Friction devices aloft

[Tree Machine]

It'd be nice to have a small device, with a lever for friction control, like the petzel stop or something similar

I'll dissuade that because of this: The other day I rigged a tree to take down from the bottom up. It was a conifer, about 40 feet tall (about the limit for me for this technique). I rigged 11 mm line through a Petzl Gri Gri, all held to the base of an adjacent tree with a tuflex rated endless loop sling - this has nothing to do with friction devices aloft, though a GriGri can be used up there, as long as your rope is no bigger than 11 mm in diameter.

Up in the air, a GriGri would work perfectly well for lowering but for me it would make my rigging unbearably slow and it would not be possible to control shockloading (as mild as they are with small limbage) as precisely as with the hand as the controller of friction.

Here on the ground, as in the illustration, the GriGri was a fair choice, it worked anyway, but the weight was probably 10 or 20 times that of what I'd attempt solo aloft. I would have been better off with a portawrap in the picture.

Anyway, the answer to Woodchux's remark about a device with a handle, I think the Petzl Stop would have been a better choice on the pictured tree too. While lowering a 40 foot tree on old 11 mm Velocity, the cam bound down very hard on the rope, and the handle seemed near the breaking point when I tried to release friction. But actually, it did the job beautifully. I doubt Petzl would approve of such use of their gear, but it worked great with smaller vertical takeups, this tree was bigger than I'd recommend for a small friction device (and small rope, for that matter).

But it's good to know.

 

[sawn_penn]

It'd be nice to have a small device, with a lever for friction control, like the petzel stop or something similar

The lever on a petzl stop is definitely not for friction control. It is for locking off when you are stopped.

 

[woodchux]

Something like an arborist block with an internal brake is what i had in mind.
Maybe a little something like this, with a control handle that will vary the applied friction.

 

[Tree Machine]

Do you mean like a bar that would tilt the device, allowing the rope to run more freely? See the device in the lower right of the picture. Are you thinking something like here?

 

[woodchux]

Or this

 

[Tree Machine]

So the lever would pull the friction posts apart allowing the rope to run.

So with hands off, the load would hang, and you use the lever to lower the limb with precision.

I would give something like that a try.

 

[woodchux]

Do you mean like a bar that would tilt the device, allowing the rope to run more freely? See the device in the lower right of the picture. Are you thinking something like here?

I am thinking of a bar that engages some type of "brake pad".
Just something that would be consistent , and easy to vary the amount of friction.

Neat little gadget in that link. But I would prefer something more heavy duty.

 

[Tree Machine]

Weight becomes an issue, speed with which it can be set, how it travels aloft with you when not in use.

I would prefer something more heavy duty.

You get to a certain level of heavy duty, you should maybe be having that device working the rope from the ground, attached to the base of a tree.

I have to keep coming back around to that we've sort of agreed as a general ground rule that in solo aerial lowering from aloft, we're not working with big pieces, so the need for a heavy duty device, while aloft, should be considered carefully.

I would want a good number of features in a tight, compact, highly specialized piece. I'd want the device to multitask. Since this is a concept friction device that does not yet exist, let's dream big and ask some things of it.

I want to be able to apply the device to the rope in under two seconds. That's my #2 requirement. # 1 would be that it would be bombproof safe.

What else? Need to be able to work the device forward and backward with one hand, left or right.

I want the sucker to fit in the palm of my hand.

 

[woodchux]

A removable or very short control handle would be a good thing.

 

[woodchux]

Well a removable handle would not be good, just something to drop.
One piece is definitely the way to go.

Maybe a stubby lever handle, a thumb slide, or knob.

A recessed push button would not snag on anything, and would probably be the best choice.

If the inner bushing were to ratchet like a mechanics wrench, you could have a reversible progress capture function. Be good for MA etc.

 

[TheTreeSpyder]

i still like the 1 way pulley strategy, without cam/pawl the bites line. Gives pretightening capability free wheeling rope towards ground, but making friction bollard on load pull side.

 

[Tree Machine]

I'm with spidey on this one as far as friction strategy goes.

The lever option requires that you have your hand directly on the device. This give potential for your glove, or possibly a long sleeve to get caught up and sucked in beteen rope and metal. No big deal, it happens. Seemingly, the bigger the load, the harder the cam would have to clamp down on the rope and there is a point where perma-pinch may occur, or point damage to the rope. There have been many time where a lowered limb gets hung and you have to rappell down and either dice it in place, wrestle it, or somehow release it. A handled device wouldn't leave you any options but to deal with it while it does a static hang, then go back up to lower it back down. I prefer to be able to lower the limb from wherever I'm standing, or hanging, regardless of where the friction device is.

That's one key benefit of working the friction from the front of your saddle, which if I were using woodchux's handled piece, I would (think...) want to have that attached to the front of my saddle and I would determine whether it could Also be used as my personal friction handler. It's always going to be right there where you need it, working in conjunction with any friction sets you have on the tree, and alongside your lifeline attachment which you also have full control over it, right there in front of your belly.

Are there ever times you'll need to work your lifeline AND lowering line at the same time? These are the (yum!) moments where you have to expand your skills, either avoid situations more effectively, or get down there and git er done.

Again, I come back to "Don't do limbs that are too big." If the thing you're lowering solo from aloft is a reasonable size, there's only so much in the way of forces and problems that can occur. Aerial solo work of this nature is not the place to 'go big'. There are other places appropriate for that.

 

[Tree Machine]

I will buy a one way pulley when they hit the market. It's a great idea and will reduce tree loading.

It gets a two-thumbs up from me in all respects except it will allow a guy to go bigger and with this, a guy is more likely to get in trouble.

Still, the one-way pulley has a lot of potential for all kinds of rigging scenarios, basically all that might require a pulley, AND all that require a bollard. Any need for false-crotch, redirect or hauling, this piece can fit. I see it as an amazing multitasker and I really gravitate toward that kind of gear.

Yea, sign me up.

 

[xtremetrees]

would you rigg to this holler spot.?

 

[xtremetrees]

One lead of the 4 is already on a fence.
Notice my watch for size comparision.

 

[xtremetrees]

Here is the fence.
I'm still not sure what caused this multistemmed popular to fail. I guesstimate the tree standing to be 14, 12, and 20 DBH. Tallest extending up to about 90 feet. The one on the fence is about 18 inches DBH and 75 feet tall.

Edit maybe that 26 inches DBH.

 

[xtremetrees]

Hollar back yo here is the 14 inch

 

[xtremetrees]

Its the tree in the sky on the left back of the house down below is the holler spot approximately 30 inches of hollow. Therefore I'll be tying into the sweeet gum at about 70 feet up and swinging over to the popular.

 

[Ian William]

Hi Tree Machine
I have been reading your threads/views on friction devices aloft and find them very interesting.....and have re-read your threads several times over. Can you please expand on these idea's relating to your set up... ie how the connection for rigging is made to your front saddle and what specific tools are used ( figure 8, karabina using munter hitch, grillion or other lowering devices etc ). I see your preference is to use 11 mm rope for lowering.

Found this topic very interesting and informative and hope no censorship will take place with your reply. Any photos/drawings would be helpful

Regards Ian William

 

[trevmcrev]

Can you please expand on these idea's relating to your set up... ie how the connection for rigging is made to your front saddle and what specific tools are used ( figure 8, karabina using munter hitch, grillion or other lowering devices etc ). I see your preference is to use 11 mm rope for lowering.

opcorn: Yeah tree machine, i'm also wondering about this. I've had a go with slings n biners but not too sure about this aspect. I guess a grigri or any device that could belay a person could be used to self belay a branch down up to a similar weight. Some guidance from your experience on this would be great.
Plus ive got a 300 meter roll of 11mm arapaline sitting here just begging for it!!!

TrevMcRev