cap n chris
Well-known member
SamT said:
Agree totally. A ropeman is something you wouldn't want to be pfaffing about with at a rebelay.
SRT-kit 'lite'
- Thread starter JB
- Start date
Agree totally. A ropeman is something you wouldn't want to be pfaffing about with at a rebelay.
Stu
Active member
Re: Prussics
Agree with Sam to some degree - Tibloc is lighter, but then how do you connect the tibloc? It's feasible to us a continuous length of cord for the prussic/footloop combi, hence no extra krab. The Blake knot used by tree bods is the dogs dangly's on muddy rope (as is the criss cross Prussic the name of which escapes me). This does assume a muddy rope though in JB's "specific" cave - which also has no re-belays nor iffy pitch heads!!
Pretty much goes to show how well evolved our SRT present kit is.
Agree with Sam to some degree - Tibloc is lighter, but then how do you connect the tibloc? It's feasible to us a continuous length of cord for the prussic/footloop combi, hence no extra krab. The Blake knot used by tree bods is the dogs dangly's on muddy rope (as is the criss cross Prussic the name of which escapes me). This does assume a muddy rope though in JB's "specific" cave - which also has no re-belays nor iffy pitch heads!!
Pretty much goes to show how well evolved our SRT present kit is.
JB
Member
Thanks for your input with this everyone. Was actually a cave that I visited in France that got me thinking about this originally (Gouffre de Cadarcet) but there might be others that it would be useful. One of the things I've found is that it's a lot easier to put this kit on and take it off so might be good in restricted places.
I should have said, I do want the thing to be fully functional i.e. I want to be able to pass rebelays and deviations if necessary only because you never know what you'll end up having to do underground. As Sam, suggested, you can make a Ropeman work as a chest jammer with a little persuasion but I'm taking a Croll as my one luxury item. I like the idea that in extremis you can just clip yourself quickly into owt with a Croll and take a deep breath.
A 120cm 9mm diameter dyneema sling works fine for me as a SRT harness although as many have said, it's not exactly comfortable. Not bad when wearing furry and oversuit. At the moment I'm using a HMS krab at the front to attach sling harness to Croll. Don't like this because of the three-way load on the krab so have ordered one of those gucci semi-circle Petzl Omni alloy krabs which are 15kN in any direction.
For a chest harness I've got a loop of 5mm bungee elastic that I can larksfoot onto the back of the sling harness, put over my head and clip to the top of the Croll with a small non-load-bearing clip (Ref: Taylor, J. (2004)).
For cowstails I'm using 7mm static cord (10kN) with a couple of Wild Country Oxygen krabs. I know we like to use dynamic rope for cowstails but I havn't got any skinny dynamic rope available and 30cm of dynamic rope don't absorb much energy. I'll not take a winger onto it.
For the footloop/safety cord arrangement I'm using 7mm cord again, a Petzl OK krab and a Wild Country Ropeman MkII. Works absolutely fine on ropes of 8mm and thicker. Did think about using even thinner cord for the footloop (5mm) but reckon the footloop would stretch and that would piss me off. Chris's dyneema sling sounds good as it's not going to stretch at all. Might fine-tune with one of those.
For abseiling I've got an alloy twistlock HMS krab which will work fine with an Italian Hitch.
I've ended up with something very similar to what Cap 'n' Chris has. You could go smaller/lighter but this is pretty-much fully functional and easy to use. Have only tried it out in a climbing wall so far but will be getting a proper test tomorrow underground.
There are some photos here showing the kit that I've ended up with and the size of it packed against my standard SRT kit. I'm pleased with what I've got so far. Just about fits in oversuit pocket and packs loads smaller.
http://www.orionmountaineering.com/cpg144/displayimage.php?album=25&pos=5
I should have said, I do want the thing to be fully functional i.e. I want to be able to pass rebelays and deviations if necessary only because you never know what you'll end up having to do underground. As Sam, suggested, you can make a Ropeman work as a chest jammer with a little persuasion but I'm taking a Croll as my one luxury item. I like the idea that in extremis you can just clip yourself quickly into owt with a Croll and take a deep breath.
A 120cm 9mm diameter dyneema sling works fine for me as a SRT harness although as many have said, it's not exactly comfortable. Not bad when wearing furry and oversuit. At the moment I'm using a HMS krab at the front to attach sling harness to Croll. Don't like this because of the three-way load on the krab so have ordered one of those gucci semi-circle Petzl Omni alloy krabs which are 15kN in any direction.
For a chest harness I've got a loop of 5mm bungee elastic that I can larksfoot onto the back of the sling harness, put over my head and clip to the top of the Croll with a small non-load-bearing clip (Ref: Taylor, J. (2004)).
For cowstails I'm using 7mm static cord (10kN) with a couple of Wild Country Oxygen krabs. I know we like to use dynamic rope for cowstails but I havn't got any skinny dynamic rope available and 30cm of dynamic rope don't absorb much energy. I'll not take a winger onto it.
For the footloop/safety cord arrangement I'm using 7mm cord again, a Petzl OK krab and a Wild Country Ropeman MkII. Works absolutely fine on ropes of 8mm and thicker. Did think about using even thinner cord for the footloop (5mm) but reckon the footloop would stretch and that would piss me off. Chris's dyneema sling sounds good as it's not going to stretch at all. Might fine-tune with one of those.
For abseiling I've got an alloy twistlock HMS krab which will work fine with an Italian Hitch.
I've ended up with something very similar to what Cap 'n' Chris has. You could go smaller/lighter but this is pretty-much fully functional and easy to use. Have only tried it out in a climbing wall so far but will be getting a proper test tomorrow underground.
There are some photos here showing the kit that I've ended up with and the size of it packed against my standard SRT kit. I'm pleased with what I've got so far. Just about fits in oversuit pocket and packs loads smaller.
http://www.orionmountaineering.com/cpg144/displayimage.php?album=25&pos=5
cap n chris
Well-known member
May I suggest you use the maillon to connect the Ropeman to the footloop - this does away with a karabiner thus reducing the packing space somewhat - you can attach the connector rope direct into your sexy Omni! My only other caveat would be that if you are expecting to ab on claggy/gritty ropes then you'll want a steel HMS rather than alloy 
cap n chris
Well-known member
Oh, and another refinement (if you're minded to adopt it) would be to re-tie the connector rope so that the loose end becomes your short cowstail and the connection to the ropeman doubles up as your long cowstail, thus meaning you lose more weight and bulk without detracting from the functionability of your rig.
cap n chris
Well-known member
Ignore the maillon/ropeman connection response above - on thinking it through this would make for pfaffage; a small load-bearing karabiner should suffice (available from Bernies, when I last visited - see pic below):
Normal HB snaplink [28kn: long axis] versus Faders mini snaplink [12kn: long axis]
Normal HB snaplink [28kn: long axis] versus Faders mini snaplink [12kn: long axis]
JB
Member
Thanks for those very valid suggestions Chris. Both would definitely save some weight and bulk. Only reason I've set it up like this is that I like having a bit of spare cord (footloop/safety cord) that I could potentially use for other things without taking my harness off. That's why I want to connect safety cord to sexy krab with a maillon. The OK krab is significantly more bulky than a maillon but generally find that an oval krab is useful to have around for other stuff so happy to take it along. Good idea about doubling up long cowstail/safety cord a la Alpine Caving Techniques. Might use that some of the time.
Bit of personal wierdness in all that.
Bit of personal wierdness in all that.
cap n chris
Well-known member
Let us know how it all works in practice and whether there are any observations/refinements which result!
JB
Member
Yep - agree Sam - good to think about these things.
Given that there are (hopefully) plenty of new cavers on the forum it's worth pointing out some of the potential problems of such a system.
Most important one for me is the use of an improvised SRT harness. Purpose-built caving harnesses have to pass a series of tests to achieve CE and UIAA standards. It's likely that my improvised harness with a sling would fail some of these tests. 'Harness Hang Syndrome' brought about by hanging unconscious in a harness is something that we should all be aware of. There is still alot that isn't known about it but I would expect that it would be made worse by the use of a home-made harness rather than a purpose-designed one. I think you have to accept that if you get whacked on the head and end up passing out hanging in a sling, that might be the end of you unless someone can get you down very, very quickly.
Secondly, what happens if you turn upside down in the harness? A well-fitting, purpose-designed harness will stop you from falling out. There's no such guarantee if you're using one of your own design.
The point has already been made about the potential for dropping a Ropeman or Tibloc at pitch-heads/re-belays. Unless you've got some sort of 'keeper cord' arrangement it will happen sooner or later. Important to have a back-up plan.
Using thinner/weaker rope and cord reduces your margins. Know the likely forces that each part of your gear is going to have to withstand and cave in such a way to minimise them. Time, wear and other factors mean that the strength of your kit is reduced as soon as it leaves the factory. Keep your kit in good condition.
If you're using lighter/less-bulky snapgate krabs in places that you'd normally use screwgates be aware that they do get levered open by contact with rock or even twisting action by the rope that's in them. Need to keep an eye on them.
There's no back-up if you lose control of the rope when abseiling with an Italian Hitch. As Sam says, you could use a prussik knot as a back-up or get someone to belay you from the bottom of the pitch.
Apologies if that's all obvious stuff but I think there are a few issues there that are worth thinking about.
Given that there are (hopefully) plenty of new cavers on the forum it's worth pointing out some of the potential problems of such a system.
Most important one for me is the use of an improvised SRT harness. Purpose-built caving harnesses have to pass a series of tests to achieve CE and UIAA standards. It's likely that my improvised harness with a sling would fail some of these tests. 'Harness Hang Syndrome' brought about by hanging unconscious in a harness is something that we should all be aware of. There is still alot that isn't known about it but I would expect that it would be made worse by the use of a home-made harness rather than a purpose-designed one. I think you have to accept that if you get whacked on the head and end up passing out hanging in a sling, that might be the end of you unless someone can get you down very, very quickly.
Secondly, what happens if you turn upside down in the harness? A well-fitting, purpose-designed harness will stop you from falling out. There's no such guarantee if you're using one of your own design.
The point has already been made about the potential for dropping a Ropeman or Tibloc at pitch-heads/re-belays. Unless you've got some sort of 'keeper cord' arrangement it will happen sooner or later. Important to have a back-up plan.
Using thinner/weaker rope and cord reduces your margins. Know the likely forces that each part of your gear is going to have to withstand and cave in such a way to minimise them. Time, wear and other factors mean that the strength of your kit is reduced as soon as it leaves the factory. Keep your kit in good condition.
If you're using lighter/less-bulky snapgate krabs in places that you'd normally use screwgates be aware that they do get levered open by contact with rock or even twisting action by the rope that's in them. Need to keep an eye on them.
There's no back-up if you lose control of the rope when abseiling with an Italian Hitch. As Sam says, you could use a prussik knot as a back-up or get someone to belay you from the bottom of the pitch.
Apologies if that's all obvious stuff but I think there are a few issues there that are worth thinking about.
cap n chris
Well-known member
Wise words, JB.
Very interesting. In alpine climbing, the justification for going ultra-light is that weight slows you down, and going fast is safer. It gets you out of danger zones (like stonefall) more quickly, and gets you back down before the weather changes. Thus it can be argued that it's more safe.
Does this apply in the question posed here? Can SRT-lite only be justified on convenience grounds or might it be safer overall (in an appropriate cave, of course)? I ask firstly as a debating issue, and secondly because being new to caving, I don't know the answer! How much faster could you go (in the rest of the cave) with such kit (maybe volume is more important than weight?) and how much is time an issue? Weather changes and flooding come to mind, and for long trips, saving time could mean not needing to carry so much food and water, etc.
Chris
Does this apply in the question posed here? Can SRT-lite only be justified on convenience grounds or might it be safer overall (in an appropriate cave, of course)? I ask firstly as a debating issue, and secondly because being new to caving, I don't know the answer! How much faster could you go (in the rest of the cave) with such kit (maybe volume is more important than weight?) and how much is time an issue? Weather changes and flooding come to mind, and for long trips, saving time could mean not needing to carry so much food and water, etc.
Chris
graham
New member
Very good questions, Chris. In most cases the answer would be a definite "no" because the requirement to carry (fairly) large quantities of rope would mean that compromising on your SRT kit would actually make little difference to the total weight carried.
In the scenario stated at the beginning, however, we are talking about quite small amounts of rope. This must qualify how you think about it; for example a couple of quite small pitches should mean that the objective dangers of undertaking SRT could possibly be somewhat lessened and the individual's ability to deal with them by being fresher and stronger may compensate.
It would be interesting to discuss this in the context of caves with which we are all familiar.
In the scenario stated at the beginning, however, we are talking about quite small amounts of rope. This must qualify how you think about it; for example a couple of quite small pitches should mean that the objective dangers of undertaking SRT could possibly be somewhat lessened and the individual's ability to deal with them by being fresher and stronger may compensate.
It would be interesting to discuss this in the context of caves with which we are all familiar.
cap n chris
Well-known member
Imagine I want to go digging in Black Hole Series in Swildon's Hole, solo. Many cavers seem quite happy to climb, unlined, up and down ladders. I do not (after having witnessed a spanking new ladder snap). Assuming I WAS happy to use ladders solo I'd need to take a ladder for the twenty, I'd also need to take a ladder to climb down one side of the Black Hole before traversing out across the gulf and climbing up the other side (dodgy as hell/foolhardy/lethal without a line BTW!). With a liteweight SRT kit I can bung a 7m bit of 9mm on the 20, ab down and continue to the BH where I have about 10m of 9mm which I ab down, self-protect across and continue on my merry journey. Since I've got lightweight kit I am able to also carry the luxury of a neo hood for the sump dive and I can also use my BH rope for the return down the sodding awkward overhang climb between BH and sump 1 on the return. So, therefore, solo to BH requires:
1 x sling for improv harness
1 x HMS krab for ab/central connection for croll
1 x thin dyneema sling footloop
1 x 6mm connector rope to footloop from croll/krab
1 x ropeman ascender
1 x croll ascender
1 x mini krab for connecting ropeman to connector & dyneema sling footloop
7m x 9mm rope for Twenty, tied directly into two anchors using suitable rigging
10m x 9mm rope for Black Hole, belayed into 2 x SD spits (take spanner), rigging through 2 x maillons
1 x sling for improv harness
1 x HMS krab for ab/central connection for croll
1 x thin dyneema sling footloop
1 x 6mm connector rope to footloop from croll/krab
1 x ropeman ascender
1 x croll ascender
1 x mini krab for connecting ropeman to connector & dyneema sling footloop
7m x 9mm rope for Twenty, tied directly into two anchors using suitable rigging
10m x 9mm rope for Black Hole, belayed into 2 x SD spits (take spanner), rigging through 2 x maillons
JB
Member
Tried the kit out in Giants Hole yesterday on Garlands Pot (5m) and Geology Pot (10m). Sling harness is comfortable enough and put the Croll in just the right place for prussiking. The bungee chest harness was too long to start with but a bit of adjusting and it works fine now holding the Croll upright. The rope feeds through the Croll fine. Ropeman upper jammer doesn't slide up the rope quite as easily as a standard Petzl jammer but OK. I've added a thin snoopy loop (section of car tyre inner tube) to the keeper wire on the Ropeman. I can slip my hand through this before I start prussiking and this should prevent dropping it at pitch heads/rebelays etc. Alternatively you could easily cable-tie the keeper wire on the Ropeman to the footloop/safety cord assembly. The cowtails and footloop work fine although I might see if I can get hold of some 5mm dyneema cord for the footloop as Rob suggested.
I'm very happy with the way it's set up now. I thought I might end up with something that would have lots of issues, would be dead inefficient and not really be effective underground. In fact, it works just like a standard SRT rig, you just end up prussiking a little bit slower. It does (just) fit in my Warmbac oversuit pocket!
Thanks again to everyone who's made suggestions. I'm away now for a week but will resume playing with it when I'm back.
Cheers,
Jules
I'm very happy with the way it's set up now. I thought I might end up with something that would have lots of issues, would be dead inefficient and not really be effective underground. In fact, it works just like a standard SRT rig, you just end up prussiking a little bit slower. It does (just) fit in my Warmbac oversuit pocket!
Thanks again to everyone who's made suggestions. I'm away now for a week but will resume playing with it when I'm back.
Cheers,
Jules