TheBitterEnd
Well-known member
Might be of interest
Falling on Cows Tails
- Thread starter TheBitterEnd
- Start date
chunky
Well-known member
cap n chris
Well-known member
The Petzl spelegycas were denounced years ago for creating a significantly injurious shockload; furthermore the OP video makes a good point about the length ergonomics being person-specific (which they are); I do like the OP video comment that the long reach side of the spelegyca is for connecting to the hand jammer while the short one is for connecting to the rebelay; arguably completely correct (according to Petzl illustrations, including those in ACT by Marbach/Tourte), which supports the view that the Cord of Shame is a UK specific anachronism serving little or no purpose. Long reach part of your safety connector goes to the hand jammer assembly while the shorter element of your safety connectors connects to the rebelay/traverse etc.. Remember, BCA public domain publication states you must loosen off your safety connectors (aka cowstails) after every use. The loosened knots absorb the shockload; if they're not loosened they won't and you risk breaking your back or rupturing internal organs. Your choice.
Last edited:
cap n chris
Well-known member
I will defer/step back as/when Mark Wright and/or Mike Hopley add their expertise to the fray. IIRC the Petzl spelegyca was denounced over a decade ago; I ceased using them earlier than that; definitely not a good design/invention/piece of kit.
TheBitterEnd
Well-known member
Because breaking things make for more likeable videos. F=ma so factor down (or up) to suit.
It does raise the question as to whether a more well padded caver might experience a lower peak load
Bob Mehew
Well-known member
The puffed up science answer is mgh, or more simply the energy you can put into a sample from a falling mass. (It is not the force which breaks the rope, it is the energy.) In our work on rope we have used over 200 kg to get a sufficient amount of energy to break the rope sample in a single (dynamic) drop. Given your sample is of a certain length, then the best you can usually get is twice that length for a fall factor 2 as h, the height. (I say usually because with crabs and chains you can push it to larger FF.) As it is difficult to increase g, the acceleration due to gravity, that just leaves you with manipulating m the mass.
Having said that used rope does require less energy to break it, so testing an old cow tail could get away with more typical values of say 100 kg which is nearer the mass of a heavy caver. (I vaguely recall that 95% of IRATA workers weighed under 105 kg though that was with them also carrying their usual tools.)
Having said that used rope does require less energy to break it, so testing an old cow tail could get away with more typical values of say 100 kg which is nearer the mass of a heavy caver. (I vaguely recall that 95% of IRATA workers weighed under 105 kg though that was with them also carrying their usual tools.)
andrewmcleod
Well-known member
As with most things, the Petzl Spelegyca does have a use although it's probably not the best tool for most cavers (especially in the UK).
It has been suggested to me that if a) you were very aware that falling on *any* cowstail is a thing you Should Not Do, and b) you were going underground on a three week camping trip where abrasion may be considerable but bringing excess gear was to be avoided at all costs, you might have more faith that the Spelegyca would still be in reasonable condition at the end of your trip than rope cowstails (which might be cored at the knots after three weeks hard caving).
It has been suggested to me that if a) you were very aware that falling on *any* cowstail is a thing you Should Not Do, and b) you were going underground on a three week camping trip where abrasion may be considerable but bringing excess gear was to be avoided at all costs, you might have more faith that the Spelegyca would still be in reasonable condition at the end of your trip than rope cowstails (which might be cored at the knots after three weeks hard caving).
andrewmcleod
Well-known member
If you are going full lightweight (e.g. you get one bag underground for 3 weeks), you don't want either spare cowstails or a safety cord.
I also enjoy the fear and worry that leads people to untie and retie their knots and worry about shock loadings etc. on cowstails (despite the lack of evidence of people either breaking cowstails or injuring themselves badly falling onto them), and then they put snapgates on the end which definitely has led to accidents in the past...
People are often bad at identifying the most significant risks (generally something like being bashed on the head by a rock or hit by flooding or getting lost or falling over/down/off things while unroped) and instead worrying about the theoretical risks that never actually happen in practice (like having a bowline-on-the-bight Y-hang fail on you, or getting 8kN vs 6kN shock load on a FF2 cowstail fall, or whatever).
JasonC
Well-known member
You've expressed this view once or twice (or 20 times?) before, and I can certainly see the advantage of reducing the amount of stuff attached to the central maillon, but I;m struggling to picture the set-up. If you have the hand jammer and foot-loop attached to the long cow's tail, doesn't this mean that when using the cow's tails on a traverse or approaching a downward pitch, you have the foot-loop etc dangling down and potentially getting caught on rock flakes or your own feet?
This seems so unwieldy to me that I feel I've misunderstood something, Do you have a photo of your set-up?
andrewmcleod
Well-known member
People who go 'Alpine style' don't always have their hand jammer and foot loop attached to their cowstail. Traditionally I think you have a locking carabiner attached to the hand jammer with the footloop attached. You leave this on your harness/wrapped around yourself when you aren't ascending. Then when you go to ascend, you put the hand jammer on the rope and then clip your long cowstail into the locking carabiner (or into the hand jammer directly, if there is space for a second carabiner or you have used a maillon/whatever to attach the footloop).
Obviously this does increase the danger of you dropping your hand ascender as it is not permanently attached to you... You also can't use your hand jammer (either directly or using its carabiner) as a third cowstail if you are using snapgates and are on some slippery death traverse and don't want to end up on a single snapgate.
Obviously this does increase the danger of you dropping your hand ascender as it is not permanently attached to you... You also can't use your hand jammer (either directly or using its carabiner) as a third cowstail if you are using snapgates and are on some slippery death traverse and don't want to end up on a single snapgate.
andrewmcleod
Well-known member
Purely out of curiosity, do you use snapgates on your cowstails? When travelling along a traverse, do you end up on a single snapgate when passing a knot?
I have absolutely no issue with people using snapgates, using Alpine style, using Simples etc. provided they are fully conversant with the risks they are knowingly taken (which are simply part of the risks that all cavers must take in order to go caving). But I don't think 'shame' is quite the right work for people who have chosen to add a bit of extra kit that reduces risk somewhat (or maybe they are just clumsy and don't want to drop their hand ascender)...
As the guy says in the video, the two biggest risks are high FF and krabs breaking. Screwgates don’t help much with gates breaking unless they have been beefed up for cross loading like in the omni.
Some basic maths would demonstrate that having two krabs attached dramatically reduces the already small risk of human error, so having three available for hanging traverses seems fairly obvious if you care at all. Two snaps is vastly safer than one screwgate, but it prob the difference between 10-3 and 10-6 chance of occurrence, so there will never be any stats on it and there are other things I would worry about rather more. I use 8mm dynamic on my safety link these days to try and reduce shockload a bit when using it as a cows tail, and also try and get a theoretical FF1 load down towards the 4kn limit before a jammer rips the sheath - but this is realistically more for my entertainment than real.
aricooperdavis
Moderator
I'm not sure how you're expressing those probabilities. Do you mean 1:1,000 and 1:1,000,000? If so the former seems a bit high?
tomferry
Well-known member
I am feeling strongly the same, about your later statement . People worrying about the wrong things …
I don't think Cap n Chris intended it to be. It was in the context of what ACT by Marbach/Tourte says, and a safety leash is called 'the cord of shame' in that book, so I took it to be just emphasising the non-UK (ie, French) attitude to it. Which you can call patronising and arrogant if you like!
cap n chris
Well-known member
No. I ceased using snapgates over a decade ago as they are lethal.
