Author Topic: Adjustable Gripping Hitch  (Read 1925 times)

asemery

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Adjustable Gripping Hitch
« on: December 16, 2020, 06:44:42 PM »
Adjustable Gripping Hitch
This knot slides along the standing end.
When tension is applied it locks into place.

 
Gripping Hitch Tutorial

tsik_lestat

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Re: Adjustable Gripping Hitch
« Reply #1 on: December 16, 2020, 08:28:22 PM »
Hello asemery

Just a query... is there a need for a third turn, and if so, is there a particular reason for which the working end does not pass through it?

I understand the need of varying from the standard poacher's noose or scaffold knot, yet the tibness is being lost.
Going knots

asemery

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Re: Adjustable Gripping Hitch
« Reply #2 on: December 16, 2020, 09:03:05 PM »
Hello asemery

Just a query... is there a need for a third turn, and if so, is there a particular reason for which the working end does not pass through it?

I understand the need of varying from the standard poacher's noose or scaffold knot, yet the tibness is being lost.
I present the knot as it was taught to me.
I just tried only two turns and the knot does not grip.   Tony

tsik_lestat

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Re: Adjustable Gripping Hitch
« Reply #3 on: December 16, 2020, 09:14:41 PM »
Understood! Thanks for sharing ! I think the two turn configuration, does grip if WE passes through both turns!

In other words , the poacher's  is secure! :)
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thorr

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Re: Adjustable Gripping Hitch
« Reply #4 on: December 16, 2020, 09:38:41 PM »
It's a variant of the Blake's/Prohaska hitch, isn't it?

Described by roo here: https://notableknotindex.webs.com/blakeshitch.html

tsik_lestat

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Re: Adjustable Gripping Hitch
« Reply #5 on: December 16, 2020, 09:47:05 PM »
You are quite right! Blake's hitch is mainly used as a slide and grip hitch, but it appears that it can be functional, tied on the standing part of the rope, as an adjustable gripping hitch /noose too, as it was presented by Asemery (Tony).
« Last Edit: December 16, 2020, 09:53:43 PM by tsik_lestat »
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Dan_Lehman

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Re: Adjustable Gripping Hitch
« Reply #6 on: December 17, 2020, 03:31:30 AM »
It should be noted that the Prohgrip --as I like
to call it (and I think Heinz likes the "Pro" if not "Proh"
part, too  ;) )
was presented by Heinz with advice on adjusting it
to accommodate one's particular cordage --saying:

a) If the knot slips from rope being stiff,
add a turn that surrounds the tail;

b) If it slips from rope being slick,
add a turn that doesn't surround the tail.

I've had instances where the knot didn't at first
grip but did so once I *loosened* its start, so
that the around-the-tail turns were a bit more
extended, and the SPart put less pull on the
crossing/tucked part to pull the knot down
without so much drawing into those initial turns.

German arborist Dirk LINGENS has presented
the knot with extra turns as an eye knot --indeed,
it is the cover-knot for his book (see
https://www.arlingtonpower.com/tree-climbers-knotbook-by-dirk-lingens).
In testing by Lyon Equip. for the HSE Report on
ropes used for safety critical work
they found this to be the surest of the gripping
hitches they tested (IIRC, Prusik, klemheist,
French Prusik, & Bachmann hitch) --to wit:

Quote
The Blake knot is the preferred knot amongst arboriculturists.
In contrast with the other knots it is tied with a rope end rather than a loop.
It was the only knot tested to hold the 4 kN force for all test combinations.
With the thicker 10 mm Prusik Regate rope it released easily. When tied in
the thinner 6 mm accessory cord it was a little more difficult to release.
cf. https://www.hse.gov.uk/research/crr_pdf/2001/crr01364.pdf

One might try the anchor bend with the tail taken out as for
Prohgrip, which can hold in some cases.


--dl*
====

KC

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Re: Adjustable Gripping Hitch
« Reply #7 on: December 17, 2020, 11:44:31 AM »
You are quite right! Blake's hitch is mainly used as a slide and grip hitch, but it appears that it can be functional, tied on the standing part of the rope, as an adjustable gripping hitch /noose too, as it was presented by Asemery (Tony).

That would be the same only closed/just to self?
Arbo's typically connect 1 end of rope to saddle 'static' connection in this.
Then from that Bitter End left (or added tail fastened to saddle) for tying Blake's/Prohgrip (or even Tautline) back to the mainline after it is bent over a branch 180 back to you.
So person rides on side of this like huge adjustable hitch tied back to it's own SPArt type expanding/shrinking loop, with single end of slack below friction hitch.  Line should have a stopper knot that would prevent from hitting ground if bailed quick chased by hornets etc.  Should be able to pick up end of  rope from ground and touch chest and still loop on ground or could run out of rope.  For is feeding from pool of 1 leg to serve 2, both sides of loop.
.
So needs 2x as much rope as a single drop SRT, but then is retrievable.
Climbing up grab the 'dynamic'/moving side line and pull for 2/1 less friction lift self like dumbwaiter .
>>Then also gives 2/1 lowering self thru hitch friction >> but that line then moving 2x as fast thru hitch than you are moving still.
.
Because system has 2 legs/loop to saddle(termination and hitch), can pull down on LOADED  hitch and it slides (if set right); The your own self as load shifts over to the static leg, just like if 2 legs and one stretching or failing; buddy leg takes the load as most firm/rigid resistance.  The relief to the hitch allows it to slide smoothly even loaded, descending, can burn finger(s) if grab top of hitch and contact the Standing Part rushing thru the unloaded hitch.  Slide effect not so much on single/SRT line.  Has no other leg to unload to and hitch wants to clamp tighter mostly instead.
.
Because, Blake's/Tautline hitch has 1 support leg to saddle to attach to 1 leg of support line can use same size rope , but not denser than host hitch rides on.  Lots of other friction hitches connect to saddle with 2 legs and still grip host 1x.  These need smaller cord, perhaps stiffer too as are gripping greater tension (host) with lesser (2 legged friction hitch) so need to make up for less rigid hitch to impose hard enough on host that is more densely rigid by virtue of loaded 2x as much as hitch.  1 leg hitch full load, 2 leg hitch 1/2 load, both grabbing /transferring full load to host to tension it greater than 2 leg hitch.  2 leg hitches can descend on the static/dynamic legged arbo loop system described, but not SRT.

.
edit: WARNING if tie Blake's WRONG where the Nipped Bitter End is  on same side as lower pull; we call that a SuiSlide....
>>MUST be under coil to opposing side of lower input pull, where that pull seats HARDEST against the host line ridden as rail
>>just like Half Hitch w/top best Nip rather than normal (worst Nip) Half Hitch.
Every once in awhile is errantly posted as Blake's on forum etc. including front page of popular arborist tools catalog ~ 2006

At the time popularized thru arbo's
There were several stories of Mr. Jason Blake trying to like patent the knot!
Few stories on Intnl.Society of Arborist's ISA bbs(bulletin board svc.; early dial-up era name for forums) that closed about 1998 of trying to license usage!   Or tell someone they could not use 'his' knot.
>>not sure if true or not, but not single incidence...
.
Life Lessons L-earned on the Nylon Highway are excellent (were knot first shown)
« Last Edit: December 19, 2020, 10:45:28 AM by KC »
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