Petzl Simple and Stop: attachment mailion modification

[Scott McCrea]

Just in case anyone wishes to discuss this further, a thread about the Lori Cori Accident has been started here: http://www.caves.org/phpBB2/viewtopic.php?t=584

[potholer]

The Lori Cori incident *was* a very old bobbin with a somewhat different and semingly more primitive catch, with possible failure modes not necessarily applicable in a meaningful way to modern devices.

[Tubo Longo]

I remember to have heard of this accident but haven't read anything about before. Thanks for re-posting it Hunter.

I disagree with a conclusion of the report, in that the use of a brake biner could have help to avoid the fatality, by just allowing to pull the rope over the bobbins in an half-lock style, but without tightening the rope completely. Btw, this is a standard trick used to slow down, sort of additional brake. Using it, the rope would have forced the side plate almost on its correct position. Of course it would have slow down quite a bit the rappel, since it anyway add friction to the system.

I noted a "strange" position of the bobbins in most of the pics in the report: it's in an almost horizontal, or definitely angled, position. Well, I'm a big guy (being at about 230 lb) but still I will have to definitely pull the rope down with quite a bit of force to position my bobbins in such a way. Which is not very consistent, in my experience, with a muddy rope, i.e. a rope which need to be feed in.

Also my impression is that the caver, although experienced, might not have had that much experience with the bobbins, since - 22 years after having traded it - he said something like “This thing seems to be working pretty well so far.â€

[Tubo Longo]

Just in case anyone wishes to discuss this further, a thread about the Lori Cori Accident has been started here: http://www.caves.org/phpBB2/viewtopic.php?t=584

Sorry Scott, have seen your post only after I posted mine. But I agree with Potholer, *that* bobbins was the first series with a gate, since before there was no gate at all. We talk of a mid to late 1970's product.

[fuzzy-hair-man]

Well, I don't. Fuzzy-hair-man state it in the opening post...
:
:
I only have bobbins with the metal gate, so I don't know how the new plastic one works with respect of this matter. Besides this, being used to rebelays, the idea to have something which would make almost impossible to open the bobbins is just - sorry, no offense intended - plain crazy to me.

Yes I can easily open the bobbin when intended to thread or unthread the rope.
The Simple and Stop with the metal spring gates also have this problem.
My original post says:

I have tried it on rope in a gym (after OKing the modification with other club members) and I didn't notice any difficulty the modification has caused in threading or unthreading the descender. In fact the first time I tried it I forgot I had it on there and only realized later, so concluded that it made almost no difference to the operation of the descender. Kewl

OK, whatever way I rotate the mailion with my hands I have not been able to get the spring gate to open. It does depress the gate slightly but not far enough for the mailion to get past the catch.

[Tubo Longo]

Yes I can easily open the bobbin when intended to thread or unthread the rope.
The Simple and Stop with the metal spring gates also have this problem.
My original post says:

I have tried it on rope in a gym (after OKing the modification with other club members) and I didn't notice any difficulty the modification has caused in threading or unthreading the descender. In fact the first time I tried it I forgot I had it on there and only realized later, so concluded that it made almost no difference to the operation of the descender. Kewl

OK, whatever way I rotate the mailion with my hands I have not been able to get the spring gate to open. It does depress the gate slightly but not far enough for the mailion to get past the catch.

OK, I don't get it, sorry. True, you first state that you can thread and unthread the rope without difficulty. Then say that you have not been able to open the spring gate, which is the part I got for good in your post.

Now I'd like to get it: do you refer, in the second part of the quote, to the maillon unintentionally opening the gate because of you moving it around or what? Because I'm definitely confused...

[fuzzy-hair-man]

Now I'd like to get it: do you refer, in the second part of the quote, to the maillon unintentionally opening the gate because of you moving it around or what? Because I'm definitely confused...

Yes,

That's it the conclusion from the Cora Lynn accident investigation was the mailion was able to twist around when the descender became unweighted and push on the spring gate popping the front plate open.

When I say ".....I have not been able to get the spring gate to open.", I mean whatever way I try to manipulate the mailion and the descender I cannot get the mailion to push open the spring gate on the descender.
I can still easily work the spring gate with my hands when I intentionally want to open the descender.

I probably could have worded that clearer

[NZcaver]

Could you (anyone) post a link to the Cora Lynn accident investigation report?

I'd be interested to check that one out...

[hank moon]

Could you (anyone) post a link to the Cora Lynn accident investigation report?

I'd be interested to check that one out...

If ya mean Lori Cori...

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

[NZcaver]

If ya mean Lori Cori...

Wait - is Cora Lynn the same accident as Lori Cori? I'm confused...

[fuzzy-hair-man]

Opps I mean Lori Cori.. sorry I think Cora Lynn might be a cave in Tasmania either way I'm not sure where I plucked the name from

No I just looked it up, Cora Lynn is in South Australia I went in there when in Adelaide. Sorry Again name must of stuck in my brain. and it doesn't even have any vertical

[NZcaver]

Opps I mean Lori Cori.. sorry I think Cora Lynn might be a cave in Tasmania either way I'm not sure where I plucked the name from

OK - no problem. I also vaguely recall something about a similar accident/incident more recently, but I think it was in Europe (former USSR possibly?) I wish I could pull up a reference, because I don't think this issue was just a one-time thing...

[Tubo Longo]

I also vaguely recall something about a similar accident/incident more recently, but I think it was in Europe (former USSR possibly?) I wish I could pull up a reference, because I don't think this issue was just a one-time thing...

There has been a deadly accident quite recently in France: a very experienced caver, while rigging solo a pit went into free fall and died. He wasn't caving solo, to be correct: he just went ahead of his party to rig the pit (100m? mostly free fall) and so avoid the party to wait while he was rigging, a system quite common in alpine caving.

Apparently the accident was caused by over confidence: he might have not locked the bobbins, not realizing that it got so loose at some point that the head of the bobbins got stuck into the brake biner. When he loaded the bobbins he went, of course, into free fall.

Common opinion is that the accident might have been avoided if: 1. the bobbins would have been locked while rigging 2. the brake biner would have been connected to the bobbins's biner instead than to the maillon.

is this the accident you were recalling?

Renato

[NZcaver]

is this the accident you were recalling?

I'm not sure - it may have been that incident. When did it happen, and is there a detailed accident report available on-line?

Common opinion is that the accident might have been avoided if: 1. the bobbins would have been locked while rigging 2. the brake biner would have been connected to the bobbins's biner instead than to the maillon.

I'm confused by your second point. My understanding is that if you use a separate braking carabiner you should always clip it directly into your maillon - and never into your descender attachment carabiner. Something like this:



As a reference, check out pages 70-72 in "Vertical" (the 3rd, 4th and 5th pages down on this link) - http://www.caves.com/6DESCENT.pdf

Have you been taught different?

[Baazalung]

A Petzl Freino would have meant a great deal to him