Author Topic: Helical slide and grip knots  (Read 9411 times)

geminijim

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Helical slide and grip knots
« on: July 17, 2009, 08:03:14 AM »
I've been thinking about that class of slide and grip knots that contains a series of 4 or more round turns taken away from the direction of pull. They include the penberthy prusik, the gripping sailor's hitch, and Blake's hitch. All have some fiddly (to me at least) way of securing the end. Can anyone tell me the disadvantage of just tying two half hitches around the standing part? I recently used this formation to attach guy lines to aluminum tent poles and it seemed to work fine. No unintended sliding, and no slipping of the end. Seems like a timber hitch around the standing part would also work.

Sweeney

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Re: Helical slide and grip knots
« Reply #1 on: July 17, 2009, 10:22:29 AM »
As one who has just had to fix a drooping shower head (broken friction catch) whilst soaking wet and stark naked I sympathise! I used a three turn rolling hitch and then took the standing end around the stem of the shower head and fixed it back with a round turn about the stem of the head support and 2 half hitches. Not the best way perhaps and certainly not elegant but I finished my shower (as did my wife after me) and until I can get to a plumber's merchant it'll stay there. If that description makes little sense all I am trying to convey is no matter which knots you know in extremis you use what's easiest to remember and quickest to tie.

Barry

roo

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Re: Helical slide and grip knots
« Reply #2 on: July 17, 2009, 02:58:41 PM »
I've been thinking about that class of slide and grip knots that contains a series of 4 or more round turns taken away from the direction of pull. They include the penberthy prusik, the gripping sailor's hitch, and Blake's hitch. All have some fiddly (to me at least) way of securing the end. Can anyone tell me the disadvantage of just tying two half hitches around the standing part? I recently used this formation to attach guy lines to aluminum tent poles and it seemed to work fine. No unintended sliding, and no slipping of the end. Seems like a timber hitch around the standing part would also work.

Eliminate all the extra round turns from the various hitches in question and repeat your experiments. Add round turns until they stop sliding.  Then you will have your answer.  It may take many trials, many different types and sizes of surfaces, and many different types and sizes of rope.   Some hitches are more efficient than others, and will handle smoother or tapered surfaces better with less rope and less surface contact.

Then there's also the simple factor of the fairly low security of two half hitches.  Knot tyers usually like secure knots that can take some buffeting.  If your application doesn't require such security, and your other needs are met, then I don't see a reason not to use a knot that is intuitive for you.
« Last Edit: July 17, 2009, 05:21:58 PM by roo »
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Dan_Lehman

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Re: Helical slide and grip knots
« Reply #3 on: July 17, 2009, 08:03:28 PM »
Can anyone tell me the disadvantage of just tying two half hitches around the standing part?

Which is an old knot, shown e.g. in Ashley's as #1760.
You might change the HHs to an eyeknot, more secure than the Clove or Timber H.s.
I don't find the ProhGrip/Blake's to be all that flimsy, but it depends on situation;
this knot provides that extra 1dia of material in the initial turns to help them make
a grip.  There are all sorts of ways to skin this cat.

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DerekSmith

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Re: Helical slide and grip knots
« Reply #4 on: July 18, 2009, 03:37:55 PM »
Have you tried the KC Hitch, or its simple version the Beefed up KC Hitch ?
http://igkt.net/sm/index.php?topic=551.0

Derek

roo

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Re: Helical slide and grip knots
« Reply #5 on: July 18, 2009, 05:29:11 PM »
Have you tried the KC Hitch, or its simple version the Beefed up KC Hitch ?
http://igkt.net/sm/index.php?topic=551.0

Derek

One obvious drawback to this is that it's not suited to tying with the end of a long rope.  It assumes a separate short-to-medium length piece of rope is laying around.
« Last Edit: July 18, 2009, 05:31:59 PM by roo »
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Dan_Lehman

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Re: Helical slide and grip knots
« Reply #6 on: July 18, 2009, 09:22:37 PM »
Have you tried the KC Hitch, or its simple version the Beefed up KC Hitch ?
Though the OP's interest is in simply a more secure closure,
not greater grip or tying tedium.

Putting a stopper in the end might help lessen risks of loosening
for some situations, adequately.  --esp. if say you were using laid
rope and first tucked the end through the lay, such as commercial
fishers do for many knots.
 :)


DerekSmith

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Re: Helical slide and grip knots
« Reply #7 on: July 19, 2009, 07:00:21 AM »

One obvious drawback to this is that it's not suited to tying with the end of a long rope.  It assumes a separate short-to-medium length piece of rope is laying around.

What has the length of the rope got to do with tying the KC hitch?

http://igkt.pbworks.com/KC-Hitch



Just wind the end round the spar,



Wind the end back down to the SPart



Close up and tie of to SPart, then load




Dan

So tedious... making all those wraps...  We just get the security and grip for free...

Derek

roo

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Re: Helical slide and grip knots
« Reply #8 on: July 19, 2009, 07:18:29 AM »

One obvious drawback to this is that it's not suited to tying with the end of a long rope.  It assumes a separate short-to-medium length piece of rope is laying around.

What has the length of the rope got to do with tying the KC hitch?

Having access to both ends of the rope or not.  Perhaps you've subconsciously recognized that by posting different version now.
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DerekSmith

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Re: Helical slide and grip knots
« Reply #9 on: July 19, 2009, 12:22:07 PM »
I guess that is what it was Roo...

Nice thing about the KC (apart from its simplicity and grip) is that you can even make it mid line by taking a bight and making it with the loop.

I posted the enhanced KC picture because the first post referred to making a hitch to ally tent poles and making the KC with a small loop like that is a sure and simple way of fixing / hanging to slick tent poles, and not forgetting one of your favourite tests - utterly jam proof.

Derek

Dan_Lehman

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Re: Helical slide and grip knots
« Reply #10 on: July 19, 2009, 06:33:37 PM »
Dan    So tedious... making all those wraps...
Okay, I've been feeling this reply coming on, pointing to some hint
of gross laziness!   touche'   :-[
But that full back-/over-wrapping consumes a lot of material.

What GeminiJim was asking about is the KC sans the overwraps,
the end reaching directly to the tie-off THHitches (or Cow Hitch,
as KC is shown.  Not sure how well these will grip vs. Blake's,
where the inserted diameter of the end tuck enlarges the initial
turns of the loaded end of the gripping coil.  --something to test.

--dl*
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