Hinged Bruce Foil Proa

Discussion in 'Multihulls' started by Manfred.pech, May 7, 2013.

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  1. proagenesis
    Joined: Jun 2013
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    proagenesis Junior Member


    as the name says > see .... http://blog.proadesign.com

    is a test boat for a 3x bigger one >
    already started .... but ???

    see .... http://www.proagenesis.org .... the picture >>>> ” in “

    actually ...
    I never thought of having it at this size for real >
    but since it workes so great ....

    we even made it available by smallboats don elliot
    as a building booklet production ... the shorter > vfp 25 !

    since there was the limit of 25’

    here is some data on both >

    loa 31’ 9.5m loa 93’ 28.5m
    boa 12’ 3.6m boa 36’ 11m
    hvf +7’ 2.1m + 16’ ~ 5m
    total 19’ 5.7m total 52’ 16m

    bowl 20” 50cm wl 4’9” 1.5m
    bodeck 24” 60cm deck 5’9” 1.8m
    draft 10” 25cm draft 30” 75cm
    draft hvf ~ 3’ 90cm hvf 7’ 2.1m
    mast 20’ 6m height 60’ 18m

    the hvf on the 3x will be most likely
    of a more compact geo metry ... then on the test proa !
    because of the stress expected ... and because we dont need
    the scale draft of 9’ on this recreation yacht !

    but contrary to a dagger board .... is striking ground >
    not that big of a catastrophe with the hinged vector fin >
    because the boat doesnt have to come to a hold !
    but will just circle around the hvf tip itself !

    head room ~ 32” 80cm ~ 6’ 1.8m
    up to 42” 105cm ~ 7’ 2.1m

    the head room for the proatest is unter the entrance hood
    if you plan on useing it as a regular boat >

    this could be increased >
    by increasing the freeboard of the hull ... some 6” - 10 ” !
    and on the 3x up to .... 1’

    bunks 2x 7’ 2.1m long up to 12x 8’ ... 2.4m long possible

    dsp 800# 350kg dsp 10 ton

    the float now is a shorter 12’ loa ... 3.6m loa > 1/2 build of the main hull !
    the float of the 3x will be around a 1/3 section >
    of the main hull only .... ~ 24’ ... ~ 7m loa

    sa main ~ 70f² ~ 6m² sa main ~ 600f² ~ 50m²
    roller jib ~ 25f² ~ 2m² roller jib ~ 200f² ~ 20m²
    ww sail ~ 25f² ~ 2m² ww sail ~ 200f² ~ 20m²
    stay sail ~ 50f² ~ 4m² stay sail ~ 450f² ~ 40m²

    sail area is not yet final !
    so far .... there is no reefing > but a storm main sail used
    used with out the roller jib > just the wind ward sail can be !

    the stay sail is on a roller .... too >
    but can be made on a halyard as well !
    since only used in lite winds ..... when there is time ....

    steering through 2x rudder on the side of the main hull
    independant control > mostly the rear one used >
    the front only on changing directions and emergencies !

    through foot sleeves below the cockpit !
    through hand lines on the 3x ?

    see http://www.proatech.org ... rudders etc for more on this .....

    the side the rudders are on >
    can be decided as for the use required
    right now they are on the wind ward side by proatest >

    because on beaching side ways > they are protected then !
    and since the vfp had the fin under the float >
    it was higher on the wind ward side then ....

    on the hvfp now > they may be better on the lee ward ?
    since this type heels a lot more more .... when steering may be ??
    and it is lower on the wind ward side when beaching ....

    you would have to hold them up ....
    when sliding side ways onto a beach though !

    the side they will be on the 3x could be the opposite as well !
    because rudder control is easier > if on the lee ward ....

    the steering effect is not that much .... different !
    actually we could use 4 rudders > one on each side ......

    this project started out as being 61’ loa !
    the tiny 1/24 model > 2’6” loa > you can see on
    http://www.proatech.org > videos !

    then I saw the effects of lenghtening > and it became longer ....
    if I had anticipated this > and being all left to myself now >

    I may have just made a 2x being 62’ loa 24’ boa dsp unter 3tons
    just sitting head room .... more I wouldnt need for myself !

    but now all the frames are done > and the center section finished !
    so its to late for that ! the shortest it could be made now >
    is 72’loa > but the steering is a lot better ... with being longer !

    even though at this size > the speed potential will not be reached
    that often .... and the waves are much smaler for ....

    the big boat !

  2. Manfred.pech
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    Manfred.pech Senior Member

    Everyone who has the illusion to be able to do the work of a navel architect without having studied it, should at least obey one law. If he lenghtens a boat two times, volume, weight, materials and cost rise with X³, that means by the factor 8. If the boat shall grow three times in length, the factor is 27.

    If this law is not akzepted, the result will be wreckage. --- Or a well experienced N.A. will do the modifications.
  3. proagenesis
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    proagenesis Junior Member

    ..... oh my god !

    we have to look at this real close >

    imagine a tri .... having in " his modern version " 3 long hulls !
    and this accompanying bridge deck > to holding the thing together .......

    then we have the cat ... having two equal hulls > and this wide structure to .....

    then we have the traditional proa .... having only ....
    one long hull and this 2/3 float + live balasting

    then we have the back ward development to the harry proa
    where all the accomodation are in the float !!!

    where the crew is exposed to this float not even knowing what to do >>
    going into this nexts wave or over it >

    there while the leeward hull could provide a comfortable ride in any thing !!!

    then we have the vfp > where there is no float to speak off
    just this vector fin ..... holding every thing level ... but following the waves > closely

    and then at the very top of the evolution > we have the hinged vector fin proa
    having no more then one long hull and this tiny float >
    just for keeping the rest of the structure
    from wallowing around in certain non flying conditions > just as a .... racing row boat could have ....
    and then this hinged vector fin >

    needing a minimal connecting structure > since mostly pulling is exerted !
    no twisting or keeping a million other hulls from going their own way .....

    meaning a minimal additional weight to
    this only long hull being around 20/1 fine
    and so low to having a resemblence to a racing .... row boat ....

    now .... can any one bring forward any valid arguments >
    that this will be comparable to the eifel tower or a pyramide

    and the rest being more or less > a high rise massiv structure >

    meaning we are having a lot less of an efford to complete this structure >
    having no fighting at all who will control the horizontal leveling
    nor an excessive connecting structure .....
    no surface to speak of for waves to do any damage ......

    and you are saying ..... you are comparing this ???
    perfect efficiency to the ????

    what did .... you .... study ..... ?

    by the way > if you compare the " proatest " figures >
    above in post 61 .... and the 3x version
    you will find the weight there 27 times ......

    regards the team of proagenesis

    ps ..... who has been designing this AC 72 " artemis " ?
    was this .... by any chance > done by one of your " studied " naval architects .....

    I would never even think of designing such ......

    and if we are going through bft 10 in the straights of gibraltar
    when the pilot boat was having trouble

    what would you be saying then ...... ?

  4. Manfred.pech
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    Manfred.pech Senior Member


    Another case of proafantasy:

    Usually daggerboards in boats of naval architects are combined with a crashbox or another provisions to prevent severe problems in the case of grounding. Centerboards do not need this, because they give away without danger. Both are protected from the boats hull and by far not so extremely vulnerable as a hinged foil in its exposed position which is responsible for the stability of the vessel.

    The "circle around the hvfp tip itself" is another fairytale of proafantasy. Imagine a 15m hinged foil proa weighting a ton coming along with a speed of 20 knots with standing sails, stabilized in its straight movement by the long thin main hull. It has a high moment of inertia and a high resistance to change its direction.

    The crash will happen within 0,50 to 0,75 seconds with the power of 2000kg (20560N) and destroy the foil totally. Then - after the destruction - after may be five seconds - the hull may change the direction of its movement. I have done the math in the "YACHT" forum, where you have just been blocked for the second time within a month. Read it and try to understand it. http://forum.yacht.de/showthread.php?135395-Vector-Foil-Proa/page25

    Proagenesis, alias proadesign, alias Fritz Roth et cetera don`t tell us fairytales. You have had five years to build a real existing hinged foil proa since you have promised it in the "YACHT" forum. Where is your new proa, where are the test results???
  5. groper
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    groper Senior Member

    I agree, if you believe your fin colliding with something solid and the entire boat will pivot around it, you need your mental health checked... There is so much inertia.

    A normal boat is damaged when the dagger hits submerged object. Your design is first damaged, then capsizes in the same scenario... And you think this is safe?

    Why do you keep beating your drum here?
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  6. upchurchmr
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    upchurchmr Senior Member


    Your disjointed writing, with no complete sentences and no complete thoughts are just a waste of time.
    People try hard to respond to you but always seem to not understand whatever you are saying, at least after you spew another load of disconnected words.

    I might take you seriously if you could or would complete a sentence and make an actual thought.

    I can't stand trying to understand what you are saying.

    The pivoted foil might actually be interesting except for your obfuscation.
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  7. CutOnce

    CutOnce Previous Member

    Before the jury condemns and convicts the plaintiff and his ideas, perhaps a little pause is in order.

    Herr Roth is at a distinct disadvantage communicating in English, and as one who lives in a bilingual home, I understand how hard it is to truly grasp the subtleties of a second language. By academic standards I'm bilingual but by idiomatic, slang, cultural and local patois standards I'm not. Many things just do not translate easily.

    There are some theoretical merits in Herr Roth's proposed designs - these are quickly apparent on preliminary inspection. Possible problems are also just as apparent.

    Just because the vocal proponent of a technology is annoying and dogmatic is no reason to discard their ideas. There are other high frequency annoying and dogmatic promoters of technology here on Boatdesign.net that have not been vilified in this manner - perhaps because their English skills are better.

    It is not immediately obvious why technology evangelists fail to prove their concepts full scale and in the real world. Most likely it is lack of resources (money, time, academic skills, experience), intrusion of real world priorities (food, shelter, kids, marriage) or perhaps advanced age and fear of failure. When I see a highly vocal and radicalised technology proponent I try to think they must be really trying to find a "helper" or "convert" to take up the fight for their pet technology and advance it further.

    The bigger problem is that once a technology crosses the threshold of science and becomes religion to an evangelist, their "faith" and bruised ego are engaged in an imagined jihad against unbelievers. Objectivity is lost and the real merits and weaknesses of their technology are forgotten in the mists of emotion. Winning conflicts against anyone perceived as a non-believer becomes more important than proving their concepts.

    I can see the real merits in proa designs - weight, righting moment, efficiency, cost and effort for speed. I can see the sliding hinged Bruce foil's potential benefits, and also see how it's weaknesses should be considered. I wish that Herr Roth would spend more time building a full size prototype of his concept instead of posting here. But then again I've said the same thing about other enthusiasts here on Boatdesign.net.

    I had a discussion with John Harris of CLC Boats about his Bruce foil configuration used on the Ama of his Mbuli design. Why did he not continue the concept on Madness? His answer was brief and clear. The first time he grounded the Bruce foil on a sandbar and walked out on the trampoline between the Akas to pull up the angled foil he snapped the foil off at the exit of the trunk from the added weight. Practical real world problem meets theoretical benefits head on - and like all conflicts between theory and practice, practice won. The frustration of dealing with an expensive repair from a frequent real world problem taught him quickly that the benefits were not worth the risk in his particular case. The best thing about discussing things with John Harris is that he has no design "ego" intruding in his observations about the execution of his ideas. You have to respect people that build full size, real world proof of concepts and let the evidence speak for itself.

    Maybe we should discuss the technology, not the people.
  8. Manfred.pech
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    Manfred.pech Senior Member

  9. CutOnce

    CutOnce Previous Member


    I am holding you responsible for the throbbing headache I now have from trying to comprehend the words written in that threaded stream of verbal diarrhoea.

    I had avoided reading many of the haikus as I do not appreciate the art form. I do however think that self-adjusting, lift compensating foils that can improve performance are interesting and worth understanding better.

    I can think at least one other member here who has been thrown out of multiple forums due more to their behaviour than their ideas. For some reason Boatdesign.net tolerates abusive and combative members more than other forums. I guess that train wrecks and car crashes generate more page clicks and traffic stats than calm, objective reason and tolerant behaviour.

    I am currently self designing and building a day-sailing/camp overnight Pacific Proa to test some concepts for a larger version to come. As a lifelong product development engineering type, I think a little differently than folks like Herr Roth. I think in terms of failure modes, failing safely and comfort and use-ability - absolute performance without compromise/safety is not my thing. One thing I like about the idea is that it can be pivoted up and out of play when not needed - reducing drag, and avoiding trunks, gaskets and failure in shallow water.

    It is not a hardship to place reinforcement for locating the structural elements for the tube on which the hinged Bruce Foil is located on the ama. I may do so to be able to test and quantify the effect it has on the boat. It would be great if the hinged Bruce foil has better net benefit in comparison to water ballast in the design. Trade off is that water ballast may not have as bad a failure mode. It would be nice to have an Ama that automatically adjusted to skim just above the surface at minimal drag and maximum downforce.

    Good news is that as long as I get the structural elements right, I can experiment with the sliding Bruce foil at a later date without compromising the basic design and build schedule.

  10. proagenesis
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    proagenesis Junior Member

    ...... righto !

    regards the team of proagenesis

  11. proagenesis
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    proagenesis Junior Member

    ..... how right you are !

    I want to hereby thank especially manfred pech for all the chances
    finding out about this worlds problems > not just in the sector proa !

    I would not even know what to do with out him ......
    and all the others with such over whelming qualities

    ps ... but we should be .... discussing the hinged vector fin proa now !
    meaning to discussing reality > not the fairy tales of any society or group


  12. michael pierzga
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    michael pierzga Senior Member

    I must admit that this thread has become impossible to follow.

    Perhaps it should be canceled, then restarted fresh.
  13. groper
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    groper Senior Member

    Ok if you wish to continue discussion...

    We have already concern for the vector fin/foil vulnerability and the fact it's responsible for the boats stability... Up to you to show us otherwise...

    The second issue I have with it, is what happens in circumstances where there is large sail effort but low boat speed, ( such as after a shunt or conditions with large wind shift) and thus little restoring force from the foil? Only the boats skipper has to be careful to prevent capsize? One of your videos shows you nearly capsize when approaching a shunt by the looks of it...

    The idea is fine, but to me seems more suited to a racing boat, rather than a cruising yacht... A cruising boat must have stability automatically, not via a secondary means...
  14. upchurchmr
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    upchurchmr Senior Member

    Having lived in Japan with poor language skills I have a great deal of sympathy for those with similar problems.

    However, we have all tried to help those who have second language problems and have achieved reasonably clear communication. It does take work.

    It won't work with someone who will not communicate, but instead says everyone is unwilling to agree because we are all ignorant.

    Time to leave this thread. Pity, I was interested in the concept.

  15. raf pali
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    raf pali Junior Member

    Hello CutOnce. I am doing the same, would much like to exchange ideas. Do you have a blog or anywhere to do so?
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