Author Topic: A better way to tie-in to the middle of a climbing rope  (Read 1951 times)

agent_smith

  • Sr. Member
  • *****
  • Posts: 1204
A better way to tie-in to the middle of a climbing rope
« on: December 03, 2019, 05:14:36 AM »
A long standing problem in the world of climbing is how to effectively tie-in to the middle of a climbing rope (to make a party of 3).

The #1074 Bowline with-a-bight has been the subject of some interest for me.
It is TIB, can be biaxially loaded and has 4 rope diameters inside the nipping loop.

A recent test report (per Kelly Byrne) suggested that adding more rope diameters inside the nipping loop can boost the MBS yield of a 'Bowline'.
Although raw knot strength is of little overall importance, it does suggest that rope wear and tear might be ameliorated by adding extra 'padding' inside the nipping loop of all 'Bowlines'.
Repeated low F/F falls can have a detrimental affect on a climbing rope - with wear n tear on the section of rope that forms the nipping loop being a possible zone for concern.

While toying with the issue of eliminating connectors from a mid-rope tie-in, I realized that #1074 might be 'problem looking for a solution'.
Refer to image below...

alpineer

  • Sr. Member
  • *****
  • Posts: 507
Re: A better way to tie-in to the middle of a climbing rope
« Reply #1 on: December 03, 2019, 10:12:03 AM »
A Bowline on a Bight using the long eye of a Butterfly as the bight is a solution offering a fully closed direct tie-in system with triaxial loading capability, though you do have to step through the bight to complete the affair.

agent_smith

  • Sr. Member
  • *****
  • Posts: 1204
Re: A better way to tie-in to the middle of a climbing rope
« Reply #2 on: December 03, 2019, 12:49:48 PM »
Quote
though you do have to step through the bight to complete the affair.
Thanks alpineer.

Although I should have mentioned that stepping through and passing a 'bight' the size of mainland USA around your body is non-sensical and not an effective or practicable solution!

I'll edit my original post to more clearly state that such a manoeuvre is not practicable.

KC

  • Sr. Member
  • *****
  • Posts: 290
    • latest project
Re: A better way to tie-in to the middle of a climbing rope
« Reply #3 on: December 17, 2019, 01:12:50 PM »
i've used RT or Girth from eye of B'Fly.
.
Drop Eye of B'Fly itself does double reeve thru securing bights nicely in smaller, kinda bulkier resistance in larger/stiffer tho
>>but moves towards more relieved first/most force bearing arc deformation
Just that it also can put some torqued twists in there, more witnessable in large or stiff (as more sensitive responder to this) but present in all even if they don't 'cry so loud'
>>Would then look at it like stretched chain holds more than kinked/twisted type examination.
Rope-n-Saw Life
"Nature, to be commanded, must be obeyed" -Sir Francis Bacon
We now return you to the safety of normal thinking peoples.
~ Please excuse the interruption; thanx -the mgmt.~

agent_smith

  • Sr. Member
  • *****
  • Posts: 1204
Re: A better way to tie-in to the middle of a climbing rope
« Reply #4 on: December 17, 2019, 02:16:26 PM »
per KC:
Quote
I've used RT or Girth from eye of B'Fly.

Using a gigantic 'eye' from a #1053 Butterfly knot is not an efficient or practical method of tying-in to a climbing harness mid-rope.

Passing a bight the size of mainland USA around your body is not exactly efficient.
I would also comment that in the event of a fall, a girth hitched 'eye' will cinch tight and cause frictional wear to the harness.

Why bother when you can tie-in more efficiently using #1074 Bowline with-a-bight?

Note that a 3rd person tying-in to the middle of a rope can also occur within the context of glacier travel (ie snow and ice environment). Passing a gigantic bight of rope around your body while wearing crampons is not exactly a user friendly technique.

Quote
but moves towards more relieved first/most force bearing arc deformation
Just that it also can put some torqued twists in there, more witnessable in large or stiff (as more sensitive responder to this) but present in all even if they don't 'cry so loud'
>>Would then look at it like stretched chain holds more than kinked/twisted type examination.
I'm having trouble deciphering your words and intent.
"Witnessable" and "cry so loud" in relation to what?

KC

  • Sr. Member
  • *****
  • Posts: 290
    • latest project
Re: A better way to tie-in to the middle of a climbing rope
« Reply #5 on: December 17, 2019, 04:49:16 PM »
Sometimes B'Fly is simply what is there, perhaps more known; and choice of knots is always good. 
.
i'm sorry was looking at this as carabinier not body wrap connection eyes.
.
Philosophically I always think that a strength of weakness is to be more sensitive meter of what is happening all along; sometimes just adding more weight to handicap self more out of power band to weakness to find best way.
Denser line is weaker to/ more sensitive of twist /torque, thus gives more tell-tale signs as 'shrieks' out louder here.  So more likely if 'listening' to groom out twists more.  Using this more sensitive apparatus as meter,  carry lesson to other softer lines that don't complain as much, but still hindered by same processing so groom like did denser.  When fills with force, will be denser anyway!
Rope-n-Saw Life
"Nature, to be commanded, must be obeyed" -Sir Francis Bacon
We now return you to the safety of normal thinking peoples.
~ Please excuse the interruption; thanx -the mgmt.~

Dan_Lehman

  • Sr. Member
  • *****
  • Posts: 3947
Re: A better way to tie-in to the middle of a climbing rope
« Reply #6 on: December 18, 2019, 02:56:04 AM »
is non-sensical and not an effective or practicable solution!

I'll edit my original post to more clearly state that such a manoeuvre is not practicable.
Clearly it generally IS *pracitCAble*; it might seem
impractical.  And it might pose a problem "down the
road" (untying in some emergency).

--dl*
====

agent_smith

  • Sr. Member
  • *****
  • Posts: 1204
Re: A better way to tie-in to the middle of a climbing rope
« Reply #7 on: December 18, 2019, 07:30:41 AM »
per Dan Lehman:
Quote
Clearly it generally IS *pracitCAble*; it might seem
impractical.

It seems I should have written; it is not practicable!

Attempting to tie-in to the middle of a climbing rope by passing a gigantic bight of rope around your body is just silly.
Even if you were silly and decided to attempt it, you end up with a girth hitched bight of rope into your harness. In the event of a fall, this girth hitch will cinch tight - causing frictional wear to the harness.

I am surprised that no one thought of using #1074 Bowline with a bight before.
Although I should qualify that by stating it must be secured by adding a Yosemite finish or perhaps a 'Scotts lock'.

SS369

  • Global Moderator
  • Sr. Member
  • *****
  • Posts: 1907
Re: A better way to tie-in to the middle of a climbing rope
« Reply #8 on: December 18, 2019, 03:44:27 PM »
Good day Mark.

I've not had the good fortune to be in a climbing situation or experience to have a need to tie in mid-line yet. But, I have used the bowline with a bight mid-line during tree felling. I use it to provide a perpendicular pull. This way I can be out of the fall line.  Also to keep from threading the whole line through.
Sometimes I do it with a 'biner', sometimes without, mostly without.

I believe I would feel confident to use the #1074 without a "lock" as long as the tail was sufficiently long enough.

SS
« Last Edit: December 18, 2019, 05:29:49 PM by SS369 »

Dan_Lehman

  • Sr. Member
  • *****
  • Posts: 3947
Re: A better way to tie-in to the middle of a climbing rope
« Reply #9 on: December 24, 2019, 01:15:09 AM »
per Dan Lehman:
Quote
Clearly it generally IS *pracitCAble*; it might seem
impractical.

It seems I should have written; it is not practicable!

Attempting to tie-in to the middle of a climbing rope by passing a gigantic bight of rope around your body is just silly.
Even if you were silly and decided to attempt it, you end up with a girth hitched bight of rope into your harness. In the event of a fall, this girth hitch will cinch tight - causing frictional wear to the harness.
"practiCAble" ~= "able to be done (not necessarily easily)";
ergo, DOING it proves the point.

IMO, the challenge to escape such bight-around-body
tied knotted structure poses serious question to its use.

But there are interesting things that can result.

Now, one might view this general *rope problem*
as being solvable by the angler's "dropper knot"
structure, where a mid-line eye knot contributes
an eye long enough to be reeved through the harness
and then back into the knot body, maybe simply
stoppered (e.g., by a slip knot, which, yes, stops
only one side of the tie-in bight --but one's enough),
or otherwise further engaged.  For this, the eye needs
only be large enough to form the finished structure;
and thus it is UNtiable w/o need to go around a body.

(In this, we might note that CMC testing of low-elongation
rope found the good ol' fig.8 eye knot nearly as strong
on THROUGH-loading as the butterfly (!),
and better than the in-line/directional fig.8[/] (whose reason
d'etra was such loading (but it is essentially a slipped square knot.)


--dl*
====

bushrag

  • Jr. Member
  • **
  • Posts: 13
Re: A better way to tie-in to the middle of a climbing rope
« Reply #10 on: March 31, 2020, 07:09:20 AM »
What do you think of the alpine butterfly water knot combo? Seems practical and doesn?t reinvent the wheel.



How about alpine butterfly with the bight reeved back through the heart then finished by using the bight to tie a barrel around the loops.

« Last Edit: March 31, 2020, 07:42:10 AM by bushrag »

agent_smith

  • Sr. Member
  • *****
  • Posts: 1204
Re: A better way to tie-in to the middle of a climbing rope
« Reply #11 on: April 02, 2020, 06:05:14 AM »
per bushrag:
Quote
What do you think of the alpine butterfly water knot combo? Seems practical and doesn't reinvent the wheel.
I dont think much of it all.
Its a composite structure that consumes a lot of rope material and induces eye loading on the #1053 Butterfly. Eye loading causes jamming in #1053.
Note that when #1053 Butterfly is through loaded - so force is axially from SPart to SPart in a linear direction, it is jam resistant (but not so when eye loaded).

Note that when untying from this composite knot, remnant knots are left in the rope - which must also be untied.
Note also that when initially tying #1053 Butterfly, you need to create an oversize eye - and if you dont have sufficient, you need to re-work the initial Butterfly to lengthen the eye.

Quote
How about alpine butterfly with the bight reeved back through the heart then finished by using the bight to tie a barrel around the loops.
It seems you dont understand the underlying reason for the #1074 Bowline with a bight?
You seem to be fixated on a composite structure built upon #1053 Butterfly?

#1074 Bowline with a bight is elegantly simple and does not depend on a composite structure.
It is one knot that is 'PET' and when untied, leaves no remnant knot.

bushrag

  • Jr. Member
  • **
  • Posts: 13
Re: A better way to tie-in to the middle of a climbing rope
« Reply #12 on: April 02, 2020, 10:58:05 PM »
I understand mid-rope tie-in from the perspective of alpine climbing, so I tackled a method of tie-in to a two point harness, which is different than your image of a caving/canyon harness one-point tie in. #1074 with a bight passed through two points on a sport/trad/alpine harness does not work like you show.

Your image of double #1074 is dangerous. If the climber inadvertently makes the second knot apart from the first, and there is slack in the rope between the knots, it subjects the belay loop to full force loading. Through-force as you call it. Bad!

You seem to think that rope material is an issue, I do not agree that this is a concern. Theres always extra kiwi coiled which can be flaked out as much length as necessary.

The climbing community logic is that bowlines should be used backed up. You do not seem to show or consider this common practice.
« Last Edit: April 02, 2020, 11:03:54 PM by bushrag »

agent_smith

  • Sr. Member
  • *****
  • Posts: 1204
Re: A better way to tie-in to the middle of a climbing rope
« Reply #13 on: April 03, 2020, 03:13:29 AM »
per bushrag:
Quote
#1074 with a bight passed through two points on a sport/trad/alpine harness does not work like you show.
Wrong.
It works the same way.
NOTE: The reason i photographed #1074 with a simple gym/challenge ropes course type harness was for clarity. Photographing #1074 with a typical rock climbing harness would add more 'clutter' to the image.

Quote
Your image of double #1074 is dangerous.
Wrong again.

Quote
You seem to think that rope material is an issue,
No - I don't, wrong again!

Quote
The climbing community logic is that bowlines should be used backed up.
That may be true in some traditional quarters where knot knowledge is limited to parroted knowledge.
Most climbers aren't knotting experts - and this fact may be hard to accept.
Climbers are users of knots... and detailed knowledge of knot geometry behavior under different loading profiles is generally considered to be the realm of academia.
When you use the term 'Bowline' - what do you mean?
There are many different types of 'Bowlines'.
Some types of 'Bowlines' are inherently secure (while other types aren't).

Quote
You do not seem to show or consider this common practice
Wrong again.

You make these comments in ignorance.
In the first instance what is [a] 'Bowline'?
When you use the term 'Bowline' - what exactly do you mean?
There are many different types of Bowlines.

If (when you use the term 'Bowline') you mean #1010 simple Bowline, then obviously this is not a secure and stable structure.
#1010 simple Bowline was never intended to be used in life critical applications (but this is plainly obvious).

bushrag

  • Jr. Member
  • **
  • Posts: 13
Re: A better way to tie-in to the middle of a climbing rope
« Reply #14 on: April 03, 2020, 09:24:00 PM »
Your own photo captures the fundamental problem with using #1074 and why I kept incorporating the alpine butterfly. 

With#1074 the through-load cannot bypass the bight, instead the load strand must fundamentally trace half of the bight.

In your photo, the knot induces a twist on the tie-in point, which is evidence of the problem.  The single point harness helps alleviate, but this issue becomes apparent with an alpine harness.



Follow the load strand and you can see it would induce torsion on the tie-in points and leave you in a strange body position if, for example, you were the middle man and you fall into a crevasse.

Quote
Now, one might view this general *rope problem*
as being solvable by the angler's "dropper knot"
structure, where a mid-line eye knot contributes
an eye long enough to be reeved through the harness
and then back into the knot body, maybe simply
stoppered (e.g., by a slip knot, which, yes, stops
only one side of the tie-in bight --but one's enough),
or otherwise further engaged.  For this, the eye needs
only be large enough to form the finished structure;
and thus it is UNtiable w/o need to go around a body.

My examples best resemble this Dan Lehman quote. There might be an interesting experimentation by using a stopper knot with a reeved AB, as a loaded AB seems like it would play nicely strangling the stopper from pulling free.

EDIT: I took a stab at the above with an overhand stopper. Seeing as the overhand would only be subjected to half the force in the loop (the AB takes the other half), I could see this working.

« Last Edit: April 03, 2020, 09:41:35 PM by bushrag »