How to Tie the Pop Lock Knot (An Innovative Bend) by TIAT

[JD~TIAT]

The "Pop Lock Knot": a means of connecting two cord ends quickly and securely for loading or general use, that also allows separation (while loaded or not) in a split second; even if the tyer's fingers have been compromised by cold weather, fatigue, or injury.



Video Instruction Link: http://youtu.be/tEeJoxwkI2o



Unlike historical bends, the Pop Lock Knot does not require dexterity to regain separate use of the connected cords.

PDF Instruction Link: http://tinyurl.com/7poqj49

[This video and its associated pdf instructions are being submitted in the spirit of scholarly peer review. Feel free to evaluate and comment upon the information presented within]

J.D. Lenzen
Tying It All Together
www.fusionknots.com

[Dan_Lehman]

JD, it would've helped to have explicitly indicated what
were the SParts/tails, in the OP.  (Orange from left,
to green from right --so the knots are pulled on both
ends, unlike e.g. the twin rolling hitches bend,
where the knots have unloaded tails.)

As pointed out in a YouTube comment, the tying method
presented in the video is highly unusual, and unwanted:
you need both ends of the (necessarily) two pieces,
which is not expected in normal bending of end-2-end.
Now, one can tie the knot in other ways; these should've
been presented, for practicality.

I'm skeptical about the workings of this knot, especially
the untying, in **rope** (i.e., material taking well more
than manual forces).  I've had some less than happy
workings of it in a rather stubborn marine kernmantle
cord approx. 5mm dia., reasonably frictive.  It occurred
to me to try an overhand noose as the knot, which
gives less resistance in the untying orientation, and also
stands to let the freed ends be pulled clean of the knot
(unslipping such things might be less than hoped).  But,
this structure takes careful setting to choke the slip-bight,
and risks capsizing into something secure but not amenable
to being pulled free.
Eh, ... .

What application is envisioned for this?  --something that
uses the lightweight, light-load slick material like paracord,
perhaps?  (I'd chase after that fireman who wanted to
try it for who-knows-what with his FD!)


--dl*
====

[DerekSmith]

Hello JD, and welcome to the Knotting Concepts board.  It is good to see you outside your normal stamping ground of Decorative structures and a brave move into the world of functional knots.

At first sight my immediate impulse was to request a move of the post into the Practical knots board as the tenor of your video implied very much that this was the presentation of a new joining knot to the practical toolboxes of knot users.  Your usual very high quality video implied a teaching process rather than an exploratory or conceptual process, and I thank you for submitting the structure in the spirit of scholarly peer review and granting us permission to evaluate and comment upon the information presented within the video and pdf files.

However, after making the binding a few times in paracord and other cords I quickly realised that this is certainly not a practical knot.  Please correct me if my interpretation of your pdf images is incorrect, but it appears that the SP carries the knot and the end is then gripped by the opposing knot.  This means then that under working load, the ends will simply pull out of the sliding grip hitch bindings.  As a bend then, this binding will fail catastrophically if the CF of the cordage is too low for the strength of the cord. 

Adding to this fundamental design weakness, the structure shows no positive feedback system able to amplify the grip as the load is applied.  It is a novel threading of the simple double overhand which imparts a slight deflection of the end, but nothing significant to set up competent positive feedback.

In conclusion, this binding may be suitable for non critical applications such as fixing decorations etc., but I feel it should carry a very clear health warning NOT to be used in any application where loading is high  or the consequence of failure would be an issue.

I would urge you to add a usage warning to your video, as one viewer has already been seduced by the style and professionalism to assume the construction is a working knot.

Derek

[JD~TIAT]

Hi Derek,

Regarding: "...under working load, the ends will simply pull out of the sliding grip hitch bindings.  As a bend then, this binding will fail catastrophically if the CF of the cordage is too low for the strength of the cord."

Respectfully, we don't need to speculate what would happen under load. Simply try it out. To date, no one has encountered a catastrophic failure (when tied properly).

 
Regarding: "...NOT to be used in any application where loading is high  or the consequence of failure would be an issue."

Agreed. If you don't trust it, don't use it.

Regarding: "I would urge you to add a usage warning to your video, as one viewer has already been seduced by the style and professionalism to assume the construction is a working knot."

It is a working knot. This said,  "If you don't trust it, don't use it." My point for presenting the knot as I did is to encourage others to test it. I'm not capable of thinking of each and every application, but there are many that wouldn't compromise heath and safety.

Here are a few uses (this information is for Dan as well):

* The knot could be used to quickly release an item that has been lowered from a greater height.

* The knot could be used to quickly release tension on a bowed branch or limb, used as action in a snaring or snagging device.

* The knot could be used to quickly release a taut line after use.

* The knot could be used to connect to or more cords, and quickly allow the modification of total cord lengths at the PLK "Pop Points". 

J.D. Lenzen
Tying It All Together
www.fusionknots.com

[JD~TIAT]

Hi Dan,

See comments above.

Further...  It's extremely easy to pass a bight through a loop (as shown at 3:12 in the video) and then to pull the bight out on the other side (the rest of the cord following with it). My having shown a cord end, prior to its insertion through the loops was purely academic (to illustrate how the knot is tied. A bundle of cord, could just as easily be passed through the loops as well.

Either way, both actions maintain the utility of the PLK.

J.D. Lenzen
Tying It All Together
www.fusionknots.com

[DerekSmith]

Hi JD,

Judging by your reply, you have misunderstood the purpose of this board, it is as the name implies, for concepts and explorations - it is not for for the showboating of new practical knots.

If you genuinely believe that this knot is practical, then please post it on the practical board where a number of people who regularly use knots will critique it for you.

If you wish to leave it here, and you do not agree with my theoretical critique of its structure, then please supply your Desmological arguments as to why you find my analysis to be at fault.  This is not the board for simply saying 'try it...'  here we are attempting to identify why knots behave as they do.

Derek

[JD~TIAT]

"A place where we can tear down, explore and build knots of all kinds, figuratively and or virtually."

Sounds like the right place to me...

J.D. Lenzen
Tying It All Together
www.fusionknots.com

[DerekSmith]

If you wish to leave it here, and you do not agree with my theoretical critique of its structure, then please supply your Desmological arguments as to why you find my analysis to be at fault.  This is not the board for simply saying 'try it...'  here we are attempting to identify why knots behave as they do.

Derek

"A place where we can tear down, explore and build knots of all kinds, figuratively and or virtually."

[JD~TIAT]

If you wish to leave it here, and you do not agree with my theoretical critique of its structure, then please supply your Desmological arguments as to why you find my analysis to be at fault.  This is not the board for simply saying 'try it...'  here we are attempting to identify why knots behave as they do.

Derek

"A place where we can tear down, explore and build knots of all kinds, figuratively and or virtually."

J.D. Lenzen
Tying It All Together
www.fusionknots.com

[Dan_Lehman]

Hi Dan,

See comments above.

Thanks.

* The knot could be used to quickly release an item
that has been lowered from a greater height.

For lowering something, one would expect to bend
the line directly to the object --i.e., a hitch (the blackwall
hitch being one that might even be released by those
doing the lowering from above!).

But, you're missing my belief that quick release
won't be forthcoming after "serious" loads,
not mere manual setting of paracord.  This
would suggest a limited range of applications,
where forces and materials are small.

* The knot could be used to quickly release tension on a bowed branch or limb, used as action in a snaring or snagging device.

!!  Not if there's much tension on this,
I think.  But some this is a YMMV situation
w/cordage & force.  Still, some sort of
slip-bight'd structure would be much more
to the liking.

Further...  It's extremely easy to pass a bight through a loop (as shown at 3:12 in the video) and then to pull the bight out on the other side (the rest of the cord following with it).
...

Whoa, this misses the point : one does NOT want
to need access to the end, SPart-side --e.g., that
might be unavailable:  tied to something or very
long.  The knot --basically, an anchor bend with
the object rope slightly differently positioned--
can be tied and then the object-end inserted.
Either way, both actions maintain the utility of the PLK.

Now, unvirtually & unfiguratively, I was just out in
the chill March air putting some force on this
structure tied in quarter-inch poly-Dac moderately
laid rope (PES fibres wrapping PP ones, so a silky
firm feel) forming a circular sling ("loop"), and
loading it between trees with a quick trucker's
hitch (Ashley's #1029 (-34?) making a fine, quick
directional eye for this!).  I couldn't untie the PopLocker
with my hands.  So, I rigged a line to secure one
side vertically above the horizontally tensioned
line w/PopLocker, and put in a sling of solid
cable-hauling tape to step in to pull the other
side downwards.

This had most unsatisfactory results --darn, it stipped
my impromptu whipping off of the rope, as the tails
Pop'd out --first, just one did, then the other.  I made
a 2nd test, with greater tension (I was *inspired*),
and got if anything a quicker Pop (!) (and the loss
of the other end's whipping).

But I remain skeptical of this working in many
real cases.  (Note that by joining the ends of a
loop, the PopLocker had half the delivered
force on it; I was just too lazy to do otherwise,
at the moment.)


--dl*
====

[WebAdmin]

Good day, Gentlemen,


I am conferring with the Moderators for a concensus of opinion as to which is the proper board.


For the moment, please continue discussing the knot, and we will let you know the decision.


Regards
Glenys

[roo]

Hi J.D.,

I have some of the same reservations that have already been discussed.  Also, heat-sealed ends of lines often have some mushrooming that will adversely affect the workings of anything that requires the ends to slip though an unrelaxed knotted body.

Have you considered just assembling some basics to do what you have in mind?  For example, you could make a round turn or two around the passive line and follow up with a Slipped Buntline Hitch, shown loosely tied in the attached image for clarity.  To keep the passive line from slipping through the round turn and slipped buntline, you could tie a figure-eight stopper knot with the passive line.

It's a watered-down version of a load-releasing mechanism intended for a solid object, shown here:
http://notableknotindex.webs.com/slippedbuntline.html

Another option:  http://notableknotindex.webs.com/triggerbend.html

[Knot_Easy]

Hi JD,
      First let me say I appreciate your work ? I was given your book last Christmas.  And in my farming work I could have used a bend or loop with the characteristics you are aiming for.  Many times I have needed to separate ropes that have been heavily loaded then dragged through mud, burrs, and a few fresh cowpats.

Unfortunately for some of the reasons mentioned above and from my own testing (without the cow pats) this doesn?t seem to be a practical solution.

Since this is the ?concepts? board I think we need a few criteria for a bend of this type to meet what is a very practical need.

My list would include:
1.  No need to pull an end (standing or working) through the knot while its still tight.
      Who, especially on this site, would have working ropes without either a whipping, MWK, eye splice or heat sealing on the end?

2.  Would leave the ropes without any knots remaining.
        If the conditions are such that some other bend is difficult to untie, then its going to be impossible to get a small, tight knot out of a  rope with your bare hands.  This is especially important if it renders the rope useless for passing through a pulley or loop, or makes it difficult to tie  a subsequent knot.

3.  A resistance to jerking loads.
     This is always going to be a problem when a binding hitch type knot is used as part of the bend but common in many applications.

I see no need for the bend to be able to be separated under load, but that is just my preference and think an entirely different problem.

Of course the biggest challenge is knowing when you need such a bend BEFORE you injure your hand, or it gets covered in slime and wet clay.

[DerekSmith]

Hello Knot_Easy,

Welcome to the IGKT Forum, and especially welcome to the C&E board.  It is so rare that we knotting nerds get a new contributor, you have made this a red letter, put out the bunting day.

Although this is your first post, earning you the appellation of 'Newbie', it is clear from the content of your post you are anything but a novice at this game, I hope you will stay and contribute to this challenge.

I agree with you that JD is a skilled artisan, not only in his development of Fusion Decorative structures, but also his extremely professional production of videos.  Although his attempt  to bring us a practical knot has exposed the limit of his practical experience, he has none the less identified an ideal challenge for this board - i.e.  Considering the aspects required for an easy to release load bearing joining knot.

Your requirements list is excellent, and I would offer to add:-

4.  That the knot should contain a strong load bearing structure which takes the major part of the load and a separate lightly loaded release structure which releases the geometry of the loaded structure so as to allow it to loose its locking or cogging attributes.

Derek

[Wed]

If this one bend do not fit the bill, use another bend. After all, there is a plethora to chose from.

Maybe there will come a bill to which this bend fits nicely. Until then, I suggest exploring its possibilities rather than what it's not suited for.