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Old 31-05-2013, 06:47   #121
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Re: In defence of the sheet bend

Seaworthy -- ingenious. I guess it will definitely end up in my repertoire
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Old 31-05-2013, 07:05   #122
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Re: In defence of the sheet bend

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Originally Posted by Dockhead View Post
Seaworthy -- ingenious. I guess it will definitely end up in my repertoire
Thanks (blushing with the compliment LOL). It is really a very simple knot.

I have a great and very easy way of tying a Bowline too that does not involve going around any trees and into any holes LOL, but that is more for the fun of it
(It does actually avoid the problem of tying a 'left handed' weaker one).
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Old 31-05-2013, 07:10   #123
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Re: In defence of the sheet bend

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Originally Posted by Seaworthy Lass View Post
Snowpetrel's report was very interesting. I feel he may be wrong thinking the triple will be worse, as I think the mechanism of action may change (see my explanation in post #80). I have never seen reports of failure like this with a Double Fisherman's before, so it would be useful to work out why it occured (possibly inadequately hand tightened initially ???). It is a fantastic knot and the Triple version is invaluable for slippery line.
You may well be right, without more testing it's hard to know, certainly the body of testing seems to show that it is a strong reliable knot? thats why my result is so weird. It was ten years ago or so, so the memory of the details are fading, but it was kernmantle dynamic rope. The knot was properly tied (the industrial rope rescue instructor running the course at our work was with us and was just as surprised) but the knot may not have been tensioned well. I do remember of all the knots in the line it had the most give, must have moved 3 or 4 inches as it tensioned. I remember some wise person saying once believe nothing you hear and only half what you see! But the alpine butterfly held with no noticable damage. As did the bowline. Maybe with a less stretchy rope it would perform better?

As far as regular knots I use.
  • Bowline, well tightened with long tails
  • Clove hitch, used with caution as I have had two dinghys escape due to this knot, and a few fenders. Now I generally back it up with a half hitch.
  • Sheet bend and double sheet bend for joining ropes
  • Round turn and two half hitches, as it can always be untied safely, normally I go three round turns and two (or three) slipped half hitches
  • Tugboat hitch as above, but better in some places with a long tail.
  • Constrictor knot, possibly the most useful lesser known knot to turn rope into a tool.
    *]Marline spike hitch for use with the constrictor or any lashing to get it really tight
  • Buntline hitch, for any lashing that needs to be CQR, but wont get undone
  • Prussik loop, easier to remember than any other variant and looks nice, easy to teach and can't be put on backwards.
  • Reef knot... for reefing, or lashings, otherwise unsafe.
  • Rolling hitch, for when I don't have a prusik loop handy, I often put a half hitch well in front of it to strengthen the grip.
  • Modified truckers hitch. my version is like the start of a bowline in the bight, with the loop half hitched around the standing part for security (it can be left hanging)

I should practice the Alpine butterfly more, so it is instinctive.
Occasionally I use and anchor bend for more permanent knots.

One thing I always like to have handy to the cockpit on larger boats is a selvagee strop made from 3mm spectra wrapped many times into a two foot loop tied together and taped into a loop. Used to make a prusik loop it will grip very well onto most line and is very strong.



Very handy for a winch wrap to to take the load of a line. It never jambs and rarely slips. much more reliable than a rolling hitch. I cow hitch one onto the dodger frame where it's always ready to hand.

I might be able to get access to the test bed in a month or so. (no promises. I don't know if it's still working) If anybody has a list of knots and materials I might be able to test them.
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Old 31-05-2013, 07:28   #124
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Re: In defence of the sheet bend

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Originally Posted by Seaworthy Lass View Post
You have hit the nail on the head. Thinking about it it was when it had never been well loaded (only tightened as snuggly as I could by hand). You are perfectly right - it is that gentle tugging that undoes it.

The knot has come undone at least a dozen times when used to secure a polishing pad to my wrist (you would think I would have learned after the first few times, but I stubbornly simply could not believe that this trusted knot could do this LOL). A bigger problem was when I used it to tie a waterproof floating light to a fender that was used to alert any little fishing boats that we were med moored with stern lines tied to shore. The knot had undone by morning and the light was lost. Dinghy was the final straw, but luckily I had tied it with a second line from the other side so no harm was done (I secured it diagonally so it would not rub against the jetty).

I almost universally add a Yosemite finish to all Bowlines now - better to be safe than sorry .
I've never had a bowline come undone, ever.

According to my experience, there are two keys to this:

1. Leave enough tail; and

2. Tie it the right way around.

It is really easy to tie it the wrong way around unless you have a particular ritual.

Mine is to shun that bravado with which many sailors use when tying bowlines, to show that they're way beyond the "tree" and "rabbit" stuff.

Standing part facing away from me, a strictly clockwise flip of the wrist to make the loop, rabbit up the hole and counterclockwise around the back of the tree, back down the hole.

Like that, you just can't screw it up, although some old salts may snigger.


The professional riggers who put my mast up a few weeks ago always went up on bowlines. They said that they would never use a shackle under any circumstances and would trust their lives only to bowlines they tied themselves, and not to any other device or knot.
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Old 31-05-2013, 07:47   #125
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Re: In defence of the sheet bend

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Originally Posted by Dockhead View Post
I've never had a bowline come undone, ever.

According to my experience, there are two keys to this:

1. Leave enough tail; and

2. Tie it the right way around.

It is really easy to tie it the wrong way around unless you have a particular ritual.

Mine is to shun that bravado with which many sailors use when tying bowlines, to show that they're way beyond the "tree" and "rabbit" stuff.

Standing part facing away from me, a strictly clockwise flip of the wrist to make the loop, rabbit up the hole and counterclockwise around the back of the tree, back down the hole.

Like that, you just can't screw it up, although some old salts may snigger.


The professional riggers who put my mast up a few weeks ago always went up on bowlines. They said that they would never use a shackle under any circumstances and would trust their lives only to bowlines they tied themselves, and not to any other device or knot.
I do not tie it the wrong way LOL and I am fanatical with leaving long tails. Test it out overnight in water sometime with something floating attached that you don't mind losing (paricularly with fine line). If there is a bit of wave action you stand a VERY high chance that it will be gone by morning.

In 25 years of sailing I had never had a Bowline fail, it was only until cruising full time and tying a lot of them under a whole variety of conditions and frequently with fine lines that I had failures. If no high load has been applied and it gets "constant gentle tugging" (as Andrew put it) it CAN undo.

I am not the only one to experience this. It is why the Water Bowline was developed and named.

As for a particular method, I think it is important to learn to tie it from all 4 directions (loose end coming towards you and away from you and passing around the object from left to right and right to left) as you are not always going to be oriented correctly and you may find yourself lost if the line is presented a way in which you are not familiar .

And I too rely on a simple Bowline in polyester braided line when going up the mast, not a shackle (and I always tie my own ). This is a perfect application for a simple Bowline.
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Old 31-05-2013, 08:50   #126
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Re: In defence of the sheet bend

Quote:
Originally Posted by Seaworthy Lass View Post
I do not tie it the wrong way LOL and I am fanatical with leaving long tails. Test it out overnight in water sometime with something floating attached that you don't mind losing (paricularly with fine line). If there is a bit of wave action you stand a VERY high chance that it will be gone by morning.

In 25 years of sailing I had never had a Bowline fail, it was only until cruising full time and tying a lot of them under a whole variety of conditions and frequently with fine lines that I had failures. If no high load has been applied and it gets "constant gentle tugging" (as Andrew put it) it CAN undo.

I am not the only one to experience this. It is why the Water Bowline was developed and named.

As for a particular method, I think it is important to learn to tie it from all 4 directions (loose end coming towards you and away from you and passing around the object from left to right and right to left) as you are not always going to be oriented correctly and you may find yourself lost if the line is presented a way in which you are not familiar .

And I too rely on a simple Bowline in polyester braided line when going up the mast, not a shackle (and I always tie my own ). This is a perfect application for a simple Bowline.
I believe you, of course, and will keep it in mind. I guess I assume that any knot can shake loose if it's not under load, although the bowline, once cinched down tight, sure looks solid.


As to method: I can tie it hanging upside down from my feet, or behind my back, but I always visualize it as if the standing part is going away from me. I can also read with the book upside down
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Old 31-05-2013, 09:28   #127
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Re: In defence of the sheet bend

Quote:
Originally Posted by Snowpetrel View Post
  • Bowline, well tightened with long tails
  • Clove hitch, used with caution as I have had two dinghys escape due to this knot, and a few fenders. Now I generally back it up with a half hitch.
  • Sheet bend and double sheet bend for joining ropes
  • Round turn and two half hitches, as it can always be untied safely, normally I go three round turns and two (or three) slipped half hitches
  • Tugboat hitch as above, but better in some places with a long tail.
  • Constrictor knot, possibly the most useful lesser known knot to turn rope into a tool.
    *]Marline spike hitch for use with the constrictor or any lashing to get it really tight
  • Buntline hitch, for any lashing that needs to be CQR, but wont get undone
  • Prussik loop, easier to remember than any other variant and looks nice, easy to teach and can't be put on backwards.
  • Reef knot... for reefing, or lashings, otherwise unsafe.
  • Rolling hitch, for when I don't have a prusik loop handy, I often put a half hitch well in front of it to strengthen the grip.
  • Modified truckers hitch. my version is like the start of a bowline in the bight, with the loop half hitched around the standing part for security (it can be left hanging)
Buntline hitch? Yikes. I used one on the jib sheets once after someone in this forum recommended it, and after a single day's sail I needed a cutting torch to untie it. An evil knot if ever one was devised.

A list of knots and hitches I've actually used on the boat in the past few years:
*cleat hitch
*double round turn and two half hitches (mostly on fender whips)
*bowline
*double figure eight (Yosemite variation)
*figure eight on a bight
*water knot (mostly with flat webbing)
*double-overhand stopper knot
*prussic knot
*trucker's hitch (mostly on canvass)
*reef knot

Knots I've rejected for nautical usage
*sheet bend
*carrick bend
*buntline hitch
*figure eight stopper knot
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Old 31-05-2013, 10:03   #128
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Re: In defence of the sheet bend

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Originally Posted by Snowpetrel View Post
I might be able to get access to the test bed in a month or so. (no promises. I don't know if it's still working) If anybody has a list of knots and materials I might be able to test them.
To start with Dyneema single braid please, different diameters as the best knot may alter with rope diameter.

It would be good to find the best bend and the best loop as a starting point.

We already know a triple Fisherman's is better than a Double Fisherman's or Double Sheet bend, but it still doesn't come close to matching the tensile strength of the line alone. Maybe it's time to test some unconventional options - a Quadruple or Quintuple Fisherman's and maybe something like the fishing knot I posted a photo of (I found that's called an Allbright) with a variety of turns (6 or 8 or 10). I will see what other bends I can find.

Regarding loops in ends there is a fishing knot called the Bimini Twist that works well. This may be worth testing. The tried and true Figure 8 end loop that performs so well in nylon for climbers does not seem to fare well with UHMWPE.

Maybe test slow increase of loading and also rapid loading to simulate sudden jerks that would build up more friction and therefore heat and therefore cause premature failure (the melting point of Dyneema is low at only about 130-152 C). If a knot is previously well tightened by hand and very slowly loaded until well set, do sudden jerks then also result in failure at the same low levels?

It would also be good to know how much the radius of curvature at the turn of a loop affects its tensile strength.

If you have time for testing, I have plenty of suggestions
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Old 31-05-2013, 12:02   #129
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Re: In defence of the sheet bend

I have had a bit of a play with two well known fishing end loops that are used on Dyneema backing line - the Bimini Twist and the Australian Braid/Plait (aka Aussie Braid/Plait). Both knots are said not to weaken the tensile strength of the line (doesn't sound right, but they may perform better than sailing knots).

I could not tie the Bimini Twist in the braided polyester line I was practicing with, but the Aussie Braid looks very promising. It may work for the Dyneema line used sailing. Snowpetrel, do you fancy testing this if you get access to equipment?

This is the Aussie braid. The loop on the end can be any size:
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Old 01-06-2013, 19:20   #130
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Re: In defence of the sheet bend

By the way . . . this: kite knots has some good information on strength of some of the dyneema type knots/bends . . . . smaller diameter stuff than we are used to but should still be relevant
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Old 01-06-2013, 21:18   #131
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Re: In defence of the sheet bend

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Originally Posted by Bash View Post
Buntline hitch? Yikes. I used one on the jib sheets once after someone in this forum recommended it, and after a single day's sail I needed a cutting torch to untie it. An evil knot if ever one was devised.
Sometimes these are exactly the characteristics you want in a knot. When I want a low-profile, secure knot that's not going to shake loose, and I don't mind if I will need a knife to remove it, I like the buntline hitch.

Quote:
Originally Posted by Dockhead View Post
I've never had a bowline come undone, ever.
I have. It was using that stupid single-braid polypropylene line, and it was supposed to hold a dinghy "just for a moment". It didn't. Had I been using l less-slippery line it would have held just fine. I had the line left over after replacing the tethers on my MOB pole. That line splices just fine, using a brummel eye splice, but take it from me, don't use a bowline.

What works with 3-strand nylon or double-braid dacron may be absolutely wrong for more slippery lines. No matter how well you snug them up, they will loosen under any sort of motion. As I see it, the three main factors are surface friction, compressibility, and "springiness".

Evans, thanks for that kite-flying knot link. If we want to use hi-tech lines, we're going to have to study the work of those who use mono-filament and other slippery lines.
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Old 03-06-2013, 18:33   #132
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Re: In defence of the sheet bend

By the way, Stan Honey tells me that the Volvo boys use the buntline hitch quite a bit . . . it's apparently their go-to "on deck" knot (to shackles and hard points) when they don't have the time or conditions (often very wet on deck) to do a good splice. This would all be in high modulus line.
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