UKC

Sure this topic has been done to death in the past, but damned if I can find the thread. Don't want to start another huge debate on the merits of prusiks for belays but would appreciate feedback as follows: -

When rigging abseils, I prefer to extend the belay plate with a sling so I have room to attach an autobloc prusik from my belay loop, without danger of the knot getting jammed in the plate. I can then keep both hands on the controlling section of the rope, sliding the prusik down the rope as I descend.

From various professional tips I've read, this seems the safest set-up. The only issue I have - and what I'd be grateful for some advice about - is whether it's safe to lark's foot a sling through the strong point on my harness (i.e. main waist and leg loop anchor points)? Or should I use a krab/maillon to prevent any dangerous 'sawing' of the between the sling/harness?

Cheers for any tips.

In reply to TRJ: no it is not. there have been several threads on this recently but basically larks footing a sling should not be done especially if there is a risk of load cycling (bouncing) on it. use a short sling (or double up a longer one) and attach it with krabs.

In reply to Ian Straton: Great, just the advice I needed. So if I doubled a 60cm sling, say, through the strong point on my harness and then clipped both ends to the belay plate via an HMS, there wouldn't be any dangerous friction between the sling and the harness? Sorry to sound paranoid but some of the warnings you read about dyneema worry me...

In reply to TRJ:

Lots of 'instructional' books warn about the weakness of the lark's footed tape sling, but also seem to condone it's use to attach a sling directly to the waist belt and leg loops of your harness at the rope tie-in point. I have seen more than one that say "this is the only time you should use a lark's foor" or words to that effect. They are usually referring to setting up an abseil rig as you describe and using harnesses that do not have a stitched belay loop (eg BD Bod etc). So, in short, yes, it'll be fine.

I don't do it BTW, I use a krab and am very careful to ensure it's correct orientation when abseiling.

In reply to TRJ:

this is pretty much the same i asked on this thread

http://www.ukclimbing.com/forums/t.php?n=177619

im trying to find the daisy chain i replaced so i can have a look at the damm thing.

i do the same as you all the time but it seems that both of us have the same renewed worry.

the locker/malion seems like the best idea in your situation as the system you use is already very simple and wont be overly cluttered by the intorduction of another biner.

Rob - watching this thread with intrest

In reply to Rob Reglinski: Is a daisy chain less vital than in the scenario of abbing? (From my very limited knowledge of aid) As the daisy chain connects you to the piece of gear that you are on, and as such a failure would not lead to dying as you would fall to your next bit of gear before the rope took.

In reply to Anonymous: Oh, I see - that's interesting. See, I'm happy to lark's foot slings as a safety precaution when setting up the top-rope on bolted routes, as there's little movement whilst you're hanging there fiddling with the rope. It's just the abseiling that worries me slightly - I try to keep things smooth but a little 'bounce' is inevitable.

In reply to Oli:

its less vital (in that you should not die) but will take more force by a long way, and it gets more abuse and wear, thus if it works for me whhen aidding it should work in the abseil situation.

when you dasiy "fall" form your top step you fall around 2m onto a static sling - by fall i mean, the next bit of kit rips during a test or being an idiot.

im more intersed in the long term wear problem which is why im watching this thread. i also use the system in question when rapping so im curious from that perspectve.

Rob

lets not digress from the subject on this thread as its a very important point

In reply to Oli: Except when you have clipped your daisy chain in and untied your rope to thred the belay bolts. If it failed at that point the rope would not stop you.
I do not think it is an issue though as you are not moving about at that point and so do not have a sawing effect.

In reply to cragspud:

i never untie from the system when only connected by one chain

to clip belay bolts for lower off:

connect dasiy chain
ask for slack
pass a bight of rope thru the lower off
tie a fig 8 in the bight and clip into it using a locker.
now untie the original knot and lower off the fig 8/ locker combo.
this way you are allways on belay

climb safe

In reply to TRJ: Lark's foot the sling into the belay loop and twist the knot so it forms a reef knot, then pull it tight. It then cannot rub against itself (it can though waist and leg loops). I prefer to have as few links in the system as possible so there's less possibility of something messing up.

Kevin

In reply to Rob Reglinski: I know that way as well, but I prefer the clarity of the other way.

i.e. bight of rope clipped off on a quick draw, undo rope from harness thread and retie to harness, unclip bight and take in.
I reconise the different potentials but in my head the clarity makes it much safer and so I am much more comfortable with it.


Perhaps the start of a new thread there.

In reply to kevinknights: How do you twist the knot to form a reef knot, 'cause like you I prefer as few links as possible?

In reply to kevinknights: Thanks, I see your point.

In reply to TRJ: I wouldn't allow the sling and the fabric of the harness to come into contact. Use a crab at both ends of the sling.

In reply to kevinknights: Thanks, I see your point. Can you other guys start another thread if you're going off on a tangent about bolt belays, please?

Alternatievly, don't bother, as the best method is as follows: -
i) Lark's foot two slings to your main harness anchor points before you start the lead.
ii) When you reach the top, clip one sling onto each bolt to make yourself safe, then come off belay.
iii) Tie an overhand loop a few feet down the rope and clip the resulting loop to your harness with a screwgate, so there's no chance of dropping the rope.
iii) Untie the knot, thread through BOTH bolts (not just one as I see a worrying number of people do), and re-tie to your harness, double-checking carefully.
iv) Unclip the looped rope arrangement and tell your partner to bring you back on belay
v) Final check, then unclip the two safety slings and lower off

This all sounds like a huge faff but it's guaranteed safe and takes less than a minute with practice.

In reply to Ian Straton: Thanks, Ian. I might be worrying unnecessarily now, but assuming I'm attaching to both the waist and leg strong points, rather than just the belay loop, will this stress the spine of the krab too much? Or am I just being paranoid as it's not going to be shock-loaded anyway?

In reply to TRJ:

i doubt you would be stressing the system too much but why not just clip the biner into the belay loop? thats what its there for.

i still dont see the reef knot idea when im using an 8mm sling and a 14-15mm belay loop, mine is also still very stiff.

Rob

In reply to TRJ: if your harness has a stiched belay loop then that is the only point to which you should attach any anchor points. The belay loop is about twice as strong as another componant in the harness and trying to clip waist/leg loops at the same time will increase the risk of an abnormal load on the carabiner.

In reply to Rob Reglinski:

I'm with you on this! Also rolling the larks foot over to produce a reef knot is unlikly to reduce the risk of failure due to melting as there is still plenty of scope for movement. Which is the real risk to dyneema.

In reply to Ian Straton:

I understand your point, but if that's the case, why do we not tie into the belay loop when on lead/top-rope?

In reply to TRJ:

Because it's untidy, that's all. (Lots of continental Europeans do BTW)
Ian is absolutely right.

In reply to TRJ: well personally I tie it through all three points mainly in order to keep the knot as close to me as possible and therefore neat. The crucial difference is that there is no metal involved, clipping a karabiner through multiple points on your harness brings the risk of cross loading, tieing onto a rope does not.

In reply to Ian Straton: Cool, thanks - really appreciate the advice.

In reply to cragspud:

Hard to explain but easy to do - larks foot it on, then push the bit that runs at 90 degrees to the line of the sling towards the belay loop - one reef knot.

In reply to Ian Straton:

Surely a harness is only as stong as it's weakest link (gear loops aside etc)?

What's the point in having a really strong belay loop, if, when it takes a sudden shock-load, the loops that the belay loop is attached to fail?

In reply to kevinknights: still creates a weak point in the slings and it still can generate a lot of heat due to slippage, rather use a crab.

In reply to kevinknights: Ta, still dont really see, but I will give it a go.

In reply to TRJ: Apart from the two slings, that is what I do. I have just one sling and yes it takes only about 30 seconds.

In reply to TRJ:

Going back to the original post, my preferred method is to clip the belay krab to the belay loop as normal. Then add prusik to the rope and attach that to my harness LEG LOOP with a screwgate.

I find this method to be very simple and uncluttered, requires minimal gear and has served me well over the years.

Using this method, it is possible for your legloop to get pulled up to the belay plate if you stop suddenly (very awkward if you have a rucksack on and no chest harness) and also tricky if you need to change hands, for whatever reason, but I've never had any problems.

Equally, extending the belay plate away from you can make it hard to get over edges and sort it out if anything gets stuck in it. This method can also give the belay plate the reach to hit you in the face, if you slip.

In reply to Petzl:

Me too with the prussic below the belay device. Never had a problem with it.

In reply to Clauso: well the load from the belay loop is transfered into the leg loops and the waist belt so the attachment points top and bottom do not need to be as strong as the belay loop because individually they will never be subjected to the entire load (unless you clip into them by mistake!).

Also if in a huge fall lets say the leg loop attahment breaks, that will take 10KN (for the sake of easy numbers) out of the system, the waist belt attachment then only has to survive a much smaller impact, whilst the belay loop must survive both impacts. From this scenario it is obvious that the belay loop needs to be much stronger than the loops that attach it to the rest of the harness,

In reply to Ian Straton:

Fair points. You'll have to excuse me. Not thinking straight today. I blame it on car problems.

In reply to Clauso: Fair enough. Sure I read a thread on here recently from a professional guide/PyB instructor (Libby Peter?) who advised using the prusik with your belay loop, rather than leg loop, so there's no danger of being inverted if you're abseiling with a heavy pack? Either way, I'm sure both systems are safe, and certainly more so than using no prusik at all.

Cue some nitwit saying they never bother with autoblocs for abseils, etc, etc, yawn...

In reply to TRJ: it's horses for courses, both techniques have advantages and disadvantages, the trick is to learn all the methods and use whichever method suits the situation at the time.

extending the belay plate away from you provides stability with a heavy pack, putting the autobloc on the leg loop reduces the problems of getting caught on a ledge. before each abseil ask your self: "am I carrying a back pack?" "do I need to negotiate any ledges?" etc... use the solution that best fits your answers.

In reply to Ian Straton: Very sensible advice, thanks.

In reply to Ian Straton:

some interesting events on here for those wondering about abbing accidents;

http://www.caves.org/phpBB2/viewtopic.php?t=747&start=15&

In reply to TRJ:
Inversion sounds like it could be a problem. On DMM saftey instructions they advise the use of the leg loop when using a prusik and the belay loop with a mechanical device. They have the diagrams and descriptions mixed up though (I emailed them about this and they kindly sent me one of their new HMS krabs in the post but still haven't changed their documentation).

http://www.dmmclimbing.com/library/downloads/DMM_Belay_Guide.pdf

In reply to TRJ: I use a similar method for abseiling and can't see any reason to change.

I larksfoot to the belay loop and pull tight - There is little chance of 'sawing' the load is limited to around twice your body weight in any case.

On a long multiple pitch abseil I'd be more worried about screwgates cross loading than I would be about wear to the sling.

However, from the other thread talking about dyneema slings, they do not handle static falls. The biggest risk by far, is climbing above the belay only connected with the sling. Taking a factor 2 fall is going to be very bad news regardless of exactly how you have everything set up to abseil.

I'd say connecting to the belay loop is better then both points of the harness - less chance of rubbing.

Also I wouldn't leave a sling/cows tail fitted indefinately as that increases what small risk there is. One of my daisy chains has some slight abrassion after a lot of use therefore I'd be tempted to recommend using normal slings so the wear is distributed rather than concentrated in the same spot every time.

HTH

In reply to IainWhitehouse:

That's not the case. We don't tie directly into the belay loop with the rope because the belay loop is designed to support a krab, *not* a rope. The belay loop is usually a loop of single-thickness tape. Strong, yes, but not designed to take the direct abrasion froma rope ( a krab's a different matter, as it's much smoother than a rope and doesn't abrade).

If you look at your harness (for most models), the leg loop centre point and waist loop will be re-inforced (at least double thickness compared to the belay loop). They're designed to handle the rope running through them. The belay loop isn't.

In reply to Mark Stevenson:

i do the same as you (larks footing around the belay loop) and have been doing so for years now, never noticed any abrasion. the way i see it is that once ive put my 14 stone weight on the larks foot its never going to move again anyway! even when i want it to come undone! all this talk of extra crabs just means extra weight and more things to go wrong (cross loading etc).

Rob in a field

In reply to Rob in a Field:
a cross loaded crab can still take around 8kn so I don't see the issue with that!

Stevo

In reply to Rob in a Field:

I should make it clear that my reference to abrasion above was with respect to a comment by someone about it being safe to tie in the *leading rope* to the belay loop, and had no reference to lark's-footing slings to the belay loop. The 2 situations are different.

In reply to CurlyStevo:

Once the krab is cross loaded the gate is in the perfect orientation to come into contact with the ropes you are abseiling down. After abseiling down 5 pitches in the dark (for example) I don't want to have to be checking whether the krab has come undone.

My personal view is it's an additional complication that adds at least as many minor risks at it removes.

In reply to Mark Stevenson:
use two crabs back to back then!