UKC

Went out for a bit of a "play" today at Goldsborough Carr. Didn't get any climbing in as such, it was freezing and howling with wind, but we used the opportunity to practice setting anchors (there are plenty of stakes at the top for this), abseiling and prusiking.

I'm pretty scared when it comes to abseiling so today really helped me with that.

Also tried prusiking up which was easier than expected once we got to grips with it so to speak.

A few questions.

1) I use a prusik tied above the belay device and attached to my harness when abseiling. I slide this down with my free hand, but can happily hang from it when needed (or if I dropped the rope for example). My friend uses the short loop from the leg attached to the braking side of the rope when descending.

Both work, but we have both been taught differently.

My method works well when walking to the edge of a cliff or descending steep ground, or when setting ropes/rope protectors etc at the top.

Is there a reason NOT to use my method?

2) For his method what stops the prusik getting jammed in the belay device? Even with the shortest lenght on the leg loop it can still find it's way up to the belay device?

3) What size prusik cord do you guys use and why? Mine is 3.5mm, his is nearer 8mm.

4) When prusking up the rope what knot is the best? We found that they all jammed and some were impossible to slide up the rope after being weighted (with his cord or mine so thickness didn't seem to have anything to do with it).

5) When ascending do you just clip the top prusik to your harness or is there a newer/safer method. My thinking here is there is no redundancy, the one prusik cord is all that is attaching you to the rope...

I've done a lot of reading but in practice things are never as they seem and on the edge of a crag, hanging from a length of cord, you start questioning if there should be more redundancy or why the damn knot keeps jamming lol.


PS - I learned a lot of my stuff in South America, he learned is in the 80's :p We are both safe and not messing around, but questions come up and I'm interested to learn newer/better techinques when appropriate.

PPS - loved prusiking up the rope and can see me doing this for fun more often :p

Not sure how to post pics but have a couple from today.

In reply to Martin1978:

1. When the prussik is below the descender it is taking less load which is probably a good thing.

2. The descender should be on a sort extender like a quickdraw sling with a pair of screwgates

3. I'd say 3.5 is too small, 8mm is too big. I think 5-7mm is "normal"

4. The 4 or 6 turn larks foot is traditional, but can jam when loaded. There are better ones out there but I am not very familiar with them.

5. This is VERY scary, especially on 3.5mm cord! A simple way is to tie a clove hitch in the trailing rope to a HMS on your harness, then wiggle it through the knot, taking in the slack, every metre or two of ascending.

Good luck, have fun and stay safe!

Dom.

In reply to Martin1978:

Most of these points are fairly debatable, but here's my two pence worth:

1. No, both work fine. Personally I used to always use the leg loop method, but now usually go for the prussik after the belay device, as it's quicker to set up (see point 2) and a bit more foolproof. I've never heard a decisive argument in favour of one method or the other. Like a lot of things in climbing neither method is dangerous, so just go with what works for you.

2. If you use the prussik on a leg loop, it's important to extend you belay device using a sling lark's footed to your harness abseil loop. This will stop the prussik hitting the belay device, which could cause it to lose it's grip and allow the rope to run freely, hence defeating the point of it being there. This method has a lot of friction, which, while being safe, can make it difficult to actually descend, especially if you're using fat ropes with a high friction belay device.

3. It depends on the rope being used, though I'd say 3.5mm is too thin and 8mm is too thick. Thinner cord will grip better but isn't as strong. I use 5 or 6mm, which is fairly normal as far as I know.

4. For your harness use a Klemheist, for your feet an Autoblock. See http://www.needlesports.com/catalogue/content.aspx?con_id=11ef054b-4ec4-4f0... for a guide on how to tie them. You can also a normal prussik (not sure of the proper name, see en.wikipedia.org/wiki/Prusik) on your harness, but they tend to jam when you don't want them too. If you have a guide style belay device then you can use this for your foot loop.

5. Yep. You could clip the lower prussik via a sling, but if the top one did fail I wouldn't like to say whether the dynamic loading of the lower know could cause it to fail. If you're using a guide plate as mentioned above, then it would be less of an issue. TBH, I've rarely had to prussik up a rope and when it's happened I've had bigger concerns on my mind...

Anyhow, hope this helps, I'm sure someone with more experience will be along to provide better advice!

In reply to Martin1978:

2) A french prussik on the leg loop will never jam in the belay device.

A tibloc is a wonderful device for pussiking and a lot of safety manoeuvres. Otherwise, when the rope climbing gets tough, a pair of ascenders or one ascender in combination with a grigri works well.

In reply to Sir Stefan:

I'm unsure what that means, do you mean:
1. It'll never reach the device
2. It'll reach and on hitting the device it'll never grip on the rope
3. It'll never get sucked into the device and be a pain to get back out

1/2. Using your friend's method - seemed more elegant to load the prusik much less by putting it below the device. But I generally extend the device so knot can never get in the device. Until reading about an incident yesterday, I hadn't thought to consider what would happen if you rolled to your left, with an autoblock on the right leg loop and a device directly off your belay loop.


3.

Rock Climbing - Mastering Basic Skills - Craig Luebben:
5-7mm cord, describes autoblock off leg loop & below device

Big Wall Climbing - Jared Ogden:
6-7mm cord, describes autoblock off leg loop & below device

50-60% of the rope width sticks in my head. I definitely wouldn't be using 3.5mm, and *above* the device so it has to take your full weight to work too.


4. I've had success with the frog system and french prusiks. They definitely didn't weren't impossible to slide, I did find it was much easier if you loosened the a bit with your thumb prior to pushing them up.


5. I attach both prusiks to my harness, so I'm not just hanging off the rope by one. I can appreciate your concern with 3.5mm cord too!


If you can find a copy of On Rope, that'll answer all your questions very well. All cavers do is either abseil or ascend ropes. It covers prusiks and several different methods of ascending ropes. I have a copy back home. Good, interesting, book.
(Interestingly it does not appear to be common practice among cavers around here to always backup rappels.)

Thanks for the replies, it is good to hear other opinions. I shall definiately be getting some 5 or 6mm cord for prusiks, I'll feel better with that. Also extending the belay device away from the leg loop is a really good idea and not one we considered, so thanks.

I shall have to look into prusiking using a guide type belay device. To be honest I was thinking of buying one of these anyway and if it has an extra use all the better.

I wouldn't want to carry ascenders and such as I like to "travel light" so to speak.

I don't intend to do it very often, but today was about practicing skills that we hadn't used for a long while, just in case we need them in an emergency situation. All about confidence building as well (in my case).

Cheers, Martin

Also: http://www.needlesports.com/catalogue/content.aspx?con_id=11ef054b-4ec4-4f0...

Great link, thanks!

In reply to Martin1978:

A french prussik will never reach the belay device. Don't bother extending the belay device for normal abseils.

In reply to Martin1978: I was told recently that a prusic on a leg loop can be dangerous on some new harnesses that have quick release type buckles where you tilt the buckle to release the loop as the karibinier on the leg can undo the buckle. Had a play with it and it can happen surprisingly easy although most harnesses of this type have a stitched loop at the end of the webbing to stop it pulling right through. Not a problem on the older type where you double the webbing back and is still what I prefer to use.

I agree that it is a good idea to extend your device away from your harness with a short sling to prevent the prusic being pulled into it.

French prusics are much less prone to jamming although a standard knot can be easily released by rolling the loop that sits across the top of the knot away from the part that you clip into (if that makes sense).

In reply to Sir Stefan:

Read one of the accidents in the first post of this thread: http://www.ukclimbing.com/forums/t.php?n=489113

Good video of using an atc guide belay device for ascending. I like this option a lot!

http://climbinglife.com/rope-rescue-systems-videos-advanced/using-an-atc-gu...

Really like this idea. Will just use a prusik for my leg loop and slide that up by hand.

Thanks for the other replies, all good thoughts.

In reply to Martin1978:

Nice! I should practice that, I always forget its even an option.

In reply to jonnie3430:

In the mentioned thread it is speculated that the autoblock (french prussik) might be the cause of one incident. I will not argue that if the prussic cord is too long and too loose then there will be a risk for it to be released by the belay device. But if it is short enough and if it has enough turns that its loops just meet in the carabiner in the leg loop, then the speculated scenario is very unlikely to happen. In my setup, when I abseil there is about 30 cm from autoblock to belay device, and 15 cm when the autoblock is engaged. When I almost fully bend my hip joint the distance is still about 5 cm.

In reply to Martin1978:

Nice and simple.

In reply to Martin1978: That's really good. I like that a lot too.

In reply to Sir Stefan:

I agree that the likelyhood of your legloop attached prusic back up hitting your belay device (and so be held open) is small, but if it does happen in a situation where your grip on the rope is not what it should be the possible or even likely consequence is death. Personally I think this is worth considering as a situation where this might occur is certainly feasible e.g. if you were to end up inverted head down becuse of a slip on awkward steep ground or maybe less likely hit by rockfall.

In my opinion definately worth extending the attachment of your belay device.

In reply to GerM: I am convinced that extending the belay device is a good idea also if using the prusik through the leg loop when abseiling. I was having another look last night, and whilst my initial concern was it jamming in the device I now realise it could be even worse and "could" be released by the belay device.

Of course, if you use my method of having the prusik above the belay device this becomes irrelevant :p

Also tried using a 120cm dynema sling on an old length of rope last-night. This is the right length for a leg loop and held well. Was easily released as suggested above, by pusing the loop over with your thumb before sliding up.

With the set-up in the video, but using a dynema sling prusiked to the rope as a leg loop, makes a system with minimal kit and all stuff I would already have on me. A major plus for mountaineering rather than rock climbing is it's a really light weight set-up.

Glad I started this thread, it has been very useful, thanks.

In reply to Martin1978:


That is the reccomended way to do it when using a prussik, but I rarely use one. The only point is to stop you falling if you get knocked out, it adds an extra level of faff into something that is already faffy and slows down the smooth motion of abseiling. Do it if you feel the need, but it isn't a must.

A common way to ensure safe abseiling is only having the first person use a prussic, the remainder abseil without one and the first person down holds the ropes so that they can be controlled in case of an accident.

In reply to jonnie3430:

Always an option not to have a backup, and personally I think that sometimes this is preferable, there certainly is an increased concentration and resulting safety in knowing that if you were to let go there could be serious concequences. It's just abount real understanding of the system you're using and it's benefits and drawbacks.

Good tip on more than one person rapping, safe and faff free.

In reply to jonnie3430:

I remember the 'holding the trailing rope' method of protection being used when I was a kid in scouts (I think it was in addition to a normal safety rope rather than instead of, and it wasn't used often). My abiding memory of this technique was its use to immobilise a young leader up a tree - we were abseiling out of the tree, and decided to tug on the trailing lines, stopping the unfortunate young man half way down. We then tied the ropes off under tension to an anchor, leaving him marooned dangling in free space just under the canopy

In reply to Martin1978:

Is a prussik a faff? Takes 60 seconds to do and can save your skin.

I like and use the method of first person prussiking and then trailing the rope just in case though.

In reply to Landy_Dom:

Yet another reason to always have two prusiks handy!

In reply to Martin1978:


A caving team did some experiments with the prusik above the belay device. They found that the instinctive reaction of a good half of the test subjects, if they started to lose control of the abseil, was to grab the rope above the belay device - releasing the prusik and rendering it useless as a backup. (The article called "The Questionable Prusik Safety" by Ray Smutek refers to these tests. It also references a fatal accident known to have resulted from this error. I can't find the article online right now but I have a copy if you would be interested to read it.)

You can convince yourself that you'd never make that mistake, but would you want to test that conviction for real if the sh!t did ever hit the fan 100ft above the ground?


I don't understand how your method is better than having the prusik below the plate for tasks of this kind. Can you elucidate?


I don't attach the prusik to the leg loop. I extend the belay device on a 15cm quickdraw, and attach the prusik directly to the belay loop. Since the prusik and the plate are attached to the harness at the same point, no amount of writhing about by the climber can change their relative positions on the rope. This is the way I was taught to do it at Glenmore Lodge ten years ago. I have always understood it to have superceded the leg loop method as "current best practice" some time prior to that.

I do the same as above as that what was taught to me as best practice. As demonstrated below on page 47:

http://books.google.co.uk/books?id=pPedGN8cfWMC&pg=PA47&lpg=PA47&am...

In reply to Denni: +1 - I was taught this by a guide only a few years ago and I think it also appears in most recent books as the standard method for a leader abseil (the second is normally backed up by the leader pulling on the braking rope from below rather than a prussik).

My guide cited the case of accidentally grabbing the prussik in a slip as the reason for not using the 'above the device' method.

In reply to Martin1978:


Both work. I personally prefer your friend's set up with the cord on the dead rope but that's just my preference.


Not really, no.


Care stops the cord running up against the belay device (it's more likely to release and become useless than jam). Short cord and if necessary extending the belay plate away from the harness on a short sling works. Doing this also means you can avoid clipping the cord to a leg loop, you can now clip to the belay loop. Clipping the leg loop can tend to loosen some buckles and it can be a little destabilising especially if you're top heavy (eg. wearing rucksack).


3.5 is a little thin, 5 or 6 is normal, 8 is a little fat. you can soften fat cord when you're cutting it by sealing one end, allowing the sheath to slip (bunch up a little) then cutting and sealing the other end. Soft cord works better and is nicer to use.


Try winding your Prussik (actual 'knot' isn't so important) with a krab spine built into it, the krab makes it easy to loosen and shuffle upwards.


Always back yourself up with the rope. A krab on your belay loop and a clove-hitch on the dead rope with a couple of meters (max) of slack is fine. You shouldn't trust a single Prussik, they can slip and the cord gets worn.


There should be redundancy. And the jamming is normal, it gets less with practice (or more likely you get sick of practising so the jamming stops too)


Be careful. Hanging from a single Prussik loop isn't that safe.


Weirdo

jk

In reply to Martin W:

[...]I extend the belay device on a 15cm quickdraw, and attach the prusik directly to the belay loop.

I've been taught to extend, but using a larks footed sling with a knot in it at about 15cm. This means you can use a crab on the rest of the sling to clip directly into your anchor whilst sorting out your belay device and prussik for the abseil. Works nicely for group abs as everything can be checked before you head off first.

Again, thanks for the replies. I haven't seen the method of attaching the prusik to the belay loop before so will try that next time we are out. I much prefer that idea to the leg loop. Only thing I am unusre of is how you manage the prusik when descending with it so high. In practice I'm sure it will make sense.

In reply to Martin W:




I found that when walking to an edge to adjust something or taking a look over, I had more confidence that my prusik would stay locked whilst I hung on the rope a bit (still keeping a hand on the rope though). Hard to explain, but I was happy to weight the prusik as an "anchor" whislt looking over the edge for example (still always holding the rope though). With it attached to teh leg loop I feared any movement(ie kneeling etc) would cause the pruusik to slip or release.

Having read more I shall, from now on, tie a knot in the rope and attach it to my harness whislt I make observations/adjustments. That way I'm not reliant on my hand or the prusik...although I will be whilst I tie that not lol.



I have just ordered a book as a refresher/update and shall continue to research on teh web. It's good to continually learn, especially f it makes things safer and hopefully easier.

Thanks, Martin