Friction devices aloft

[xtremetrees]

The nice thing about picking up friction from devices or caribiners is that it's a regular, consistent predictable friction. Through a crotch or over a limb, you'll get more more friction, but how much depends on the texture of the bark, diameter of the limb, wet or dry. Steel biners never really change, so the friction they offer remains relatively constant. This consistency offers predictability and results from one climber to the next should be essentially the same.

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[xtremetrees]

TM do tell you have been cuttin trees like this for years?.
Using mechanical advantage is faster,safer, and more self-reliant. This info can save alot of head aches, it keeps the ground guys clear and off your ropes! :notrolls2:

 

[TheTreeSpyder]

i like that technique, have used it for years, use a quick release on the tail to speed it up. With the the line thru krab only is for light limbs only because of the sharp bend. Another way is to lower the first, till 1 end is on ground and hitch is still 4' up or so, then use that tight line to speed line other stuff down on, then pull line out.

A couple of times i've used it to lower to a 2nd story roof, then lowered myself to roof, to cut up and throw off or even re-rig from there to ground in real tough spots. Then swing self off roof.

 

[Tree Machine]

That's what I meant. Lowering 300lbs. Is not very difficult to do using one hand so even though it a 2/1 MA due to two legs of the rope on the load. The climber never sees close to 150lbs but really sees loads maybe as low as 20lbs. on the held end.

So true, so true.

I did a rig from the ground yesterday, we were removing a 12" DBH Cherry, vertically, from the ground-up. It looked strikingly similar to Spidey's diagram a page ago.

I asked my ground guy how he'd do it, "4 or 5 wraps around this tree, one guy cutting, one guy holding the rope, another guy moving out the firewood." First, we're only two guys today and second, how would you do it if you were solo, or as we're ABOUT to do it, as if it were one man working alone? "5 wraps?"

This setup was done from the ground, major friction on a vertical trunk, but can just as easily be done on a horizontal limb. It is a near-instant friction set for controlling friction withou any device other than a caribiner. For the sake of the diagram, I will point it out as 'major friction', though it is one of three friction points. The hand control needed is fingertip control

This is another personal rigging scenario where you really want to only do this with smaller trees, and only when you have another tree VERY close.

 

[Tree Machine]

Hey Tree Machine, why don't you use a real friction device, why just the biner, or sling and biner. Why not use a GriGri, or an ATC or something?

First, I'm starting with the simplest friction control systems, part of every tree guys rig; slings and biners. This will suffice for light rigging, which is what we're talking about as we've agreed that rigging big, heavy material should NOT be done solo-aerial.

I can and do use mechanical devices aloft, but only when I rig off of 11 mm lines. Most devices are not sized for or 13 mm lowering lines. You're limited on what you can use, but I would still recommend, the simpler, the better.

Here's a typical aerial rig, using one biner and your hand for belay. This may seem similar to taking a wrap, but actually you just flop a bight over the limb and clip it one of two ways. Saves the time having to run and feed rope. With this on, you're depending on the tree for friction, not my favorite means, but I am starting simple here.

 

[trevmcrev]

GO Tree Machine, GO. Dont hold back now. Great stuff, i am definately learning some new tricks here. I understand its limits. It shouldnt be this hard to discuss something like this here.



Trev

 

[kennertree]

Great techniques tm. Im starting to enjoy this thread.

 

[Tree Machine]

So far you've seen methods where friction is utilized from the limb/crotch. or by passing through caribiners. I often favor little tricks where the rope either runs alongside itself, causing partial friction of rope upon rope, or where the rope crosses over top of its own self creating friction that can be controlled not just by your belay hand, but by pressure, or tension.

This is what a friction hitch does; friction of rope upon rope, only without a biner in the middle of it.

Here's a pic similar to the ones prior, it looks like a a 2:1 but is actually a 1:1 where there is some rope upon rope friction because the rope passes through one of the slinged biners twice and it passes and runs in opposite directions. This is a good method for aerial lowering of stuff when I have someone to unclip the rope, and the material is getting bigger than 'normal'. This one you get to keep all the slings. I'll show this one in three steps.

 

[Tree Machine]

Here's yet another variation. At times I'll use this simple 3:1 mechanical advantage for lowering things that are questionably too big for solo aerial lowering. This one you can go a bit bigger, the lowering is slower, but still allows you hand control with a very light touch. Big deposit into the friction account passing the rope over a limb in two places.

This one utilizes the friction of one limb, twice, as well as one pass through a biner with minor rope upon rope friction at the biner. Be careful. A 3:1 means for every meter the limb is lowered, three meters of rope pass through your belay hand. Make sure you have enough length in your lowering line.

 

[xtremetrees]

Ive thought often how a short rope could become to short in a hurry TM when applying your technizues. I have also wondered if a smaller diameter yet stiffer rope be more than appreciated as well.

 

[TheTreeSpyder]

Pretty tight bights to be working that rope thru i think; better to come under load with bight, then krab to side of sling that goes up to coonect to single leg/ termination, to secure bight. Not good to impact 3/1 with friction so close cuz no elasticity.

 

[Tree Machine]

Good point, Spidey. What I find, though, is that there will rarely be a shock load for a couple reasons. First, we're not talking big weight here. Second, your control of the cutting and of handling the line avoid the limb 'running'. This keeps the forces in check.

If you're dealing with low mass and low to no acceleration of that mass, your forces will not be much beyond that of the static weight force.



Xtreme, on your question about thinner lines and stiffer rope, I use a retired Velocity as a lowering line every now and then, though it is generally too short to be practical (that's why its retired). I like the fact that it's lighter to schlepp around up there and i can experiment with devices other than slings and biners if I'm in that sort of mood.

11 mm can handle it easily because 1) the weights we're dealing with are not large and 2) your precision cutting and rope handling assure that any shock loads are minimal.

You are a better judge of the weight and behavior of the limb than a ground guy a distance away. With YOU controlling the rope at or near the point of rigging, there is no room for any degree of rope stretch since the distance from rigging-to-limb is so very short.

As long as you don't go too big and create a runaway train (which could happen just as easily from a handler on the ground) the rigging and cutting procedures should be pulled off with precision, confidence and 100% control during all phases.

Hey Spidey, what is the quick-release you use instead of a caribiner when coming around tight bends on a limb? If the bend is that tight, this tells me the limb is quite small and any forces also small. I fully understand about sideloading a steel biner around a limb smaller than the diameter of your wrist, but when it's that small and the forces are minimized by the smallness of the limb and you accurate control of it, I tend not to worry. This is because over the thousands of times I've lowered limbs, I've never experienced a biner blowout or break or failure of any kind. I use the stainless steel non-locking slideline biners from Kong. I use the locking ones for my climbing duties and they never see rigging duties (except for redirects).

 

[woodchux]

Has anyone tried the Tuba friction device ?
Says it will pass knotted ropes easily.

 

[Tree Machine]

I've played with it at the Petzl booth at TCIA. It's a Portawrap-esque device, to big, IMO, for aerial lowering. It would work, but you gotta schlepp it around up there. I do like the design, quite a bit, actually. I would love to test drive one of those if it were made in a mini style, something that could fit in the palm of your hand. I think that has the potential to be exceptional, but it's one of those great devices that doesn't exist yet. I don't see a convenient way to soft lock or hard lock. It needs a couple horns.

 

[Tree Machine]

Like this, or something akin to it.

 

[woodchux]

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

 

[xtremetrees]

Whats wrong with the black widow and mini portawrap?
You might could even burn an aliumium biner in half, cut it right into? recon?

 

[woodchux]

Iv'e never used blackwidow, but i LOVE my new mini portawrap

 

[trevmcrev]

Just when you thought this thread was dead!

Ok so i had a proper go at lowering from aloft yesterday
Now as the business owner im not normally onsite but with 2 climbers off at the moment i had to jump in. I think i blew the groundies socks off with this. Perfect tree for it too. Lots of small branches needed lowering. It was so fast they didn't know what was going on, every time they turn around another branch was on the ground, they look up as if to say "how'd you do that" then it changes to "how'd you get the rope back" I look at them like "outta the way, another ones coming"

Priceless.

Thanks Tree Machine for persisting with this. Yes ive done this for the odd small branch before here & there, but not as deliberate method for dismantling much of the tree.

It was back to big rigging today though with the removal of a big Manna Gum. I quoted it and allowed a full day for them, but again climbed it myself and had it done by midday

Its funny how you sorta forget why you got into this in the first place, but i love climbing, must do it more often, maybe once a week or so for fun (and to keep the "climbers" honest) hahaha.

Trev

 

[Tree Machine]

Trev McCrev, I'm glad you found a groove. Many times you can pretty much just hand belay a limb without much friction from anything else than your gloved hand, but to have a sling and biner connecting the rope to a limb adjacent to you, keeps the rope from getting away from you and you maintain control at all times. There are methods where some of the friction equation comes from a device which is attached to the climber's saddle. Now that's a totally different chapter. That's the domain I climb in. That would most certainly get the censor stamp.

But back to McTrev and your safe and swift experience. Swift is the word, really. Trev, were you working both ends of the lowering line? Of course you were. You were up there crackin the big whip, workin it safely, really diggin on it. Good on you, Mate.

Sling and a biner. Quite a versatile player on Team Saddle. I like to carry a minimum of three and a max of 6 or 7 for zipline work. Slings are mainstays of the rigging diet, especially when it come to using friction devices aloft, or more often, using the biner as the friction device,


which,


hey.....

That was a point brought up about 11 pages ago, the concept fo a modified biner AS a dedicated friction device. This is that device that doesn't yet exist that would handle friction in a way much differently than it's being done now. We could create that device right here. Just some imagination and Photoshop. We could design it here together. We create a friction device that does not currently exist at Storrick's site, . It would be some work. It would be a stretch to stay focussed on the design and see it through to finish. I don't see the piece being very complex, but since it would be a buildable device, I would volunteer to build it, or at least give it a good whack. :rockn: