Petzl Stop Poll

[cucc Paul]

I jst found this bit of kit on the web

http://www.petzl.com/petzl/ProProduits?MotRecherche=Quick+Search&pays=0&Langue=en&Activite=0&Famille=29&SousFamille=0&Produit=205&Conseil=&ProduitAssocie=

Petzl ID it seems to have a panic and grab fail safe and lots of fancy fail safes... as does the stop??? but has any one ever seen one or better yet road tested one in a cave. I'm not a cyber caver honest but not allowed ou the house much still so have too much spare time to surf... real caving is much better

 

[mudmonkey]

To answer a couple of people's points: If you use the lever to control speed of descent you can almost guarantee a jerky abseil (OK - I can't get it smooth) and will wear out your Stop much more quickly. Andy, afraid I respectfully disagree with your methods at this point though I can see the reasoning.

Petzl ID: I was on a Titan trip where someone (a ropie by trade) used an ID as a test-run. He found it incredibly fiddly and changed over to a rack halfway down.

 

[rich]

I've always used the tail to control decent as im used to using other devices such as an atc or figure of eight so it made sense for the stop to be no different. I do, however use the handle if i want to stop mid pitch as its impossible to fully stop your decent using the tail end on its own, unless im a weakling

You really should be able to stop dead pretty quickly when abbing just through friction on the tail end (whatever descender you're using). How fast were you going?

As a long-time Stop user, I have religiously NOT used the handle to slow descents, as per manufacturer's instructions, but have often wondered why, as it seems a logical way to add friction to your descent. WHY does Petzl advocate "all or nothing" handle-squeezing?

Because it knacks the rope?

 

[darkplaces]

It goes against the grain, I am still a biginner SRTer and Andy is a mighty one praise him, but I strongly disagree with Andy.

My my view begineers should not be tought to use the leaver as part of the decending system, it should be made clear its a last ditch failsafe and that control from day one should be by gripping the rope as if using a figure 8 or rack. I have converted to to the idea of safety line and putting a krab though the eye to disable the leaver for inital training, the leaver later then becomes the replacement-ish for a safety rope for experianced rope users.

I dont like the idea of begineers relying on the leaver.

 

[kay]

I don't think he's getting beginners to rely on the lever - they're still supposed to be using the rope to control descent. But by squeezing the lever rather than pushing it down as far as possible, they are limiting the maximum speed they can go at.

But that makes me wonder - suppose you're a beginner, holding the lever just far enough depressed to go at a reasonable speed (for whatever value of reasonable suits you), and using the rope to control your descent from 'zero' to 'reasonable' - and then something freaks you and you press the lever in panic, so now you have a wider range of speed available to you, from 'zero' to 'faster than reasonable' - might you not, as a beginner, panic even more and forget about using the rope to control your speed?

In other words, speaking from my position of petrified ignorance, I can see the logic of training with the lever completely depressed, so that using the rope becomes second nature, even if you later change to haviong the lever not completely depressed.

 

[cucc Paul]

Not fast i always ab slowly when using a stop. normally cause i only use them in caves (the exception being for for srt practice outside of caves) and dont want to have an accident by risking a faster than average ab.

 

[cap n chris]

Fast abseiling shouldn't be encouraged - it's OK in the movies to impress people - but the temperatures generated by your abbing device and then transferred to the rope are potentially unhealthy. A descent of less than a metre per second is a good rule of thumb on dry rope, so I've heard.

IIRC wasn't there a case where someone fast abseiled in Gaping Gill, stopped half way down and the rope melted, resulting in a fatality?

 

[Duncan]

IIRC wasn't there a case where someone fast abseiled in Gaping Gill, stopped half way down and the rope melted, resulting in a fatality?

David Huxtable, way back in 1974.

I think I once read that the rope involved was made of polypropylene, which has a considerably lower melting point than the nylon that's used these days.

 

[ChrisMorgan]

The oldest CUCC (cardiff not cambridge) kit is ~5 years old although there have been many new stops bought over the years as replacements.
It sounds like as Paul grabbed the tail end with both hands the auto-lock feature of the stop failed because of a combination of poo and possibly being jammed open with kit/poo.

The club ropes I believe are all 10.5mm, unless they have recently bought other stuff.

 

[cap n chris]

10.5mm rope with a relatively new Stop should normally provide loads of friction so the "poo effect" seems pretty severe.

 

[darkplaces]

Cool, have I started the common use of the word 'poo' or has it been around longer... poo poo poo poo cow poo everywhere including on my ropes!

The STOP is only rated for a max of 2 meters/second if I remember . An abbing instructor ran down the face, face forward with a figure 8 rather fast, as youngsters then we were all impressed.

 

[kay]

A descent of less than a metre per second is a good rule of thumb on dry rope, so I've heard.

I was told you should always wet the rope first. What do others think?

 

[rich]

Not fast i always ab slowly when using a stop. normally cause i only use them in caves (the exception being for for srt practice outside of caves) and dont want to have an accident by risking a faster than average ab.

I've always used the tail to control decent as im used to using other devices such as an atc or figure of eight so it made sense for the stop to be no different. I do, however use the handle if i want to stop mid pitch as its impossible to fully stop your decent using the tail end on its own, unless im a weakling

So does that mean you always have a problem stopping fully when abbing or just when your rope is covered in cowshit? It sounds like the former from what you said, but I'm finding that a bit hard to understand assuming all your kit is set up correctly.

 

[cucc Paul]

i can stop fine but if you have to stay stopped for any lengh of time it always seems to creep down so ive found its easier to release the handle than hang on to your tail end to stop your decent. Although always not letting go of your tail end...

 

[danthecavingman]

If you are stopping for any length of time then it's very easy to soft lock a stop by taking the tail end of the rope under the handle and over the loaded rope. This stops any creep and also means that the handle cannot be accidentally depressed. For a better lock form a bight out of the live tail, pass it through the krab and over the whole stop. Hope that makes sense. After you have locked off your descender you can let go of everything! You should always lock off a descender when you're not actually abseiling.

Dan.

 

[mudmonkey]

Kay - wet rope - very handy for long drops where, even at slow speed, your descender can get VERY hot.

 

[cavermark]

A TIP FOR TRAINERS TO STOP ANY CLUTCH AND PLUMMET:
ROPE BRAKING FROM BELOW.
Now in an ideal world training will give people surface practice on any abseil device; training will be good and all the pros and cons of devices discussed. Petzl info. will be read by users, shops will advocate proper training before use of gear. Even then, shit happens.
What about BRAKING FROM BELOW: someone experienced goes down the pitch first, holds onto the rope tail and then if plumentos occurs, pulls down hard - caver stops!!! works for all devices and even worst case scenarios such as fainting.

THOUGHT ON ANDY'S QUESTION TWO: Would making novices aware that the stop has a bad accident record change anything?. Cars have a bad accident record, therefore we learn how to drive safely. Going into a vertical environment is the dangerous bit - made safer by correct and thorough training in the equipment to be used.

ASIDE ON PETZL I.D.'s: twas I that tried a Petzl I.D. underground. I found any variation in the rope such as grit or mud caused it to lock - very tedious and jerky, therefore. Bit strange as being an industrial device it's presumably used on rock jobs - anyone tried?

 

[MSD]

Bottom braking doesn't work very well. THe person at the bottom has to first realise (in a dark and possibly noisy place) that the person above has lost control. By this time they will be travelling pretty fast. The belayer than has to pull hard enough on the rope to arrest the fall. Since the person is travelling fast, they have to pull very hard. This in turn takes time to achieve, because of the stretch in the rope. It takes even more time to achieve if the bottom belayer is standing to one side of the pitch because even more rope needs to be hauled in (trigonometry shows this easily).

Standing directly underneath an 80kg abseiler that you think might lose control is a bad idea....

 

[Stu]

Something I've tried out is to tie a knot as far up the rope as possible (a single slip knot that can be released with a sharp tug from below) which we've managed to stop plummeting abseilers from decking out. Only tried it on 15m pitches but even with rope stretch we missed the floor.

Not perfect but another option to add to safety rope & bottom braking (which doeas work very well - check out the military).

 

[MSD]

The slip knot is a neat trick, I'll remember that one. (I've previously just tied a knot sometimes, but it's a bit awkward to undo).

I don't really believe in bottom belaying, but can you describe the Armed forces technique in more detail? I'm always willing to be convinced by something new.

Simple maths shows that you have to react and move VERY fast for a traditional bootom belay to be effective. But if you want to use this technique, stand on a boulder or ledge 1-2 meteres off the floor and clip into the rope with a minimum of slack. Any problems, just jump off and you will get a good tension on the rope very fast.