grigri

W

woodpecker

Location
San Jose, CA, USA
Been a long time since I have been up on the forum so you guys may have talked about this previously, but here goes?

Is a Grigri legit as a replacement for a taunt-line hitch? I have found lately that running through the grigri attached to my "D" and up through a micro pulley attached to a handled ascender is making my life a lot easier in the big trees. I figure it is okay for ascention up to my tie-in, but not as confident in it's legitimacy for fall protection in movement around the tree canopy.

Any thoughts or experience?

Staying tied in,

Brian
 
You're using a Frog setup. During my SRT quest I used a GG for a while. It does have some merit. The issue that I have is that in a panic, the climber is very likely to grab the release handle. This will lead to a fall, maybe not to the ground, but a fall.

For working up and down through the crown I don't think that it's the proper tool. If the climber was going up and then basically rapping down, and not working the crown, I could see using the GG.

You can add a safety check to the system. When I make a change to my climbing system I tie an overhand on a bight with a loop about +12" some distance below my hitch. That way I'll only fall half that distance if everything goes pear-shaped. The stopper knot gives me confidence to try new things.

Have you used the I'd? It has a panic stop and is designed as a tool for dynamic climbing. The GG is meant to be used as a belay tool.
 
Tom-

I appreciate the thoughtful response. I have not used the "I'd". What is it and where can I see it?

As fas as the panic thing, how is the grigri anymore dangerous than a climber freaking out and not letting go of his knot when he is descending? Since you have to flip the handle over to use it and it stops you if you let it go I don't see any other way that you might get into trouble with panicking.

I have found this setup with the grigri useful for walking around due to the ease of the 2-1 action going up or in. I haven't gotten as good an action out of any of the different prusik knots that I have used, but maybe the I'd will fit the bill. Always up for more toys.

Still tied-in, but always walking the line

Brian
 
thats not a frogger, tom, thats a RAD. frogs are inline and use a chest ascender; there is no 180 bend in the rope at the harness.

"Geriatric assist," i think you once called it.

A better backup with less confusion on the down line is to snap thatascender above the grigri. If you have a safety bridge to the ascender ( a Quick Attachment like ON ROPE suggests) then you are connected twice to the rope. This must fundamentally be better than the single attachment point of the hitch, which is also rather sensitive to being pressed on.

GG much better for SRT than Ddrt...there is a risk of the anchor half of the rope keeping it from locking properly.

The I'd is rather bulky , and you cant pull on the tail to take up slack like a grigri or a tended hitch... if you are going to pull down hard in a panic you shouldnt be playing around with new gear anyways!
 
Yoav is right. RADS not Frog.

"rope ascending descending system" into Google will get info.

I feel that in a panic, with a rope, the climber's hand will get hot and automatically let go. Our fear of fire/heat is pretty high on the auto-response hierarchy. The fear of falling reaction is to grab tighter. Not good when using a tool like the GG.

The GG is an OK tool but it does have limitations.

Look for the I'd on Petzl.
 
Tom wrote: "I feel that in a panic, with a rope, the climber's hand will get hot and automatically let go."

Tom,

There may have been a time when I might have agreed with you on this matter, however, during a training session this past summer, a Hispanic climber was trying to traverse from one limb to another, and accidentally slipped from the limb and began to fall. As he was falling, he tried to grab the climbing hitch tighter, in which he thought this would slow his decent, but it actually made him fall even faster. There was a tech in the tree, and a number of Hispanic climbers on the ground, yelling at him, to let go of his knot, in which he never did. He fell about 25', and luckily, was not seriously injured.

I once read a rock-climbing report, that, in many cases, when an un-trained person is rapping with an auto-block (a safety prussic back-up system), and if the person begins to fall, and panics, they will only grab the knot tighter, thus increasing the speed of their fall. In essence, the report was saying that it's a very unnatural response to "let go" of something when a person is falling. This certainly proved true this past summer.

Mike D.
 
Gary Storrick has a pretty persuasive article on not backing up rappels on his site.

There will always be times when all the bad things in life come together. If a climber's hand got hot when they were using a hitch they're more likely to let go than from a device. Although, as you experienced, not always.

I spent a lot of time with the GG, both in a DdRT and SRT setup. In DdRT it's advantages weren't enough to offset it from a more traditional hitch system. In SRT it works OK. In order to function a RADS needs to be used. There are times when there is no, or little, load on the rope that the GG will slip just a little. The GG acts on centrical force to lock it off. If the climber doesn't use a self belay below the GG they will experience this slip occasionaly. It will lead to a serious butt pucker! This doesn't happen often but it did happen a couple of times that might have been dangerous if I was using a chainsaw. This slip has happened to rock climbers when they use it as a belay tool. The belayer is lolly gagging and the lead slips. The slack can lead to high loads. this has popped anchors which then lead to a fall.

If you do choose to use the GG, it is a good idea to tie stopper knots like I described. I think that stoppers would be a good thing for arbos, especially new climbers, use as a general practice. When I teach new climbers they all tie stoppers. This limits the "Oops Factor" just a little. At first, it's counter-intuitive to "let-go/lock-off"
 
Tom

In reply to the idea of letting go b/c of the heat factor; At first this may seem like second nature. However, i think the fear of falling may overcome the burning sensation.

I witnessed this a couple years ago, while witness to a new climber's training. When the guy was instucted to unclip his safety lanyard and set back into his climbing hitch, he panicked. First thing he did was grab on to the hitch w/ a death lock, nothing would have made him let go.
He flew 25 feet to the ground as fast as the hitch would allow. Landing on his feet, and crumpling do to impact.
He'd burned the skin between his forefinger and middle finger down into the meat. As well as fracturing his leg slightly above the ankle.
Later, i asked him if he'd noticed the burning as he was falling, he said the only thing on his mind was trying to stop himself, and he hadn't even noticed the burn until a couple minutes after falling.

Just my two cents worth of witness.
 
yeah, gg definitely doesnt match up to the friction hitches for doubled rope. Nowhere near the sensitivity. A gg is an on/off switch rather than a throttle.

For SRT i find an acceptable self belay is an ascender with a bridge back to me...you can leave a carabiner on the handle and turn it into a rads system when the urge strikes you.
 
I appreciate all the responses to my post. I assume from all the replies that it is a legit use of the Gri-Gri although it doesn't seem to have much appeal with you guys. Just for clarification-in my DRT system I leave the handled ascender with the micro pulley on at all times. Using it for mechanical advantage to go up and then swapping it to the static end to tend the tail otherwise. This alleviates the on/off nature of the Gri-Gri allowing it to run smoother when walking on limbs or descent. It is problematic for crowded canopies, but is very nice for open canopy and large removals that require a lot of up and down. I like it for the right tree in the right situation, plus I can use all the geriatric assist I can get.

Moving slower, but still moving,

Brian
 
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