Karabiner research report

L

Lazarus2

Location
UK
The conclusions to this report suggest that karabiners need to be secured to prevent them turning. Rotating karabiners leads to gate mechanisms opening from prusik loops and bowlines running against them, and are easily cross loaded. The best way I have found of securing the end of a line or friction hitch tail, is to tie the half double fishermans (incorrectly called the single fishermans in the UK Guide to good climbing practice - a single fishermans is two opposed overhand knots tied to pull two ends of line together). This can be done very quickly (steps displayed on www.treemettlenexus.com). Try wrapping the line over three fingers rather than the entire palm for a shorter tail.

Report link:
http://www.hse.gov.uk/research/hsl_pdf/2003/hsl03-18.pdf

If you're still using a bowline in the end of your line for climbing, do industry a favour by reducing accident stats and replacing it with the half double fishermans. If you're still using the classic 3 knot closed system, replace the bowline with a clove hitch. Both knots are quick to tie and untie, and much more secure. Splices can be a problem - long ones can be girth hitched to grip the karabiner. Short ones may be effective with certain designs like Geckos, but don't always prevent the krab from rotating as effectively as the half double fishermans.
 
One of the proposed changes to the Z133 is to require the use of cinching terminations on ropes. A tight eye splice, girth hitched eye splice or several examples of cinch type hitches will be suggested.

This change makes so much sense. From a user stand point it's much easier to manipulate the biner or rope snap with the rope snubbed off. Other wise they flop around like fish. The study adds a lot of credence to the suggested changes too.
 
I was hoping you'd add that Tom, I didn't have the time. What is interesting, is despite this research, accidents stats and the new Ansi z133 recommendations, the bowline is still being taught by many as THE endline termination in the UK.....?!

The Bowline is the king of rigging in its many guises - but there are better alternatives for endline climbing terminations.
 
Since Tom has brought up this point for us; my awareness of this has increased beyond the few mentions in mountain/rescue etc. Thanx (A-Gain!)

i haven't liked too much using double noose etc. when repositioning TIP; so tried the girth of bowline. Need an extra long eye, beyond just the needed length, so that line doesn't sit in torque/twisted tightly fashion. i have found a simple roundturn, instead of turn to be about the same; at least in my use. But, both these options do place more loading towards the gate side/ away from the 'spine' of carabiner (where load should be carried); especially in DdRT with split tail on same carabiner. So have re-lented that the other single turn on carabiner instead of girth or roundturn (to make up for non-cinching hitch); are more proper; as Tom originally suggested.

This is also outlined in Samson Rope's Arborist Catalog on page 12.
 
Oh man, another long one..................

Lazarus2 wrote:

[ QUOTE ]
the half double fishermans (incorrectly called the single fishermans in the UK Guide to good climbing practice - a single fishermans is two opposed overhand knots tied to pull two ends of line together).

[/ QUOTE ]


Ashley and Budworth both call this a scaffold knot. If you want to use the words 'double fisherman's' I think double fisherman's noose is a better name than 'half double fisherman's' which is a different (though similar) knot (RescueMan first pointed this out).

A true 'half double fisherman's' is a double overhand knot and is a stopper knot. The knot you show, a double overhand tied around it's own standing part, is a sliding loop (a noose) and is called a scaffold knot. It cannot be used as a stopper knot.

The terminology below comes from Ashley, The Ashley Book of Knots; Budworth, Knots and Ropework; and Smith and Padgett, On Rope.

It's probably easiest to start with the 'single' version.

Tie an overhand knot in the end of a line and it is a single overhand knot. Tie that same overhand knot around the rope's own standing part and that knot is called a simple noose. Tie that same single overhand around the end of another line; and then use the end of the second line to tie another overhand around the end of the first line, and the resulting knot is the English knot, aka a (single) fisherman's knot, as you point out. This knot is also called Englishman's, Waterman's, and Angler's knot. It is essentially a bend because it joins two rope ends joined together.

Now to the 'double'. If just one (1) two-turn overhand is tied in the end of a line then it is simply a double overhand, aka a blood knot (when used on a cat-o-none tails), a barrel knot, or half double Fisherman's. It is sometimes used as a stopper knot in a rope's end. If one (1) double overhand is tied around the rope's own standing part (as shown in your website) then it is called a scaffold knot and is a sliding loop or noose. This won't work as a stopper knot because it will come undone if there is not something in the noose.

Tie that same double overhand around the end of another line; and then use the end of the second line to tie another double overhand around the end of the first line, and the resulting knot is a double Fisherman's knot, aka Grapevine knot or double English knot. 'Double' refers to the fact that there are double overhand knots. When used to join two rope ends together it is essentially a bend, but in Ashley and in Budworth the name 'double fisherman's bend' is used for another knot. Smith and Padgett, however, do use the name double Fisherman's bend for this knot.


The name of the knot of which you are using 'half' is the 'double fisherman's' which is composed of two double overhand knots. If you use half of this, i.e. half a double fisherman's, then the knot is just one double overhand and it is a stopper knot, not a noose knot.

If you tie just one (1) double overhand around the rope's own standing part then it is a scaffold knot. This is a noose knot and will come undone if used as a stopper knot in the end of a line.


Tree Syder wrote

[ QUOTE ]
...so tried the girth of bowline...

[/ QUOTE ]

Not sure what you mean here Ken.
 
Just like girthing a long splice's eye around krab; only make a long eye bowline(thinking of bowline as a temporary/ non-shrinking eye). Make too short of an eye (splice or bowline), and the line can't relax from twists(?)/ sits 'tourqued' arond krab. Even simplifying to just a roundturn, kinda need a bigger eye, to allow line to 'relax' through curves around krab i think.

i try to extinguish between a double noose as anchor to self to form eye. Such as Buntline is clove to self to form eye; similarily cow to self to form Lobster (not recomended for our life support uses i don't think, but hides/keeps bitters termination smoother). But, i think of a Dbl. Fisherman's as similar to Dbl. Noose, only the turn of the anchor is a crossed turn/ crossed roundturn (as if to start to make clove/buntline only finishing as anchor, not clove)for Dbl. FisherPerson's; instead of a simple/uncrossed roundturn of what i try to seperate from the mess as a Dbl. Noose.


Buntline/Lobster or 2 half hitches?:
If the bitters is on the 'free'/open side, not more securely trapped agianst krab in the Buntline and Lobster (Buoy) type lacings; then they are more properly termed turn and 2 half hitches(Improperly maid Buntline) half hitches opposing(Improperly maid Lobster). In these 2, as in all lacings, the placemeant of the bitters/working end is imperative to security. In these 2 examples, so much so that the names are even different!

Some picky names, but i think that every change is a change in the mechanical properties. Worthy of separation for that point alone, and also to understand and segment other factions of knot lacings.

Thoughts? (Couldn't be worser than mine!)
-KC
 
Thats an interesting point between the buntline and round turn and half hitches Treespyder; the buntline is a great knot for tying a rigging line to a krab or other fitting. However, I have experienced buntlines tied with a short tail in climbing lines and lanyards, that work themselves loose. Especially stiff kernmantle lines used as a sliding bridge in some harnesses, or lanyards. This is because it is easy to 'break' the knot - great for heavy loadings in rigging - bit of worry in climbing. A sufficient tail can be left in rigging line, but tends to get in the way because it exits at 90 degrees on a climbing line. A half double fishermans can be tied with safe 2 inch/5 cm tail, although mine are 7 to 10cm to allow for settling slippage. They also exit at a more convenient angle.

Tie offs that extend along the top bar of the karabiner can weaken the MBS/Tensile strength by 50% on a Klettersteig or Offset D krab. Best to use an HMS or HMS hybrid designed for this loading.
 
[ QUOTE ]
...the half double fishermans ...This can be done very quickly (steps displayed on www.treemettlenexus.com).

[/ QUOTE ]

I did some more reading and as a result did some editing to my earlier post.

The knot-tying demo shown on the website is very well done--clear and easy to follow. But that knot is not a half double fisherman's. A half double fisherman's really just a double overhand knot. It is a stopper knot and is used to prevent the end of a line from accidentally running through something.

The knot shown on the website is a sliding loop (a noose) and will not work as a stopper knot. Both Ashley and Budworth call the knot you illustrate a scaffold knot, but I have also heard it refered to as a double fisherman's noose.

I don't know if it matters whether it is called a scaffold knot or a double fisherman's noose. But, if someone ties the knot shown on the website (the sliding loop/noose) and thinks they are tying a stopper knot they could have an accident. /forum/images/graemlins/aaa.gif
 
You may (k)not have noticed, but I haven't called the knots on my website anything, so I can hardly be blamed for stupid people coming off the end of their rope.

If Ashley and Budworth clearly call the knot a scaffold knot - then that is what it is, not a double fish noose or any of the the others. I wasn't aware that is what they called it.

A HDF can be a stopper knot and a loop, just like a figure 8 can, although granted, no-one is going to fall off their rope with a figure 8 loop in the tail : )

'On Rope' also call the HDF as a stopper a Barrell Knot. So a Sliding Barrell Knot would fit the bill also.

A double fishermans noose makes me think of a sliding double fishermans.

By the historical authority of Ashley and Budworth, a 'Scaffold Knot' it is then! Period (Full Stop).
 
[ QUOTE ]
You may (k)not have noticed, but I haven't called the knots on my website anything,

[/ QUOTE ]

I did notice. This:

[ QUOTE ]
[ QUOTE ]
...the half double fishermans ...This can be done very quickly (steps displayed on www.treemettlenexus.com).

[/ QUOTE ]


[/ QUOTE ]

was copied from what you wrote in one of your posts in this thread.




[ QUOTE ]
A HDF can be a stopper knot and a loop,..

[/ QUOTE ]

If you tie a double fisherman's knot, untie one of the double overhand knots and pull that end of rope out of the remaining knot, the 'half' that is left is one double overhand knot. The double overhand is in the end of the line. There is no loop.

The sliding loop/noose that is the Scaffold Knot is formed by tying a double overhand knot around the ropes own standing part.
 
You obviously want to have me drawn and quartered Mark for calling people to their deaths.

The quote you took out of context just to prove a point, was specifically part of an explanation to tie a karabiner/snap to the end of a line; hardly implying it is a stopper knot. It IS KNOWN as half a double fishermans to many arborists, which is why I called it that. It should be called a scaffold knot according to your quote of Ashley and Budworth.

As for your noose knot - stick your neck in it pal! : )
(sense of humour required)
 
[ QUOTE ]
As for your noose knot - stick your neck in it pal! : )
(sense of humour required)

[/ QUOTE ]



[ QUOTE ]

--------------------
And the enlightened returned to the cave, only to be killed by the shadow watchers.
Plato.

[/ QUOTE ]
 
Gentlemen, to your corners.

I was discussing this over the phone with Tom, and it is indeed a semantic problem in this family of knots.

This might be pretty basic, but I learned the difference in tying the loop vs the stopper after having to re-enter the tree to retrieve a few false crotches because the loop or noose pulled apart. That's not the argument (mathematical context used) here.

I'm certain the Ivory Tower sorts could do a dissertation on the taxonomy of knots. Could? Have already. Would you or our industry adopt it? No.

Tradition needs to be honored here, and self policed. The use of the knot in discussion by Mr P and Mr M has come into widespread increased use, we could agree with that. Might we need to asterisk every publication forward? The Knot Formerly Known As Fisherman's Knot But Wasn't Sufficently Distinct But We Call It That Anyway is now known as Knot Known By Some As The Scaffold Knot? Long live Monty Python.

So, to return to Tom and my conversation, I ended up needing to listen to his description with notes. I'll have to tie what I think of it, take a picture of it, get it verified, and THEN put it into use. I'll do that because rocks are hard and gravity sucks.

Yes, our fellow rock climbers have this same semantic problem. One of their rope attachment guidelines recommends a "triple fisherman's". We know what this is, but its the newbie that gets it wrong.

Anyone going from one crew or company to another where the result is the same but the name is different knows what I mean. I experienced this several times at ITCC this summer. Its the same, but different.

As an industry, we do pretty good. Keep it together.
 
Jim, Just to keep us confuzzled on knot taxonomy someone like Kenn Shawcroft comes along extolling the virtues of the Alabama Booger Knot. I still don't know what he's talking about but I'm guessing it isn't pretty.
 
Jim, I hope you can post a picture of the knot and directions for clarification for us that are new, so as to keep us all on the same page.

Stumper... I'll pass on the Booger knot. /forum/images/graemlins/grin.gif Thanks anyway.

Jim
 
[ QUOTE ]
Tradition needs to be honored here, and self policed. The use of the knot in discussion by Mr P and Mr M has come into widespread increased use, we could agree with that. Might we need to asterisk every publication forward? The Knot Formerly Known As Fisherman's Knot But Wasn't Sufficently Distinct But We Call It That Anyway is now known as Knot Known By Some As The Scaffold Knot? Long live Monty Python.... As an industry, we do pretty [well]. Keep it together.

[/ QUOTE ]
But how did this industry come to such wrong-headed use of that name?
"Fisherman's knot" is pretty well established in general and other knots books
as a knot that joins two lines by opposing single overhand knots. How sensible is
it to use that established name for a knot that a) hitches a line to an object with
b) a dbl. or triple overhand?
You cannot think that you escape confusion by hiding your head in the industry
sand, for test results relevant to "Fisherman's Knot" will be out there for the real(tm) one,
and others for the Strangle Noose will have some different names anyway (though
maybe not (yet) that one :o).
This silly use of F. shows a misunderstanding of what "dbl. F." meant--i.e., that it
wasn't the two opposed things that merited "dble", but the SINGLE structure itself,
a Dble.Overhand. To go contrary to this nomenclature is turn afoul of much more
than just the Barrel Hitch/Strangle Noose/Dbl.Oh.Noose issue.
And all because, why, some bozo writing a book had near-zilch breadth of knots
knowledge?

And presumably arborists would like to (and need to) communicate with (rock)climbers,
cavers, and SAR folks, and then don't want to have to use a different set of names
for each application for similar knots!

*knudeNoggin*
 
Jim;

[ QUOTE ]
I was discussing this over the phone with Tom, and it is indeed a semantic problem in this family of knots.

This might be pretty basic, but I learned the difference in tying the loop vs the stopper after having to re-enter the tree to retrieve a few false crotches because the loop or noose pulled apart. That's not the argument (mathematical context used) here.

[/ QUOTE ]

I understand that it can be difficult to learn knots over the phone. And, searching and reviewing all of the references in Ashley can take hours (at least it took me that long, maybe I'm a little slow). But, someone could have taught you the difference between the 'loop' and the 'stopper' in less time than it took to gather and put on your climbing gear. They could also have taught the differences, similarities, and names of all of the knots that are under discussion here in less time than it took to climb to and retrieve the first stranded false crotch. The other stranded false crotches (however many there were) could have been prevented. You are arguing against taking time and energy to learn things, but spending more time and energy because those things haven't been learned. You now know the difference between the 'loop' and the 'stopper', and it would probably help to learn the names and characteristics of the other knots as well.

The difficulty is that some of those things have been learned incorrectly. These things have to be unlearned, and then learned again. This can be harder than learning something that is completely new, but it is nonetheless important to do.


[ QUOTE ]
The Knot Formerly Known As Fisherman's Knot But Wasn't Sufficently Distinct But We Call It That Anyway is now known as Knot Known By Some As The Scaffold Knot?

[/ QUOTE ]

This is wrong. It makes it sound like 'Fisherman's' is the original name and that 'Scaffold' is the new name. In reality, 'Scaffold' is the original name. We have just misused 'Fisherman's'. As I said above, this has to be unlearned, and then learned again. This can be harder than learning something that is completely new, but it is nonetheless important to do.


[ QUOTE ]
Anyone going from one crew or company to another where the result is the same but the name is different knows what I mean. I experienced this several times at ITCC this summer. Its the same, but different.

[/ QUOTE ]

The same, but different. Sometimes the result is the same, and the name is different. Sometimes the result is different, and the name is the same. And sometimes there are two or more variations of a different name. Or a result.

Why foster added confusion? If we learn the standard terminology now, and then pass that along to others (new and experienced) then we can avoid potential confusion in the future.




knudeknoggin wrote:

[ QUOTE ]
You cannot think that you escape confusion by hiding your head in the industry
sand,

[/ QUOTE ]

I think he is right.
 
I like the idea of using the half double fishermans, scaffold, noose, whatever you want to call it, as my termination. It can untie easily, and as someone said, doesn't allow the biner to flop around like on a bowline.
So, those of you who have switched from a bowline termination to a noose, what have you been using as a safety knot? Anything, or is it already secure enough? I guess it doesn't really need one. I use the noose without a safety on both ends of my friction hitch to terminate it on either side of my tending pulley, and I haven't had a problem with the tails pulling thru.
 
Finally, we have turned the corner and ended back where we started - the safe use of end line karabiners.

Incidentally, to follow the common useage, and monty python threads, a karabiner was a karabiner before it became a carabiner, so is it a Krab, a Crab or a 'biner................................I can hear those hornets coming /forum/images/graemlins/grin.gif /forum/images/graemlins/crazy.gif
 
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