cap n chris
Well-known member
IIRC there's a 27 page thread on this very topic.
JB
Member
I'm familiar with all the standard arguments. I just think it's wrong to say that a Petzl Stop "should not be used to train novices" as it's a perfectly servicable and popular descender. With the right coaching, some people can figure out the workings and limitations of a Petzl Stop quicker than you obviously give them credit for! Others might benefit from some time abseiling with a different device to fully grasp the notion that the hand on the dead rope should be controlling their descent. A 'one size fits all' approach to teaching skills like this is rarely the best in my experience.
I'm sure there's nothing more to be gained discussing this so I'll leave it at that.
I'm sure there's nothing more to be gained discussing this so I'll leave it at that.
L
Langthwaite Pot
Guest
Les W said:Known by None said:
A Stop descender when used correctly is perfectly safe!
There is no reason to be paranoid, just get good training and get familiar with your kit.
Personally I think you should be a bit paranoid about using stops. I think that due to the configuration of the bobbins they're much more prone to giving a sudden loss of friction on glazed/quick sections of rope than the simple. I guess the distance you plummit is relative to your experience of using the device which is why I don't think they're ideal for novices. I also find the simple much smoother in general, and when combined with a Raumer Handy you'd struggle to go into free-fall if you let go of the rope.
George.
A sudden decrease of friction, possibly, but personally I've only noticed that where the rope has had a sudden change of character, usually either dry rope that has become intermittently wetted when briefly hanging (or from limited water input into a tackle bag of dry rope), patchily muddied rope, or or rope weighted from gear, etc. tied on the bottom that suddenly becomes unweighted as the gear lands on the ground as the caver descends and stretches the rope.
Even so, don't most descenders have a fairly significant (and immediate) response to changes in rope characteristics?
Even so, don't most descenders have a fairly significant (and immediate) response to changes in rope characteristics?
K
ken
Guest
cap 'n chris said:
to make a long story short......60 meter freehanging pitch, 10mm speleo rope dry, I weigh 90 kg and had 15 kg tackle hanging under me.
The rope streched and i let go of the handle when around 45 meters down. It wouldn't hold itself and the rope was either tangeld up on my foot or my tackle bag (didn't really have time to look around). I tried pulling the handle out, didn't help. Couldn't pull the rope over the stop (couldn't pull it up because it kept slipping and there was a weight on it somehow) and i free falled.
Partner managed to stop me around 2 meters above the ground. needless to say the trip was over for me.
fazit= (3 years srt) after burned hands and having 25years scared off of my life,I learned.Everyone has their preferences to whatever device, anything over 40 meters (we do that often and never had a problem) and I'll take a shunt with me and a simple. I'm not the only one who has a stop slip, it happens quite often.
Besides using a stop over 40 meters gets very,very hot. not a nice feeling knowing you have only air under you and a "plastic" rope.
W
Walrus
Guest
So: what would be the recommended 'cut off' between using a Stop and another device? 40m? less?
M
MSD
Guest
[/quote]
to make a long story short......60 meter freehanging pitch, 10mm speleo rope dry, I weigh 90 kg and had 15 kg tackle hanging under me.
The rope streched and i let go of the handle when around 45 meters down. It wouldn't hold itself and the rope was either tangeld up on my foot or my tackle bag (didn't really have time to look around). I tried pulling the handle out, didn't help. Couldn't pull the rope over the stop (couldn't pull it up because it kept slipping and there was a weight on it somehow) and i free falled.
[/quote]
Were you using a braking karabiner?
Mark
to make a long story short......60 meter freehanging pitch, 10mm speleo rope dry, I weigh 90 kg and had 15 kg tackle hanging under me.
The rope streched and i let go of the handle when around 45 meters down. It wouldn't hold itself and the rope was either tangeld up on my foot or my tackle bag (didn't really have time to look around). I tried pulling the handle out, didn't help. Couldn't pull the rope over the stop (couldn't pull it up because it kept slipping and there was a weight on it somehow) and i free falled.
[/quote]
Were you using a braking karabiner?
Mark
M
MSD
Guest
I don't buy the simple+shunt set up. It's more complex, heavier, bulkier and it takes twice as long at each change-over. Extra complexity brings risks as well as safety. If you want to go with a simple, then go with a simple and leave the shunt at home.
Mark
Mark
footleg
New member
ken said:
This nicely highlights two important points about these descenders:
- You should never use the braking handle on a stop as a brake!
- These descenders do get very hot on long dry rope descents.
Personally I use a simple (or bobbin as I have always called it). I think one of the big dangers with the stop is that there is a natural tendancy to use the braking handle to control your decent and to reply on it as a brake then stopping on the rope. This is not how it was intended to be used. The braking mechanism is supposed to be a safety feature so that if something happens to cause you to let go of the descend you do not fall to the bottom.
The heat problem can be overcome in most cases (in the UK at least) by soaking the rope in a stream before rigging it. If this is not possible then the decender will get very hot. Too hot to touch in fact. So wear gloves, don't try to go too fast, and take it off the rope promptly when you get to the bottom. If you descend slowly then the bobbin will cool as fast as it heats up so things don't tend to get worse (except it feels pretty scary when you realise how hot it has gotten). If you try to go fast then things do get worse!
On very long pitches the stop or bobbin descenders are not so suitable. A rack is far better in those cases, but we don't have such long hangs in the UK.
Footleg
Is that 90kg plus caving gear (another 10-15kg)?ken said:
[quote author=ken]The rope streched and i let go of the handle when around 45 meters down. It wouldn't hold itself and the rope was either tangeld up on my foot or my tackle bag (didn't really have time to look around). I tried pulling the handle out, didn't help. Couldn't pull the rope over the stop (couldn't pull it up because it kept slipping and there was a weight on it somehow) and i free falled.[/quote]
Did the stretching contribute, and if so, how?
Were you using gloves or bare hands?
How did the rope feel in your right hand? Did it just suddenly start rushing through? How much grip did you need to apply to control descent before you sped up? Was the rope generally fast or slow, or just normal. What was different about the rope before and after you started to speed up (dampness, tension, etc)?
Sudden increase in speed does seem likely to be due to some sudden change in conditions, and it doesn't seem likely anything suddenly changed in a Stop. I'd be interested to know what did suddenly change (rope properties or tension).
Still, it's rapid response from your fellow caver. Noticing what was happening, applying tension and stopping a near free-fall descent in a matter of seconds would be quick reaction even for someone who already had the rope in their hands.
[quote author=ken]Besides using a stop over 40 meters gets very,very hot. not a nice feeling knowing you have only air under you and a "plastic" rope.[/quote]
It's certainly better if ropes can be wetted before use, especially on long pitches, but a very hot descender is still only likely to glaze a dry rope, making it more unpleasant to use, rather than do anything more serious.
D
darkplaces
Guest
I like upsetting people and I tend to be a little blunt sometimes so here goes nothing new.
Ken, sounds suspiciously like control was not being maintained by the right hand, the handle is not the break your right hand is (I'm sure you know this). Are you saying the friction in the device with breaking krab was not surfactant to control or halt the decent?
Because I too have had this experience on yellow rope (static but yellow) dropping down Oxlow Caverns entry shaft. At one point I had to release the handle and hold the dead/tail (what ever is the name) rope in both hands to control the decent, I had a breaking krab in place. I still trust the STOP, its the rope that was at fault as everyone else had the same issue. I had no problems what so ever on the preceding 3 or 4 pitches (cant remember).
So could we be putting a lot of blame on the STOP when really its the rope that is the bit that's changing and causing the problems?
Ken, sounds suspiciously like control was not being maintained by the right hand, the handle is not the break your right hand is (I'm sure you know this). Are you saying the friction in the device with breaking krab was not surfactant to control or halt the decent?
Because I too have had this experience on yellow rope (static but yellow) dropping down Oxlow Caverns entry shaft. At one point I had to release the handle and hold the dead/tail (what ever is the name) rope in both hands to control the decent, I had a breaking krab in place. I still trust the STOP, its the rope that was at fault as everyone else had the same issue. I had no problems what so ever on the preceding 3 or 4 pitches (cant remember).
So could we be putting a lot of blame on the STOP when really its the rope that is the bit that's changing and causing the problems?
mak
Member
Also how worn is the stop, I know we cavers like to hold on to our money and believe kit lasts forever but it does wear out - and of course once worn the friction in the descender decreases.
I remember my first stop descender - I knew it was becoming worn and a little "quick" - what finally decided me to replace the worn parts was lending it to a competitor in the hidden earth SRT race (dry ropes) and watching them abseil quite fast without touching the handle
I remember my first stop descender - I knew it was becoming worn and a little "quick" - what finally decided me to replace the worn parts was lending it to a competitor in the hidden earth SRT race (dry ropes) and watching them abseil quite fast without touching the handle
c**tplaces said:
Interesting point - I've taken a very exciting freefall on a very glazed rope, even with already knowing it was in that condition and double looping it round my braking krab as I wasn't the first down it.
Of course, the obvious solution is always to have a rebelay just a few metres off the deck so that even complete freefall on the upper part of the pitch results in a
on the loop to the lower anchor rather than a on the floor.
anfieldman
New member
ken said:
I think that judging by the time you typed this thread your problem may be tiredness Ken.
Only joking. I know someone that plummeted down a little way and it is not a funny situation. That was their mistake though. A simple 'clutch & plummet' accident. I can't understand how it could have happened to you. I would never trust a stop to 'stop' you when you let go of the handle, even on a large diameter rope that is old.
As long as you are using something that you now have confidance in then thats all that matters.
K
ken
Guest
Walrus said:
ok,now I'm gonna get kramps in my fingers from my hunt and pick method of typing :-[
Everyone hast to decide themselves what they want to use as a "up to here point". I wont go over 40 meters again without a shunt (stop blocked and a shunt).
Like everyone else says, it depends on a lot of different things, Rope condition (wet,dry,dirty (who has a clean one anyway?),clean....Weight plays a big factor, rebelays (I'm talking about a 60 meter freehanging pitch with no rebelays here.)
mak said:Also how worn is the stop, I know we cavers like to hold on to our money and believe kit lasts forever but it does wear out - and of course once worn the friction in the descender decreases.
I remember my first stop descender - I knew it was becoming worn and a little "quick" - what finally decided me to replace the worn parts was lending it to a competitor in the hidden earth SRT race (dry ropes) and watching them abseil quite fast without touching the handle
about 300 meters total used...pretty good condition because the wearbutton was ok.
c**tplaces said:
there wasn't ANY breaking with a krab or the stop at all. the krab was on my leg harness and the stop in my central. by the timeI realized what was happening I had burns on my hand and then everything started giong downhill very fast.
Did the stretching contribute, and if so, how?potholer said:Is that 90kg plus caving gear (another 10-15kg)?ken said:
ya, I'm healthy
[quote author=ken]The rope streched and i let go of the handle when around 45 meters down. It wouldn't hold itself and the rope was either tangeld up on my foot or my tackle bag (didn't really have time to look around). I tried pulling the handle out, didn't help. Couldn't pull the rope over the stop (couldn't pull it up because it kept slipping and there was a weight on it somehow) and i free falled.
Were you using gloves or bare hands?
How did the rope feel in your right hand? Did it just suddenly start rushing through? How much grip did you need to apply to control descent before you sped up? Was the rope generally fast or slow, or just normal. What was different about the rope before and after you started to speed up (dampness, tension, etc)?
Sudden increase in speed does seem likely to be due to some sudden change in conditions, and it doesn't seem likely anything suddenly changed in a Stop. I'd be interested to know what did suddenly change (rope properties or tension).
Still, it's rapid response from your fellow caver. Noticing what was happening, applying tension and stopping a near free-fall descent in a matter of seconds would be quick reaction even for someone who already had the rope in their hands.
[quote author=ken]Besides using a stop over 40 meters gets very,very hot. not a nice feeling knowing you have only air under you and a "plastic" rope.[/quote]
It's certainly better if ropes can be wetted before use, especially on long pitches, but a very hot descender is still only likely to glaze a dry rope, making it more unpleasant to use, rather than do anything more serious.
[/quote]
even with 4% on a static rope 50 meters down a straight pitch the rope gets somewhat smaller.
It started ok with a little bit of feeding required (10 meters). The next 20-30 were ok with self feed then everything went to H*** in a handbasket. The speed picked up and I couldn't pick up thre rope to lock it over, trying this I burned my hands. Let go of the handle and it went faster......then I screamed :spank:
thank god I wasn't the first down the pitch and my friend has free beer for quite a long time
yes I had gloves...but they were not leather
those melted also.
L
Langthwaite Pot
Guest
potholer said:
I'm pretty sure that my simple doesn't respond to changes in the ropes characteristics to anywhere near the same extent as my stop does. I've certainly never 'plummeted' with my simple. It could just be me, but I'd be interested to know if other simple users have found the same.
George.
Why 40m? It doesn't seem like your problem was caused by the length of rope above, but by the nature of the rope you were on when you started speeding up.ken said:
[quote author=ken]there wasn't ANY breaking with a krab or the stop at all. the krab was on my leg harness and the stop in my central.[/quote]
Do you mean the leg loop (metal ring?) attachment to the central maillon, or through the leg loop itself?
[quote author=ken]even with 4% on a static rope 50 meters down a straight pitch the rope gets somewhat smaller.[/quote]
Hardly. The rope weight itself (~5-10kg?) would give something like 0.2-0.4% stretch on a 4% stretch (at bodyweight) rope, which would probably change diameter by ~0.1-0.2% above the bodyweight-caused stretch, which in your case (90kg plus tackle bag + caving gear) might have been a bit over 4%.
On a 10mm or thicker rope, I don't think I've *ever* had a particularly hard-to-control descent apart from muddy ropes, and once when abbing down someone else's brand new rope that hadn't been properly rinsed before use. Once hitting the wet section on that, it did take a bit of gripping and wrap-round-leg friction to keep a controlled descent.
Mind you, I'm only ~70kg, and I do notice it when I start having a *lot* of tackle weight hanging underneath me. I suppose the comfortable rope diameter might be a bit more for more substantial people.
[quote author=ken]It started ok with a little bit of feeding required (10 meters). The next 20-30 were ok with self feed then everything went to H*** in a handbasket. The speed picked up and I couldn't pick up thre rope to lock it over, trying this I burned my hands. Let go of the handle and it went faster......then I screamed.
thank god I wasn't the first down the pitch and my friend has free beer for quite a long time.[/quote]
Even given the Stop's imperfections, for something to suddenly speed up from a normal descent (with presumably smoothly increasing right-hand friction) to be too fast/too low-friction to stop with a gloved right hand on 10mm rope, there has to be something other than the Stop that was the fundamental cause.
K
ken
Guest
Do you mean the leg loop (metal ring?) attachment to the central maillon, or through the leg loop itself?potholer said:
my stop was in my central maillon and my braking krab through my leg loop on the right leg.
[quote author=ken]even with 4% on a static rope 50 meters down a straight pitch the rope gets somewhat smaller.[/quote]
Hardly. The rope weight itself (~5-10kg?) would give something like 0.2-0.4% stretch on a 4% stretch (at bodyweight) rope, which would probably change diameter by ~0.1-0.2% above the bodyweight-caused stretch, which in your case (90kg plus tackle bag + caving gear) might have been a bit over 4%.
On a 10mm or thicker rope, I don't think I've *ever* had a particularly hard-to-control descent apart from muddy ropes, and once when abbing down someone else's brand new rope that hadn't been properly rinsed before use. Once hitting the wet section on that, it did take a bit of gripping and wrap-round-leg friction to keep a controlled descent.
Mind you, I'm only ~70kg, and I do notice it when I start having a *lot* of tackle weight hanging underneath me. I suppose the comfortable rope diameter might be a bit more for more substantial people.
do you mean fat? :-\ heavy people are good in caves also.....we dry the wet crawls for the people coming behind us
We only use 10mm static ropes execpt for life line wenn we use a 10 mm dynamic.[quote author=ken]It started ok with a little bit of feeding required (10 meters). The next 20-30 were ok with self feed then everything went to H*** in a handbasket. The speed picked up and I couldn't pick up thre rope to lock it over, trying this I burned my hands. Let go of the handle and it went faster......then I screamed.
thank god I wasn't the first down the pitch and my friend has free beer for quite a long time.[/quote]
Even given the Stop's imperfections, for something to suddenly speed up from a normal descent (with presumably smoothly increasing right-hand friction) to be too fast/too low-friction to stop with a gloved right hand on 10mm rope, there has to be something other than the Stop that was the fundamental cause.
[/quote]
it very well could be something else.
The thread was about stop versus simple and if anyone has had problems, which was better or worse in which situation.
The stop is rated for 150 kg at 100 meters. It does not say which diameter rope was used to arrive at this rating. For me anything over 40 meters with a 10mm rope I will use something else.
Friends of mine use a rack with a straight pitch over 70 meters because they also have problems with the stop. If there are rebelays in the pitch (somewhat in the middle) then a stop is for me is no problem.
