APPLICATION/PROBLEM
I have a tree pruner on an extendable shaft, and it comes with a pull cord with a nice handle on it.
Unfortunately, when the shaft is not fully extended, the cord is too long to use the handle, so I need a way to shorten the cord.
I would like it to be easy to tie, remain tied while slack, be secure under load, and easy to untie.
SOLUTIONS USING STANDARD KNOTS
Overhand loop ABOK#1046.
Con: hard to untie after it has been loaded.
Sheepshank ABOK #1152 - #1154.
Cons: does not remain tied while slack; not very secure
Butterfly loop ABOK #331, #532,[1] #1053.
Meets stated requirements. Probably the best standard solution.
Cons: this is not a well-known basic knot, so novices may have trouble tying it. Also, untying requires prying the knot open.
PROPOSED NEW SOLUTION: two interlocking overhand loops
Choose two spots on the cord so that the distance between them is the amount by which the cord needs to be shortened
Tie a slip knot (ABOK#529) at each spot. Tie the two knots in the same way, i.e. in the same orientation.
Adjust each knot so that its loop is big enough so that the other knot can pass through it.
Identify which of the two slip knots tightens when its free end is pulled and call it knot A. Call the other one knot B.
Push knot B and its loop through the loop of knot A and tighten knot A by pulling its free end.
(You can confirm the knot is secure by pulling on both free ends.)
(The result is a knot with two free ends, a small loop on one side (that of knot B) and a larger loop on the opposite side (the slack that needed to be eliminated)
TO UNTIE:
Tug on the ends of the large loop to find out which one tightens the loop of knot B, and pull that one to collapse knot B and pull it out of the loop of knot A.
The rope is now back to its original length with knot A left, which can be collapsed by pulling.
First, I would like to see a picture of what you?re offering.
Second, in regards to the cord length challenge on your pole pruner. What I have done with mine is slide the handle to where I want it and tie a slip knot below the handle and let the surplus just dangle
How is the cord secured to the device’s handle?
I’m wondering if it were secured with a stopper knot,
you could simply pull cord out and put in new stoppers
(slip knots) as you needed them.
[Which has been the first responder’s solution, I see.]
You could also just tie off the line by taking two bights
of it --leaving the slack needed drooping-- and tying,
say, a sheet bend / square knot.
- PROPOSED NEW SOLUTION: two interlocking overhand loops
Choose two spots on the cord so that the distance between them is the amount by which the cord needs to be shortened
Tie a slip knot (ABOK#529) at each spot. Tie the two knots in the same way, i.e. in the same orientation.
"Same orientation" allows both to be one way or other;
I'm thinking that you might need them to be in particular
orientations to you pulling handle --which you need to say.
Adjust each knot so that its loop is big enough so that the other knot can pass through it.
But when I continue in your instructions,
I don't see a need for BOTH ... --only for one (one & done)!?
Identify which of the two slip knots tightens when its free end is pulled and call it knot A. Call the other one knot B.
?! They are in same orientation, same knots,
so they should both tighten. You're doing something
that you've not described, to make this make sense.
Push knot B and its loop through the loop of knot A and tighten knot A by pulling its free end.
(You can confirm the knot is secure by pulling on both free ends.)
It should be the case the knot B's free end can pull
out its slip-bight/loop, no?! (A's is toggled by B being
put through it.)
The sheepshank btw can be made more secure by
tying bowlines for its knots. I.e., form the version
with marlinespike hitches as its knots and then
collapse those knots into the bowlinesque/sheet-bendesque
form --something I’m amazed has not been put into the
literature LONG ago! (But, then, I’m still puzzled about
how these knots ever worked in Real Life!!)
I have a tree pruner and the old cord handle mechanism never worked right (always slipping halfway through a thick cut), so I removed the handle and replaced it with a short and thick wooden dowel and then tie the quick Pile Hitch for instant attachment wherever I need it:
It is now a dream to use. Much simpler. It also grips the dowel so it doesn’t get lost.
If you want to introduce another rope, an ascender knot could be used on the pull cord to allow variable positioning of the handle. With all the extra short sections of rope I have laying around, I might just do that with my pruner for extra ease of adjustment.
Thanks to you all for your prompt and to the point replies!
And the winner is:
SS369: slide the handle to where I want it and tie a slip knot below the handle and let the surplus just dangle
Runner up:
Inspired by Roo: slide the handle to where I want it, form a bight from the surplus, and bring it over the handle, around the standing end and around the end of the handle into a simplified pile hitch. Advantage: can be done with one hand.
That being said, here is an updated description, along with 4 pictures:
So here’s the updated description with pictures:
Tie two overhand loops in the cord, in the same orientation*, separated by the distance by which you need to shorten the cord.
Identify the loop & knot (A) that can be tightened by pulling the free end, and bring the other knot & loop (B) through it, acting as a toggle.
Pull the free end of A to tighten loop A, trapping knot B. The knot is now ready for use. Both free ends are equivalent.
To untie, try to pull on each end of the middle section: one of these ends will collapse loop & knot B and pull it out of loop A, which can then be collapsed by pulling its ends.
*Because they are in the same orientation, one free end is “dead” (non-slipping), and the other free end is slipped but will be blocked by a toggle.
I hope this description with pictures is more clear.
I think this knot may be a good choice for my original application if the handle is fixed to the cord and does not slide.
It would compete with the Prusik knot, and I think it may be easier to teach and it is definitely easier to untie.
@Dan_Lehman: Honorable Mention eagerly and humbly granted.
I also liked your suggestion
“You could also just tie off the line by taking two bights of it --leaving the slack needed drooping-- and tying, say, a sheet bend / square knot.”
I tried it out (pictures 1 and 2), but I found the resulting knots rather bulky, and also (unless properly dressed) prone to coming undone when pulling on the ends, as the bights pulled themselves through.
I then realized the two bights could be used asymmetrically, and I wonder if this is what you had in mind? (pictures 3 and 4)
one bight would be used as a single strand, as the bight that starts a a sheet bend or one bight of a square not
the other bight would be as a double strand, to form the sheet bend or square knot.
Now, for situations where the handle cannot slide on the cord and therefore the cord must be shortened, I find three knots appealing:
one noose (overhand loop) fed through another as a toggle – relatively easy to explain to somone who can tie a noose (overhand loop), and easiest to untie
a sheet bend formed by a bight fed through, around, and over the other bight and tucked under itself – easy to explain to someone who can tie a sheet bend, and quickest to tie
a butterfly knot – secure and compact, and if it needs to be taught, an added bonus is that this is a multi-purpose knot with many benefits
It’s nice to have so many options and so many trade-offs
New poster here.
Secure the sheepshank by taking the bightes, above each half hitch loop at either end, and wrap them around both standing ends, turning them to form two half hitches.
In other words, take the two loops, and tie them off around the working ends of the rope or cord.
… and if instead of wrapping it dives through the nipping
turn on itself it will form a sort of bowline, also pretty secure.
(It surprises me that this variation wasn’t found ages ago;
but many of the surplus “sheepshanks” I think are done
purely for show --both of the tying & result!)
That is what i’ve done for long time if used this, more cumbersome to adjust but can be done.
But, want Bowline-esq finishes to be tight, not floppy or are more of just end of run stops(hopefully), not solid hold.
In classic form w/o Bowline endings, the problem i see is the dutifully tied HH locking against self
can roll out to just a Round, 360 of the pressing parts not aligned to lock;
bypass each other and ‘fold’ out, dumping it’s load of the sandwiched host.
We still visualize HH, but not the mechanic employed in this model.
Even in Bowline proper, want the collar stiff enough/short enough/close to leveraging to force HH to keep at 90 degrees.
where nipping loop tension is lower than input to output tension of HH as also seen in pre-fixing HH on lengthwise pull
if HH rolls out/loses 90 shelf like look, then the nipping loop is a Round(360) and as inline now /not 90 to input/output of HH
is tenser, as in forceline now, 90 degree wasn’t
Increased force, near miss, can roll out and dump host as rope runs to freedom!
.
In log dragging, any kind of eye, pre-fixed by HH, will say seems HH pulls about 70% of log weight (or more), subsequent choked/running eye is just cleanup of extra weight and keeps pressure on pre-fixed HH.
.
To me Sheepshank more ornamental and classical than functional; outside these lessons.
To stash up to 2x rope length i might run mainline to bight and come back to main with Cow or 2
even transition from Cow to Cow and to next step ProGrip/Blakes are ALL opposing transitions,
even start to go for Cow look/opposing into ProGrip but ‘change mind’ and do Blakes from there.
for small stuff i usually finish with tuck under 1st turn, over 2nd, tuck under 3rd for neater tail i think.
stiff cord i go with 5 turn ProGrip a/n. HHs of Cows can be omitted, the do give extra grip especially if going to do actual pull and not neatness stash; but mainly for neatness most days with this
OH, fig8, a/n to finish bight.
.
3x length stashing, i make smaller cord Prusic to have adjustable Trucker’s effect
can give series of HHs, i prefer string of opposers, as to me seems straighter Cow bar, gives straighter, cleaner rope fall
again HH pre-fixes can be omitted but do take force transfer off Prusic more in this more Bellringer part of the build when used for pulling or other full form loading.
Dang, I wish you’d turn those BWLs around to show
the front side of the knot --not the same ol’ wrong/back side
which has plagued BWL images forEVER (about all Google
Images delivers, but for Mark’s “Detail View” ones, thankfully).
Your “Sheepshank : BWL end”, please note, is NOT what I described
a couple times above, which is to use the SS’s bight that normally
goes through nipping turn and hangs “floppy”-wise instead to make
a complete BWL in-around-tree-out path,
resulting in 4dia for the nipping turn to crunch (milder turn!).
And to get “non-floppy”, make the path that of the Myrtle BWL
BWL --just a surrounding loop, wrapping towards the SPart.
–and be happy as a spider in a web! ;D
k, few days.
Have tried that Bowline-esque finish on ends too, just not what came to mind and this i did this previously and slid it in here.
Main topic when made was pointing out the ‘flop’ due to lack of stiffness allows lock of hitch to come out to 2 competing, barely misaligned crunchers, now with more force than at 90 degree angle and frictions, to even more so work it’s way out. This style ending pictured was to illustrate that fail..
I am new here and would love to understand more about the bowline showing the back. To me, the knot doesn’t have a front nor a back. It is also without a top and a bottom. It’s merely my perspective that gives the knot these attributes. The concept of a knot being backwards is novel and I could use some education on the history and reasoning behind this topic.
Reason for detail view is in thee PACI Bowline paper.
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By design, the Sheepshank does not keep a firm lock that is usually carefully placed/but then lost;
perhaps better in stiffer, more friction bearing ropes that can help mediate, but not completely overcome this fail;
as seems noted in history, during usages of such materials, as not an optimum /lacking.
.
ABoK reflects on Sheepshank more ornamental than functional for the sailor
many have questioned it’s continual including in collections
some have faulted BSA for teaching still as a hold out
Digging thru the way back machine tracked into lost Henry Bushby presentation for Mariner’s Museum and his works quoting John Smith’s of Jamestown book “A Sea Grammar” in 1627 then another author expounding on this “1644, Henry Manwayring published his Sea-Mans Dictionary, which provided more detailed descriptions of the knots first mentioned by Smith”. This page quotes that they depended on 3 knots at sea mostly: Sheepshank, Wall and Bowline. But then in picturing 3 versions of Sheepshank 2 are locked against above fault:
The illustrator is clear enough on the bottom knot of the
leftmost structure, but the upper knot can be SEEN other
than was (surely) intended --to be an NSUE knotting!
See the top knot as a Slip-knot. (The real structure,
which is given in some other places, has OH knots at each
end, with bights reeved through their spines.)
I recently realized that the two HH’s version of the
sheepshank --which itself is a stability improvement–
can be altered by casting the 2nd HH back around the
first, and then snugging it into position there; where
it wraps around the bulk of the initial HH’d part w/o
the risk of capsizing, and w/some slack-security.
And this tactic I think produces a slightly better
result if the 2nd HH comes in larkshead orientation
(opp-handed).
Now, I learned the hard way that the stands in the span
between knotted ends matter :: that simply illustrating
the upper knot as seen to be NSUE and then rotating
a copy of this illustration to complete the whole …
will result in, yes, end knots that can be untied w/o
ends, BUT … --surprise-- the span’s parts form a knot.
There IS a way to avoid this, but it’s complex in needing
anticipation of the knotting spread out in the span and
… jumping through hoops of clever arrangement not
really worth it.
–esp. with better alternatives, anyway.
(Along the way in my adventure with this mis-seeing
I found that one could knot the EDK/OWK in each
end to make the structure --but that’s also a PITA.)
