coastal redwood camp and climb

[moss]

Look at rappel racks too, they are the cadillac of long rappels, best at dissipating heat.

I don't know of any studies on rope damage from rappel devices/heat. If the device is too hot to touch you're going too fast ;-)

 

[John@TreeXP]

I've thought it would be hilarious to rig a bottle of water above a Grigri and send a steady stream on it during a long rappel, see how much steam you can make ;-) With a Grigri or similar device on a long rappel just take it slow, no problem. Devices like the Rope Runner, Bulldog Bone, or Hitchhiker are excellent for long descents and no rope hockling. ZK-2 Rope Wrench is good too. For any device or system use common sense, take it slow for the big descents.

275' rappel single line with an ATC sounds near to brutal. The current Grigri 2 is not great for big tree climbing, it's so small not much mass for transferring heat off the rope, plus the handle is flimsy. If you have an original Grigri better. If you can pick up a Petzl Rig even better. A figure 8 is better than an ATC, for both devices setting up an autoblock/back up below the device is a wise move. It gets awkward tying off a fig 8 if you want to stop in the middle of a long descent and have no contact with the tree (always the case on these big ones).
-AJ

I agree completely with using an autoblock/prusik on a fig 8, or any non-mechanical descending device, but a rescue 8 has ears that may prevent the outdated fig 8 from accidentally auto-locking the climber to the line, if the lines slip around and up to the top. Unfortunately, while repelling, a climber may not be able to uncook a scorched line by not going slow enough, once it's too late. In a way, it's like the reverse of ascending during a scuba dive and stopping every 10' to avoid embolisms (bends). I'd still like to see more definitive test-studies, in this regard.

In defense of the ATC, it does offer a ground-person/fireman an ability to control the climber's descent, by adding tension to the climbing line.

 

[moss]

In defense of the ATC, it does offer a ground-person/fireman an ability to control the climber's descent, by adding tension to the climbing line.

I don't have a lot of experience with ATC's but when I've used them double rope they run pretty nice, on single rope not so much. The rope bend radius on an ATC is pretty tight, I think that contributes to the less than smooth operation single rope. If you get a chance, check out the Rope Runner, super smooth for a long descent.
-AJ

 

[moss]

I hear you on wanting to see studies on rappel devices, rate of descent, heat buildup etc. You can probably determine some of this for whatever devices you use by testing on short rappels, say in the 50-60 range. You can try different rates of descent, not enough distance to cook your rope going too fast but you will see which devices dissipate heat the best. The strategy with the go slow approach on long rappels is check the device temperature frequently as you descend, you'll quickly determine what's a good descent rate for your device before going into an overheated state. Sometimes I've put my face close to my Grigri to get an initial reading on heat buildup, fingers can only read heat when they touch something.
-AJ

 

[John@TreeXP]

When I was on the single-line ATC, I had to add a 2nd carabiner, because I weight about 200lbs and for a less jerky and better controlled descent. I'll probably want to use a different descending device, next time I try that. Having a water bottle to douse or cool down an overheated, or smoking device, may be a wise idea if you don't control your descent well enough and avoid the accidental overheating issue in the first place.

During my week of climbing redwoods, I think I recall hearing something about CTCI (Cornell Tree Climbing Institute) performing various studies in this regard, on behalf of manufacturers who hire them to perform these types of tests. Unfortunately, they probably agree in advance not to disclose their findings to the public, but the fact is CTCI does have their students use the ATC device (with an auto-lock) for long rappels. For that matter, they also taught us newbie/climbers to use the sit-stand ascending approach with a hand ascender, a Croll and a jacob's ladder-like foot loop. College age students were much better able to endure the long arduous ascent than I was, which is why I've since converted to the rope-walker style.

 

[moss]

Rope walkers are the way to go for long hauls. I wonder why the CTCI standardized on an ATC, not the most friendly for single rope. Could be a simple cost equation.

 

[moss]

Yeah I've noticed that they only use a single foot loop in their ascent system. For their setup a double foot loop is much easier to go the distance with both legs involved.

 

[John@TreeXP]

Yeah I've noticed that they only use a single foot loop in their ascent system. For their setup a double foot loop is much easier to go the distance with both legs involved.

Agreed. A double foot-loop system is preferred when using the sit-stand approach. Still, I was able to put both my feet into one loop, after switching back and forth a bunch of times. CTC has hopefully upgraded their tool box since 2015. They're still offering places on these annual Eastern Sierra/Sequoia climbing expeditions to the public, but the cost has more than doubled since I went.

 

[Flex Abednego]

I hear you on wanting to see studies on rappel devices, rate of descent, heat buildup etc. You can probably determine some of this for whatever devices you use by testing on short rappels, say in the 50-60 range. You can try different rates of descent, not enough distance to cook your rope going too fast but you will see which devices dissipate heat the best. The strategy with the go slow approach on long rappels is check the device temperature frequently as you descend, you'll quickly determine what's a good descent rate for your device before going into an overheated state. Sometimes I've put my face close to my Grigri to get an initial reading on heat buildup, fingers can only read heat when they touch something.
-AJ

https://www.amazon.com/gp/aw/d/B008...1_2?ie=UTF8&psc=1&refRID=C0FPD1XNJBY2RRG7HKPV

Here you go. Is it just when I click on it, it shows my ladies amazon account or is that built into the link?

 

[Leroy]

Just for you I think.

 

[ARLO]

I agree with Moss that the Grigri is really not a good tool for long descents because it heats up too much unless you really go slow. Once I switched to a Petzl RIG I quit using Grigri's altogether. The Petzl ID is ok as well, but I prefer the RIG because the panic-locking back-up on the ID is really irritating and not needed for experienced climbers. It just adds weight and makes the descent more difficult if you occasionally pull too hard on the handle. Another advantage of the ID and RIG over the GriGri is that they can handle the weight of two climbers in a rescue, whereas the Grigri is too whimpy for that kind of abuse.

Why anybody would teach the old-school squat-thrust methods as the preferred way to do SRT is beyond me, unless the concern is expense. Rope walkers make it much easier to go up a rope. And if you use a chest roller with a rope walker system you can literally walk or run (if you are young and fit) up the rope without using your arms. That is what allows me to keep climbing!

 

[JTSpear]

I'm sitting in the sempervirens room at Big Basin Redwoods state park using their wifi. Will be headed north along the coast from San Francisco starting Thursday afternoon and I really need to climb a tall tree. If anybody knows someone who may know where I can legally climb or would be willing to climb with me, pm me please!