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Old 05-02-2008, 07:21   #16
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See the heterogeneous rode treatment from another Alain, Alain Fraysse, referenced above at Rode - Static Behavior . He shows that a kellet can provide the various benefits described by advocates (although not all at once without multiple kellets since placement differs for each effect) BUT that the weight required of a kellet to be significant in those effects is 1. significantly greater than that sold/built/used and 2. impractical.

I would suggest that the *other* anchoring bromide of carrying "up one size" is yet more effective.

Like so many anchoring discussions opinion overwhelms information, and most empirical data is not scientifically significant. That Rez and the other boat he refers to above did not drag may be a greater statement of their anchoring skill than that they happened to use kellets.
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Old 05-02-2008, 12:09   #17
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rather than carrying an extra 30# of weight with no other purpose, use 20-30 ft of your anchor chain as a kellet. Much of the chain between 1/4 and 3/8 inch weighs 1 to 1.5 lbs per foot. Use a shackle or bolt to make a loop or two in the chain, about half way down the rode (at least after the anchor is on the bottom).
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Old 10-02-2008, 01:43   #18
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The math to this is simple and is not up for debate. Simulations may easily illustrate the exact angle of pull on the anchor, and this is what my article above speaks to. Alain Fraysse's (not Poiraud's) work labors the point of this (Poiraud's book includes a chapter which is directly contributed by Fraysse, it is not written by Poiraud). This is not complex physics with unproven theories - side swipes at this body of knowledge by way of comments about "theory vs practice" is unhelpful and betrays an ignorance of the topic.

As an anchor manufacturer we want people to reduce the angle of pull on the anchor. Obviously the anchor's performance is compromised with higher angles of pull. I have no problem in saying that, it's just basic seamanship that should be general knowledge to any boater. Some anchors will handle higher angles of pull comparatively better than others, and weight becomes more of an important factor, but it is nonetheless a fact that any and every temporary small boat anchor will give higher ultimate performance the closer to horizontal the pull.

However, the notion that a kellet (at least one that is practical, as Auspicious touches on) will assist the anchor in this regard, is dangerously misleading. If the anchor is anything better than an undersized type of a very poor design, it will not.

In my article we consider a kellet which is the same weight as the anchor (!) to give it the best chance possible. In conditions that are likely to trouble the anchor, the rode is tight and the kellet is making so little contribution to the pull angle as to be useless. In this scenario, the only practical way to help the anchor is to deploy more scope, up to the point of diminishing returns around 8:1 or so. The only way to improve the anchor's ultimate performance is to up its size.

***

Kellets do have a number of other uses. Some find they improve the boat's motion and comfort, as someone mentioned above. That's great - but it does not speak to "dragging risk". It's simple: use a well sized anchor, a snubber if you need to for shock absorption, and a good amount of scope.

***

As to c.spots's suggestion re looping chain, that's fine too, but it can be a pain as are other techniques, and the likes of a dedicated product such as the Anchor Buddy can make the deployment/retrieval process easier and is well worthwhile if one is to use a kellet regularly.
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Old 10-02-2008, 02:21   #19
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The math to this is simple and is not up for debate.
You are in the public domain. Even debate is up for debate
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Old 10-02-2008, 12:19   #20
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And it will always be up for debate because it is "an opinion". Just like the Alain Fraysse's Opinion". Seafox has an opinion too. Seafox's anchoring technique works well. He has never dragged. He has been in serious weather, including a major cyclone. I think this makes Seafox as much a voice in Anchoring technique as anyone else. But it is still an opinion. I have my own. I will continue to use my own technique till it fails and I try something different and if something different works better for me, I will form a different opinion. If using an anchor buddy helps some, they don't mind the extra work, then that is up to them.
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Old 10-02-2008, 21:56   #21
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Conspiracy........................ahhhh
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Old 10-02-2008, 22:53   #22
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Originally Posted by craigsmith View Post
The math to this is simple and is not up for debate. Simulations may easily illustrate the exact angle of pull on the anchor, and this is what my article above speaks to. Alain Fraysse's (not Poiraud's) work labors the point of this (Poiraud's book includes a chapter which is directly contributed by Fraysse, it is not written by Poiraud). This is not complex physics with unproven theories - side swipes at this body of knowledge by way of comments about "theory vs practice" is unhelpful and betrays an ignorance of the topic.
I think you'll find that many who do like kellets and think they do work are the types who have actually had practical experience with them. Obviously those that do will disagree with those who haven't. I'm sure we could rustle up more than a few 'names' who will agree.

Theories are just that and have on so many occasions proved to be very wrong. Practice is what is/has actually happening/happened.

To say 'it's maths so it's right' just doesn't cut the mustard. The 'maths' said the Space shuttle won't explode, it did twice. Maths said the Titanic wouldn't sink, it did. The maths said the twin towers wouldn't fall down but they both did. The math said the world was flat but I'm informed it's not. Feel free to jump in with any of the million more examples there must be....

Maths is far from bad but it can turn evil if used wrong.

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is dangerously misleading.
Yes we must take good note of this. As we know Craig is very knowledgeable when talking 'dangerously misleading'.


Personally I don't have that much experience with kellets. The odd time I have used the secondary anchor as one to help a anchor hold, which I do believe they did. I have stretched out some chain and hung weights off it. The load cell did indicate some noticeable increase on loads with some, which has us thinking that they can increase the force required to pull the anchor out.

We did have to play around a fair bit which the amount of weight and position to get the larger numbers though. Anything less than 10-12kg (22-26#) didn't do that much really but we were playing with 10mm chain so on lighter boats it probably would. A 10kg on a 25fter would be very noticeable for example.

I do know many people with kellets who do believe they work. I tend to put more faith in knowledgeable people who have actually 'done it' than spreadsheets sorry.
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Old 10-02-2008, 23:02   #23
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Ok, I'll call ya Craig. I'd like to see the math please!!!
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Old 10-02-2008, 23:05   #24
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these anchor buddies work

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Old 11-02-2008, 00:23   #25
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Ok, I'll call ya Craig. I'd like to see the math please!!!
I've seen the math and it does look on the surface quite convincing but then it just doesn't seem to stack up with what I've seen, experienced and what many people have told me of their experiences.

I can see where and why Craig is so convinced but I just can't relate it back into real world experience. One of those 'economics' type things where they say 'do this and that and then that will happen', on the face of it it looks pretty damn right. Then go watch Mrs J Average at the supermarket and she just doesn't do 'that' and in the process shoots the theory to bits.

I'd say kellets are just like most other anchoring gear. Get the right size in the right situation and it'll work well. If you don't it may just not.

And of course the old chestnut. Millions of people have used CQR's for decades without dieing which does sort of shoot down the 'CQR's are natural born killers' line some anchor seller uses. Just like the many 1000's (maybe a lot more) people use kellets and say they work. Many 1000's of actual uses verses a spreadsheet. Not really a contest is it.
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Old 11-02-2008, 01:41   #26
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I would still love to see the Math, but I doubt I will.
There are many variables outside of a perfect equation. Now if one were to apply Quantum Mechanics to the math, the results would be a lot more in line to the actual real world performance.
Quote:
Mrs J Average at the supermarket and she just doesn't do 'that' and in the process shoots the theory to bits.
I know that woman. He has a Sailboat with a battery that is not deep cycle yet gets used as such and has never been properly charged, yet got 10yrs out of the thing. My argument was totaly lost.
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Old 11-02-2008, 03:21   #27
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I think you'll find that many who do like kellets and think they do work are the types who have actually had practical experience with them. Obviously those that do will disagree with those who haven't. I'm sure we could rustle up more than a few 'names' who will agree.
Theories are just that and have on so many occasions proved to be very wrong. Practice is what is/has actually happening/happened...
A valid theory explains (the how & why) practice (observable phenomena). Unlike a hypothethis (a speculative explanation, or conjecture), theory supports, but does not replace, experience. A theory has been extensively tested, and is generally accepted, while a hypothesis is a speculative guess, that has yet to be tested.

I don’t have the skills to debate (test) the merits and/or accuracy of Alain Fraysse’s mathematical treatise on Kellets
Perhaps some of more learned members could test and offer critical comment on the accuracy of Mr. Fraysse’s physics and mathematics (support or refute).
See
"Tuning an Anchor Rode" ~ by Alain Fraysse
Tuning an Anchor Rode

I do have significant experience, based upon many practical observations - none of which support his conclusions regarding Kellets on anchor rodes.

My, possibly erroneous, conclusions are that Kellets, deployed in various configurations, are very efficacious:
- Kellets appear to increase the catenary of combination chain/rope rodes, reducing the load on the vessel and the anchor.
- Kellets appear to reduce horsing, or sailing at anchor, which greatly reduces the loads on anchor & boat.
- Kellets definitely allow dividing the total weight of useful anchor gear, increasing the total weight (of anchor gear) my smaller boat could safely carry, and that the crew could deploy & retrieve.

I'm Gord May, and I authorize the foregoing message.
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Old 11-02-2008, 06:28   #28
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[B]
My, possibly erroneous, conclusions are that Kellets, deployed in various configurations, are very efficacious:
- Kellets appear to increase the catenary of combination chain/rope rodes, reducing the load on the vessel and the anchor.
- Kellets appear to reduce horsing, or sailing at anchor, which greatly reduces the loads on anchor & boat.
- Kellets definitely allow dividing the total weight of useful anchor gear, increasing the total weight (of anchor gear) my smaller boat could safely carry, and that the crew could deploy & retrieve.
I think Alain, Alain, and Craig have agreed with these points. Their argument was that a kellet had to be used differently to obtain each benefit. So one couldn't have the best of all worlds simply by adding a kellet.

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