International Guild of Knot Tyers Forum

General => Practical Knots => Topic started by: Hereward on January 15, 2010, 07:45:02 PM

Title: best advice for towing
Post by: Hereward on January 15, 2010, 07:45:02 PM
Hi,

my first post!

As a Landorver driver rescuing vehicles has been a frequent recent activity. In general we use pre-made strops and shackles BUT sometimes we need to use ropes where it is difficult to attach with a shackle.

So the obvious question: what knots should be used with what type of rope. Obviously the knot (should) be easy to tie and undo. Also what is the effect of the type of knot on the strength of the rope. A bit of elasticity helps in towing, the attachment point can be broad or narrow.

And by comparison how do these knots compare with an eye-splice?

Many thanks for all your help.
Title: Re: best advice for towing
Post by: roo on January 15, 2010, 09:29:11 PM
As a Landorver driver rescuing vehicles has been a frequent recent activity. In general we use pre-made strops and shackles BUT sometimes we need to use ropes where it is difficult to attach with a shackle.

So the obvious question: what knots should be used with what type of rope. Obviously the knot (should) be easy to tie and undo. Also what is the effect of the type of knot on the strength of the rope. A bit of elasticity helps in towing, the attachment point can be broad or narrow.

And by comparison how do these knots compare with an eye-splice?

Welcome!

As you seem to know, just about any bend (for making a large circle), loop, or hitch form that is easy to untie will be what you want.  Towing typically doesn't require a lot of resistance to loose flogging (security).

Here are some semi-random ones:
http://notableknotindex.webs.com/Zeppelin.html
http://notableknotindex.webs.com/bowline.html
http://notableknotindex.webs.com/sailorhitches.html
http://notableknotindex.webs.com/pilehitch.html
http://notableknotindex.webs.com/timberhitch.html

I doubt you'll know the precise load in the line, so just size your rope (I'd choose nylon) comparable to large tow strap capacity.  Knots or any curvature (from anchor points, terrain) in the line may reduce strength by up to roughly 50%.

You can use an eye-splice if you want, if your rope is splicable, and if you know that you can flip your eye splice over a hook.  Aside from the time and skill it requires, it tends to concentrate wear in one spot.   It may be stronger than many knotted options, but if you're using properly-sized rope, that will not even be an issue.
Title: Re: best advice for towing
Post by: Hereward on January 15, 2010, 10:30:12 PM
Cheers.
I have always used a bowline  but add a halfhitch round the loop as on one occaision the short end pulled through. I had always found it worked well. But one of my fellows derided it as unsuitable. Hence the question.

My question on the eyesplice is : is it stronger than say a bowline? When I use a pre-made loop I use a strop rather than a rope. But I have never learned to make a good job of a splice. Maybe I should try.
Title: Re: best advice for towing
Post by: roo on January 15, 2010, 11:21:35 PM

My question on the eyesplice is : is it stronger than say a bowline? When I use a pre-made loop I use a strop rather than a rope. But I have never learned to make a good job of a splice. Maybe I should try.

An eye splice is stronger than a bowline, but if you're breaking rope, you grossly undersized your rope.  A tow rope getting dragged across an obstacle will also reduce the rope strength more than an eye splice, temporarily.   Tow rope is something that deserves to have a significant factor of safety. 

I tend to avoid eye splices if I use the rope for more than one purpose.  I hate to have an unused loop dragging around snagging things.   It sounds like you might have to get inventive with your rope in the envisioned field of use. 
Title: Re: best advice for towing
Post by: DerekSmith on January 16, 2010, 10:20:57 AM
Hi Hereward,

Yes, knots weaken rope.

The answer then is - Don't use knots.  Or at least, if you have to then don't put all the load on them.

Enough cryptic.  Just learn one knot - the B&Q knot (AKA Rosendahl, Zeppelin) - why ?  because it is reasonably strong, very secure, but most importantly, I have never been able to load it sufficiently to make it jam - even with cold wet fingers it is the perfect gentleman to untie.

Now to taking the load away from the knot.

Pass the rope through (around) the load tow point, back to your vehicle and around (through) your tow point.  Then join the two ends together with the B&Q knot.  Don't worry if you don't have access to both ends, the knot is usually shown being tied using the ends, but you can just as easily tie the knot using bights or just tuck a slip loop through to lock up the knot.

The vehicles are now connected with two lengths of rope, only one of which has a weakening knot in it.

If the towing points are reasonably slick, and if your rope is say 8mm nylon (it has excellent elasticity for towing), each length will only be taking half the load.  With a typical breaking strain of 1.3 tonnes, and say a 50% weakening from the B&Q knot, then you will be able to make a 1.3 tonne haul by the time the B&Q is at risk of failing.

Want even more pulling force with the same rope and still only one B&Q knot?

Middle your rope and take the mid bight to the load, through (or around) the hitch point and back to your vehicle, drop the bight loop over your tow hitch.  Now back at your vehicle, join the two ends using a B&Q, making the rope into a large single loop which has been threaded through your load.  Drop the second loop end you have just made by joining the ends over your tow hitch and you now have four lengths of rope between you and the load and only one knot.  The load in each rope is quartered and so you should theoretically be able to apply 2.6 tonnes of haul before you put the B&Q in danger.

Finally, you could have done this without putting any knots under serious load.

Take the loop to the load and back to your vehicle, dropping it over the tow hitch as before.  Now take the ends and make two round turns around the tow hitch and tie then out with a half hitch.  Very little of the load will have made it to the half hitch and only intact (i.e. unknotted) rope will have been taking the load - nearly 5 tonnes breaking strain haul from a little 8mm nylon rope...

Happy hauling, and see how many people you can pass the B&Q on to - it is a great little knot.

Derek

Corrected re Hunters bend pointed out by DL
Title: Re: best advice for towing
Post by: sharky on January 16, 2010, 10:26:27 AM
Just came back in off the water, and I'm a little scatterbrained at the moment, but get some 24-32mm 8 strand nylon rope. It's pretty easy to splice the ends, and is good for 20- 25 tons. It ties and holds knots well, and you can store it by stacking instead of looping or flaking. If you are going to be treating it roughly, such as dragging it on concrete and so forth, get some cheap polyethylene rope and do a french whip over the 8 strand as a chafe guard. You can make the chafe guard as long as you need it to be, and the french whip will allow the rope to maintain flexibility during use and storage. Hope this helps...
Title: Re: best advice for towing
Post by: Fairlead on January 17, 2010, 05:32:01 PM
Derick,
Once again you have jumped in with both feet without reading the question and come up with a heap of useless advice.
Hereward is talking about hauling/recovering off-road vehicles - to which none of your answers are suitable.
Hereward,
there are some good offroad sites with excellent advice on the use of ropes for recovery - most favouring the 8 strand multiplait and of late the use of Soft Shackles instead of metal ones. 

Gordon
Title: Re: best advice for towing
Post by: Dan_Lehman on January 17, 2010, 08:03:42 PM
Quote
generally use strops, but sometimes we user ropes where it is difficult to attach with a shackle

But might this rope use be supplemental, serving merely to attach
stuck vehicle to shackled strop?  -- to make a bridle, as it were.

You have a broad range of possible materials.  Elastic ones have the asserted
benefit of sustaining tension w/o careful matching of towing to towed vehicle
speeds -- i.e., of stretching and having that energy stored in the rope.  This
is also a potential hazard, as a snapped attachment can send things flying.
(I distinctly recall one anecdote of a strop breaking off a trail-hitch ball and
delivering it INTO the stuck vehicles now-silenced engine!)  Low-stretch
materials (strops by constuction tend to be lower than ...) such as HMPE
rope have less recoil, and immediate transfer of force.

So, how the rope is to be employed will suggest which knots to use.
In short, though, the bowline, if applicable, should be fine AND able
to be made a tad stronger & more secure by tucking the tail back
through the central nipping loop, which should also help preclude
capsizing.  A similar structure can effect a bending of end-to-end:
in one side of the to-be-formed ring of rope make the nipping loop,
and then "tie a bowline" with each end, in opposite directions
(which means that the knot makes a sort of bow -- eyes to
either side of it, in effect).

As Roo suggests, questions of strength should be handled by using
amply strong material, not tip-toeing hundreds of pounds force below
some perceived load threshold.  Splices indeed can/should be stronger
than knots.  (But re this, it was comical to read a Practical Sailor
magazine article in which some reputed rigging firm's experts with
hi-mod ropes had eyes pull out before a to-be-tested bowline broke(!),
which, wasn't at much force.)  Splices are usually more economical
in material consumed, and then in structure to handle (no knob);
but they are also permanent (practically).  Suit your needs.

Quote
the B&Q knot (AKA Rosendahl, Zeppelin or Hunters bend)

I have a good idea what Rosendahl's Zeppelin bend and (Smith)Hunter's bends
are like -- and they are NOT "aka", except in error.  "B&Q" I take is a moniker
offered to suggest the geometry of the former.  SmitHunter's, btw, can jam.

It sounds as though you might have sufficient connections to acquire some
discarded rope, such as from SAR or caving groups.  I'd think that some
not-in-bad-shape 11mm low-elongation ("static") caving/rescue rope,
coupled with 1" tubular nylon webbing put around the rope for either
full-sheath redundancy or just here-&-there chafe guards would serve
well, used esp. in some doubled (load-sharing) manner.  Similarly, some
discarded other beefy line as one might get from the docks.  The smaller
stuff though might work best in making attachments (with some sort of
chain or hardware against harmfully-edged metal parts) beneath a vehicle.
The sort or protection suggested by Sharky with a flattening form of
polyethylene/polypropylene rope can be helpful, too -- one can see this
(just simple wrapping, all I've noticed) on commercial-fishing gear.


And, hey, come back with some further reports, and maybe some photos
of cordage in use!

--dl*
====
Title: Re: best advice for towing
Post by: DerekSmith on January 18, 2010, 12:36:18 AM

I have a good idea what Rosendahl's Zeppelin bend and (Smith)Hunter's bends
are like -- and they are NOT "aka", except in error. 

--dl*
====

And the error was mine - thanks Dan - post corrected.

Derek
Title: Re: best advice for towing
Post by: squarerigger on January 18, 2010, 04:01:30 AM
Absent some definite research results (i.e. proof with a note of the research conducted to derive this statement) that a bowline is made "a tad" stronger by adding structure to it, I think it behooves us not to recommend such a maneuver without further explanation, preferably accompanied by a photograph.

Quote
In short, though, the bowline, if applicable, should be fine AND able
to be made a tad stronger & more secure by tucking the tail back
through the central nipping loop, which should also help preclude
capsizing.

This does not seem like replicable instruction and, with a knot that, when poorly tied is capable of capsize and release (particularly with HMPE), it seems improper to discuss or recommend use of such a weak structure to be used in towing.  About security there can be little doubt - almost anything you do with the tail on a bowline will improve its (the knot's) security.  To suggest it will also make it a tad stronger (i.e. able to take a higher load without failure) flies in the face of logic.  I would like to know how this happens (makes it a tad stronger) and how does it help preclude (i.e. stop or prevent) capsizing?  Your explanation of these events is most welcome Dan.

SR
PS  Derek - could you please explain where to find the B & Q knot - it does not show up in a Google search - did I miss it somewhere here?
Title: Re: best advice for towing
Post by: Sweeney on January 18, 2010, 11:35:38 AM
For what it's worth I would use the Rosendahl/Zeppelin as a loop knot rather than a bowline. It is not difficult to tie with a little practice (and the bend can be tied by the same method though it is easy to tie SmitHunter's by mistake).

Barry
Title: Re: best advice for towing
Post by: DerekSmith on January 18, 2010, 02:13:45 PM
snip...
PS  Derek - could you please explain where to find the B & Q knot - it does not show up in a Google search - did I miss it somewhere here?

'B&Q' or more correctly 'b and q' from the easy to remember tying method. In the UK we have the large chain store B&Q with the tag line "You can do it if you 'B' and 'Q' it", so kids find it very easy to remember this knot by calling it the B&Q knot. http://en.wikipedia.org/wiki/Zeppelin_bend (http://en.wikipedia.org/wiki/Zeppelin_bend)

Also sometimes called 'Fishes' or '69' for ease of remembering http://www.survivaltopics.com/survival/how-to-make-a-zeppelin-bend-knot/ (http://www.survivaltopics.com/survival/how-to-make-a-zeppelin-bend-knot/)

If I teach kids the Zeppelin bend, I can virtually guarantee they will forget it.  Where I have taught them and called it the B&Q knot, I see it being used all over the place.

Derek
Title: Re: best advice for towing
Post by: Sweeney on January 18, 2010, 02:53:04 PM
The loop version can be tied as in this video clip:

http://www.youtube.com/watch?v=ocoUUu1E520 (http://www.youtube.com/watch?v=ocoUUu1E520)

The bend can also be tied in the same way though it's not as easy as the "B&Q" method.

Barry
Title: Re: best advice for towing
Post by: SS369 on January 18, 2010, 03:50:01 PM
Although I am not recommending its use I'll share a recent personal experience.
I had to pull a small tractor up a slippery slope of soggy mud and grass. With no traction for the tractor to bite I resorted to towing from the top of the incline (no lower access or egress available) with my 4 wheel drive truck.

I didn't have a suitable length of tow chain so I used an arborist's bull rope. Being old-ish and stiff I made a long continuous loop of it using the Zeppelin bend, but I took the working end and made a second pass through the loops that would then tighten down on the increased bulk.
I took a smaller cord and cinched with frapping/lashing, the larger right behind the ball hitch to aid it staying there during the slack moments. The other end was just looped around the front (smooth edged) bumper before the bend was tied.
I left the bend tails long and at the end of the task I had no problem untying and the knot did not slip, even with the multiple jerking and slacking that is inevitable with towing.

I personally think that the use of over sized to-the-task rope be used regardless.

Just a personal experience.....

SS
Title: Re: best advice for towing
Post by: Dan_Lehman on January 18, 2010, 08:37:42 PM
Absent some definite research results (i.e. proof with a note of the research conducted to derive this statement) that ...

Goodness.  One cannot get out of bed, by this criterion!
Nobody has this, much, for anything knotting.

Quote
[this statement that] a bowline is made "a tad" stronger by adding structure to it, I think it behooves us
not to recommend such a maneuver without further explanation, preferably accompanied by a photograph.

Attempting to rise above the level of behooved animals,
there has been some ("a tad bit of", one might say) testing re this,
presented on this very forum -- to wit:  http://igkt.net/sm/index.php?topic=1239.30 (http://igkt.net/sm/index.php?topic=1239.30)
There have been images --sketches & photos-- as well.  I'll attach one previously
presented photo (which is easier for me to fine in my computer than
in the forum, alas) here (oh, maybe a duo).

Quote
In short, though, the bowline, ... // when poorly tied is capable of capsize and release (particularly with HMPE),

Any research results showing this?
I speculated that it might be so, but then saw video of rather
different (and astounding) behavior -- steady slippage under load.
In its great INelasticity, HMPE cordage lacks one attribute that I surmise
enables the deformation making capsizing more likely.


Quote
it seems improper to discuss or recommend use of such a weak structure to be used in towing.
About security there can be little doubt - almost anything you do with the tail on a bowline will improve its (the knot's) security.
To suggest it will also make it a tad stronger (i.e. able to take a higher load without failure) flies in the face of logic.
I would like to know how this happens (makes it a tad stronger) and how does it help preclude (i.e. stop or prevent) capsizing?

And I'd like to know what logic it is that "it flies in the face of" !?
-- and how the bowline came to be "such a weak structure" in our scheme of things?

My reasoning is repeated and simple:  you have increased the material around
which the heavily loaded (100%) line bends into the knot by 50% (2, +1).
Now, the exact orientation of this triple-diameter mass I think also influences
curvature and thus strength.  It might also make it easier for the SPart to slip
slide around the mass, collapsing the eye, as was seen in the Brion Toss videos
-- but note that that came with (1) very slippery cord (HMPE 12-strand) AND
a most accommodating low-friction & broad diameter object (metal ring 15x? diameter).

An admittedly weak, suggestive confirmation of this strength gain came
in Agent_Smith's testing, reported in this thread, which page I've linked
to has my summary of results:   http://igkt.net/sm/index.php?topic=1239.30 (http://igkt.net/sm/index.php?topic=1239.30)

-- yes, a most paltry case of a few tests' average, for a slight difference
(really, even IF this difference were fully acceptable --and I mean that in this
limited testing it cannot be--, it's not much to write home about).

So, again to this forum are photos of versions of what I've generally called
"Janus Bowlines" -- because they are two-faced, in that the knot is symmetric
("the same coming as going", so to speak) in topology (but not loading).
I prefer to begin with the tail-on-outside bowline, which I think gives a
nicer geometry to the tucked strands.  The collar made around the
eye legs with the tail should be drawn up more tightly than that around
the SPart, to enhance slack-security.

--dl*
====

Quote
'B&Q' or more correctly 'b and q' from the easy to remember tying method. In the UK
we have the large chain store B&Q with the tag line "You can do it if you 'B' and 'Q

In the southern hemisphere,
or, at least, so I hear,
you're more likely to see
things done p & d
(and for making fast you'll do
this knot tying PDQ!)

-- Anon. II
Title: Re: best advice for towing
Post by: Hereward on January 29, 2010, 05:56:36 PM
Gosh. I have been away for a few days and there is a lot in these replies. Lots of good advice but clearly no straightforward answer.

Thanks for all the replies
Title: Re: best advice for towing
Post by: Dan_Lehman on January 29, 2010, 08:37:52 PM
Lots of good advice but clearly no straightforward answer.

You can't expect a "straightforward answer" for a problem that is only
loosely defined.  So, the various answers might be appropriate for various
situations as you might encounter.  Give us more constraining details of
your situation, and you might see some narrowing of responses -- but
there are still usually many ways to solve the problem.

Cheers,
--dl*
====
Title: Re: best advice for towing
Post by: Hereward on January 30, 2010, 11:46:23 AM
You can't expect a "straightforward answer" for a problem that is only
loosely defined. 

I wasn't really expecting an easy answer. I particularly appreciated the empirical studies for which a link was provided. It has set me thinking of doing some of my own. Particularly in regard to snatch loads.  Ah well, something to think about for the summer.
Title: Re: best advice for towing
Post by: sharky on January 30, 2010, 06:38:34 PM
Can't go wrong with 28mm eight strand nylon...you can lift cars with that stuff...can't get more direct than that...
Title: Re: best advice for towing
Post by: Walter Seltzer on May 11, 2010, 11:59:23 PM
There are three knots I prefer for this purpose:

 1. Bowline
 2. Bowline
 3. Bowline

They hold, maintain rope strength, any sized loop you need and are easy to untie.  And, there are many ways to tie them... straight up, in a bight, etc.


It is one of the six essential knots I insist my deckhands know before even getting on the boat.

Cap't Walter M Seltzer
threelees1@aol.com


Title: Re: best advice for towing
Post by: jcsampson on June 01, 2010, 11:54:37 PM
Quote from: Hereward
". . . what knots . . . with what type of rope [?] . . ."

Hi Hereward,

If the rope that you are to use is made of man-made materials and has a safe working load that can meet the demands of towing, then the type of rope (such as solid-braid, hollow-braid, twisted, and kernmantle) is not likely to matter much. Twisted tends to be stronger and less expensive than braided, but it has that annoying tendency to . . . untwist. And the sheaths of kernmantle have that annoying tendency to . . . wear easily to expose the core, putting you in the position of having to buy more rope more often. (Rope manufacturers love kernmantle.) Hollow braids can flatten, but should still be suitable for many applications.

I don't know the specifics of the connecting hardware that you'll be using in your towing operations, so it's difficult for me to be specific. Even with standards, there may be enough subtle variations from one vehicle to the next. . . .

When you need to hitch, I would recommend structures that result in more than one turn or loop around the hardware. If you have access to an adequate length of thick-enough rope, and the span between vehicles allows for it, I would recommend running the rope a number of times back and forth between the two vehicles, being certain that there is no way for the rope to pop off the hardware.

Therefore, if I had to tow, I would probably find a secure way to have the rope run back and forth three times: Over the hardware of Vehicle 1, under the hardware of Vehicle 2, over the hardware of 1, under the hardware of 2, over the hardware of 1, under the hardware of 2, until the rope has wrapped three times around the hardware of each vehicle. Then, I would use my favorite bend to join the rope ends, which happens to be Hunter's Bend. (The Zeppelin Bend is another good choice, but I dislike that diagonally lopsided beast that has no identifiable front and back. They say that it's easy to untie, but unfavorably, it's easy to untie even when you don't want to untie it. Hunter's Bend is easy to untie [when you're damn good and ready] by holding the tails at the front of the knot and, with the other hand, pulling the side bumps down.)

JCS
Title: Re: best advice for towing
Post by: roo on June 02, 2010, 12:14:44 AM

Hi Hereward,
He hasn't been active for many months, incidentally.


Quote
Therefore, if I had to tow, I would probably find a secure way to have the rope run back and forth three times:

 :o  Because you live in a land where the supply of rope is unlimited, no doubt.

Quote
(The Zeppelin Bend .... it's easy to untie even when you don't want to untie it.

 ??? False, especially in the context of vehicle recovery where little to no loose flogging is expected.


Quote
Hunter's Bend is easy to untie

Very false.  That bend can jam badly with little effort.

We just had a thread where another poster re-confirmed this problem:
http://igkt.net/sm/index.php?topic=1832.0
Title: Re: best advice for towing
Post by: jcsampson on June 03, 2010, 12:52:32 AM
Since I recommended Hunter's Bend in this thread, specifically

http://igkt.net/sm/index.php?topic=1638.msg12511#msg12511,

and Hunter's Bend was derided as being prone to "jam," see

http://igkt.net/sm/index.php?topic=1832.msg12379#msg12379,

I will defend both myself and the knot:

Tie a single Overhand Knot in a single rope, tighten it, and try to untie it. THAT'S difficult to untie.

Take two ends of a rope, tie a Hunter's Bend, and try to untie it. Hold both tails at the front and, using the other hand, pull the side bumps down (one at a time) so that you can access the inside portions. Smile and think of me when you realize that it's not difficult to untie.

I've used Hunter's Bend for years in a variety of applications (using thin strings, too) and it has never been difficult to untie. Maybe I'm doing something wrong? Maybe I'm doing something right?

Think this, too: There are no memorable stories of the Bowline's having been responsible for breaking a rope in its long and safe application history. But, there they are, those who forever lament that the Bowline has a breaking strength of just 60%.

What's more important? A knot's application history or what happens in a lab? What happens in a lab can be useful, but it is merely a supplement to a knot's application history, which is much more important.

Look at the application history of the Reef Knot and--for the benefit of us all--never use it for anything but tying shoes, sweat pants, and perhaps the occasional Christmas bow.

Sure, Hunter's Bends may jam in labs, when tied using "thin stretchy cords" by those who might be intent on making them jam. But aside from that, Hunter's Bend has a satisfying application history.

Finally, I have noticed a distinct pattern: It is less often the case that a knot is one thing or the other and more often the case that a knotter just doesn't know a knot well enough in order to manipulate it to a satisfying degree.

I would rather enjoy the remaining useful properties of Hunter's Bend, than tie something else just to save twenty seconds when untying it.

JCS
Title: Re: best advice for towing
Post by: roo on June 03, 2010, 03:25:37 PM
I've used Hunter's Bend for years in a variety of applications (using thin strings, too) and it has never been difficult to untie. Maybe I'm doing something wrong?

I can guess, since I was just able to make 3/16 inch nylon rope jam with some relatively undemanding loading.  It will take much, much longer than 20 seconds to get it apart.  This was no exotic test with exotic materials.

Would you care to do a similar test?  Too many rope users don't realize how lightly they are actually straining their rope in their particular field of use, especially if they only apply puny human-arm-based loads.  Put the bend between two bars, and hold down one bar with your feet, while holding the other bar with your hands over your knees while seated and do a calf-raise exercise.  

Start with moderate loading, before moving up.  This progression of loading may save you from having to cut your knot free versus just taking 30 or 60 minutes to untie it.

P.S.  For even more dismaying results, repeat the tests with wet rope.
Title: Re: best advice for towing
Post by: Dan_Lehman on June 03, 2010, 08:12:00 PM
Tie a single Overhand Knot in a single rope, tighten it, and try to untie it. THAT'S difficult to untie.

Ha, let it be in 3/4" old nylon hawser that a trawler has lazily leaned
into for, oh, the past week / month / year !  Best hope is some soaking
of oil (vegetable) to gain slipperiness and then some iterative
efforts to work the knot loose, using pliers to grip & bend ... .
There is so little material from which to gain any contribution
to loosening (at the focus of your effort) in the minimal knot!
OTOH, there was some resistance to full collapse on its
tightening, the ends being pulled in opposition.  Eh ... .

Quote
Smile and think of me when you realize that it's not difficult to untie.

We can smile thinking of some of your assertions for other reasons.
Having invented this knot in 1973-4, I was taken by this apparent
quality, but then only used it in make-rope-use play for the excuse
of tying knots, largely.  Later, with e.g. 6mm climbing kernmantle
and a 2:1 or 5:1 pulley to put "real" force on the knot, I learned
otherwise.  I well know how to untie knots.  This one can jam.

So, to bring to light again a variation on SmitHunter's bend, I've just
"bumped" an old thread on interlocked-Overhand bends which shows
a few of them including the original and variation just discussed.

If the knot is left with large/loose collars, it might not jam, but then
it won't have the nice geometry of the snugger dressing either.

And then you also opined that Rosendahl's Zeppelin bend was prone
to untying:  that's something I think isn't really true.  It's looseness
might make it vulnerable to some snagging of its collars, and maybe
over some considerable time be more-loose than it was intended;
but in the context of having just been tied for a job, I see little risk
of any undesirable loosening.  (My keys have some thin binding cord
tied for ages, admittedly aided in this by the *blossom* of loose end
that is snug at the knot, acting a little like stoppers.)

Quote
Think this, too: There are no memorable stories of the Bowline's having been responsible for breaking a rope in its long and safe application history. But, there they are, those who forever lament that the Bowline has a breaking strength of just 60%.

True, that.  Some might count the presumed difference between some
cited strengths for the bowline vs. Fig.8 eyeknots as worth observing:
from D.Richards's data, it is over a half ton in half-inch low-elongation
nylon kernmantle, but 300# (about 10% of Bwl strength) in 10.5mm
dynamic rope, and less %-wise in nylon accessory kernmantle.  YMMV.
What's the probability that some loading will fall into just this difference?

Quote
It is less often the case that a knot is [claimed to be] one thing or the other and more often the case that a knotter just doesn't know a knot well enough in order to manipulate it to a satisfying degree.

Sometimes; sometimes it's a case of different opinions arising justifiably
from different circumstances (different conditions & materials).  Be assured
that Roo & I know well how to untie interlocked Overhands such as the
two cited by him.  (#1425 is rather different in this untying regard.)

Quote
Look at the application history of the Reef Knot and--for the benefit of us all--never use it for anything but tying shoes, sweat pants, and perhaps the occasional Christmas bow.

Sure, Hunter's Bends may jam in labs, when tied using "thin stretchy cords" by those who might be intent on making them jam. But aside from that, Hunter's Bend has a satisfying application history.

Frankly, I'd like to know what it is you're referring to for knowledge
of this "application history" ?  (I know that Ashley makes an assertion
re the SquaREef bend, but that's just that --his assertion-- , and I'm still
looking for the bodies.  Beyond that, the knot remained as a required
bend in one maritime organization (on a test:  rumor was that in practice
it was ignored).  Ashley's comment has been parroted ad infinitum, which
given the popularity and even official recommendation of the knot begs
for evidence of his worry!  Still, I'm happy to use other knots.

As for any such history for SmitHunter's bend ... ?  Huh?  I've never found
it "in the wild" -- have you?!

(Really surprising to me:  I've never found Ashley's Stopper (aka Oysterman's
Stopper
) in the wild, despite its being a quite simply tied knot with
good characteristics!?  I'd have thought that that would catch on.)

--dl*
====

Title: Re: best advice for towing
Post by: jcsampson on June 04, 2010, 12:03:48 AM
Response to roo:

Does that represent one of your typical applications?

And why don't I find you arguing in defense of OTHER knot properties in addition to the property of ease of untying? Is that the ONLY property that matters to you?

Did you notice that, in

http://igkt.net/sm/index.php?topic=1638.msg12511#msg12511,

I said, "The Zeppelin Bend is another good choice . . ."?

Hmmm?

Now, what about all those other knots that are difficult to untie? They need to be EQUALLY disparaged, in all fairness. . . .

Response to Dan_Lehman:

It can be argued that each knotter will have a different set of needs and history of knot use obtained from fulfilling those needs. Most of what a knotter knows is likely to come from personal experiences. If everyone had the same history of knot use, knotting would be less interesting than it is.

In my personal history of knot use, the Reef Knot has let me down . . . almost every time I've used it, though it still manages to keep my sweat pants up. Good thing for that. I have heard bad words about the knot from a variety of sources, so I have an adequate consensus upon which to base my opinion of the knot. If I ever come across Ashley saying, "The Reef Knot is the best binding knot we have," my opinion of the knot will stay the same--and my opinion of Ashley will change.

It's a good knot to teach to show how knot designs can relate to each other (e.g., its conversion into a cow-hitch structure) and . . . what NOT to use and WHY.

Strangely enough, the "tightness" of Hunter's Bend pleases me.

I'm looking forward to tying/trying your SmitHunter Variation.

JCS
Title: Re: best advice for towing
Post by: roo on June 04, 2010, 12:25:06 AM
Response to roo:

Does that represent one of your typical applications?
Insofar as the test represents nylon rope under moderate strain, yes.

Quote
And why don't I find you arguing in defense of OTHER knot properties in addition to the property of ease of untying? Is that the ONLY property that matters to you?
We were discussing a specific erroneous statement that you made.  I stick to one topic at a time.  It makes it much easier to arrive at the truth.  You can start another thread if you'd like to ask about other knot properties.


Quote
Did you notice that, in

http://igkt.net/sm/index.php?topic=1638.msg12511#msg12511,

I said, "The Zeppelin Bend is another good choice . . ."?

Hmmm?
It happens to be irrelevant to the problematic statement(s) at hand.

Quote
Now, what about all those other knots that are difficult to untie? They need to be equally disparaged, in all fairness. . . .
Is this an admission that the Hunter Bend jams?  If you bring up other knots that are difficult to untie, I'd be happy to "disparage" them as well, especially if someone wrongly says that they are easy to untie.
Title: Re: best advice for towing
Post by: jcsampson on June 04, 2010, 02:24:41 AM
Response to roo:

I've still had an easy time untying Hunter's Bends in my applications; the applications have been numerous enough for me to feel very good about the use of Hunter's Bend, at least in the ways by which I have used it. The use that is recommended to Hereward in this thread is consistent with that use.

JCS
Title: Re: best advice for towing
Post by: roo on June 04, 2010, 04:21:22 PM
I've still had an easy time untying Hunter's Bends in my applications; the applications have been numerous enough for me to feel very good about the use of Hunter's Bend, at least in the ways by which I have used it.
So you're not going to do the suggested test to expand your horizons? 

Quote
The use that is recommended to Hereward in this thread is consistent with that use.

Even though you have no idea of the level of strain Hereward's unknown rope might see from unknown loading during vehicle recovery?
Title: Re: best advice for towing
Post by: jcsampson on June 05, 2010, 03:36:36 AM
Response to roo:

I will likely (and eventually) do some tests like the one you spoke of in your post. One of the reasons for visiting this forum is to expose myself to the kinds of ideas that I normally wouldn't be exposed to. (I recall mentioning something previously about my admiration of "different perspectives.")

Quote from: roo
"Even though you have no idea of the level of strain Hereward's unknown rope might see from unknown loading during vehicle recovery?"

Well, the reason I'm not too worried about that is this: I suggested a three-coil-ring construct to wrap around the hardware. Such a construct remarkably reduces the burden that the knot in that construct will have to endure (which is precisely why the Fixed-Gripper Coil Binder works as well as it does) as well as the burden that each length of rope (of the six functioning lengths in that construct) will have to endure. . . .

I'll make a deal with you: You try the Fixed-Gripper Coil Binder and I'll try the Hunter's Bend Jam Test.  ;)

JCS