Tanker proa

Discussion in 'Multihulls' started by Konstanty, Apr 18, 2016.

  1. Angélique
    Joined: Feb 2009
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    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    The videos in post #67 show hogging and sagging and twisting as seen from inside.

    Here some 80 m (262½') Catamaran info, to relate the post #69 ship motions a bit to a multi...

    Sagging Moment
    [​IMG]

    Hogging Moment
    [​IMG]

    Transverse Split Force
    [​IMG]

    Pitch Connecting Moment
    [​IMG]

    Transverse Racking
    [​IMG]

    global strength analysis
    [​IMG]
     
    Last edited: Apr 8, 2018
    UpOnStands likes this.
  2. UpOnStands
    Joined: Nov 2015
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    Location: Sydney

    UpOnStands Senior Member

    thanks for the information.
    Also checked out the Tally Ho project.
     
  3. rob denney
    Joined: Feb 2005
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    rob denney Senior Member

    You are using advanced examples (powered flight vs Icarus, chronometers vs sun dials, computers vs abacuses, assy kites vs jibs on sprits, Dunlop's bikes vs Da Vinci's) of ancient ideas. You can bet the first people to suggest each of these was laughed at for his "crazy idea". It is like saying that the idea of putting a man on the moon was treated seriously by NASA, when Galileo was threatened with death and excommunication for suggesting the earth was not the centre of the universe 400 years ago.

    When you look at some of the nit picking ridiculousness that passes for "reasoned criticism" of new ideas on this forum, it is pretty obvious that a lot of posters are far more interested in scoring points and seeing their names in print than they are in development. These people never acknowledge the benefits of anything novel and always focus on the negative aspects, regardless of how petty these are. They rarely, if ever have ideas for improving things, just "reasons" why they won't work.

    I am pretty sure Frank realises his idea won't work on a supertanker in an Aghullas gale. I am equally sure that there is more development to be done on the idea. Instead of pointing to worst case scenarios, why not use our collective intelligence to help develop it? The idea has merit for boats reaching across the Trades. When we were developing kites for ships, we learnt that two of the reasons ships don't have sails are the capital cost and the loss of deck area. If a ship owner was offered a tanker proa (or a kite flown from a blimp) on the basis of a percentage of fuel saved, and did not have to worry about it before and after it was coupled, the idea has some potential. The IMO is (hopefully) about to mandate that shipping become greener. Ideas like this are what might help it happen.
     
    Doug Lord likes this.
  4. chinaseapirate

    chinaseapirate Previous Member

    Wow, a "proven" yacht designer and a model builder extraordinaire with technical background both like the post above. Count me in. I vote yes on the proa tanker concept. At the moment the moment though I am attracting bugs (possiblly a single bug with multiple personalities and similar logic), so I don't wish to offer them any food on designing a tanker proa. (yet!) Mr. Denny I read your designs, I don't remember how many published in "multihulls". Soon after between completing backyard project boats #7(Philippines) and #8(California), I scaled "HarryProa" up (or am i getting this confused with boat by a different designer) to 120+ ft or so, stretched the beam and added a hydrofoil under slung from a crossbeam and canted out toward the weather hull (in concept). The purpose of the hydrofoil was only to keep the weather hull relatively level and add lift upwind. The wide beam would "fight" to keep the flying hull in the water whereas the hydrofoil wouldn't allow it, thus creating a "negative loop" similar to canard airplanes and WIGs. I wanted to win the Transpac with inexpensive sails/rigging based on DLR and minimal drag NOT bruce#. My father, an original member of Malibu Outrigger Club and former Transpac winner (handicap) 2nd overall, looked at it for a good 30 seconds (all the weights/LWL/stability specs included the three profile/top view/mid cross section drawings) stared at the ceiling another 15 then motioned his hand in a wave like representation while verbalizing "W h o o o o o p" finishing with his hand upside down. I disagreed of coarse, but project never even made it out of the dining room. All I know about proas are that they are most efficient marine design bar none except submarines and that ships are easier to design than sailboats. Lets see how this goes...
     
  5. CT249
    Joined: May 2003
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    Location: Sydney Australia

    CT249 Senior Member

    I'm not going to bet about what I have no reason to know. There is no proof that the creators of sundials, abacuses, etc were laughed at, and there is proof that many of the more recent ideas were accepted very quickly and that criticism of them was generally perfectly reasonable.

    Asking for proof of claims made by promoters is perfectly reasonable behaviour. One doesn't accept claims made by car makers, cigarette companies, tourist destinations or banks at face value so why should we not ask questions of other people who are promoting their products?

    I did assume that Frank was actually talking about technology that is developed within a fairly short timeframe like a human lifespan. If we are talking timeframes of hundreds of years, yes I agree that I was wrong, and that we can't predict what can be created in the future. However, surely we can assume that Frank was not actually looking at a development timetable in the order of 400 -2000 years. If so, he will require very long-sighted investors indeed.

    The nautical developments of which I have some knowledge or experience include assymetric spinnakers, sinker windsurfers, and "funboard" windsurfers. Each one of those was generally received with great interest, great respect, and very fast development. Instances like these are evidence that there is no universal tendency to reject new ideas.

    There are many other examples in which a game changing technology was treated with great respect from the start - for example it was only about a decade between the first powered flight and the design of the first aircraft carrier. Similarly, as Michael Hutchinson explains in his book about the social technology of bicycle development, Dunlop's tyres (the Da Vinci bike is a hoax) were also treated with great respect from the moment they won their first race.

    Yes, some of us may be too quick to take on a negative attitude, however on the other hand it can be said that many innovators are too slow to accept comments and to accept that there may be issues with their designs.

    In this instance, it seems surprising that the promoters of the TankerProa cannot provide simple answers to the questions that have been asked. Given that there are structural requirements for tanker design one would have thought that they could simply have said "we have assessed the structural loads for a MARPOL Cat 1 tanker and confirmed that the tanker proa would pass SOLAS requirements" or something as simple as that.
     
    Last edited: Apr 15, 2018
    rwatson likes this.
  6. chinaseapirate

    chinaseapirate Previous Member

    Yes, some of us are too quick to take on a negative attitude, however on the other hand it can be said that many innovators are too slow to accept comments and to accept that there may be issues with their designs.

    Yes, True. And the #1 issue, at least on this site is "market potential". Although a reality, not really an issue unless your livelihood depends on it and certainly not a concept flaw in either case. In the case of multihulls it has always been lack of parking in larger sizes and lack of accommodation in the trailerable size. In the commercial field it is their incompatibility with landlubber regulations. If you enjoy the status quo this site is for you. If you question or worse embarrass it, you will get sanctioned - with out of context quotes, accompanied with contrived responses, and even your posts deleted. Why is there a separate section for "multihulls" and not a separate one for "leadbellies"?

    "A supertanker is a complex and highly engineered structure, to which you can't add major add-ons without technical consequences for the close within the safety limits designed original structure, it should at least be engineered as a whole to get it structural right."- Of coarse.
    "Now being this far in the project, did you get any fiat of a supertanker designer for this add-on yet . . ?" - I'm ready.
     
  7. CT249
    Joined: May 2003
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    Location: Sydney Australia

    CT249 Senior Member

    Well, there's separate sections for Hobies and Formula 18s (the two most popular cat classes) on the CatSailor Forum, as well as a bunch of other sections. And on the Australian catamaran forum, there's also lots of separate sections - some for popular classes, some for inactive or tiny classes. Over on the Australian Seabreeze site there's a separate forum for windsurfers, one for kiters, one for boat sailors, one for longboarder surfers, one for shortboard surfers, etc.

    So since multi sailors (and windsurfers, and cyclists, and history buffs and everyone else) also divide forums into sections based on a very wide bunch of criteria with no apparent rhyme or reason (which can be as simple as doing what posters ask) then there's no reason to think that there is any bias or other significant reason.
     

  8. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    NASA was created to put a man on the moon
     
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