll finish by sounding like every other thread - I'm being completely redundant - it's important to know your equipment before you have to use it in a real situation.

[sonnylawrence]

1. The various ropes used in the testing by Ropeworks/BLM were all around 7/16" (~11mm). You can certainly expect more slippage for smaller diameter ropes. But how much? (Sonny? ;) )

Paul Stovall has rigged a dynamic test device similar to the one shown in the link Charley provided on this thread. Mostly we need some rope. Tom Jones has furnished us with Imlay Canyon rope to test. It would be nice if someone donated a Shunt to the cause. I have plenty of junk biners to test with. Message me side band if you have about 20 feet or so of rope to send me.

[rcwild]

Love my shunt. I've been carrying it for years, primarily because of its versatility. Over the past couple years, as more people have started using ropes on the narrow end of the shunts range, I've noticed I'm using it less. During a recent guides course, students set up a system with two tiblocs, that has me re-thinking the gear I carry on my harness.

The problem I gave them -- a subject, stuck on rappel on two ropes rigged toss 'n go, who needed to be hauled up to the top. They rigged their "ratchet" with two tiblocs on one wide HMS carabiner. They clipped this carabiner over the spine off the tiblocs to capture the rope as I showed them for a previous exercise.

I did not allow them to use a rescue rope, so they set up a 2:1 pig rig, then another 2:1 pig rig to add more power. Total 4:1. This is the solution I was expecting. But ... after they hauled and reset a few times, they noticed they had a bit of slack between the ratchet and the anchor. They added another rope grab downhill from the ratchet and used the slack rope to rig a double-strand z-rig (3:1). Because they clipped the HMS carabiner over the spine of the tiblocs, they were able to convert the carabiner to one of the pulleys in the haul system and the tiblocs became self-minding.

They had less mechanical advantage, but were able to pull longer distances between resets. The lower mechanical advantage was not a problem with two guys pulling.

Normally, I would have used my shunt or a prussik as the ratchet for this type of system, but neither would have been self-minding. Slick. So I'm going to start carrying my shunt inside my pack and two tiblocs on my harness. Added benefit ... I've been ascending with one tibloc and one hedon. Works fine, but ascending with two tiblocs will be smoother.

[rcwild]

I was a long-time fan of the Petzl Shunt until I experienced an issue with slippage on a 9.2mm rope. I decided it didn't have as much utility as it did when my guiding ropes were all 10mm+. Rethinking my position. Here in Mexico I am watching leader and guide candidates who were students or who were influenced by students a few years ago when I was using my Shunt regularly. I guess I forgot how handy it can be in so many situations ... like ascending double ropes or when you actually want a rope grab that will slip free on demand (which the Shunt can do because it lacks teeth).

A specific technique to illustrate: We include a timed event in our exams. Examinees ascend, pass a knot, transition to rappel, rappel past the knot. When the upper rope grab is a Shunt, there is no need to remove it during the transition; simply release it and bring it down with you. When you approach the knot, let the Shunt grab the rope and hold you while you remove your rappel device from above the knot and reinstall it below the knot. You can use the rope wrapped around your foot to stand up and release the Shunt so it comes down to the knot. Remove it, unlock your rappel device and continue rappelling.

I just might start carrying mine again.

[oldno7]

It may not work for everyone but it does me.(sometimes) You can use the shunt just like a Valdy tied in a French braid.
By slowly pulling up on the lever I can slowly slide down the rope, no need for using a footloop to release.
My problem became that at times it would slowly creep down the rope while weighted, it lacks consistancy IMHO.

[rcwild]

The incident that caused me to set aside my Shunt months ago reoccurred today. One of the candidates used his Shunt to ascend and it slipped, flattening the 9mm rope on the way down. The rope's round cross-section is now oblong in one section.

There are other threads in the forums that discuss the issue in more detail. Petzl specs the Shunt for >10mm if used on a single strand and >8mm if used on double strands. Problem is occurring on a single strand of 9mm.

Still worth carrying, just be aware of the limitations.

[rcwild]

I just merged several threads about the Petzl Shunt into this one thread. Lots of pros and cons in the posts. I had forgotten about Koen's comparisons to the Kong GiGi. Since the two slots on my Totem will function like a GiGi, carrying a Shunt would be redundant.

[mountain man]

saw this from petzl on the shunt
http://www.petzl.com/en/pro/news-pro/2012/01/10/petzl-statement-special-use-petzl-shunt?utm_source=twitter.com&utm_medium=%40petzl&utm_campaign=shunt-statement&utm_content=en