Sailors wrong for thousands of years?

Discussion in 'Sailboats' started by backyardbil, Feb 7, 2011.

  1. jehardiman
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    jehardiman Senior Member

    Then we are in agreement, as I said in post #17, that they are engineering "toys"; i.e. neat little technical dead ends like magnetic motors, gyroscopicly powered vechicles, and ornithopters all of which work, but cannot be economically useful in large sizes to take over from existing solutions. The "commercial" and engineering part of it is a harder point though, especally if offered as plans or for sale. Just like the press on eyes of a stuffed teddy bear, there is a onus on the designer, legally and ethically, that all "reasonably foreseeable" failures are designed out. While anyone can build one, they must also realize that there are risks, not just to themselves, associated with the design, suitability, and construction. A 200 gm blade flying off is one thing, a 200 kg blade breaking at 40 rpm is another. That is also a "commercial" consideration.
     
  2. Windmaster
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    Windmaster Senior Member

    Regarding these "Health and Safety" issues. I'm sure you would be the first to agree that in "normal" sailing there are many health and safety type issues that have never been designed out.

    For example, low booms at head hight that will bash heads in accidental gybes (there are hundreds of accidents every year - some resulting in death) entrappment of fingers in winches, trip hazards from rope lying all over a cockpit floor etc. etc. these are all considered to be part of the normal hazards of sailing - so in comparison, I don't think this is a really big issue.

    I've never heard of a sailing boat designer being taken to court for not considering his responsibility on these issues.
     
  3. backyardbil
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    backyardbil Junior Member

    You still haven't commented on the fact that the traditional windmills, although large, and made crudely of wood, do not suffer from blade failures. If you say that blades in large sizes cannot be made strong enough, and imply that they may come off, how can you explain why these giant mills do not suffer failures?
     
  4. jehardiman
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    jehardiman Senior Member

    No, but the have been taken to court for keels falling off, which is better comparison than " the normal risk of the mariner".

    They due suffer from blade failures. Lets get specific are you talking about sail type windmills, slat type windmills, or blade type windmills. Sail type are designed to blow out, slat types fail the slats to preserve the central rib, and blade types feather in what could be considered moderate wind at sea. It is, as I stated before, not a matter of wether you could devise a blade system that would protect the mechanics of the blade in moderate air, but wether you could design a system that would protect the vessel in heavy wind. Unlike a land based system you cannot just feather the blades and walk away allowing the non-moving earth to be a steady foundation, it must be designed to be intergral to the survival of the vessel in sea states and winds beyond useful operation. You don't get to pick and choose you conditions at sea.
     
  5. Windmaster
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    Windmaster Senior Member

    Did I say they had to be at sea in ALL conditions? I've already said they are most suitable to be used in rivers. There are many boats that would not survive at sea in the most extreme conditions. They just have to be operated within their limits. No- ones claiming a panacea here that will supersede all other boats, just a useful attribute that has its uses and should not be ignored.
    Before it was demonstrated, many said it was impossible. See this page http://www.sailwings.net/objections.html Now it has been demonstrated, they retreat slightly change their ideas and put forward a variety of excuses ranging from "we don't need it" to "it will chop your head off" to the latest "it will fall to pieces". Now I hear that "anyone can build one" - my answer to that then is: "Why don't they then?" - they certainly work ok I think I have demonstrated that.
    It's really hard to believe that in the age of Jumbo jets and supersonic flight it's NOT POSSIBLE to mount a windmill on a boat to drive it along!
     
  6. jehardiman
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    jehardiman Senior Member

    Why not you ask?. Because, for most people looking for windward work in a watercraft, the effort and cost are too high for the provided benefit.

    Anyone who has had high school physics, or even a moderate interest in science as a child, can build a telegraph, semaphore, or heliograph but today they carry a cell phone. This is because the limitations of the technology do not support the continued investment in those devices. Just because the technology works in limited conditions does not mean it should be embraced.

    You stress that there are limits to the useful conditions of wind rotor driven vessels. The question the engineer/designer/buyer needs to answer is: why not pole/row for less cost, pedal/motor for more speed, or just plain sail? All those technologies bring more to benefits to the table for less effort and cost. Yes, there might be some niche that these devices might fit, even the "isn't this a cool toy" niche occupied by HPV's, foiling dinghys, and wave propulsion devices (FWIW, I leave kite sails out of the "neat toy" catagory because I feel they are on the cusp of becoming technologically viable). The device today is barely the equlivant of Escargot . And until we develop a cost effective, most weather, most oceans rotary wind propulsion system (and Revelation II is getting there) it will remain a neat toy, not a serious contender to meet most peoples needs in a watercraft, and therefore vessels with them will not be constructed in significant quantities.
     
  7. Windmaster
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    Windmaster Senior Member

    You still don't get it do you. I never said or have ever said it is a "serious contender to meet most peoples needs" etc. You insist that I am saying it is better than anything else. I have indicated several times that I am not saying that. However, it is an interesting subject for research, especially since so many believe it is not even possible, and have never even considered it. It's unlikely to "save the world".

    I've done a lot of (conventional) sailing on the local rivers, locally we notice the wind seems to follow the river, therefore it always seems to be dead ahead, and you have the ardous task of tacking in confined waters with quite a few other boats to contend with. Hard work and you don't make much progress. It's great to discover there is a way of going directly windward to overcome this difficulty that doesn't use any fuel, I'm sure you will agree.

    By the way. The owner of Revelation II is a complete recluse and tries to keep everything about the boat secret. That's why you won't find much about it on the web. Word is that it doesn't work in any wind below 10 knots - maybe that is why he is so secretive.
    Heres a question for you. If you have researched this you should know the answer.
    In what fundamental way does my craft differ from Revelation II which makes it perform better in low windspeeds - a clue - do you know the tipspeed ratio I am using?
     
  8. Windmaster
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    Windmaster Senior Member

    Apologies for the tone of my last reply. I hope you didn't take any offense, certainly didn't mean to cast doubt upon your professional abilities.
    However, although well argued your comments are misguided and I will point out why.

    Who has tried it? so how would they know the benefit?

    Nobody understands the "limitations" because who has tried it? (Similar answer)

    Row/Pole: How long would anyone want to pole or row directly against a strong wind? When it is easily possible to let the wind take you against itself and the stronger the wind the greater your speed into it, and you can do it 24/7 which you certainly could not do by rowing.

    Pedalling: (as in Escargot) is the same case, and I'm also doubtful if with the large windage of the big body, escargot could make much progress being pedalled against the wind even in a lake, yet alone the sea. I'm sure any pedeller would welcome the wind to do some or all of the work.

    Motor: Sure you can motor, but you are using fuel, why do that when you can acheive the same result without using fuel. What sense does that make?

    Sail: Sailing you can do, but no way can you sail directly into the eye of the wind. This can.

    So this can improve upon all the alternatives you mention.


    For your information, the wind-turbine driven boats developed by myself are different than the (very few) others.
    The obvious, and in my view misguided approach is to configure a land mounted electricity type generating turbine to be the most efficient and simply mounting it on a boat.
    I think this is the wrong approach, and I consider that pencil thin blades whipping round near the speed of sound just above your head is as objectionable as it can be.
    The more user-friendly, gentle, but effective approach I use is not allow the blades to rotate ANY FASTER than the wind. In other words I use a 1:1 tipspeed ratio. Anyone who has checked my videos and website can see how effective this is.
    The benefits are as follows:
    1. Not so dangerous as high-speed blades. (Being hit by one is no different than being hit by a boom in an accidental gybe) - both should be avoided!
    2. Because they are not subjected to horrendous forces, blades can be light and simply made.
    3. Self-Starting: Fast rotating blades, (such as those of the Aeolus landcart races in Europe) do not self start.
    4. NO gyroscopic effect. Because of the slow rotation rate there is no noticeable gyroscopic effect.
    5. They work better, I look forward to the day when anyone else produces an equivalent or better result to my own.

    Anyone who would like to know more (and has an open mind) can visit http://www.sailwings.net to find out more. You could even read the article about it, and I welcome informed comments.
     
  9. Leo Lazauskas
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    Leo Lazauskas Senior Member

    Maybe I have missed something here.
    Doesn't a slow rotation speed also mean that Reynolds numbers are low, and so the efficiency is also fairly low?

    A "biscaph" is probably aerodynamically more efficient, and it can be connected directly to a Voight-Schneider-like propeller which could be useful in some shallow waters, but it has many obvious disadvantages. It's another device that probably won't make it out of the toy/research stage.

    Leo.
     

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  10. Windmaster
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    Windmaster Senior Member

    True enough, but the advantages outweigh this disadvantage. Design compromises often have to be made.

    I'd like to see the "biscaph" working, but I'm not sure if it has ever been constructed?
    Unlike the Rotary Sailing craft, which has been constructed, works, and does not have many disadvantages.
     
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  11. Leo Lazauskas
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    Leo Lazauskas Senior Member

    I seriously doubt that anything but small backyard models have been built.
    If anyone decides to build a large biscaph, they should attach a rubber glove to the bottom of each wing. As the turbine rotates the gloves will fly out and slap them across the back of the head as a reminder that they are being silly.
    Just my opinion, of course :)

    Good luck!
    Leo.
     
  12. YachtManuals
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    YachtManuals Junior Member

    Revelation II
    [​IMG]
     
  13. BATAAN
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    BATAAN Senior Member

    After 50 years of seagoing I have learned one brutal, unchangeable fact about using the wind for power. The wind is capricious, powerful, ever-changing and breaks or wears out everything eventually. As cute and logical as this concept is, it still relies on engineering of a fairly complex sort with gear boxes, torque shafts, blades and other stuff and I do think it works, I don't think it will last or be at all economically viable when used over a long time on the real ocean. And if it isn't strong enough to go to sea and is only for flat water, seems pretty useless. The only real advantage is being able to 'sail' straight upwind, something seldom needed and taken care of fine with a small auxiliary engine in most sailboats. Otherwise the performance will be poor, especially downwind with low relative wind conditions.
     
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  14. CutOnce

    CutOnce Previous Member

    Amen brother! Pass the Rum.

    If there is one thing I've learned from this site, it is that there is a huge almost unbridgeable chasm between people that actually sail, actually build boats, actually pay to operate and those that endlessly "think" about doing things. Armchair theoreticians that do not bother to try practical application of their ideas are the most argumentative, annoying and difficult people there are to deal with. You can not disconnect money, weather, the sea and experience from design.

    Wild ideas and fringe experiments can be fun - and there is always the remote possibility that something new may be discovered. The chance of "revolutionary" change in Naval Architecture today after centuries of "evolutionary" refinement is pretty minuscule. Every one of these rocket scientists claiming they've started a new revolution is to a great degree insulting every one of our predecessors by intimating they missed something important - and I for one respect the people who have gone down this path before I.

    Naval architecture has more history and evolutionary refinement than any other form of transportation - most other forms (automotive, air travel, trains etc.) are mere infants in comparison. You could take a sailor from many centuries past and they would still quickly understand how to get BMW-Oracle moving. Similarly, any one of us could be put on a reed/papyrus boat predating written history (or go to Vietnam) and we would quickly figure out the basics.

    --
    CutOnce
     

  15. Doug Lord
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    Doug Lord Flight Ready

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    This post sums up the most reactionary attitude in regard to new development in marine design that I have ever read. If it wasn't for visionaries like Hobie Alter, Greg Ketterman, Dr. Sam Bradfield, Bill Burns and the CBTF Team, Frank and Julian Bethwaite, Jim Drake, Hoyle Schweitzer, Eric Sponberg, Jim Pugh and John Reichel, John Ilett, Thomas Jundt, Alain Thebault, Yves Parlier and others the world of sailboat design and development would be a much duller place. Comments like this come from someone who complains about new design ideas being posted on a design forum and who has never once posted a design of his own or a new idea he thought might be viable. Critical comments are part of any design review but when always negative and coming from no experience whatsoever in sailboat design and development the efficacy of the remarks must be subject to serious skepticism. Too many times I've read comments about "building" an idea as a response to a design concept rather than an analysis of the design concept-that gets tiresome and ignores the fact that before something is built it must be designed. By posting new design ideas on this forum I have received great feedback, learned a lot and hopefully helped to inspire others.
    --
    Bataans comments were a great analysis of a particular system not an indictment of new ideas-there is a difference. Maybe rum would help you, once(bistros)!
     
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