V.T prussik with pulley instead of gri gri on tope rope

Hi guys I just started boulder climbing and I was wondering if one could use some sort of a prussik system to secure himself on the rope on a top rope scenario, or would that be too risky? I've been tree climbing for a while now and my favorite set up is a VT prussik with pulley  and I've never had any problems with that till now as long as you always remove slack.

do you mean on a top rope that is fixed to the top of a route (top rope solo) or do you mean on a belayed top rope with a partner?

There are many suggested TR solo belay setups in the TR Setup thread. I don't think VT+pulley is one of them. That might tell you something. Any setup that requires you to pull the rope through to eliminate slack is not worth having IMO.

Sawyer W wrote:

do you mean on a top rope that is fixed to the top of a route (top rope solo) or do you mean on a belayed top rope with a partner?

Fixed top rope because it will then be the exact same technique that we use in tree climbing basically 

Dorian Fediuc wrote:

Fixed top rope because it will then be the exact same technique that we use in tree climbing basically 

Your in a whole different world now, a prussic isn't a substitute for a grigri or micro trax for progress capture when tr soloing.

Get a microtrax. 

I expect that professional arborism requires higher safety margins and much higher expected loads in your industrial rigging systems.  If a prusik and pulley are standard procedure in tree climbing then I would do a careful comparison to rock climbing to understand the differences between rock and trees before adopting the same method.  Is it possible that there is a new failure mode related to climbing (the climber isn't constantly weighting the self arrest system?  the climber isn't tending the prusik while focused on rock climbing?)?

If there are no new failure modes introduced then I'd proceed with caution and test it with a backup at first.  The arborists that I have rock climbed with put climbers to shame in their skillful use of ropes and rigging systems.

Search on "top rope solo."  

Jason4Too wrote:

I expect that professional arborism requires higher safety margins and much higher expected loads in your industrial rigging systems.  If a prusik and pulley are standard procedure in tree climbing then I would do a careful comparison to rock climbing to understand the differences between rock and trees before adopting the same method.  Is it possible that there is a new failure mode related to climbing (the climber isn't constantly weighting the self arrest system?  the climber isn't tending the prusik while focused on rock climbing?)?

If there are no new failure modes introduced then I'd proceed with caution and test it with a backup at first.  The arborists that I have rock climbed with put climbers to shame in their skillful use of ropes and rigging systems.

Dude professional arborists make climbers look like a bunch of pansies. These guys are up there on old, rotten trees, hacking away at the thing that’s holding them up. When they cut pieces off, the load structure changes, and the trunk can swing wildly. They’re wearing (essentially) crampons and usually using a ratty-ass old rope. Oh yeah, they’re also carrying a sharp-as-fuck chainsaw. Safety is not a thing in that industry.

I promise you that safety is everything in that industry.  A sloppy arborist will have a very short career.  The OP is in Austria, their professional standards a bit tighter than the standards in the wild west.  I think we can agree that we both have a lot of respect for arborists.

Gunkiemike wrote:

There are many suggested TR solo belay setups in the TR Setup thread. I don't think VT+pulley is one of them. That might tell you something. Any setup that requires you to pull the rope through to eliminate slack is not worth having IMO.

This. The prusiks require you to pull the rope through. All of the other devices you will find in the TR solo threads are self-feeding allowing you to climb almost like normal.

A neck tender will work with a friction hitch just like ascenders to manage the slack.   Most in tree work carry a lanyard which can be placed over a shoulder and connected to the hitch instead of the neck tender.  A hitch does require some knowledge and skill to get it right to function properly, can’t just buy it off the shelf.

The failure mode that concerns me is the friction hitch failing to grab during unexpected falls. This happened in a TR solo scenario at Smith Rock, and a kid broke some bones I think. If I remember correctly, it was a church group thing with incompetent leaders.

The core of the concern is how does the friction hitch respond to a load applied over a very short time. From what I've seen, I'm not ready to bet my life on it.

Here are some factors to consider:

Slack in the system- this is the easiest to mitigate, but if there is some slack that's not good...with a microtrax, you live in a ff1, and you can look up the Petzl tests. How many tests have you done with the exact rope/cord/hitch falling on it with slack? I bet there are some cases that grab, but probably a lot of failures too. I realize that arborists use much more suitable materials with a wide range of hitches.

Tension on rope- in my experience, friction hitches don't grab well on a tensioned rope. Might be an issue at the top of long pitches with no rebelays, or if you weight the end of your rope for better feeding. If the hitch starts sliding, I doubt it will grab while you're picking up speed.

I think that friction hitches respond too unpredictably to unexpected falls to make me happy with them for TR solo, unless there are no alternatives. If I had no other gear and desire to find a workable setup with a VT/pulley, I would do A LOT of tests with falls onto slack (with a backup system of some sort) to really understand the limits of the system. Rope soloing is all about personal responsibility.

Brocky wrote:

A neck tender will work with a friction hitch just like ascenders to manage the slack.   Most in tree work carry a lanyard which can be placed over a shoulder and connected to the hitch instead of the neck tender.  A hitch does require some knowledge and skill to get it right to function properly, can’t just buy it off the shelf.

We don't do that. Idk who told you that. The only time we use neck tending devices is for SRT ascending. And most arborists don't use SRT. Hitches are easy. I can tie five different variations that all work fine. One is using the same rope onto itself Incase you drop your gear. 

Buy a zigzag, you'll never use the vt for tree climbing ever again. Honey Bros sells them for cheap. It tends the rope very smooth and would self tend itself if you weight the end of your rope. I use my microtraxion instead because it's much safer to fall on. 

I recommend buying a microtraxion from banana fingers for top rope solo. You can use your VT hitch at the top to descend if you want to. 

Also, European arborists are not safer than us Americans. They just have a million more regulations to follow than we do. If they didn't have to wear screaming orange uniforms, they wouldn't do it. Lots of them wish they could work here instead.

J C wrote:

The failure mode that concerns me is the friction hitch failing to grab during unexpected falls. This happened in a TR solo scenario at Smith Rock, and a kid broke some bones I think. If I remember correctly, it was a church group thing with incompetent leaders

Tension on rope- in my experience, friction hitches don't grab well on a tensioned rope. Might be an issue at the top of long pitches with no rebelays, or if you weight the end of your rope for better feeding. If the hitch starts sliding, I doubt it will grab while you're picking up speed.

I think that friction hitches respond too unpredictably to unexpected falls to make me happy with them for TR solo, unless there are no alternatives. If I had no other gear and desire to find a workable setup with a VT/pulley, I would do A LOT of tests with falls onto slack (with a backup system of some sort) to really understand the limits of the system. Rope soloing is all about personal responsibility.

Sounds like not enough wraps on the prussics. It's a touchy sweet spot. You gotta test them out on the ground. The VT is not a popular version of a prussic hitch in tree climbing because of how dramatic the friction difference is between 3-4-or 5 wraps. I really like it with 4 wraps on an ocean prussic. VT hitch runs horribly on my beeline prussic, always slips and doesn't wanna grab the rope

Erik Strand wrote:

We don't do that. Idk who told you that. The only time we use neck tending devices is for SRT ascending. And most arborists don't use SRT. Hitches are easy. I can tie five different variations that all work fine. One is using the same rope onto itself Incase you drop your gear. 

Yes, I meant for ascending only.  If more arborists did use SRT it would probably extent their climbing careers, it has mine. Agree about hitches, if tied correctly will reliably grab and don’t slip on slacked or tensioned ropes.

Petzl says the Zigzag shouldn’t be used on a fixed rope without the addition of their version of the Rope Wrench.

The VT’s function depends a lot on how long the legs are from the last braid, or crossed round turn.  If they are too long it will not grab reliably, using a hitch cord of a set length, that isn’t the right length, might cause this problem.  

Facts, SRT definitely helps with the older Generation of climbers staying in the trees, no need to tear your biceps humping up a rope. I use it for pruning and some removals, but I find myself throwing my lanyard around the trunk and walking up it 9 times outa 10. It's just so much easier than any other form of ascending imo. Forsure he should definitely get a rope wrench/chicane if he uses the zig zag for this. I really.hope he doesn't though. I tried it once and that's all the testing I needed to decide "fuck that". I was mostly just trying to show that, yes we have tools that will "work", but I don't recommend them 

You also make a really good point about the prussic. My.beeline is two inches longer and probably makes a big difference trying to use the same knot.

A bit late to the convo, but as an arborist in the US, the obvious answer, if you want to use a prussic, is to use it with a Rope Wrench or Hitch Hiker.  Both are used in SRT situations. Both work on tensioned rope and can self feed if the rope weight is sufficient and you use a neck/chest attachment.  Or use any of the mechanical devices on the market (akimbk, rope runner, zigzag+chicane).  I would recommend backing up every 10-15 feet with a stopper knot just in case.

The RW and HH aren’t needed for ascending, they are only helpful with descending.