How would you join SRT rope ??

[Geoff R]

If it should become necessary to join two SRT ropes together on or for a pitch, how would you choose to do this, bearing in mind you want to consider a stopper knot on the end of the first rope and a loop for clipping in a cow tail and it all needs to ideally be easy to untie later after loading. 

Starting this off, how about using one half of a double fisherman's as the stopper knot, then completing this to join the new rope and then isolating the double fisherman's using an Alpine Butterfly?.. so the fisheman's is not loaded and therefore not too difficult to untie ??

OR  how about one half of a double fisherman's ties in a LOOP of rope (to form a clip-in for your cowtail) and which is then used to complete the double fisherman's when tying on the next length

ideas and experiences ?? What would you do ??

   

 

[damian]

I try to avoid any form of double fisherman's, basically because they're a nightmare to undo. Anything tied between the two halves makes quite a big knot, which makes passing it more awkward.

I tend to use either a double figure of 8 on a bight (fancy name for a "normal" fig of 8 ) in the end of the previous rope and then thread the new rope back around it to create three strands of rope running around in an * shape. This is really easy to undo and the loop to clip into and the knot are the same thing, so reducing the size. This makes it easier to pass.

Alternatively, I always use a Cappuchin knot as my stopper knot in the end of ropes, so if I can't be bothered to untie it, then I thread the new rope through the middle of the Cappuchin and tie one half of a double fisherman's in it. This is reasonably hard to untie but you can usually get some leverage in the Cappuchin.

The other option I have thought about but not tried is a barrel knot tied onto a maillon and the new rope attached to the other end of the maillon with a barrel knot. This is then fairly easy to undo and the barrel knots don't take up too much space (unlike figs of 8, which would also do here apart from their size).

Clearly in all cases above there is a reasonable tail left in the rope ends and these used to create large double stopper knots too.

 

[JB]

Some discussion here:

http://ukcaving.com/board/index.php/topic,1514.0.html

I use a Capuchin in the end of the top rope and then thread the end of the bottom rope up through the middle and tie half a double fisherman's. Neat and short knot which gives you a loop to clip into. However, recently had a bit of a problem with this method. Passed the knot going down and found that the half double fisherman's had been pulled into the Capuchin rather than sitting nicely above it. This only happened when I weighted the lower rope after passing it and by then it's too late to sort it out without re-passing it upwards. It didn't fail but I didn't like the look of it! I think the most likely cause was an incredibly stiff top rope which left a window at the top of the Capuchin knot for the half double fisherman's to get pulled into. Also, the fact that the top rope was old 10mm and the bottom rope new 8mm may have been a factor. I'm going to have a play sometime to see if I can re-create what happened.

 

[Dep]

...
double figure of 8 on a bight (fancy name for a "normal" fig of 8 )
...

No - that's a figure 8 loop knot.

The fig-8 on the bight is a completely different knot - very similar to a bowline on the bight to make a Y-hang but with the knot 'core' based on the fig-8 rather than the bowline.

But whatever you call it - the method of joining ropes as you describe is sound - its simple, secure and can be untied fairly easily.

Double fishermans can't.

I also suggested using a reef knot, with the tails both fastened back to the main ropes as capuchin knots* (AKA half fisherman's or lover's knots) The tails can also be used to form an additional loop.

* Thanks JB - I've been rackng my brains to remember what that knot is properly called when used in isolation.

But a rethreaded triple fig-8 is what I would do if I wanted a loop, if I didn't it would be a flat fig-8 with ends capuchined back to the main rope for security.

 

[JB]

But a rethreaded triple fig-8 is what I would do if I wanted a loop, if I didn't it would be a flat fig-8 with ends capuchined back to the main rope for security.

As Damian says, re-threading a fig-of-8-on-the-bight with the lower rope to give a 3-strand fig-8 makes sense as it gives you a nice short knot with a loop to clip into. Reading the other thread Andy Sparrow posted that this can fail when different diameters of rope are used. Just wondered if anyone has tested this to see if it pulls though with different diameters of rope? (and how different do they need to be?) I'd normally be happy using the Capuchin/half double fisherman's combo with any diameter of rope (as long as I can get rid of all the windows in the knots!)

Dep - what I know as a Capuchin isn't the same as half a double fisherman's. The Capuchin is tied on the bight and gives you a loop in the end of the rope.

Jules.

 

[Geoff R]

Im interested to get ideas and experiment myself and in parallel set up a poll and get posters views; regretfully as Ive never set one up, it remains to be seen what happens!

Capuchin
JB if Ive understood your posting correctly, a Capuchin is a half double fishermans tied on a bight and is easily distinguished as the resulting loop cannot slip closed (unlike its similar Barrel knot)

(If this is correct, this was my intended 2nd idea to start this thread)

The problem Im experiencing is that web searches for Capuchin knot have not produced a drawing; no mention in LOAL2, no mention in Alpine Caving Tech (unless as my wife often says, Im just not looking properly; which is actually highly likely)

Geoff
 

 

[Downer]

This is a scary! I thought knotting ropes together was a completely standardized part of basic SRT. Everyone making up their own knots sounds distinctly dodgy. I particularly like the idea of sideways-loaded knots "rolling" off the rope. Perhaps everyone should tie the loose ends together with a double fisherman's while they experiment, just in case.

 

[martinr]

 

[paul]

I use a Capuchin in the end of the top rope and then thread the end of the bottom rope up through the middle and tie half a double fisherman's. Neat and short knot which gives you a loop to clip into.

Same here (following suggestion from Dave Elliot).

I haven't experienced the problem you describe but I always use Club ropes which are all of similar diameter.

If you want to defintely untie two joined ropes afterwards the reef knot with the tails tied as half-fisherman's either side will work - although a bit more bulky for knot passing.

 

[Dep]

...
Dep - what I know as a Capuchin isn't the same as half a double fisherman's. The Capuchin is tied on the bight and gives you a loop in the end of the rope.
Jules.

Ah! I had a Google for a picture of it but could not find one on any knots site, the only one I did was a single rope knot.
But it was an obscure post and not on the subject of knots so I guess misidentified...

I'll have to find myself a copy of the ABOK.

 

[wormster]

According to PETZL (http://en.petzl.com/petzl/SportConseils?Conseil=43&Activite=26)

use a fig 8 derivation.

 

[Geoff R]

Now Ive found it - The Capuchin knot used by French monks of the Capuchin order - Knots and Splices by Des Pawson

BUT he clearly states that you make four or five turns around the rope to tie this knot;
and the monks make even more.
Its made on the tail of their belt cord (and not to form a loop)

So Im wondering if we should be using this name for what we prob mean here as just a half of a Double Fishermans ?
the web does not seem to clarify this matter ....? 

As Martin R posts,  Im certainly happy to use a Double Fisherman's (with or without a reef knot added into it) and tie a separate Fig8 loop for clipping into,  but wonder if there are better ways ?

 

[martinr]

web searches for Capuchin knot have not produced a drawing;
   

 

[martinr]

If you tie capuchin in top rope and half of the double fishermans in lower rope you then get:

I usually tie the capuchin first, then thread the lower rope straight up the inside of the capuchin before finishing with a half double fishermans above the capuchin - see below. Difficult to describe - can anyone improve this description?

 

[Geoff R]

Interesting - I searched and could find no ref - thanks. 

Packed my 50m rope bag 2 hours ago (for tonight) and yes its a Capuchin thats sitting ready at its bottom as my personal choice, at present, for stop knot and joining. 

Would it be normal practice to also add a safety knot to the tail of the lower rope ?
IMHO it would be a nice to do, (but not essential and makes knot bigger for passing).

Geoff

 

[paul]

Would it be normal practice to also add a safety knot to the tail of the lower rope ?
IMHO it would be a nice to do, (but not essential and makes knot bigger for passing).

Do you mean have a knot at the end of the lower rope while its packed in the bag? - YES.

Or a knot on the tail of the lower rope remaining from the half-fishermans after joining upper and lower ropes? - not necessarily.

 

[Geoff R]

Would it be normal practice to also add a safety knot to the tail of the lower rope ?
IMHO it would be a nice to do, (but not essential and makes knot bigger for passing).

Do you mean have a knot at the end of the lower rope while its packed in the bag? - YES.

Or a knot on the tail of the lower rope remaining from the half-fishermans after joining upper and lower ropes? - not necessarily.

I do mean your second option; 
a safety knot on the tail of the lower rope, as it forms the top located half-fisherman's joining the two ropes together

 

[martinr]

Would it be normal practice to also add a safety knot to the tail of the lower rope ?
IMHO it would be a nice to do, (but not essential and makes knot bigger for passing).

Do you mean have a knot at the end of the lower rope while its packed in the bag? - YES.

Or a knot on the tail of the lower rope remaining from the half-fishermans after joining upper and lower ropes? - not necessarily.

I do mean your second option;   
a safety knot on the tail of the lower rope, as it forms the top located half-fisherman's joining the two ropes together

There is no need. The half double-fishermans is all you need.

Incidentally, we are talking about half of a double-fishermans knot. You should not be tying half a fishermans knot, which is something different.

The upper knot is one half of a double-fishermans knot.
The lower knot is one half of a fishermans knot.

 

[Geoff R]

Yes, Im only talking about a half of a Double-Fishermans  (did not spot my typo).
Agreed - a Fisherman's knot (without the word Double added) is very different


However I recall Andy Sparrow advocating tying a Double-Fishermans (with a reef knot inside it for ease of undo)
AND then tying the tails to form ANOTHER double fishermans (hence also forming a loop to clip into)

This is what made me question whether indeed just one portion of a double fishermans knot alone is reasonable, without a safety knot of some sort also added. 

 

[martinr]

whether indeed just one portion of a double fishermans knot alone is reasonable, without a safety knot of some sort also added. 

A feature of a double-fishermans knot is that it gets tighter under load. It will not work loose so there is nothing to be gained by adding another knot. See http://ukcaving.com/board/index.php/topic,4722.msg67505.html#msg67505 above.