Zeppelin Bend - next best thing to sliced bread

[Seaworthy Lass]

I winched a moderate amount, as this was only about 6mm line and I didn't want it snapping and wholloping me. I left it sitting for about 10 minutes, then photographed each knot with a piece of white paper behind for clarity.

I then released the load and tried to undo the three knots.

This is how the three looked while under load:

The "original" Zep loop:




The Zep bend:




Imaginary Number's Zep loop:

[Seaworthy Lass]

Originally Posted by ImaginaryNumber

As SWL pointed out, her version of the Zeppellin Loop tighten up when a large load was applied. Also, as was mentioned in the IGKT discussion, this isn't truly a Zeppelin knot because, while one leg of the loop does enter the Zeppelin knot as would the standing end of the line in a proper Zeppelin Bend, the other leg of the loop enters the Zeppelin knot where the running end of the Zeppelin Bend would exit. The running end (or the tag end) was not designed to carry part of the load of the loop, and that is why it jambs.

The "original" was not my version, just one I had seen. Easy to derive it though. I currently have no internet on board so, as I couldn't remember how to tie it, I just wound it around so one standing end joined one working end. Your version is much more innovative.

Just a comment that the original version of the Zep Loop is not truly a Zep loop: it is a no less "proper" term than calling an Alpine Butterfly Loop by that name. If you load the AB loop you are actually loading what were the working ends, not the standing ends. Yes, it too jams awfully when higher loads are applied. I learned that one the hard way .

SWL

[Seaworthy Lass]

Now you are probably all sitting on the edge eof your seats wondering about the results, so I won't keep you in suspense .

Exactly the same load was applied to all 3 knots, as they were in line. The same line was used, although the wear may have varied a little along its length.

The Zep bend undid easily with one hand, just as I have found it always does. This bend never ceases to amaze me. It does not shake loose, it is secure underwater (I sleep easily at anchor when it is holding our boat on occasion), it is one of the strongest ways of joining two lines, yet a two year old could undo it after load had been applied.

The "original" Zep loop could not be budged by hand. I will try using a marlin spike on it later, but this failed the last time I tried. One side still had a throat that could be opened, but on the other side the overhand knot had seized. This is what happens with an Alpine Butterfly loop as well. The Zep bend and AB bend belong to a family of four that are based on intertwining overhands.

Imaginary's Zep loop could be opened easily with two hands. The throat on one side was open (as with the other two knots) and on the loop side it just needed a little coaxing. Chalk and cheese compared to the "original".

I have lots of comments to make, but need to head back on board, so will write more later.

SWL

[ImaginaryNumber]

Originally Posted by Seaworthy Lass

...Just a comment that the original version of the Zep Loop is not truly a Zep loop: it is a no less "proper" term than calling an Alpine Butterfly Loop by that name. If you load the AB loop you are actually loading what were the working ends, not the standing ends. Yes, it too jams awfully when higher loads are applied. I learned that one the hard way .

SWL

I agree with you. The oZep Loop certainly is an authentic Zeppelin knot, while the iZep Loop, although having the essential configuration of a Zeppelin knot, as a result of its doubled strands isn't quite as pure of a Zeppelin knot. However, the important virtue of the Zeppelin bend is retained by the iZep Loop -- that of being easy to untie after carrying a load.

Under certain circumstances the iZep Loop has another advantage; it can be tied in the middle of the line. However, the iZep Loop cannot carry a load from the running end of the line without jamming.

[Seaworthy Lass]

Originally Posted by Seaworthy Lass

I have lots of comments to make, but need to head back on board, so will write more later.

Originally Posted by ImaginaryNumber

Under certain circumstances the iZep Loop has another advantage; it can be tied in the middle of the line. However, the iZep Loop cannot carry a load from the running end of the line without jamming.

That was part of what I wanted to discuss, but ran out of time.
I agree that iZep Loop is should make a good midline loop, but it can only be loaded on the loop and one standing end.

I thought at first the iZep Loop couldn't be tied around an object, but that is not the case. It took a bit of complex weaving, but it can actually be tied around something. You would not want to be in a hurry though .

I am not sure of the iZep Loop's usefulness though, unless it can be used on dyneema. The Zep Bend slips, so that is unlikely, but in an emergency it may be the best alternative we have.

As a midline loop the Bowline on the bight is excellent when you need to have the loop and either end loaded (but not on the two ends simultaneously). The Alpine Butterfly Loop is very simple to tie and is a good choice when the two ends are loaded. I now use that to bypass a worn section of line.

As an end loop the iZep Loop will probably turn out to have a higher breaking load than the bowline, but we rarely need to push past the bowline's limits. It will probably not shake free underwater as the Bowline can do, but the water version of the Bowline or one with a Yosemite finish doesn't either.

I like having a "best of the best" assortment of knots that I can tie in my sleep (it sometimes feels like I need to do that when it is 3am ) and that I can select almost without thinking about it. At the moment I can't think of much the Zep loop would be outstanding for.

SWL

[ImaginaryNumber]

Originally Posted by Seaworthy Lass

...I am not sure of the iZep Loop's usefulness though, unless it can be used on dyneema. The Zep Bend slips, so that is unlikely, but in an emergency it may be the best alternative we have...

SWL

I am very doubtful that you will be able to make the iZep Loop slip in dyneema. Remember, the tag end will only have available half the total load of the standing end to make it slip.

I have a scrap of 1mm or 2mm slippery hollow-braided line (dyneema?) that I found. It looks a bit like this stuff, but more coarse.

1.3mm SL Dyneema® Fiber Braid Spear Fishing Cord Flat

I tied an iZep Loop in each end, marked the running end with a felt-tipped pen at the knot, put a piece of wood in each loop, and pulled until the line broke (which happened at one knot). Neither knot slipped, and both could still be untied with a little effort.

To be fair, I also tied the same line together with a Zep Bend, and pulled to failure, and it did not slip either.

I also have some 1/4" dyneema line that appears to hold both the iZep Loop and the Zep Bend securely. However, I don't have the capability of loading it to failure. Would anyone be interested in testing the iZep Loop for slippage in a slippery, larger-sized line?

[Seaworthy Lass]

Originally Posted by ImaginaryNumber

I am very doubtful that you will be able to make the iZep Loop slip in dyneema. Remember, the tag end will only have available half the total load of the standing end to make it slip.

I have a scrap of 1mm or 2mm slippery hollow-braided line (dyneema?) that I found. It looks a bit like this stuff, but more coarse.

1.3mm SL Dyneema® Fiber Braid Spear Fishing Cord Flat

I tied an iZep Loop in each end, marked the running end with a felt-tipped pen at the knot, put a piece of wood in each loop, and pulled until the line broke (which happened at one knot). Neither knot slipped, and both could still be untied with a little effort.

To be fair, I also tied the same line together with a Zep Bend, and pulled to failure, and it did not slip either.

I also have some 1/4" dyneema line that appears to hold both the iZep Loop and the Zep Bend securely. However, I don't have the capability of loading it to failure. Would anyone be interested in testing the iZep Loop for slippage in a slippery, larger-sized line?

That's very interesting! I can't find a reference to Evans Starzinger testing the Zep Bend in dyneema, but I thought he did and found it slipped.

I don't have the capability of loading thicker dyneema to failure either. We need an enthusiastic member with load testing gear .

I fit doesn't slip, it would make the Zep loop a very valuable loop (either version, jamming doesn't matter when we have so few options that hold).

The knots that I know Evans tested in dyneema that slipped were the Bowline, Buntline, Sheet bend, Double Sheet bend and Double Fishermans. The Figure 8 held, as did the Figure 9, Water Bowline and a version of the Bowline with a tucked tail (I don't know if that was the Yosemite finish). Plus the EStar hitch, which is a modified Buntline. These all broke at 40-50% of line strength (EStar was 54%).
Edited to add: Unlike the tests in double braid polyester, diameter of the dyneema tested was not specified as far as I can tell.
Note: As diameter is increased, slippage is more likely to occur.

SWL

[ImaginaryNumber]

Originally Posted by Seaworthy Lass

That's very interesting! I can't find a reference to Evans Starzinger testing the Zep Bend in dyneema, but I thought he did and found it slipped.

I don't have the capability of loading thicker dyneema to failure either. We need an enthusiastic member with load testing gear .

I fit doesn't slip, it would make the Zep loop a very valuable loop (either version, jamming doesn't matter when we have so few options that hold).

The knots that I know Evans tested in dyneema that slipped were the Bowline, Buntline, Sheet bend, Double Sheet bend and Double Fishermans. The Figure 8 held, as did the Figure 9, Water Bowline and a version of the Bowline with a tucked tail (I don't know if that was the Yosemite finish). Plus the EStar, which is a modified Buntline. These all broke at 40-50% of line strength (not sure about the EStar).

SWL

www.bethandevans.com web site appears to be down (a huge loss, if permanent), but looking at the Wayback Machine I found a reference stating that Evans found that a Zeppelin Bend slipped in dyneema.

https://web-beta.archive.org/web/201...s.com/load.htm

I certainly accept his extensive testing over my limited testing. I wonder if the Double Zeppelin Bend or the Tucked Zeppelin Bend adds appreciably to lack of slippage?
Water Zeppelin

And I still would like to know whether an iZep Loop slips in the diameters of dyneema/Spectra line that recreational sailors typically use?

[Wotname]

Originally Posted by Seaworthy Lass

........

I don't have the capability of loading thicker dyneema to failure either. We need an enthusiastic member with load testing gear .

........

SWL

I luv a challenge

What size dyneema would you like tested to failure and what knot / bend etc???

Can't promise until I get more detail

[ImaginaryNumber]

Originally Posted by Wotname

I luv a challenge

What size dyneema would you like tested to failure and what knot / bend etc???

Can't promise until I get more detail

Thank you for your kind offer to test some knots using dyneema line. SWL likely has a list of knotty questions she'd like you to explore, but in case you're chomping at the bit here are some of mine.

I have three general questions regarding tying knots in dyneema/Amsteel/Specta. Likely some of these questions have been answer before somewhere, but I just haven't run into them. And your patience may run out long before the questions run out.

1) Will all fiber variants and braid styles hold knots equally well? And to what extent is line strength lost by tying in a knot, compared, say, to nylon or polyester (Dacron).

2) Which bends are strongest and hold the best, while still being easy to tie and loosen?

3) Which loops are strongest and hold the best, while still being easy to tie and loosen?

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1) In this photo are two single-braid dyneema lines, listed as being 1/4" (~6mm) diameter, but measuring (when not under load) closer to 5/16" (8mm) diameter. The orange line is made of thicker yarns, the braid an over-under style, is easier to separate with a fid, and the line feels stiffer. The gray line is made of finer yarns, the braid is an over-one-under-two style, is harder to separate and run a fid through without snagging, and is more pliable.

If you happen to have two lines of the same diameter that appear to be made of different sized yarns it would be helpful to know which held knots the best? I would expect the line made of finer yarn to hold knots better. It's also possible that the line made of finer yarn would also lose less strength at the knot. So that would be another parameter to test.

I'd also be curious about two lines made of the same yarn, but with the line size different (say 3/16" (4.7mm) diameter vs 3/8" (9.5mm) diameter). Would they hold a given knot equally well, or would the knots in larger lines slip easier, or would the knots in smaller lines slip easier?

And again, does dyneema loose strength faster in a knot than does, say, nylon or Dacron? For example, maybe for a particular knot, nylon looses only 20% of its strength, but maybe dyneema looses 50% of its strength.

^^^^^^^^^^^^^^^^^^^^^^

2) BENDS -- Which bends work best in dyneema?

Evans Starzinger says that dyneema slips in a Zeppelin bend. My tests crude tests with a ~1.5mm line suggested that it didn't slip before breaking (at the knot). Can you replicate Evans' tests with larger line (3/16", 1/4", 3/8", 1/2" -- or whatever sized line(s) you have)? If a Zeppelin bend slips, would you also try a Double Zeppelin and a Tucked Zeppelin bend.

If you use the "69" method for tying a Zeppelin bend, as I understand it the Double Zeppelin is tied by making two loops for the "6", and two loops for the "9", then tucking tag ends through the resulting four loops.

As I understand it, the Tucked Zeppelin is tied by making single loops for the "6" and "9", but then passing the tag ends through the "69" loops twice each.

For both the Double Zeppelin and the Tucked Zeppelin it would be helpful to know how easy they were to untie after being loaded, compared to a standard Zeppelin.

There are lots of other bends one could try with dyneema. Apparently Evans has tried some of the more common ones -- they all slipped, I understand. But if you really got carried away you could try other types of bends, though I am not knowledgeable to guide you towards which ones to try.

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3) LOOPS -- Which loops work best in dyneema?

The recent discussion in this thread was if a Zeppelin loop could be tied in dyneema; one that would not slip, yet would be easily untied.

SWL introduced a Zeppelin loop here (which I called the oZep Loop; "o" for original), but she gave up on it because it jammed under load. If you wanted to experiment with it anyway you'd have to ask her what the best way to tie it was.

I introduced the iZeppelin Loop here (I'm using "i" to differentiate it from the oZeppelin loop SWL presented.) I'm hopeful that this iZep loop will both be easy to untie after being highly loaded, and will not slip in a dyneema line. If you could try it out in a couple of different line sizes that would be very informative.

Thanks again for offering to help us out with dyneema knot ideas.

[JPA Cate]

Wow, Wottie,

You're not planning on using your log splitter for this, are you? If so, stand well clear! [Joke!]

;-)

Ann

[Seaworthy Lass]

Originally Posted by Wotname

I luv a challenge

What size dyneema would you like tested to failure and what knot / bend etc???

Can't promise until I get more detail

Hi Wottie
Thanks for the generous offer .

What I would love to have tested above all is my Bullseye weave (see my avatar) made up in a removable soft shackle type version.

If you have load testing equipment, what I will do later this year is make up 10 samples for you in about 6mm dyneema and post them to you with a LF ring, maybe with some standard soft shackles using a diamond stopper for comparison. I think this is the number of samples Evans Starzinger used in some of his trials and it should be enough to provide statistically significant results.

A very grateful SWL x

[dannc]

Originally Posted by ImaginaryNumber

www.bethandevans.com web site appears to be down (a huge loss, if permanent), but looking at the Wayback Machine I found a reference stating that Evans found that a Zeppelin Bend slipped in dyneema.

I could not get to their website now either. However, by pure chance, I was on their website earlier in the week, around the 3rd or 4th, so hopefully the outage is just a network or server issue.

Later,
Dan

[Wotname]

IN and SWL, I will get back to this thread in a few days - bit busy ATM.

[Wotname]

Okay, the Easter bunny has been and all such matters have been attended to .

Now is the time for some destruction . I prefer to break things rather than test them but...... I can make some comparisons by breaking stuff and if the results are interesting, I might work out some way of measuring the force required to cause failure .

I don't have formal load testing equipment but Ann T has clocked me; I can only assume she knows me too well!

Originally Posted by Ann T. Cate

Wow, Wottie,

You're not planning on using your log splitter for this, are you? If so, stand well clear! [Joke!]

;-)

Ann

Yep Ann, that is exactly what I am planning to use. The ram will generate approximately 40 tons when extending and perhaps 20+ tons when retracting. It is far easier to setup rope testing in the retraction mode and also this mode may be easier to monitor the pressure on high pressure side on the ram at the moment of failure. FWIW, the pump has a maximum of 3,500 psi (I think).

Originally Posted by Seaworthy Lass

Hi Wottie
Thanks for the generous offer .

What I would love to have tested above all is my Bullseye weave (see my avatar) made up in a removable soft shackle type version.

If you have load testing equipment, what I will do later this year is make up 10 samples for you in about 6mm dyneema and post them to you with a LF ring, maybe with some standard soft shackles using a diamond stopper for comparison. I think this is the number of samples Evans Starzinger used in some of his trials and it should be enough to provide statistically significant results.

A very grateful SWL x

First lets break some stuff

I tried some used 10 mm polyester double braid yesterday and it broke it without blinking.

I'm thinking some series knots and bends in different lines to see what slips, what can be undone and what breaks first.

There is not a lot of exotic lines available locally but I can get spectra in common configurations in Hobart (or on-line - I guess).

I will have a look at some DIY way of adding a strain gauge at the end of the ram or perhaps just a pressure gauge on the high pressure side of the pump. Any ideas on how to achieve this are welcome.

Over to SWL and IN...