Potrero Chico Accident: Any more info?

aikibujin wrote: That's what I guessed, but I'm just really surprised that you would have so much trouble with an autoblock below the belay device backup. You're probably getting too much friction from the autoblock. If you're using three wraps, try two. If you're using 5mm cords, try 4mm. Basically try something that reduces the friction.

Thanks for the suggestions! I've tried using fewer wraps, but not a thinner cord. I find that using thinner ropes help, as well as an ATC with larger slots, e.g. the BD ATC has bigger slots than the Petzl reverso. Friction side up.

I typically push the rope up to feed it in better, that is one reason the autoblock gets in the way. If I dont lift the rope, typically I don't move until I get halfway down. But it's definitely workable and I think I will re-incorporate it into my multipitch rappels.

Ana Tine wrote: Thanks for the suggestions! I've tried using fewer wraps, but not a thinner cord. I find that using thinner ropes help, as well as an ATC with larger slots, e.g. the BD ATC has bigger slots than the Petzl reverso. Friction side up. I typically push the rope up to feed it in better, that is one reason the autoblock gets in the way. If I dont lift the rope, typically I don't move until I get halfway down. But it's definitely workable and I think I will re-incorporate it into my multipitch rappels.

A thinner cord increases the grabbing with friction knots generally

Which is why its not recommended to use prussiks close to the diameter of the rope itself

The "knot argument" is up to each individual and their partner, but there have been many many accidents which could have been prevented with knots at the end of the rope

As someone said you can always saddlebag the rope, and with the proper technique and practice it doesnt take that long

A very sad set of accidents

bearbreeder wrote: A thinner cord increases the grabbing with friction knots generally Which is why its not recommended to use prussiks close to the diameter of the rope itself

Ah I remember now. Then I want to use thicker cords for less friction. I'll just use what I have and get used to it.

Ana Tine wrote: Ah I remember now. Then I want to use thicker cords for less friction. I'll just use what I have and get used to it.

No, actually you want the opposite. Bearbreeder is correct, a thinner cord increases the grabbing, which means you can get away with fewer wraps and achieve the same "grab" as a thicker cord with more wraps. And generally the more wraps you do with the autoblock, the less likely you can slide it along the rope smoothly. Which is probably what's giving you a jerky, stop and go rappel. With a thinner cord and fewer wraps around the rope, you should be able to get a fairly smooth rap even with an autoblock backup.

Ana Tine wrote: Ah I remember now. Then I want to use thicker cords for less friction. I'll just use what I have and get used to it.

What you should actually do is extend your rappel on a cow tail, then attach your regular autoblock to your belay loop. This will give you more space between your ATC and your autoblock, giving you more room to "pump" the rope through. It is also arguably safer having your autoblock clipped to your belay loop instead of the leg loop. You'll need to experiment a bit to find the optimal length for your cow tail and autoblock cords.

More info: climbing.com/skill/pre-rigg…
And a good blog post with video: blog.alpineinstitute.com/20…

One other option would be to switch to using a Mammut Smart Alpine as your belay device. On rappel, you can flip it upside down and rappel with it in a "non-locking" configuration which is also quite low friction. It would probably feel like "regular friction" to a person of your weight. When I rappel with it I descend very quickly - gloves and an autoblock knot are almost mandatory at my relatively heavy 185 lbs. However, I suspect it would be great for you.

Ana Tine wrote: You don't have to knot the ends of the rope if you don't want, definitely your own choice, and I'm not the knot-police. But I'm going to.

Fair enough, Ana.

aikibujin wrote: No, actually you want the opposite. Bearbreeder is correct, a thinner cord increases the grabbing, which means you can get away with fewer wraps and achieve the same "grab" as a thicker cord with more wraps. And generally the more wraps you do with the autoblock, the less likely you can slide it along the rope smoothly. Which is probably what's giving you a jerky, stop and go rappel. With a thinner cord and fewer wraps around the rope, you should be able to get a fairly smooth rap even with an autoblock backup.

Thinner cord tends to negate the less wraps

The OP has it correct

Thicker cord and/or less wraps

Just make sure its stil enough to hold you in mid air while yr bouncing on it

Experimentarion (with a proper backup) and practice are the key

As well as knowing that if you were to rap on a thin slick rope youll need more raps/thinner cord and vice versa fora thicker fuzzy rope

Also some knots grab better than others

And lastly always test the system before taking off the safety

Aikibukin & bearbreeder: Okay, I got it now, thinner cord for more grab in order to get away with fewer wraps which will push doen easier. Will try it.

Jon: thanks for the link on the modified extended rappel, and moving the autoblock configuration to the belay loop. Will also try this, and maybe the alpine smart since I am a gear collector. They are right, when rapelling second normally, there isn't the benefit of a second set of eyes. Probably saves time to be hooked up by the time the first is down. I also use belay gloves on multiple rappels to avoid rope burn.

Does anyone ever try rapping with the rope instead of tossing it and worrying about it getting snagged on something? It's not the most difficult thing to wrap it up and hang it off of a sling on your harness so it feeds out as you go. I've done it at crowded crags to avoid people as well as natural obstacles.

I'm having trouble picturing a scenario where the only option is rapping without knots.

I've always liked Twight's idea for wind and projection issues, lower the first person to the next stance, you don't have all that butterfly to deal with.

Ana Tine wrote: Ah I remember now. Then I want to use thicker cords for less friction. I'll just use what I have and get used to it.

Ana one benefit of that would be if both rope ends were even, and depending on how far above the rap device a conditional belay sits, it could save your life since the rope will run out of the belay device first and hopefully be caught by the conditional belay, again depending on how far apart they are. Try it some time safely, you'll see its not that different. Also technically a leg loop is generally not a full strength piece of the harness or at least not as strong as the belay loop or tie-in points. Using the leg loop is not as safe and just poor form if your are trying to do it right. Just something to think about...

Respectfully,

Matt

H.. wrote:I'm having trouble picturing a scenario where the only option is rapping without knots.

I can think of two categories of answer:

The first category is personal choice (bear with me for a moment), sometimes for the reasons already mentioned. I believe this is not uncommon for folks who often do multiple-rap descents. I'm having a hard time recalling any of my climbing partners over the past 10 years who always knotted the ends. In fact, I can recall only a few isolated circumstances (literally) where we did. But maybe that's just the climbing culture in which I "grew up." ... and, well, this arguably is not because it is the only viable option.

Second is indeed efficiency. For anyone who might read this thread, there are climbing routes that are simply too long to finish (i.e., get up and down) in daylight for current abilities. And there are routes that are well within your abilities to finish before dark. And then there are those routes that are in the gray area ... where there is no room for time-consuming hang ups ... and where saving a couple minutes at some repeated task can make a difference.

Time savers include: going off belay as soon as possible using a single - hopefully bomber - anchor piece so partner can eat, pee, etc. while rest of anchor is built; simul-climbing; reliance on auto-braking belay device (e.g., ATC guide in guide mode) while not religiously keeping brake hand in place at all times; free soloing some exposed 3rd, 4th or even 'easy' 5th class (e.g., to get up to where the "real" climbing starts); etc.. I've tried to list time savers that add a degree of risk ... things that, for the most part, I do not normally do. But I have consciously done each of them at least once as part of the team's plan for the route.

Consider that knotting the ends each time and piling them into a bucket (or butterfly coiling with staggered loop lengths) takes minutes. If one is on one of those "gray area" routes and has 10+ raps ahead of you, a longer rap task can prohibitively add more time to the day.

Time Wave Zero is definitely a route where I would need to start thinking about time savers that add some risk - if I wanted to do the route. And since the decision to do such a "gray area" route centers on desire, category 2 - efficiency - is within category 1 - personal choice ... much like the decision to have climbing in one's life at all (JSH sums this up well a few comments below).

H.. wrote:Does anyone ever try rapping with the rope instead of tossing it and worrying about it getting snagged on something?

Yes - and usually because of high winds. But in that case, I'm more likely to lower the first person down as Tom Stryker mentioned up thread. And if high winds were in the forecast, I'm unlikely to be on something that is in the "gray area" for me - but it could happen.

OAW wrote: Also technically a leg loop is generally not a full strength piece of the harness or at least not as strong as the belay loop or tie-in points. Using the leg loop is not as safe and just poor form if your are trying to do it right. Just something to think about... Respectfully, Matt

The leg loop is perfectly fine to use for autoblock purposes. Another way to say it is, using the leg loop is THE WAY you rig an autoblock below your belay device.

Lowering the first person, IMO, only really works when you know where the next anchor is and have good communication. The windy conditions that make lowering desirable can also make communication difficult.

Sorry if this seems too obvious to mention, but in a situation where the midpoint of the rope is unclear (no or hard to see midpoint mark, one end cut off and other intact, etc), if you have both ends in your hand at the start and lower them at the same time, you will end up at the midpoint. When I could double check w a known-to-be- good midmark, never been off by more than a few inches using this method.

Seems obvious, but have climbed w a lot of experienced climbers that didn't know this trick.

Relying on your memory to remember which way to adjust a cut-at-the-end rope from the midmark doesn't seem like a good idea.

Christian wrote:Sorry if this seems too obvious to mention, but in a situation where the midpoint of the rope is unclear (no or hard to see midpoint mark, one end cut off and other intact, etc), if you have both ends in your hand at the start and lower them at the same time, you will end up at the midpoint.

This is also a time-efficiency decision. It can be faster to thread the next anchor concurrent with pulling the rope from the last anchor.

When speed is primary to the climber, it's hard to beat simply pulling one end through all the way to the middle mark, assuming accuracy/visibility ... and no knots to tie / untie.

James Hicks wrote: The leg loop is perfectly fine to use for autoblock purposes. Another way to say it is, using the leg loop is THE WAY you rig an autoblock below your belay device.

I tend to extend the atc with a runner and rig the autoblock off my b/r loop.

Bill Lawry wrote: This is also a time-efficiency decision. It can be faster to thread the next anchor concurrent with pulling the rope from the last anchor. When speed is primary to the climber, it's hard to beat simply pulling one end through all the way to the middle mark, assuming accuracy/visibility ... and no knots to tie / untie.

That obviously wasn't safe practice in this context.

Again, this is a terrible way to be reminded of rappel safety. It can get anybody, of that there are too many examples. Terrible odds it happens twice in the same area so close together. My condolences to the grieving family and friends.

Colonel Mustard wrote:That obviously wasn't safe practice in this context.

Maybe ... or, more significantly so, does it add too much of a challenge for a team to count on remembering to offset the middle mark and insure you're doing it in the right direction and for the right amount.

Every. Single. Rap.

A common theme among many accidents is the category where it was the end of the day or on the descent. If it could be measured, rising numbers of critical decisions near the end of the day likely correlates with rising probability of an accident. Keep it simple sometimes counts a lot.