Disappointed with Alpine Loop- Stuck

[preventec47]

l came here a long time ago to find the best few knots to learn and use in my boating and wilderness activities.   I selected for loop in the middle of a line the "Alpine Loop".   For a loop at the end of the line I selected the "Water Bowline knot"  as the knot I always use  except when I can tie a dozen or more loose half hitches  followed by a tight two half hitches to hold the assembly together whatever it is.    I have found that nothing is easier to untie than loose half hitches.

Meanwhile today I had to pull a trailer out of a ditch and used an "alpine loop knot" with 3/4" synthetic cord with sheath and core at around 1500 to 2000 pounds max tension.    Now I cannot untie the knot.   I have not tried yet  hammers or pliers or large spikes etc.   I also am thinking
about some kind of lubricant such as WD-40, motor oil,  Silicone Spray,  dish soap and water etc.
I did not want to use lubes until I checked here as I dont want the knot to swell up and become
tighter nor do I want any chemical effect which could weaken the rope fibers etc.

So,  Is there an easier to untie loop knot for use in the middle of a line than the Alpine Loop ?

What is the collected wisdom of using lubricants ... how and which ones when trying to untie
knots ?

What about the idea of using some kind of tapered spikes of one half to a full diameter
of the rope that could be inserted when dressing the knot  before pulling tight.  These
smooth tapered spikes could be easily backed out creating some looseness in the knot.

What about lubricants  ?

[Dan_Lehman]

I vaguely recall using vegetable oil, which can
be washed off later --with some success.

As for a (marline)spike, you might have some
screwdriver that is unoffensively sharp which
can be used, taking care on inserting it.  (I've
an old dull-edged one that I have around only
for rope use.)

It would be nice to see a photo of what shape
your butterfly --I presume you mean this-- knot
is in, of how it was dressed & oriented (as it is an
asymmetric knot, and allows various dressings).

There is a version of it that should behave pretty well.
Now, 3/4" rope and towards a ton of force is getting
well removed from ready manual strength, and some
of the should-be-easily untied knots can be less so!

--dl*
====

[alpineer]

Try turning your Butterfly into a 'four wings' Dragonfly by re-tucking the ABK's eye back into the knot's central opening from the opposite edge of the opening.

[Z]

I am not totally sure how you loaded the knot in the middle of the line. Pics would help. Anyway...

How about using a Marlin Spike in the middle of a line to get purchase?

Or a Span Loop is super easy to untie depending on how it is loaded. It takes a little practice to dress correctly though.

[agent_smith]

Meanwhile today I had to pull a trailer out of a ditch and used an "alpine loop knot" with 3/4" synthetic cord with sheath and core at around 1500 to 2000 pounds max tension.    Now I cannot untie the knot.

Should we assume that you mean #1053 Butterfly eye knot? The naming and positive identification of knots is an ongoing issue. The use of 'ABoK' numbers do aid in the positive identification of knots (where an ABoK number exists).
If yes, the Butterfly is vulnerable to jamming when eye loaded.
When 'through-loaded' (SPart loading) - they are resistant to jamming, although I hesitate to warrant absolute resistance as I have encountered instances of jamming when 'through-loaded'.

I am curious as to why you loaded the #1053 Butterfly eye knot in this way - assuming I am understanding you correctly - this type of loading profile on a Butterfly eye knot is not its optimum application - because it is intended for 'mid-line' use, not end-of-line.

...

So,  Is there an easier to untie loop knot for use in the middle of a line than the Alpine Loop ?

The problem here is your apparent stated application. Heavy loading of the eye of a Butterfly knot will result in jamming. And this is not a loading profile that is optimal.

A better choice of knot would be a Bowline or perhaps a 'Zeppelin eye knot' (if end-of-line loading is your intention).
Although an extra wrap of the eye through the centre of the Butterfly (per Alpineer suggestion) will add extra padding and bulk and so may improve resistance to jamming.

[KC]

Go backwards to go forwards?
Can you re-load line on long axis only (eye not loaded) to perhaps re-align lacing to more square?
From there would seek to lever slack from free ends into/past very first crossing of that free end/ Standing Part,
work slack into the domain of lacing from there.
Can you like wise lever/'slurp' slack from eye past it's first crossing?
.
This is good knot to isolate weak part of line in eye/loop;
fair also for less loaded eye pulling perpendicular to to higher loaded long axis / free ends / standing parts
.
Using in 3/1 Trucker pull is a common usage, but with faults.
free ends/standing parts aren't equally loaded any more, and eye is loaded in between not less, and eye is pulled inline not perpendicular.
.
per input pull:
1 Standing Part is loaded 3x
1 Standing Part is loaded 1x
The Eye is loaded            2x
Look for distortion in knot form unbalanced loading, play with cord tied in knot, mimic knot situation
>>If fibers are fused, can be a game changer but more of a dry land scenario.

[Harold Kahl]

 Is there an easier to untie loop knot for use in the middle of a line than the Alpine Loop ?

I suggest a bowline on a bight.

[agent_smith]

Quote from: preventec47 on May 28, 2018, 12:50:33 AM


     Is there an easier to untie loop knot for use in the middle of a line than the Alpine Loop ?

Reply from Harold Kahl:

I suggest a bowline on a bight.

No Harold...you might have missed the key word; "middle".

What preventec47 is referring to is through loading...where load is entering the core of the knot from 180 degree opposed SParts simultaneously. That is, the core of the knot is bi-axially loaded along a linear direction.

Try this for yourself:
Tie #1080 Bowline-on-a-bight and then grasp an SPart in each hand (that is, grasp one SPart in one hand and then grasp the other SPart in your other hand.
Now pull apart both SPart's simultaneously (so that you are pulling each SPart in an opposite relative direction).
Observe what happens.
What did you observe?

...

Now, due to language limitations and vagaries of interpretation, it is possible that preventec actually means an end-of-line eye loading. But, he used the word 'middle' - which suggests otherwise.

If preventec indeed meant an end-of-line loading on an 'eye' - any of the Bowline family of eye knots would be non-jamming.
And so is the Zeppelin eye knot.

But I'm sure that preventec knew this already...most knot tiers understand that Bowlines are jam resistant eye knots.

Its his use of the term 'middle' that plays a key role in understanding the loading profile he suggests.

A #1053 Butterfly eye knot is designed to sustain a through loading profile (ie bi-axial loading), and in fact, it can sustain a tri-axial loading too.

[Harold Kahl]

No Harold...you might have missed the key word; "middle".

What preventec47 is referring to is through loading...where load is entering the core of the knot from 180 degree opposed SParts simultaneously. That is, the core of the knot is bi-axially loaded along a linear direction.

What I assumed was that preventec47 was pulling his trailer out of the ditch with a rope that was longer than necessary, and so he wanted to tie the loop in the middle of the rope to shorten it without cutting it.

[agent_smith]

What I assumed was that preventec47 was pulling his trailer out of the ditch with a rope that was longer than necessary, and so he wanted to tie the loop in the middle of the rope to shorten it without cutting it.

Although this is one possible interpretation of what preventec wrote... interestingly, he did not state his question in this manner as you have clarified.

Your solution presumes a very long 'tail' - and that it is unwieldy to tie a common #1010 Bowline as an end-of-line eye knot (due to having to manipulate a long tail in forming the knot).

I think this comes down to interpretation - and I think that this will remain an open question until preventec weighs in and clarifies what he meant to say.

I applied a different interpretation - largely because he used the word 'middle' - which implies 'through loading' (bi-axial loading).

Preventec did not specifically use the term "too long a tow rope" and; "I need to shorten it by tying an eye knot part-way along its length".

Although not commonly used these days, he could have shortened his tow rope using a 'sheep shank' (#1152) and then tied a #1010 common bowline to form the end-of-line eye knot.

EDIT NOTE: I should comment that leaving very long tails in vehicular tow ropes is risky. I recall seeing a towed 4WD (SUV) run over the dragging (long) tail causing a sudden jolt/snap resulting in tow rope failure.

[KC]

What I assumed was that preventec47 was pulling his trailer out of the ditch with a rope that was longer than necessary, and so he wanted to tie the loop in the middle of the rope to shorten it without cutting it.

This is kinda what I was imagining.
Butterfly should load end to end, especially end to eye can end up 'twerked' to side lock like this.
Bell Ringer#1147 works well, but also BoB etc.
.
Some notes on ball hitches:
I prefer rope pull directly off of frame, ball hitch is at most leveraged angle from frame
>>always figure pull comes from frame, and pull from any position must route force thru truck to frame
>>frame simply then rides on 2 spindles.
.
Ball hitch is small , slippery rope mount, ball shape wedges rope parts together
>>sometimes re-enforced base is slanted too, so if any turns on ball can get squished together
>>quick snatches, slippery chrome steel, hi and low parts of ball and base ramping RT etc. to pinch and sometimes fused together.
.
This makes pulling by ball hitch unlike other host mounts of extreme use, and chain of multipliers might not consider!

[DerekSmith]

Hi preventec47,

We clearly failed you when you first came here, in that we did not give you the two golden rules of knotting :-

Rule #1  When using heavy loads - DON'T USE KNOTS - they jam and they weaken the rope.  Use loops and round turns and a cleat to tie off with.  In most cases fitting an eyesplice onto the end of the rope is the most useful rope termination and fit a cleat to your tow vehicle.  Fit the Eyesplice with a thimble and a bolt shackle for attachment to your tow point.  Then pass a bight through the tow point of the trailer and bring it back to your truck.  Clip the bight and the rope through the bolt shackle and tie the end off at the cleat using hitches.

Rule #2 If you must use a knot - USE A KNOT THAT DOES NOT JAM - such as the Carrick Loopknot, super easy to tie and unjamable in most cordage.

Your idea of employing a removable wedge is an excellent suggestion.  I tried this using a bright metal spring clip pin from my tractor tow bar, passing it into the Alpine Butterfly between the loop legs.  The knot performed exactly as normal and simply fell totally slack when I removed the pin - great idea, thank you.

I hope you managed to free your jam.

Derek

[Ulxaaf]

The author or this thread is already lost

[DerekSmith]

The author or this thread is already lost

Indeed, but we aren't.

Thanks to this post I learnt a very interesting trick to relax a jammed Alpine Butterfly.

Derek