Wear out ascender rubber with change-overs?

[Stridergdm]

Single carabiner attachment = do rappel test every time.
Double carabiner attachment = do rappel test every time.
Maillon Rapide = do rappel test every time.
Any attachment = do rappel test every time.

The rappel test catches other problems besides the attachement.

Agreed. Having heard (my back was turned) the sound a person makes when they realize they've just suicide-rigged their rack (fortunately this was at a demo and he was able to grab the wall before moving more than an inch or two) I'm BIG fan of doing the rappel test every time.

I also often find myself the LAST person to go down a drop. So it's pretty difficult to have someone ELSE check my rig.

I have to admit, until my NCRC Level 1, I had never been aware of the test (also didn't do much vertical before then and it had all been on knots). But since then I've done it every time.

Now, so far I don't recall it catching any potentially fatal problems. But it only has to do it once to make the minimal extra effort all worth it.

[NZcaver]

(Partially my fault.)

[I was thinking of splitting the topic, but there's already other "rappel test" discussions in various places on the forum.]

[Anonymous_Coward]

It's kind of a hassle, but I've been using two biners on my rack just to be sure. Check them, locked, check them again and again.

This describes exactly why I attach my rack with a wrench-tightened maillon instead of a biner. (I still do the rappel test, don't yell at me Scott) I've found that by omitting the carabiner, I reduce the check points to three: D-ring, and two leg loops. Makes a huge time and hassle difference when you are going to be on and off rope many times during the trip.

Like Greg, I agree that having someone else check my gear is not always applicable. So I always check it myself.

[Marduke]

It's kind of a hassle, but I've been using two biners on my rack just to be sure. Check them, locked, check them again and again.

This describes exactly why I attach my rack with a wrench-tightened maillon instead of a biner. (I still do the rappel test, don't yell at me Scott) I've found that by omitting the carabiner, I reduce the check points to three: D-ring, and two leg loops. Makes a huge time and hassle difference when you are going to be on and off rope many times during the trip.

Like Greg, I agree that having someone else check my gear is not always applicable. So I always check it myself.

And I would argue that you should STILL check the maillon with a wrench. On more than one occasion I have seen gravity and time work one loose until it's open, and even seen them being bent under load once open to the point of being a pretzl.

[Anonymous_Coward]

And I would argue that you should STILL check the maillon with a wrench. On more than one occasion I have seen gravity and time work one loose until it's open, and even seen them being bent under load once open to the point of being a pretzl.

Well, if we are going to argue, I would counter-argue that the rappel test takes care of this worry. When doing the test, I look down to see that all is working properly with the rack, including whether or not it is still attached to me!

I have been using wrench-tightened 7mm oval maillons on my ascenders and racks for ten years, and have never seen one work loose. I'm not saying that it couldn't happen, just that it's not very likely, and my maillons have been exposed to plenty of time and gravity. I figure the rappel test will alert me to a problem with one on rappel, and there is redundancy in my climbing system for a problem there.

Seems like if they were bent under load, they would actually straighten instead of becoming a pretzel but I will defer here to your first-hand experience. Maillons are however sold by the Pretzl corporation, so you may be on to something here.

I certainly will not be checking the maillon with a wrench before each drop. The point of my earlier post was to explain how I have saved time by reducing self-check points in my system. Checking the maillons with a wrench is something I may do at home before a trip, but would be inefficient to do as a pre-rope check on a multi-drop cave trip. I let the rappel test do that work for me. My hand-tightened main D-ring is another story. As I mentioned before, I check it and the leg loops on my harness before each rope.

[chh]

I'll chime in here and say I that I do use a carabiner for my descender attachment most of the time because while it does add something more to check you don't even have to look at it usually to check it and it's very quick. I don't like having the descender permanently fixed to one spot, or I should say a spot that might require a wrench to move. But I cave with folks who do use maillons. I say whatever floats your boat, no right or wrong so long as you check things out before you commit. Once the rappell test becomes part of the routine you almost don't even notice the time it takes. In my experience ill fitting equipment or lack of conditioning will trump the time it takes to do just about anything else in the extended vertical scenario. I realize this is but that's the story of my life

[Lava]

I notice that the Petzl Stop tech note recommends against using a mallion attachment to the harness D-ring. Anybody know why? One would think a mallion of the right rod diameter and bend radius would be just fine.

[Anonymous_Coward]

I notice that the Petzl Stop tech note recommends against using a mallion attachment to the harness D-ring. Anybody know why? One would think a mallion of the right rod diameter and bend radius would be just fine.

In the right (wrong) circumstances, a maillon can trip the saftey catch and actually detach a caver from the bobbin causing free-fall. The most famous case of this is the Dick Graham fatality in Lori Cori Cave in Virginia in 2003. For this reason, simples and bobbins should only be used with a fat carabiner like the Attache and never with a maillon. There was a detailed write-up on how this can happen with photos in an NSS News after the accident. Maybe someone can dig it up.

[NZcaver]

I notice that the Petzl Stop tech note recommends against using a mallion attachment to the harness D-ring. Anybody know why? One would think a mallion of the right rod diameter and bend radius would be just fine.

Yes, this is exactly why. Most Maillon Rapide links used to attach a descender to the harness (or harness screw link) are oval in shape and even those with a thicker (10mm) rod diameter and larger bend radius can cause problems springing the safety catch on a Stop when twisted in a specific way. Personally I attach my micro rack with a 10mm Zicral oval MR (larger than most oval MRs used in the US). But I would never use that with my Stop, because a Petzl Freino and most regular locking carabiners are perfectly adequate for the task.



Analysis of the Dick Graham accident in Lori Cori Cave can be found here

More information on descender attachments here

[Lava]

I notice that the Petzl Stop tech note recommends against using a mallion attachment to the harness D-ring. Anybody know why? One would think a mallion of the right rod diameter and bend radius would be just fine.

In the right (wrong) circumstances, a maillon can trip the opening lever and actually detach a caver from the bobbin causing free-fall. The most famous case of this is the Dick Graham fatality in Lori Cori Cave in Virginia a few years ago. For this reason, simples and bobbins should only be used with a fat carabiner like the Attache and never with a maillon. There was a detailed write-up on how this can happen with photos in an NSS News after the accident.

Thanks Andy,

Just refreshed myself on that incident with this link:

http://www.bstorage.com/speleo/LoriCoriAccident/

I can't tell from the article if this was a function of the bend radius of the mallion or the diameter of the mallion rod stock, or both. Would the same be true of, say, a Petzl Speedy:



Or a small locking biner like a Trango Superfly?:



EDIT: Jansen, we posted at the same time! The pics you posted make the problem much clearer, thanks!
EDIT 2: Just went through all eight pages of the descender attachment thread. Good info! I know what I'll be doing for an hour this evening with all three of my Stop-style descenders...

[NZcaver]

Jansen, we posted at the same time! The pics you posted make the problem much clearer, thanks!

Yeah, I shot those photos a few years ago after somebody else asked the same question.

Just went through all eight pages of the descender attachment thread. Good info! I know what I'll be doing for an hour this evening with all three of my Stop-style descenders...

Only 3?? I'm not one to boast, but... I'm up to 6 (not counting duplicates).

Gear addiction is a serious problem which I've been struggling with for years. Unfortunately my peer support counselors are Gary Storrick and Jay Kennedy, so I'm pretty much screwed.

[Marduke]

Gear addiction is a serious problem which I've been struggling with for years. Unfortunately my peer support counselors are Gary Storrick and Jay Kennedy, so I'm pretty much screwed.

Bit OT, but I challenged a friend of mine to a "Biner War". He thought for a minute, smiled, and replied "You know, I rather like that idea..."

I mentioned it to his wife, and she hit me

[NZcaver]

You know it's getting bad when you have to sneak out to check the mail so the wife doesn't see you with another package...

[Lava]

UPDATE:

So I got out these Stop-style descenders:
* Petzl Stop
* Kong Indy
* SRTE Stop

And these locking carabiners:
* Trango Superfly
* Petzl Attache
* Petzl OK
* Omega Jake
* 9mm steel hardware store mallion

Results:
* Petzl Stop - opened easily by mallion and Superfly, could not be opened by Attache, OK, or Jake.
* Kong Indy - opened easily by mallion and Superfly, could not be opened by Attache, OK, or Jake.
* SRTE Stop - opened by ALL carabiners; very easily by the Superfly, Attache and OK, moderately difficult with the mallion, and extremely difficult with the Jake. I had to spin the Jake around to the narrower end and push it up onto the gate a little and then really torque it over to do so.

I'm probably okay with using the Jake with the SRTE as I think the odds of it opening the device the way I did it are astronomically low. But I gotta say, I am bummed. I just spent a lot of money on that SRTE and I love its performance compared to the others, and now I discover this undesirable feature! I don't want to have to use a huge biner on this thing. I was all prepared to move to it as my main descender.

I did some measuring and the problem is that the carabiner hole is too long on the SRTE (15mm from gate opening to base of hole) in comparison to the Petzl and Kong (8mm and 9mm respectively). If they shortened the hole so that it was too short to allow the carabiner to leverage the gate, everything would be fine. I think I may make a video and send it to SRTE, because this is a totally easy fix.

[NZcaver]

Easy fix. After attaching your SRTE Stop to your harness with the carabiner of your choice, take your short cowstail and clip it into the same attachment hole. Two carabiners, one hole. Problem solved.