Author Topic: I need the least secure knot you got  (Read 10405 times)

SirCantaloupe

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I need the least secure knot you got
« on: November 08, 2009, 05:36:10 AM »
I am in a quandary here, as I have been trying to teach myself secure knots. But I've found I need one which lacks that quality. I'm trying to hang something from my keychain carabiner which will hold just enough to resist low level everyday stresses (hanging at rest or swinging slightly with my stride) but will release reliably with a sharp tug on the standing part. I've spent a good few hours trying and failing to either create this knot myself or find a suitable one online. Does anyone have any ideas on this? It's pretty much the antithesis of all this forums stands for, so I'm interested to see what you all have to say.

This is going to be tied in parachute cord, by the way.

Thanks in advance!
« Last Edit: November 08, 2009, 05:50:09 AM by SirCantaloupe »

alpineer

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Re: I need the least secure knot you got
« Reply #1 on: November 08, 2009, 06:06:31 AM »
This is an interesting question SirCantaloupe, but you may courting nigh the impossible. You're asking a knot to be stable, but then also release, within a very narrow loading range by hand generated forces. Perhaps some form of slip knot? Good luck.  
« Last Edit: November 08, 2009, 08:58:44 PM by alpineer »

skyout

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Re: I need the least secure knot you got
« Reply #2 on: November 08, 2009, 08:15:11 AM »
Welcome to the forum SirCantaloupe.

If it doesn't "have to be" a knot, I think stormdrane has a link to the necklace/lanyard break aways.

Here's one used by Shamr0ck that works with paracord:
http://www.lighthound.com/Lanyard-Break-Away-Connector_p_737.html
And link to the thread:
http://www.khww.net/forum/viewthread.php?thread_id=715&highlight=necklace+break+away&pid=6694#post_6694

SS369

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Re: I need the least secure knot you got
« Reply #3 on: November 08, 2009, 03:11:16 PM »
Hello SC and welcome.

If it does have to be a knot, perhaps using the marlinspike hitch with the standing end as the spike and cinched up very tight would be a fair suggestion.

IMHO it would be better to hitch the keys more secure and just undo the biner. Sort of what they are for right?

SS

[Inkanyezi] gone

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Re: I need the least secure knot you got
« Reply #4 on: November 08, 2009, 03:28:32 PM »
To me it looks like some safety release, like the one that people of some professions have on their necktie. There, it is just a patch of velcro. If you try to strangle the person with the necktie, it just breaks loose. Something akin of a safety valve. I guess knots are not for that sort of thing, because even if we have knots that reliably break loose, they might not reliably hold, as they may change their form or tightness during use. And if the knot will reliably hold, it won't break loose. I think it might better be accomplished with some kind of mechanical contraption, as for example a plastic catch that won't open unless you give a firm tug. Such a catch may be made by adjusting the hook(s) of a snaplock, so that it will inevitably open on a hard tug.
« Last Edit: November 08, 2009, 04:48:24 PM by Inkanyezi »
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DerekSmith

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Re: I need the least secure knot you got
« Reply #5 on: November 08, 2009, 03:31:09 PM »
The problem is a common one for jewellery - bracelets, necklaces etc.. a decorative bracelet made out of 3mm polyester braid for example, would have several hundred pounds breaking strain, and if it ever became caught up on a moving object, it could easily take a hand off.  Ricks second link has a number of valuable methods.

The two principle methods involve using either a release knot or a friction grip.  Which method you choose will depend mostly on how often you want to be opening the connection.

If you want to be opening the knot regularly, then perhaps the best is a stopper knot captured by a slip knot.  By way of example, tie an overhand knot in one end of the cord and tighten it to make the stopper knot (use as fancy a stopper knot as takes your fancy).  Then in the other end of the cord tie a slipped overhand - pop the stopper end through the slipped OH and tighten the OH down down - the stopper will prevent the 'fly' end from sliding out, even under quite substantial force.  However, when you want to release the connection, pull the slipped loop end to undo the slipped OH and the knot will fall apart. There are two risks with this knot - first that the stopper end will get passed through the slip loop - this will prevent the slip from opening, and second, the slipped loop end may accidentally be snagged and pulled, releasing your lanyard unintentionally.

The second principle - using a friction grip is easy to set up.  Tie a Strangle or double strangle (double or triple OH), but before tightening it, pass the 'fly' end through the centre of the Strangle, then tighten the Strangle until the 'fly' end is held tightly enough to resist the forces of normal use.  To release, just pull the 'fly' end out of the Strangle.  The principle risk with this method is that the cut end of the 'fly' end must not present a restriction to being pulled through the Strangle.  Melted ends can 'blob' up and effectively act as stopper knots, jamming in the Strangle.  The end needs to be carefully sealed and be smaller than the cord itself.  Of less risk are the issues of the cord surface becoming slick with use and failing to grip, and the fact that to get the grip, the strangle needs to be quite tight, which makes it hard to undo if you want to remake the connection.

Using and tying knots which will undo when and where you want them to, is just as important as tying knots with massive security.  The challenge is to get both or at least to get the relationship right for the job at hand...

Derek
« Last Edit: November 08, 2009, 03:33:23 PM by DerekSmith »

Dan_Lehman

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Re: I need the least secure knot you got
« Reply #6 on: November 08, 2009, 09:38:51 PM »
...  I need one [that] will hold just enough to resist low level everyday stresses (hanging at rest or swinging slightly with my stride) but will release reliably with a sharp tug on the standing part.
...
This is going to be tied in parachute cord, by the way.

Thanks for stating both the purpose/environment and the material!

I have a quick idea for you to try.  What should occur to folks in contemplating
this rope problem is the relative security of the so-called "quick release"
slip-tucks/slip-bights.  Consider one's shoelaces:  they endure some regular
jostling, et cetera, but will release when the ends are pulled (if not pulled
through a bight, that is!).
.:.  put a bight in the S.Part and tie the end to it with a clove hitch;
the Clove should be oriented so that the end is towards the bight,
not making the choke of the lightly loaded bight legs.  (And a beefier
2nd idea would be a Rolling Hitch so tied; or is it better with the double
turn put in by its end?  It should give more friction to resist the unwanted
untying/loosening.  Note that the very bight-end bulge, perhaps not all
so large in this cord, has itself some added resistance to being pulled out
-- something I think a lot of supposed quick-release knots advocates ignore.)
The Clove should keep things together, but a sharp tug on the S.Part should
pull out the nipped/hitched bight, and leave the Clove in evaporation.

I'll add that the Clove-hitch solution above can be implemented with the
keys on one end and a long-enough eye knot on the other, and then
the lanyard S.Part be folded to make bight with which to tie the Clove
as a 2-sequence quick-tie, first-step Bowline maneuvre -- where one
casts the Half-hitch/turn into the side of the eye, then again, and bring
those together to form the Clove (Cow might work, too); this might
be quicker than tying with an open end.

For added security if needed, substitute a locked Clove, er, Constrictor
binder for the regular clove.

-- QED.

Derek was on the right track, but surprisingly suggested the non-TIB Strangle
vs the Clove/Rolling/Constrictor, all of which become nothing with the removed
object-bight around which they'd be tied.

Inkanyezi's suggested release brings to mind the Highwayman's hitch and
improved versions of that:  one must just sharply tug the open end and
not the business end w/keys -- which would be problematic in a case of
multiple such sets of things (i.e., 3 key sets each so tied:  whose end is
this one?! ).

--dl*
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alpineer

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Re: I need the least secure knot you got
« Reply #7 on: November 08, 2009, 09:59:09 PM »
I say all of these knotty suggestions are 'too practical by half' ;D Go with a mechanical contraption as skyout alluded to.

Dan_Lehman

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Re: I need the least secure knot you got
« Reply #8 on: November 09, 2009, 05:57:00 AM »
I say all of these knotty suggestions are 'too practical by half' ;D Go with a mechanical contraption as skyout alluded to.

Wow, the heresy of bypassing knotting for some cheap-o commercial
gadget!  In which case somehow there is some bit of dangle for the
secured object, for a loop gadget-connected, and the attachment to
the object.  (Frankly, I didn't understand how the male-half of the
breakaway connector was to have an end inserted and then melted
to a knob to stop it?!
)

Really, I've not sought out some paracord for testing, but in some soft,
cheap-o cord off of a shopping bag, I find a Clove to work pretty well
-- tighter/grippier if oriented like the buntline hitch, which for me was
too grippy (depending upon the anchorage of the tied-to 'biner).  One
can further the gripping by putting in a Slip-knot into the S.Part's
nipped bight (S.Part being the moving, slipping strand).  Then, again,
we don't know what exactly is being suspended and jostled about?

It might matter how often this breakaway & rejoin needs to be performed.

--dl*
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SirCantaloupe

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Re: I need the least secure knot you got
« Reply #9 on: November 09, 2009, 06:37:15 AM »
I am very impressed and surprised with the level of feedback I've gotten back so quickly! So far what I'm seeing as most promising is Dan's clove hitch idea. I've been learning my knotting exclusively from diagrams and videos, so my reading comprehension for written instructions is dodgy at best. If it were spelled out to me in kindergarten language, so to speak, I should be able to make sense of it.

The mystery object is going to be a largish ball bearing weighing around 130gm, wrapped in a monkey's fist or if I can do it a Turk's head. I find it handy to have a casting weight at hand, it looks good, and if needed it can become a tool of self defense. All in all, this knot will be employed pretty infrequently.

WebAdmin

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Re: I need the least secure knot you got
« Reply #10 on: November 09, 2009, 08:50:27 AM »
Hi,

Thanks for such a good question.  I often have this need when hoisting boxes and bags into my loft unaided.  I use two or more slipped loops tied close together.  For something circular I could use slipped constrictors, but haven't needed to yet.

:) Glenys
Lesley
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DerekSmith

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Re: I need the least secure knot you got
« Reply #11 on: November 09, 2009, 11:39:36 AM »
snip...
Derek was on the right track, but surprisingly suggested the non-TIB Strangle
vs the Clove/Rolling/Constrictor, all of which become nothing with the removed
object-bight around which they'd be tied.
snip...
--dl*
====

I'll raise your 'surprise' to 'startled' and see you...

Yes, I fully accept your criticism that the Strangle will not self destroy when the contained line is withdrawn (in fact, I think I mentioned this as one of the negatives).  However, the choice of the Strangle over any of the Clove/Constrictor style bindings was deliberate, even at the cost of being left with the knot after release.  In fact it is this very property which is at the heart of my choice process.

The Strangles (single, double etc) are self contained and self constraining and once dressed and set, they can be a real bugger to get them back open.  In their final dressed form they are stable, the forces are all inwards and are not attempting to create any structural change. 

This stability gives a knot which stays tight and stays in exactly the same shape through any amount of physical abuse.

By contrast, the Constrictor and its like, rely on the core for their structure (obviously - because that is why they fall to pieces when the core is extracted).  However, the forces of the Constrictor are not balanced and self contained and the knot is not in its 'lowest energy state' - i.e. its most stable state.  The forces within the Constrictor are attempting to transform it into the Myrtle which is the lowest energy form of this structure (once it has collapsed to the Myrtle, it has no where else to go and is then in its lowest energy form).

When the Constrictor is made onto a solid core, these forces are fully resisted and the Constrictor is nicely stable, but if the Constrictor is tied on a core of flexible material, then the forces within the knot will bend the flexible core and in doing so will release cord from the constrictor, loosening the overall binding.  If this slack is taken up and the forces reapplied, the Constrictor will continue to bend and wrap its core around until it has formed the stable Myrtle.

Of course, all sorts of complexities come into this equation if the core is made of cord, especially if it is doubled as Dan has suggested - stiffness of the core, friction, compressibility, elasticity and of course, the amount of physical work that the knot must endure.  All these might conspire to make this knot adequately stable - or they might not, for this reason, the knot is not an ideal design for the job in hand.

Finally, we come to the act of deliberately releasing the knot.  The Strangle is an 'inline' knot with the standing part running straight out from the core of the knot and tied in this manner, the gripped line will run straight out the other side of the knot.  A pull to release the knot will pull the gripped cord straight from the centre of the knot without any twisting or binding.

A Constrictor by contrast is a 'tangential' knot, the SP entering the knot at right angles to the cord and at right angles to the load.  So when the core is pulled, the SP will impart a tilt to the knot which will resist the flow of cord through its core.  Add to this the fact that the tip of the bight is thicker than the two cords laying side by side and this will bind like a slight stopper when it reaches the nip of the now 'offset' knot under the tension needed to pull it open.


One final note SC, I don't know where you live , but here in the UK, if I were to be caught walking around with a quarter pound steel ball hanging by a cord from my belt, I would almost certainly be arrested for the possession of a lethal weapon with intent to use, and could expect to spend a night in the cells and have a DNA sample taken to go onto my record along with the charge of carrying an offensive weapon in a public place !!

Derek

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Re: I need the least secure knot you got
« Reply #12 on: November 09, 2009, 03:53:17 PM »
One final note SC, I don't know where you live , but here in the UK, if I were to be caught walking around with a quarter pound steel ball hanging by a cord from my belt, I would almost certainly be arrested for the possession of a lethal weapon with intent to use, and could expect to spend a night in the cells and have a DNA sample taken to go onto my record along with the charge of carrying an offensive weapon in a public place !!

You took the words right out of my fingers, Derek.  I didn't have time this morning to add that bit in :)

Regards

Glenys
Lesley
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Dan_Lehman

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Re: I need the least secure knot you got
« Reply #13 on: November 09, 2009, 05:27:07 PM »
I am very impressed and surprised with the level of feedback ..

Yes, I had my surprise, too.   :D

Quote
So far what I'm seeing as most promising is Dan's clove hitch idea. I've been learning my knotting exclusively from diagrams and videos, so my reading comprehension for written instructions is dodgy at best. If it were spelled out to me in kindergarten language, so to speak, I should be able to make sense of it.

With a single-strand end (as opposed to my suggestion for tying the Clove
in an eye), picture your tied-to object cross-section as the center of a clock;
your lanyard goes around clockwise from 9:00 to 3:00;
the S.Part at 9:00  is folded into a bight  that extends horizontally through 3:00;
the end will tie a Clove h. around this bight.
Now, this Clove can have the end lie on the outside/right -- which seems to be
less secure -- , or on the left.  Tighten Clove a bit, pull on hitched bight to draw
the Clove snug to the object; further tighten the Clove.  (You will want to try
different settings to see what works best --if the anchorage is not all that strong
(a belt loop e.g. is often not so strong), you'll want to avoid having to use a
big "sharp tug";" of course, the tying must hold until released.

Quote
I find it handy to have a casting weight at hand, it looks good, and if needed it can become a tool of self defense. All in all, this knot will be employed pretty infrequently.

This, esp. the latter use, suggest less need for pulling the object (ball)
than the end, which might put the device into the needed position for
use -- i.e., swinging the ball.  (Were you to yank the ball itself, you would
be holding it -- to throw, maybe, but ... -- ; also, qua casting weight,
you are presumably going tie something to its end, and how it comes
off of the anchorage is irrelevant (unclipping an eye, as Roo . . .
MIGHT suggest, . . . but actually it was SS369 who did).

--dl*
====
« Last Edit: November 10, 2009, 05:17:19 AM by Dan_Lehman »

roo

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Re: I need the least secure knot you got
« Reply #14 on: November 09, 2009, 06:51:08 PM »
I am very impressed and surprised with the level of feedback I've gotten back so quickly! So far what I'm seeing as most promising is Dan's clove hitch idea. I've been learning my knotting exclusively from diagrams and videos, so my reading comprehension for written instructions is dodgy at best. If it were spelled out to me in kindergarten language, so to speak, I should be able to make sense of it.

The mystery object is going to be a largish ball bearing weighing around 130gm, wrapped in a monkey's fist or if I can do it a Turk's head. I find it handy to have a casting weight at hand, it looks good, and if needed it can become a tool of self defense. All in all, this knot will be employed pretty infrequently.

I'm not going to discount any of the creative solutions proposed thus far.  But I'll point out that a sphere on a cord is quite effective at getting tangled on various things (think bolas).  So a low-tension release system may generate a lot of nuisance releases, even if not considering long-term security from general motion or bouncing.

A Slipped Buntline Hitch (or another slipped hitch) may provide the quick release you desire, without the nuisance "trips", and with proven long-term security as an added benefit.

http://notableknotindex.webs.com/slippedbuntline.html

see also:
http://notableknotindex.webs.com/tumblehitch.html
« Last Edit: November 09, 2009, 07:27:19 PM by roo »
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