Technique to release trunk anchored SRT line remot

Hunabku on the TCC forum tested the system today using a washer, a link and stopper knot, he said it worked well, his post is in this thread:
http://treeclimbercoalition.org/phpBB/viewtopic.php?p=6579#6579
-moss

Ok Moss, so if you want to climb SRT why not just run a carabiner up the rope to the TIP and not use a ground anchor?

I was toying with this idea this morning. Could you use a rescue 8 in place of a home-manufactured plate? I came up with this ideas as I was going to try the rigging plate idea that Trebuchet posted on the other forum. My rigging plate was in my vehicle though, so I opted for the next best thing.

Pass the rope through the small hole in the 8, and you basically have the same device. Nice rounded edges, and rated strength. If you're concerned about the strength, Kong makes a similar device, that I like a lot, in S.S. steel too. I often use mine in place of a rigging plate.

http://re3.yt-thm-a02.yimg.com/image/25/m3/2650358932
CMI Figure 8 - aluminum

http://re3.yt-thm-a01.yimg.com/image/25/m5/3175839464
Kong Rescue 8 - steel

Baker wrote:

I was toying with this idea this morning. Could you use a rescue 8 in place of a home-manufactured plate?

Oh, you mean hitch the lanyard through the large hole and use the small hole for the rope? No carabiner. No pulley. No link. No washer.

I just meant you could use an 8 if you didn't have a rigging plate.

I stole this from Canopy Chatter:



Replace the rigging plate, in the drawing, with an 8 rigged backwards and you'll see what I mean. It still spooks me to hang my life on a slip knot, but it's a whole lot better than a fifi hook.

Yikes!

Baker wrote:

It still spooks me to hang my life on a slip knot, but it's a whole lot better than a fifi hook.

I couldn't do the slip knot thing. I even gave up using it as my periodic safety knot.

[Davej] Please reconsider. Don't abandon use of the safety knot while climbing. Learn how to tie it correctly, and get it into muscle memory. It is extremely worthwhile!

[Baker] Great minds think alike! I don't own a rigging plate, but I do own a rescue 8. I used it during my testing. Unless I find a rigging plate with equivalent radius, I won't go there. The following image is a close-up. The remainder of the testing/report is posted on the TCC forum. The one test returned anticipated results.

I rigged through the center hole in the rescue 8. I hear from some that it is a belay hole. I trust that routing, softness, and strength are more than adequate. It is probably not possible to do the same with most two-hole figure 8s.

I'll include the caution/disclaimer here again...
CAUTION: This technique includes a risk that can only be mitigated by superb throwline slack management. Said, another way, if you can't watch the safety knot loop and also observe that slack is maintained in the attached throwline during your entire climb to the current TIP, don't use the slipknot method for retrievable trunk tying!

That's the way I configured it! The only difference is that I used a W3P2 made out of tubular webbing to anchor it to the trunk.

And Dave:

If a 5 year old can tie and use a safety slip knot, then so can you. Be safe. Back it up.

Davej wrote:

Ok Moss, so if you want to climb SRT why not just run a carabiner up the rope to the TIP and not use a ground anchor?

That can be done too, but tie a bowline or other loop knot. Never use a carabiner. Making a loop by clipping a biner back on the rope will cause the carabiner to be cross-loaded when the loop is drawn over the anchor. Cross loading has been shown to be one of the primary causes of carabiner failure.

Davej wrote:

Ok Moss, so if you want to climb SRT why not just run a carabiner up the rope to the TIP and not use a ground anchor?

I use a cinched limb anchor quite a bit. As Baker mentioned, never by running a carabiner up the rope. I used a backed up Running Bowline to cinch the limb. Many climbers use a rated Mallion Rapide (MR) to cinch the limb. The MR can be cross-loaded and is perfect for this application.

In many tall trees it can be very difficult or impossible to isolate a limb, so in that case a ground/trunk anchor is used. The \"remote release\" trunk anchor is something that would be implemented by a limited number of climber in specific circumstances. It's not anywhere near being a primary technique for anchoring an SRT line.
-moss

Baker wrote:

If a 5 year old can tie and use a safety slip knot, then so can you. Be safe. Back it up.

No, I went to using a single overhand on a bight as my safety. Slip knots slip.

Having never held a figure-eight I didn't realize that the small hole was so large.

Thanks Moss for explaining why you would want a ground anchor.

Davej wrote:

No, I went to using a single overhand on a bight as my safety. Slip knots slip.

Having never held a figure-eight I didn't realize that the small hole was so large.

Thanks Moss for explaining why you would want a ground anchor.

Interesting that you ended up using an overhand on a bight for your safety knot. I was facilitating a climb the other day and one of my climbers tied her first safety correctly as a slip knot then all the rest as overhands on a bight. From a slight distance they look the same. The overhand/bight is very effective to stop the hitch from coming down. From a climb facilitators point of view it's a pain because they can't be released remotely from the ground, but for the climber it was very effective. For a solo climber I don't see an problem with the overhand/bight. It will make it more difficult for a person on the ground to assist a climber who has descended hard onto the knot. I've noticed that the slip knot is more likely to fall apart on some ropes more than others, and definitely on newer rope. You can tighten the slip knot down pretty hard by holding the down rope above the knot and pulling the knot down from above, that'll lock it.
-moss

Baker wrote:

...tie a bowline or other loop knot. Never use a carabiner.

Ok, I hadn't considered carabiner cross-loading. I'd hope this is a very special super-safe bowline.

I was just thinking; why use throwline to pull the rope back? Why not just tie the rope into a loop and let the fisherman's be the stopper?

Davej wrote:

Baker wrote:

...tie a bowline or other loop knot. Never use a carabiner.

Ok, I hadn't considered carabiner cross-loading. I'd hope this is a very special super-safe bowline.

I was just thinking; why use throwline to pull the rope back? Why not just tie the rope into a loop and let the fisherman's be the stopper?

Tying the rope in a continuous loop would work except when you're maxing out the length and don't quite have eonugh to complete the loop. You'll still need to guide with a throw line when you drop the tail

I back a Running Bowline for a limb cinch anchor with a Yosemite Finish followed by a double overhand (one half of a Fisherman's Knot) to further secure the tail. It's secure, I wouldn't climb on it otherwise
-moss

moss wrote:

Tying the rope in a continuous loop... You'll still need to guide with a throw line when you drop the tail

Oops. Ok.