Rigging Rebelays

[cucc Paul]

What would be the effect of this occuring on a stop, as you would in effect be hanging from the control side, or would it act like a bobin? As people have said if you were using jammers you would probably be looking at a fatal incident although it might all twist and colide together stopping your fall or slowing it down.

The chances of this happening I would have thought were minimal especially on something like 'P' hangers unless some very bad rigging has been emlployed.

 

[Stu]

I had 10 minutes spare and went and had a very limited play on the SRT rig. Set up a rebelay with an Alpine, clipped short cowstail into the loop and proceeded to weight it in preperation to changeover the ropes. The knot turned on its side and what I can only describe as inverted. It looked an ugly beast! I spent what little time I had left looking it over to see what was going on. I didn't proceed down the next piece of rope so not sure if it would re-arrange itself. Initially it struck me as something that, although probably not unsafe, could cause some other problem later on. My early conclusion is that it turned because it didn't have it's other standing part acting as a counter and holding the shape.

Will do some more jigging about. That's the thing about thinking out of the box when looking to use "other solutions"; real life may dictate that the good old methods are just that for very good reasons.

 

[damian]

Interesting stuff, Stu. Will also have a play this evening if I have some spare time - but it's looking like it might be a big "if" unfortunately! 

 

[Dep]

For confused SRT Novices (like me) its worth people agreeing on a default solid answer that wont fail even if your not clever and abusing the knot (like novices do), rather then trying to work out the answer from some of the technical answers given.

To me if someone just wanted a simple answer I would say Figure 8 for re-belays I would use the ABK for traverse lines, Y hang (figure 8 on upper P bolt then at the right height ABK at lower like in ledge pitch of Hunters). ABK's for clipping in etc.

I'm thinking until I'm a rope expert I cant go wrong with that idea.

** Hang on If I use a ABK as the lower connection of a Y hang and the top one fails, what happens to the ABK? It would be loaded like a re-belay wont it??????

Yes - all good simple basic stuff except your odd Y-hang. Use a regular bowline as it is simpler, or learn the bowline on the bight "bunny ears". And then you have a basic set of knots that will take you anywhere.

 

[darkplaces]

I like the 'bunny ears' Y hang, seams solid and secure, then I get moaned at for using too much rope and being 10ft from the bottom of Hunters Hole

 

[Geoff R]

For confused SRT Novices (like me) its worth people agreeing on a default solid answer that wont fail even if your not clever and abusing the knot (like novices do), rather then trying to work out the answer from some of the technical answers given.

To me if someone just wanted a simple answer I would say Figure 8 for re-belays I would use the ABK for traverse lines, Y hang (figure 8 on upper P bolt then at the right height ABK at lower like in ledge pitch of Hunters). ABK's for clipping in etc.

I'm thinking until I'm a rope expert I cant go wrong with that idea.

Yes - all good simple basic stuff except your odd Y-hang. Use a regular bowline as it is simpler, or learn the bowline on the bight "bunny ears". And then you have a basic set of knots that will take you anywhere.

Darkplace's rebelay Y hang made from a Fig 8 knot then "immediately" a butterfly knot (you can argue which type) works really well for a lot of  "Y rebelays" (indeed such as ledge pitch direct route in Hunters Hole, which is exactly as I happened to rig it on Sunday). 

I agree with Dep when he suggests also learn the "bowline on the bight". 

Geoff

 

[Stu]

I had 10 minutes spare and went and had a very limited play on the SRT rig. Set up a rebelay with an Alpine, clipped short cowstail into the loop and proceeded to weight it in preperation to changeover the ropes. The knot turned on its side and what I can only describe as inverted. It looked an ugly beast! I spent what little time I had left looking it over to see what was going on. I didn't proceed down the next piece of rope so not sure if it would re-arrange itself. Initially it struck me as something that, although probably not unsafe, could cause some other problem later on. My early conclusion is that it turned because it didn't have it's other standing part acting as a counter and holding the shape.

Will do some more jigging about. That's the thing about thinking out of the box when looking to use "other solutions"; real life may dictate that the good old methods are just that for very good reasons.

Retried this yesterday. The shape changes alarmingly but does hold after weighted. No more movement or slippage occurs after the initial inversion. Who knows what effect it has on strength without being tested. When I abbed and prusiked the lower section of the rope, no further slippage occurred. It was difficult to undo after just one up and down - which belies the "easier to undo" reason for using this knot in this application.

 

[Joel Corrigan]

Bit late on the uptake as usual, and have only glanced at the replies, but for what it's worth I get really irritated with that lovely band of people who insist upon using butterflies for single anchor rebelays.  Sorry about that but it's a pet hate of mine!
Regardless of what any books may or may not say, I challenge anybody to undo a well-loaded butterfly that's been rigged in thin, muddy rope (and I'm talking about 5.5mm to 8mm) whilst down the bottom of a deep alpine pothole.  If you put yourself in these places often enough, you'll find that one day you do need to untie that knot whilst you've got cold and battered hands in a cave that's near-freezing and you've got a casualty down below that you need to extricate as soon as possible.  Don't know about laboratory tests but in the real world fig 8's are far better and less troublesome. 
The other argument that I hear is that if the rebelay fails then a butterfly will suddenly be loaded in the manner that it was intended (i.e, laterally) whereas a fig 8 will be distorted.  Probably true but also irrelevant in my opinion.  I think that the only situation that this may be more important is if you've had to rig that rebelay very close below your previous anchor: something that is discouraged but not always avoidable.
Anyway, not had much sleep so hope I'm not inventing stuff or rambling too much... 

 

[paul]

Bit late on the uptake as usual, and have only glanced at the replies, but for what it's worth I get really irritated with that lovely band of people who insist upon using butterflies for single anchor rebelays.  Sorry about that but it's a pet hate of mine!
Regardless of what any books may or may not say, I challenge anybody to undo a well-loaded butterfly that's been rigged in thin, muddy rope (and I'm talking about 5.5mm to 8mm) whilst down the bottom of a deep alpine pothole.  If you put yourself in these places often enough, you'll find that one day you do need to untie that knot whilst you've got cold and battered hands in a cave that's near-freezing and you've got a casualty down below that you need to extricate as soon as possible.  Don't know about laboratory tests but in the real world fig 8's are far better and less troublesome. 
The other argument that I hear is that if the rebelay fails then a butterfly will suddenly be loaded in the manner that it was intended (i.e, laterally) whereas a fig 8 will be distorted.  Probably true but also irrelevant in my opinion.  I think that the only situation that this may be more important is if you've had to rig that rebelay very close below your previous anchor: something that is discouraged but not always avoidable.
Anyway, not had much sleep so hope I'm not inventing stuff or rambling too much... 

Fair points Joel, but it's "horses for courses" and if you are rigging a pitch with thin rope for a long period, undoing the knot afterwards is higher priority than easy adjustability. When rigging using 10mm or thicker rope on a "normal" trip, the priority is usually the reverse and then Alpine Butterflies come into their own.

 

[cap n chris]

What I want to know is .... how do the Dachstein Gang undo their harness maillons (or, for that matter, how do the girlies undo their bras)?

 

[Ian Holmes]

You should come out Chris and then you might find out ...  8)

 

[Piglet]

(or, for that matter, how do the girlies undo their bras)?

Wouldn't YOU like to know!!! 

 

[Robert Scott]

What I want to know is .... how do the Dachstein Gang undo their harness maillons (or, for that matter, how do the girlies undo their bras)?

Ask Kylie?