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Abseiling off slings?

chug1

11-Nov-2006
11:55:23 AM

Hi

Im a bit confused about the unspoken law against 'abseiling off slings'.

Does this refer to
- the sling itself passing through the deascender
or
- a sling being used as part of your rope's anchor system?


gremlin

11-Nov-2006
12:07:51 PM

More so being cheap and not leaving a biner on an anchor.
IE: You throw a sling around a tree, loop the rope through the sling and rap...
Probably works, but ANY movement would cause a hell of a lot of friction and heat

Material on material is not a good thing...


muki

11-Nov-2006
1:07:44 PM

On 11/11/2006 gremlin wrote:
"but ANY movement would cause a hell of a lot of friction and heat"
I disagree that ANY movement will cause a hell of a lot of friction and heat, the sling will be burned
and possibly fail if the sling is used as the point that the rope runs through when body weighted (quite
often the sling will be burned to just within the point of failure on short raps,but long ones will definately
fail) . as in top roping (repetative body weighting) or tieing in at the top and then raping/belaying
yourself down causing the sling to be burned by the friction of a body weight on the rope runing through
the sling at the top, but rapping off on two ropes ie rapping 25 m on a fifty doubled or 30 m on a sixty
doubled will not burn the sling because the rope is not moving. pulling the rope down will rub it a bit
and cause a slight burn but not enough to fail the sling,but continued use in this way will cause
cumulative damage,and that adds up to eventual failure.using a sling is standard practice for people
who want to bail off a route, and is fine. if I found a sling at top and wanted to bail off I would replace
the unknown quantity with a fresh one of my own,(somtimes a good sling that has been there too long
is damaged by UV radiation ie sunburn) and check all points that connect my sling to the cliff/
mountain and if acceptable ,rap out. the bomb


JamesMc

11-Nov-2006
2:37:02 PM

bomber pro has got it right.

It's OK to ab from slings, but don't do it from old slings.

Of course it all depends on how much money you have. If you're rich enough, you can always abseil off a cluster of Friends.

A specific advantage of using slings in wilderness areas (like remote canyons) is that you can use natural fiber that will eventually rot and disappear, leaving no permanent trace of your passing.
>

James Mc


gremlin

11-Nov-2006
7:17:35 PM

> but rapping off on two ropes ie rapping 25 m on a fifty doubled or 30 m on a sixty
> doubled will not burn the sling because the rope is not moving. pulling the rope down will
> rub it a bit and cause a slight burn but not enough to fail the sling,but continued use in this
> way will cause cumulative damage,and that adds up to eventual failure.using a sling is
> standard practice for people

You screw up and one side slips through faster than the other, or you swing around a bit...
You could also damage your rope as you pull it down...

Might work in desperate situations, but i sure wouldn't use it as 'standard practice'.
$20 for some old biner(s) and cord is a small price to pay for a much safer descent...

SirOinksALot

11-Nov-2006
8:37:35 PM

On 11/11/2006 gremlin wrote:
>You screw up and one side slips through faster than the other, or you
>swing around a bit...
We're talking about rapping of slings here????
Has this actually happened to you (and if it has maybe you should take up another sport!!) or is it a rumour you heard in the gym??

>You could also damage your rope as you pull it down...

No you can't unless you try really, really hard. I would challenge anybody to do this under lab conditions?

>Might work in desperate situations

This is a common and CHEAP way to get off routes and has been practiced for decades!(This was the way you got off the top of routes before the NBF decided otherwhise, you just flick the rope afterwards and the sling comes down too!!)If you don't know how to do it maybe you should learn it, might save you one day!!!!!!!

>$20 for some old biner(s) and cord is a small price to pay for a much safer descent...

Old beeners and cord is hardly a safer option than new sling, and a couple of raps ($40) is a week living in the dirt an the pines!!!


dave h.

12-Nov-2006
2:12:06 AM

Perhaps of some relevance to this discussion is this link:
http://www.uiaa.ch/web.test/visual/Safety/SafComdownloads/Lowering%20off%20and%20abseiling.pdf

As I understand it (and I hope I do!) it confirms the view Bomberpro put forward: lowering off, with the rope through a sling, is a big no-no and will make you quite dead. Abseiling from a sling on a doubled rope, however, is more or less ok.
-Dave

chug1

12-Nov-2006
10:55:54 AM

Thanks for all the replies people.

I have another question.

When setting up a rope for only abseling (walk to the top) what is the best way to backup that rope? There seems to be plenty of information concerning backing-up the descender, but not much on backing-up the rope.

Thanks


muki

12-Nov-2006
3:39:07 PM

On 12/11/2006 chug1 wrote:
what is the best way to backup that rope?

Not sure what you mean by that?... The rope is the strongest part of any system!, ( it is rated to
many more kilo-newtons than any piece of gear you own including the harness! ) depending on the
age and wear and tear the rope it can suport two tons on a static loading. if you are realy concerned
with the rope breaking then take up another sport.or look at perchasing the latest in ropes that have a
sharp edge rating ,they have teflon on every single internal thread of the kern , so when a sharp edge
is loaded the the heat from friction as the strands pass each other is not generated, other than that I
would make a redundant anchor, ie multiple points all equalised and no sharp edges, I prefer non
dynamic slings or static rope over an old dynamic rope used as a setup rope for the anchors because
they do not strech when loaded/unloaded, causing a single point of the anchor to rub back and forth on
the lip or sharp edge. steel biners at the focal point of the anchor, over the edge of the lip for top
ropeing, but if you are just rapping off it then tie in one end at the top far enough away from the lip or
edge to get on the rope safely then use an edge protector if the lip is sharp, an old jumper or sweat
shirt/pack is ok just make sure it is tied on to a seperate thing from the main anchor ie tree or nut by
the sleeve/shoulder strap ,so it doesent fall down in a gust of wind,I make my edge protectors from old
fire hose , cut a length 1/2 m and then cut it down one side to open it up glue or sew some velcro to
close it again and make it possible to put on the rope after you pass it on the way down. ( for top
ropeing turn it inside out so the canvas is nice and slipery on the top rope and the rubber side grabs
the rock ), a small hole in the top to tie on a string for locating it without it falling down and its finished.
just read some good books (rock climbing getting started and talk to people who have done heaps of
climbing and you will pick it up , it just common sense and risk assesment. the bomb


dave h.

12-Nov-2006
4:32:12 PM

Maybe if you were really worried about the rope failing during an abseil you could also have a separate rope and belay each abseiler from above as they descend.

I think most school groups probably do this when taking students abseiling.


Andrew_M

12-Nov-2006
4:46:42 PM

Chug, don't stress about abseiling off slings. It has been the standard way of setting up abseil anchors for decades in many (most?) places. Jeez, here in the blue mountains you could easily do hundreds (or thousands) of abseils a year off slings in one canyoning season alone. It's interesting that there are even people who are querying it...does everybody just do sports routes with loweroffs or something??

It's really only a weighted rope moving over a sling that is likely to cause problems. Of course, as others have said, NEVER top rope directly off a sling. Always go through a biner (well two for redundancy). If you are abseiling on two ropes of very different diameter with some devices there can be differential slippage and running of the rope through the slings, or maybe if you did something crazy like attach a backup prusik to a single strand but this is not normal usage. Old weathered slings can also be an issue, as can slings that have had ropes repeatedly pulled through them... if in doubt cut the old slings out and replace.

And backing up a rope? It's not commonly done. Bomber Pro makes some good points. The main thing is to set up the ropes so that they don't run over sharp edges, and pad any sharp bits. Still if you are worried there are a few things you can do particularly if you will be abseiling with people who aren't proficient and may therefore abseil in a jerky manner (bad if there is any edge).

A 'simple' way is to have the doubled rope running through the anchor sling(s), but just below the anchor, tie an alpine butterfly in each strand, then clip a biner between the two loops of the butterflies. Better yet is to tie two separate figure eights in the rope and clip each into the anchor. Abseil on both strands in both situations.

Disclaimer: Don't solely base important climbing decisions on what some random nut says on the internet. Read a good ropework book...better yet hire a guide to show you.


brat

12-Nov-2006
4:47:59 PM

What about using a macrame knot?


albion

13-Nov-2006
10:40:17 AM

Another (related) debate I've had on occasion is whether it's OK to set up a top rope which ends in a single sling (and screw-gate) at the end - i.e. 3 slings or tripled cordette which meets at a point and then is extended over an edge by one sling. I'm definitely no expert on the subject, but I've always assumed that thrashing around on a top rope puts more loading on a system than an abseil and so am suspicious of such a set up.


EJ

13-Nov-2006
11:53:36 AM

On 13/11/2006 albion wrote:
>Another (related) debate I've had on occasion is whether it's OK to set
>up a top rope which ends in a single sling (and screw-gate) at the end
>- i.e. 3 slings or tripled cordette which meets at a point and then is
>extended over an edge by one sling.

By doing this IMO you've just lost the redundancy gained by using independent anchors or a triple cord etc... It's unlikely that the sling or biner used to extend the system will fail but...... You only connect to your belay device to your harness with 1 screwgate, if your abseiling on a double rope it only takes one side to fail. I think it depends in the context in which you use it, in a top rope situation I'd make it as safe as possible by having multiple redundancies.

gfdonc

13-Nov-2006
1:28:22 PM

I'm excessively paranoid about toprope anchors. I justify this to myself with the belief that an unattended anchor doesn't have someone around to watch it as problems arise, unlike (say) a belay.

I normally connect two independent slings to (both of) two screw-gates with their gates reversed. Make sure there's as small an angle between the two slings as possible (to avoid 3-way loading on the 'biners). Each sling might be connected to multiple attachment points of course. A cordalette arrangement makes a good way of equalising and of providing extra strength at the connection point, as well as removing the 3-way loading issue.

I have some longish pieces of 8mm and 9mm cord that I use in these setups, rather than joining lots of slings. I've seen other Chockstoners use 11mm static, and felt slightly outclassed in my level of paranoia.

Make sure the biners aren't cross-loaded over an edge.
- Steve

earwig

13-Nov-2006
2:51:45 PM

I think my brains are cross-loaded over an edge ... but still!

How long are your longish pieces of cord/cordalette? I'm tired of joining lots of slings.


IdratherbeclimbingM9

13-Nov-2006
4:52:49 PM

On 11/11/2006 chug1 wrote:
>Does this refer to
>- the sling itself passing through the deascender
No.
>or
>- a sling being used as part of your rope's anchor system?
Yes.
>When setting up a rope for only abseling (walk to the top) what is the best way to backup that rope?
Use more than one anchor and use more than one sling.
... or use any excess rope to tie back into multiple anchors, but make sure you take out any slack if you do this.

earwig wrote
>How long are your longish pieces of cord/cordalette? I'm tired of joining lots of slings.
Take note of how often you join slings and measure the combined length to get a feel for what is useful.

If you climb long enough you will eventually have heaps of excess rope as you buy new gear (for one reason or another, eg a core shot* damage), and relegate the old stuff to toprope anchor use only. At that time you may decide to cut it into specific lengths to suit your local toprope location.
If you move to other toprope locations you may find several lengths to choose from is the way to go.
I find slings of 3 or 4 metre length quite handy, and/or short ropes of 6 to 10 metres length too. Sometimes the anchor/s will use a combination of both for appropriate redundancy and angles of loading.

You could always leave the old rope in it's original length (*cut at the core shot), but for most toprope anchor use this is an excessive length and amounts to extra weight to carry to location.


jkane

15-Nov-2006
1:36:41 PM

There are two good books available for VCC members to borrow from the club library "Anchors" and "More Anchors". Come to a meeting (see VCC website for details) and take them home for a month.

Also a good cure for insomnia.

Jim

One Day Hero

16-Nov-2006
5:50:55 PM

On 11/11/2006 JamesMc wrote:

>A specific advantage of using slings in wilderness areas (like remote
>canyons) is that you can use natural fiber that will eventually rot and
>disappear, leaving no permanent trace of your passing.
>>
>
>James Mc

WTF??? Do you prefer hemp or cotton slings? Who stocks these?

Paul

17-Nov-2006
11:31:11 AM

Oversease it is common to use steel rings to prevent the rope rubbing on slings factor. Then all you sacrifice is a metal ring worth $1 and a sling. These rated metal rings are not common in Australia but I have heard of people using a single link out of a piece of chain as a sacrifice piece of gear combined with a sling, far cheeper than leaving a karabiner behind.

There are 24 messages in this topic.