Author Topic: rope clamp, friction hitch from bight, named pallastek  (Read 950 times)

agent_smith

  • Sr. Member
  • *****
  • Posts: 1202
Re: rope clamp, friction hitch from bight, named pallastek
« Reply #15 on: July 07, 2020, 12:24:42 AM »
Hello KC,

Thank you for your reply.

However, the majority of your post has nothing to do with the OP's proposition and line of thought.
While it is of interest to note how Arborist's climb and use their 'saddle' (which is a fancy word for 'harness') - it is morphing into something of a different character.

A few points I would like to reiterate and amplify:

1. The Swabisch, Prusik, Blakes, Purcell, Klemheist, French Prusik (Machard), etc etc,... are all classified as 'Slide and Grip Hitches'.
All of them require a 'host', without which, the slide and grip hitch would lose structural integrity and collapse.

2. The 'Swabisch' hitch cannot be formed on a 'host' if tied using a round sling (without access to either end of the 'host').

3. The 'Prusik' hitch (#1763) can be formed on a 'host' using a round sling - at any point on the host (without access to either end).

4. The 'Prusik' hitch is symmetric... while the 'Swabisch' hitch is asymmetric.

5. I made the point that Arborists tend to use slide and grip hitches that are tied from an open ended (linear) length of cord.
Note the word 'tend' - which means having a tendency. This does not mean that Arborists never tie a slide and grip hitch from a round sling. It means they simply have a tendency to do so. In contrast, mountaineers/climbers have a tendency to tie slide and grip hitches from a round sling (eg #1763 Prusik hitch).

6. There is a mind boggling variety of slide and grip hitches - all having different geometries - with different gripping+releasing characteristics.
All were invented to satisfy a need - and to boost performance in a given application.

7. Slide and grip hitches can be categorized into the following general types:
[ ] Dual-leg loaded: formed from a round sling (this is the type that is most often employed by mountaineers/climbers)
[ ] Dual leg loaded: formed from an open ended linear length of cord
[ ] Single-leg loaded: formed from an open ended linear length of cord

In addition, geometries can include a 'noose hitch' - eg the 'Purcell' (which has an adjustable eye)
In contrast, the 'Swabisch' hitch is not a noose and it does not have an adjustable eye.

The host of a 'Purcell' is its own SPart (standing part).

8. bepal made his original post in the 'New knot investigations' section.
A reasonable person would therefore conclude that he is making a claim of originality.
Otherwise, why post in 'new knot investigations'?
I pointed out that his original presentation is simply the first stage of tying a 'Purcell' - one more turn/coil creates the Purcell.
I know that many operators have experimented with this 3 coil partial Purcell and found the 5 turn/coil version to be more reliable (in employment as an adjustable eye / noose).

...

per KC:
Quote
Arbos don't always climb on an SRT(Single Rope Technique) system.
Can tie static/termination to saddle, rope feeds up over redirect back(limb or pulley) and returns to saddle
But not to termination, but to a friction hitch 'dynamic' connection .
>>Called Doubled Rope Technique (DdRT) and is a deceptively generous change in mechanix
Single length fall below climber but dual leg support above climber in same continuous rope
>>this affords 2/1 - friction over own self in lift (like 'dumb waiter')
>>as the friction hitch itself is only half loaded
This also means climber better be able to pick up free end of line and touch chest
>>or can run off of end of life line column, as needs 2 lengths of line to descend into, that become supports!
This also affords being able to DESCEND on a friction hitch w/o change over
>>as if the dynamic leg was failing when Prusik pulled down on, and the static leg is stiffer/takes load
>>allowing friction hitch to slide
Placed on SRT w/o other helper static support leg, same setup locks tight to host lifeline mount/can't descend.
.
Arbos may use open end Taut Line or Blake's/Prolaska friction hitch of same diameter as host line
>>as perhaps is leg of host line of long Bitter End from saddle static termination left for such purpose /make friction hitch back to main section
But as go to dual leg support friction hitch (Prusik etc.) go for for smaller diameter friction hitch than host line grabbed
>>i think this works because dual leg friction hitch is only half loaded per host lifeline grabbed
>>so hitch is trying to grab more rigid lifeline
>>dropping diameter of friction hitch; can make it more rigid as same force packed in smaller diameter
>>is now set to compete/impress host line grabbed better by this mechanic
.
Using the all-in-one/starter kit of tying termination to saddle and leaving ~1.5'  BE/tail
Then serving the long end of termination over re-direct back to connect friction hitch to
>>doesn't afford disconnect to avert the many obstacles/branches w/o retie
separate friction hitch/not all-in-one affords working each end of support to saddle (static and live) separately
>> not in closed loop that makes obstacle impassable w/o reTie.

While interesting, all of the above belongs in a new topic thread - titled; "Arborist climbing techniques"
« Last Edit: July 07, 2020, 12:32:45 AM by agent_smith »

KC

  • Sr. Member
  • *****
  • Posts: 290
    • latest project
Re: rope clamp, friction hitch from bight, named pallastek
« Reply #16 on: July 07, 2020, 10:01:46 AM »
Very sorry,my bad as have never been on another forum where that was such a rule, focus; let alone critique.
.
But i do try to show the pivotal principles, when they are amplified most cleanly to catch best view of as a harvest of occurance;
to then be familiar enough to then sift out of many things lurks in.  This is just one of those views.
.
This  folded configuration as a recursive mechanic from 1x to 2x can give some counter-intuitive differences that should be observed in talking of them, but also; those same mechanix appear in other places too.  Sometimes hidden in tight microcosm of a knot, but same principle to already know/trust inside. 
.
i think most readers hear when see Arborist friction hitch are not aware of the unique mechanix if friction hitch is not sole support, and it is a game changer in some ways to it's success and even subject matter . 
.
The prospect of rope tension as key factor not only by force but also hardness/rigidity imbued, prevails thru all knots, to me this  1(single) or 2(open or closed loop) legged friction hitch is KEY time to show this, and it's (cord diameter)mods to correct; to perhaps then see rigidity factor in ALL knots/nips.
« Last Edit: July 07, 2020, 12:31:24 PM by KC »
Rope-n-Saw Life
"Nature, to be commanded, must be obeyed" -Sir Francis Bacon
We now return you to the safety of normal thinking peoples.
~ Please excuse the interruption; thanx -the mgmt.~

agent_smith

  • Sr. Member
  • *****
  • Posts: 1202
Re: rope clamp, friction hitch from bight, named pallastek
« Reply #17 on: July 08, 2020, 02:48:10 AM »
per KC:
Quote
Very sorry,my bad as have never been on another forum where that was such a rule, focus; let alone critique.
?
I am not a moderator and I do not make the rules.
All I can give you is my personal perspective.
Your posts are interesting but, you have a tendency to drift into subject material that is completely off-topic.
In most forums, it is an implied (or assumed) rule that posters try to directly answer the OP's question or add discussion that contributes and clarifies salient points.


bepal posted an image of an asymmetric slide and grip hitch - in this section (which is new knot investigations).
This strongly suggests that he is making a claim of originality (otherwise, why post in this particular section?).
bepal could have made a mistake - in that he accidentally posted in this section?
Maybe he meant to post in 'Knotting Concepts and Explorations"?

bepal then posted further information in relation to the 'swabisch' slide and grip hitch and drew comparisons between it and other structures such as the Purcell and #1763 Prusik hitch.
He appears to be using some type of translator program - which (at times) makes the English translation a little 'clunky'.

Dan Lehman than pointed out the inconsistencies with 'On Rope' publication - with 1st Ed showing one geometry and 2nd Ed showing something else.
This was in relation to the ability of the hitch to firmly grip its 'host' (when loaded in a particular relative direction).

bepal (I think) was trying to advance that his presentation grips effectively when loaded in one direction, but releases and slides relatively easy when pushed in the opposite direction (with the proposition that this is a factor related to its geometry).

After all that discussion, KC then posted information about Arborists 'saddles' (a harness), SRT and DdRT, all in one starter kits, re-directs, obstacles and branches in a tree, support to saddles (static and live)... all of which (in my view) is drifting into Arborist climbing techniques and PPE.

Anyhow, thanks for your insight KC :)