I (Think/Hope) I Developed A New Hitch Design

[Knotorious]

Yesterday, I felt compelled to try and figure out a way to gain greater mechanical advantage than a 3:1 pulley system while still only using three pulleys in order to test hitches with much greater forces. I have more pulleys, but they're currently across the country in MA, so this mini project was especially important.

After a good amount of playing around, and after recalling more "advanced" knowledge about mechanical advantage which had been collecting dust somewhere in my brain, I arrived at this bad boy arrangement of pulleys and prusiks. As far as calculating mechanical advantage is concerned, I have never been the best at it, but the attached photo shows what I believe is a 9:1 system with progress capture.

If I'm correct, that means I managed to 3x how much force I can exert onto test hitches, all while still using only the same three pulleys. I think that is pretty mind blowing to be honest. I haven't used it yet, but I'm sure it will work great.

In an effort to maximize my testing opportunities for hitches, I am using the Bioassay hitch at two critical points on this system and, of course, it will be connected directly to a third test hitch that is in either an SRS or MRS setup.

 

[Burnham]

Hmmm...I'm not as sharp at this stuff as I used to be, but I think I'm seeing 5:1.

And don't forget, even if I'm mistaken on that, for sure that ring will draw off some MA, lost to friction that the pulleys better mitigate against.

Nonetheless, a nice setup that will work well.

 

[Knotorious]

Firstly, you're absolutely correct about the ring, but it will hopefully still be much more efficient than my 3:1.

I managed to find a diagram of what I have set up. It's fascinating how altering the placement of that one pulley (in my case that pulley is the ring) makes such a huge difference insofar as efficiency. I don't fully understand how that can be.

Can anyone out there verify that the attached image is correct and/or explain why? Yesterday, when I made the system, I seemed to think it was a 9:1, but I don't remember why that was. Anyways, this image seems to corroborate my calculations, but I'm also not going to blindly assume that some random JPEG on the interwebs is conclusive evidence.

 

[Knotorious]

Wait, I figured it out. Each leg is valued at 1 and every "bridge" made by connecting a pulley to a previous leg via a hitch cord is valued at 2, so 2+2+1+1+1+1+1 = 9.

 

[Bermy]

You’re are correct, I didn’t catch the mistake, even when redrawing and naming!

I see things
Fun thread

 

[Bart]

Is your testing intention to see how much max load before the locked hitch slips? You need a load cell, friction compounds mercilessly and ruins many stage MA systems. Seems to me locking up is easy for most hitches. The hard part is nice modulation and initially getting it unlocked under load. Bit more instrumentation for measuring that. You could break into new territory if you pursued that. Numbers to back up climber's opinions. Best of luck in your endeavours.

edit - in that 9:1 drawing, it's a 3:1 pulling the rope entering a 2nd identical 3:1. draw a line across the ropes just after the green prussic and you see that the 1 is the rope tension coming out of the green prussic and the 3 is that there are three bits of that same rope pulling upward on the weight. Same analysis for the 1st 3:1 pulling on the green prussic. Clear as mud? 3x3 = 9 Best I can come up with on the quick.

 

[Brocky]

Hey, those drawings are fabulous. You have to be very right brained to have the spacial recognition to needed to draw a complex object on a 'two dimensional' sheet of paper.

As far as your rendering of the Trinity hitches, I recognize the top right as the Trinity 2 and bottom right as a Trinity Hitch! The top left looks like it also. It all matches up! Well done!

Who created the Bermie? Yourself? It looks really solid.

Attached are photos of both of my hitches shown from quadrants so that every detail is visible.

I've decided that I'd better rename my second hitch. Going forward, the Trinity 2 is now called "Bioassay." Yes, it's my username and, no, I'm definitely not a narcissist. The word has strong meaning to me and it flows nicely on the tongue and stands out.

Thanks for everyone's help, enthusiasm and support! I'm legitimately excited to be able to make a contribution to arboriculture. I'm very grateful that ropes and knots are a part of my life.

The not named hitch is more like the Bermie, the Trinity is a little more complex, I came up with both.

 

[Burnham]

Ah, yes...3:1 pulling on a 3:1. I see that now. Thanks Bioassay and Brocky.

 

[Knotorious]

Is your testing intention to see how much max load before the locked hitch slips? You need a load cell, friction compounds mercilessly and ruins many stage MA systems. Seems to me locking up is easy for most hitches. The hard part is nice modulation and initially getting it unlocked under load. Bit more instrumentation for measuring that. You could break into new territory if you pursued that. Numbers to back up climber's opinions. Best of luck in your endeavours.

edit - in that 9:1 drawing, it's a 3:1 pulling the rope entering a 2nd identical 3:1. draw a line across the ropes just after the green prussic and you see that the 1 is the rope tension coming out of the green prussic and the 3 is that there are three bits of that same rope pulling upward on the weight. Same analysis for the 1st 3:1 pulling on the green prussic. Clear as mud? 3x3 = 9 Best I can come up with on the quick.

I wish I could pursue something as friendly to the scientific method as that, but I am a humble climber with an equally as humble bank account. I'm mostly just trying to see if I can identify patterns of behavior with hitches using relatively tame human-induced forces (i.e - normal working conditions) the same way a prison psychiatrist might attempt to predict recidivism in an inmate. This is purely for pleasure and to alleviate compounding boredom post-operation. Great suggestions, though!

 

[Knotorious]

The not named hitch is more like the Bermie, the Trinity is a little more complex, I came up with both.

That's wonderful that you have come up with your own hitches! How many have you documented via handmade illustrations? I've found it to be very rewarding, even if it never sees mainstream adoption. Although, I'd like to hope that someday mine might. If I can come up with two solid candidates in a week, then possibilities are truly endless.

Does anyone have statistical data on how many combinations, working or otherwise, a hitch can be formed into relative to, let's say, a 30" cord (although, 28" seems most popular for some reason. I always go 30-32")?

I know that, with rope, even with one strand there exist multiple thousands of possible outcomes (per Ashley Book of Knots). However, the parameters for this measurement is not revealed and I'm not certain if available rope length is a factor.

 

[Marc-Antoine]

Rope length is definitively a factor, both to tie the hitch and often for its working ability in this sort of use. On some hitches, the length of the legs doesn't matter much. But other ones change their behavior when you modify this factor, like shorter legs grip harder, or long legs can make the hitch bardly catches the rope, if not at all. That's the problem with the hitch cords from the factory, you don't have a continuous choice of length and you can have a hard time to find the sweet setting. It's easier to make your trials with a long hitch cord knotted to size which you can adjust at will, instead of the factory ones with spliced/sewed eyes.

 

[Brocky]

I have come up with around 3-4 dozen originals, some good, some not. The drawings are an attempt to show how to tie hitches with a single picture. These two are the best in my opinion, both can be used for stand alone SRT, no binding up or need for adjusting. Synergy X, not my invention, only one overhand for a stopper, needs a longer cord. The Sticht is on the right.

 

[lxskllr]

The SynergyX is attractive, but it looks like a hassle to tie.

 

[Brocky]

After the wraps it just repeats, keep it snug while tying so that it doesn’t spread out too much, it self tends easily, so does the Sticht.
Spreading it out shows the simple pattern.

 

[Bermy]

The sticht looks like about the most simple 'hybrid' srt setup you could get. The rings providing some friction as well as the hitch.
I assume both eyes come through the blue ring at the end?

 

[Brocky]

The blue ring in front allows the twist in back to form a slight bend in the rope, it’s the four sections of hitch cord pinching the rope, with the bend, that causes enough friction to make it release easily.
The bronze bushing, or a piece of pipe eliminates the unneeded friction from the twist, and can make tending as easy as a pulley.

 

[Knotorious]

Brocky, both of those hitches are truly unique. I especially like how you chose to incorporate multiple pieces of hardware into the hitch design. Until you first shared some hitches with cord interlaced through anchor rings, it hadn't occurred to me to do any experimentation with hardware. This morning I was inspired to try and create a functional hitch using a ring.

The first ring hitch I made looked awesome, but it grips a little more than I would like where the hitch cord legs crossover in the center of the ring. The result was predominantly moderate difficulty tending the hitch. However, this could potentially make the hitch perform well, with greater control/smoothness during descent.

The second ring hitch I came up with was much looser and starts with three wraps like the first, but the legs then twist like they do with an XT, keeping the wraps from losing their form, potentially making it more reliable. This variant tends beautifully and effortlessly, especially where the ring is situated.

Attached are labeled pictures of both hitches.

 

[Knotorious]

I was just playing around with my split tail and came up with an easy to tie, responsive, easy to tend hitch that doesn't appear to bind very easily. It relies on the working end, after making the last wrap at the top, going back down to the first loop, going through it and then being finished with a bulky stopper knot (I chose a Stevedor's knot) which prevents the hitch from unraveling.

When under load, that very first wrap behaves like a marl while the rest of the wraps above it stay neatly together. Because of the stopper knot being locked in by the same loop that the standing end goes through, tension is evenly distributed through the hitch from both the bottom and the top. Most split tail hitches only pull the hitch tight from the bottom.

Photos attached.

 

[Knotorious]

I'm on a roll here! Introducing the "Binary" hitch, so named for its two separate sets of wraps, each isolated using an assymetrical round turn around the bottom wraps. These round turns should ensure that the wraps don't lose however much tension you dial in during the setting and dressing process and provide a more consistently reliable grip. It is designed to be used with a split tail/rope that is the same diameter of the access or rigging line. As long as the user finishes the hitch with a solid stopper knot, they shouldn't have to worry about this hitch warping or failing.

Bear in mind that I've only done a small amount of testing with this hitch. However, I'm optimistic that it will perform well in real world settings.

 

[lxskllr]

Hmm... I've never used a single leg hitch. Trying to think of a situation where it's explicitly better than a double.

 

[Knotorious]

Brocky, I created a response to your really ornate hitch that you showed next to the one with the hardware. The only difference is I only used one strand. I'm trying to think of how to finish the end so the last wraps don't disrupt the pattern too much before exiting out with a stopper knot. This hitch does indeed work as long as you make sure it's tightly dressed and set.

I haven't yet come up with a name for this one. Quite honestly, that's the hardest part of all of this hitch experimentation. I might call it "Macrame" for reasons which are hopefully obvious. Solid name, methinks.

 

[greengreer]

Hmm... I've never used a single leg hitch. Trying to think of a situation where it's explicitly better than a double.

Hip thrusting you can get some length between you and the hitch, with a pulley on the terminal end of the rope you can just pull your weight thru the hitch. Wait, who does hip thrusting anymore...

 

[lxskllr]

When I was hipthrusting, I used a long prusik loop. Pretty much everything was manual. Haul myself up, slide the prusik up, reset. God that sucked :^D

 

[Knotorious]

Hip thrusting? Ew, gross. Why would anyone want to do a silly thing like that? I'm pretty sure archeologists recently found well preserved, fossilized human remains in British Columbia, dating back to the Jurassic period, of an early form of man hip thrusting using vines to form hitches of comparable efficacy to today's. The act is that archaic.

I'm obviously (or perhaps not that obviously) joking! Ha! In all seriousness, I'm pretty sure a lot of people still do hip thrust, but it's undoubtedly going out of style. I believe (or hope) that hip thrusting remains a quintessential starting point for new climbers, if not only so they will possess that skill in case of an emergency.

Anyways, I now introduce to you the Macrame hitch v2.0. Greatly improved from its predecessor. The way that all the strands interlock at every twist and turn keeps the hitch's tightness from deviating away from its ideal setting. I wondering if it would work for SRT, without a wrench, without jamming. That has yet to be determined. Lastly, this hitch could be very slightly modified to be made using an eye to eye instead of a split tail.

 

[Brocky]

This is my version of the Chinook Hitch, which uses two rings instead of wraps as main grabbing force. Keeping the rings together is important, and a couple of crossed turns/ braids, is all that’s needed, I added the Sticht finish for Single Rope use.


Your Macrame is another type of Series hitch, there are multiple variations, interesting to explore. Another option for a single eye hitch cord, or the end of rope is the Knut H hitch, it self tends.