Threading a mid-rope anchor

aricooperdavis

aricooperdavis

Moderator
If I need to rig a traverse line with a thread anchor in the middle, but find myself without a sling or any rope to rig it with, what is the best knot to use to go around it?

Could I simply take a bight of rope and tie a bowline around the thread with both strands, like this?



If not, is there a different/better knot that I could use? (You're not allowed to make the loop and pass it over the top of a thread, like a stal, and you're not allowed to take the end of the rope. You can assume that the anchors on the left and right are secure and won't slip).

TIA  :)
 
F

Fulk

Well-known member
The problem with a re-threaded butterfly is that you could ? potentially ? have to thread a lot of rope through, and it could get a bit messy; a bowline would certainly be simpler.
 
F

Fulk

Well-known member
You can assume that the anchors on the left and right are secure and won't slip).
Click to expand...

So, is the rope tied off to said anchors? In which case, it's unlikely there'd be enough rope sagging down to tie another knot.
 
alastairgott

alastairgott

Well-known member
Mike Hopley

Mike Hopley

New member
aricooperdavis said:
Could I simply take a bight of rope and tie a bowline around the thread with both strands, like this?

Click to expand...

Yes, that is the ideal solution (double bowline with secure tie-off).

It's important that the knot is tied off securely, ideally with a barrel knot. Which is exactly what you've done in the photo. :)

Obviously the rope may take some wear in this situation.
 
Mark Wright

Mark Wright

Active member
As Mike says, this method will likely wear the rope in a mid position which is not ideal.

The amount of rope the bowline and security knot method uses up will take up a lot more room in your tackle bag and be a lot heavier than simply taking a sling and a crab and will be a lot safer.

Mark
 
Mike Hopley

Mike Hopley

New member
Mark Wright said:
The amount of rope the bowline and security knot method uses up will take up a lot more room in your tackle bag and be a lot heavier than simply taking a sling and a crab and will be a lot safer.
Click to expand...

Indeed!

An even lighter and more compact option is to use dyneema cord and tie directly to the rope. This removes the need for a carabiner. It is also convenient to work with.

However, this is only appropriate if you fully understand the techniques and safety issues involved with using dyneema (i.e. do your homework / not for beginners).
 
aricooperdavis

aricooperdavis

Moderator
The alpine butterfly would be my go-to, but I'm placing some restrictions on myself, mainly out of interest.

Fair point from Fulk, the other knots in the line woudl have to be adjustable to have a reasonable traverse line.

Thank you for your suggestions all  (y)
 
Mike Hopley

Mike Hopley

New member
Ian Ball said:
Do people use rope slings at all 8mm?
Click to expand...

Yes, I like them for for some fixed rigging.

Compared to webbing, rope slings have the advantage that it's easier to tell when they're getting dodgy.
 
M

mikem

Well-known member
Tape slings are fine as long as you know their history - so not suitable for club use.

Provided it is long enough, you can always cut a length off the end of the rope & use that for the thread...

Mike
 
Mark Wright

Mark Wright

Active member
Simon Wilson said:
Only ever use rope slings in caving. Tape slings have no place in caving - not for anything - never.
Click to expand...

47 x tubular webbing slings for sale. 7 years old, used for only 1000 descents and ascents of the Gouffre Berger, all in a perfectly serviceable condition. P.O.A.

Mark
 
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