Increasing friction on an ATC

[Deathcricket]

Can anyone point me to a reference on increasing friction for an ATC? I'm looking for a super sloth mode. I noticed with this 8.3 rope on single strand, even an extra beener on the leg strap isn't enough sometimes. I use a Piranna and frigging love it, but I notice the noobies always bring an ATC and wanna help them out. So think about a 220 pound guy wearing a 40 pound pack doing a 170 foot mostly free rap. How would you set it up?

[trackrunner]

search the forms it has been discussed on here. a few different ways. My preference single strand atc on a thin rope would be in this order: your first method should be an extra binner under the device, second option could be the redirect off a binner on a leg loop. third option could be the rappel z redirect off a binner above the device. needs to be small enough that the belay device will not slip through.

could make a case because of the risk of sheath slippage to always use an extra binner under the atc with SRT.

could also use two belay/rappel devices, or the ATC and a binner with a munter hitch

[Deathcricket]

Thanks man. I know it's been discussed but I can't find any documentation, like a picture would be nice. I always thought the "biner on the leg strap" would be enough but I'm looking for something a bit more. That link you pointed me to really doesn't have any info either. I'll keep searching though I know it's here somewhere, lol.

[spinesnaper]

Here is a url for an article describing Z rig for the ATC: http://www.outdoorstogether.com/cany...s/rappel_z.jpg



Ken

[trackrunner]

That link you pointed me to really doesn't have any info either. I'll keep searching though I know it's here somewhere,

doesn't have info? it's the supporting documentation about sheath slippage (that's what she said) claim and why an extra binner under an ATC may reduce the risk.

[Deathcricket]

Here is a url for an article describing Z rig for the ATC: http://www.outdoorstogether.com/cany...s/rappel_z.jpg



Ken

Ahhh that is it!!! I knew it was on here somewhere but could not recall where I had seen it, thanks bro!

[spinesnaper]

No problem.

[hank moon]

Can anyone point me to a reference on increasing friction for an ATC? I'm looking for a super sloth mode. I noticed with this 8.3 rope on single strand, even an extra beener on the leg strap isn't enough sometimes. I use a Piranna and frigging love it, but I notice the noobies always bring an ATC and wanna help them out. So think about a 220 pound guy wearing a 40 pound pack doing a 170 foot mostly free rap. How would you set it up?

Ways to increase ATC friction w/o using a redirect as shown in the Z-rig diagram above.

1. Use two carabiners instead of one to attach ATC to harness. The rope is captured by two identical carabiners, both of which are attached to the harness strong point/belay loop. This gives a ton of friction, senor sloth.

2. Extend the device (http://www.climbing.com/print/techti...d-fit_rapping/) and note that in this drawing, the "overhand knot" looks like a slip knot. Experiment with extension length to suit your body type/height. The device should not be extended out of reach. An earlier thread with info on this: http://www.bogley.com/forum/showthre...-Piranha/page2

Comment on the Z-rig diagram (shown earlier in this thread):

Holding the rope above the device is (generally) wasted energy and other negative stuff. It is (generally) better to have both hands on the brake strand to share the load. More on this in the earlier thread linked above.

[ratagonia]

Ways to increase ATC friction w/o using a redirect as shown in the Z-rig diagram above.

1. Use two carabiners instead of one to attach ATC to harness. The rope is captured by two identical carabiners, both of which are attached to the harness strong point/belay loop. This gives a ton of friction, senor sloth.

Hi Hank!

Also helps if your "two carabiners" are fat carabiners, like a Petzl Attache or William. Skinny carabiners will produce less friction.

Three carabiners can also be used. Three fat carabiners might be too much, how about three not so fat carabiners?

T

[hank moon]

Hi Hank!

Also helps if your "two carabiners" are fat carabiners, like a Petzl Attache or William. Skinny carabiners will produce less friction.

Three carabiners can also be used. Three fat carabiners might be too much, how about three not so fat carabiners?

T

Good points, TJ. I haven't tried 3, though - that goes beyond sloth, right? Slime mold?

Speaking of carabiners, I am loving the Rock Exotica Pirate (HMS) and RockO (Oval). The locking mechanism (screwgate) is the best I have used. It resists overtightening (stops on both ends of the sleeve), has superior gritlock resistance, and the beefy sleeve has an inward-loading* rating for alla you dinos out there using figure 8s, brake bar racks, or similar, large-attachment-eye devices. Great gate opening size, too, due to angled gate hinge (gate swing path non-coplanar with frame, oh nerdly ones).

Pirate = fat (and fits the Pirana)
RockO = not as fat


*If you don't understand the danger of inward loading, see here:

http://goo.gl/Y3Mxp

More interesting stuff:

http://goo.gl/IuRjk

[ratagonia]

Good points, TJ. I haven't tried 3, though - that goes beyond sloth, right? Slime mold?

Speaking of carabiners, I am loving the Rock Exotica Pirate (HMS) and RockO (Oval). The locking mechanism (screwgate) is the best I have used. It resists overtightening (stops on both ends of the sleeve), has superior gritlock resistance, and the beefy sleeve has an inward-loading* rating for alla you dinos out there using figure 8s, brake bar racks, or similar, large-attachment-eye devices. Great gate opening size, too, due to angled gate hinge (gate swing path non-coplanar with frame, oh nerdly ones).

Pirate = fat (and fits the Pirana)
RockO = not as fat


*If you don't understand the danger of inward loading, see here:

http://goo.gl/Y3Mxp

More interesting stuff:

http://goo.gl/IuRjk

Ditto. Will be adding those to the site, soon.

T

[Bo_Beck]

Ditto. Will be adding those to the site, soon.

T

For some reason I'm not getting it? First time I did a long free hanging rappel with a fair amount of mass was out of Heaps. I had a 65Lb. pack (dry) and at that time I weighed 155Lbs. My wetsuit was wet and of course minus the 300' (dry) Bluewater accessory cord (10Lbs) my pack weight was 55Lbs. so total mass around 1kn., and I used single strand for the descent hooked up to a CMI Mini Eight (anodized of course!), my descent was on an 8mm Bluewater accessory cord, and was smooth as butter.....no "Vertacos" no added friction.....nada? Why the heck are folks gripping so tight (or so percieved?).....oh yeah, the pucker factor! I've seen climbers "Dent" the rock because they gripped so hard! Ease up and preserve some enregy for lower down (or in the case of climbers...higher up).Personally I've never added friction on any descend using my ATC. I take it back....I've wrapped the free end around my leg before to ease up for a moment. Am I missing something that others are experiencing???????????

[ratagonia]

For some reason I'm not getting it? First time I did a long free hanging rappel with a fair amount of mass was out of Heaps. I had a 65Lb. pack (dry) and at that time I weighed 155Lbs. My wetsuit was wet and of course minus the 300' (dry) Bluewater accessory cord (10Lbs) my pack weight was 55Lbs. so total mass around 1kn., and I used single strand for the descent hooked up to a CMI Mini Eight (anodized of course!), my descent was on an 8mm Bluewater accessory cord, and was smooth as butter.....no "Vertacos" no added friction.....nada? Why the heck are folks gripping so tight (or so percieved?).....oh yeah, the pucker factor! I've seen climbers "Dent" the rock because they gripped so hard! Ease up and preserve some enregy for lower down (or in the case of climbers...higher up).Personally I've never added friction on any descend using my ATC. I take it back....I've wrapped the free end around my leg before to ease up for a moment. Am I missing something that others are experiencing???????????

If you ate more ice cream, Bo, and plumped out to a pleasant roundness like the rest of us, I think you would understand. Unfortunately you are metabolically challenged and unable to put on weight. So sorry for you bud, once you get a little older, maybe it will happen.

But, a good point, so let me actually address that, now that I've ejected some snide remarks...

On short rappels, one can use an iron grip to compensate for not really setting up your rappel device correctly. As the rappel gets longer, or steeper, or scarier, this over-gripping is not so effective, so the friction actually needs to be set up "correctly" ie, so that only a small control force is needed to control the rappel.

But on even bigger rappels (> 200 feet, say) an adjustable-friction plan is needed to maintain proper friction on the rope as the weight of the rope drops out of the equation. At the top of the rappel, a lower friction setting is required as the weight of the ROPE (ie, not accessory cord, BO!) adds additional control force. As this force decreases, the wise rappeller likely has a plan for adding a bit of friction mid-rappel.

For Heaps, this is a big deal as it is all free-hanging. Me, I tend to set up the Pirana at 1 or 2 to start, then add a leg loop biner, then add the Z-rig for the last 100 feet. Generally works like a charm. A bottom belay, radio-enhanced, has proved a life-saver on at least one occasion, when I made some serious miscalculations. Having an ultra-reliable, hand-strong friend at the bottom, with radio, is highly recommended!!! (Thanks Chris).

Oh, and (back to Snidely Wiseacre): Bo - rapping single strand!!! The horror, the horror!!!!!

Tom

[The Good Cop]

Tom, thanks for the precise breakdown on what works for one person on the final Heaps rappel, while I have heard a number of options mentiooned before, I do not believe I have ever seen it described in those clear 3 distinct friction steps. Good stuff, and easily adaptable to an ATC-XP (my current device), I have not ever done the double step-up on friction that you describe, but then I haven't done 90m free-hanging either, so that is much-appreciated.

Wayne

[ratagonia]

Tom, thanks for the precise breakdown on what works for one person on the final Heaps rappel, while I have heard a number of options mentiooned before, I do not believe I have ever seen it described in those clear 3 distinct friction steps. Good stuff, and easily adaptable to an ATC-XP (my current device), I have not ever done the double step-up on friction that you describe, but then I haven't done 90m free-hanging either, so that is much-appreciated.

Wayne

Thanks, but... be sure and try it in a safe place and see what works for you.

You CAN test how a 90m rappel feels by keeping the rope in the bag, and hanging its weight on the rope near the end of the rappel. It takes at least two people to do this, but worth it when gearing up for your first or next BIG rappel.

Tom

[The Good Cop]

Always smart to try it somewhere safe first, I enthusiastically agree. The interesting thing about the biggie on Heaps is the combined size plus psychology, or so it seems to me, not having done it. I know the size of the first drop on Englestead did have a psychological impact for me. Anyway, I've done decent-sized free-hanging drops, and changed friction part way down, for example on Behunin's last drop, but switching to a leg loop biner was enough of a change on the less than 200 feet of rope hanging experience there (canyon fire, FWIW). And I've done 90m walking (Englestead) with a new 8mm Imlay rope, but we over-rigged, so the only nuisance was helping the rope through the device (we tried the 2 ATCs in series technique, recommended somewhere, but just too much friction for us). As a side note, we tested it previously, but underestimated just how much impact the rope weight would have. In any case, it would sure be nice to not over-friction - but still maintain enough of course - and having a 2-level step-up in friction like you descibe seems to my intuition to be a good approach. I look forward to playing with the Z-rig as a second friction upgrade after the leg loop biner in the future, thanks for giving me the concept.

And as always, thanks for the cautious, error-on-the-side-of-safety input,

Wayne

[hank moon]

Bo - rapping single strand!!! The horror, the horror!

[Bo_Beck]

So sorry for you bud, once you get a little older, maybe it will happen.
Tom

You mean I have "fat and bald to look forward to?" Halfway there!

[Bo_Beck]

Good thing it was Bluewater Accessory cord and not some low friction, low stretch super stiff and durable rope made specifically for canyons!

[Bo_Beck]

You mean I have "fat and bald to look forward to?" Halfway there!

See!