Democratic boat design & some help

Discussion in 'Boat Design' started by jiggerpro, Dec 11, 2007.

  1. jiggerpro
    Joined: Sep 2007
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    jiggerpro Senior Member

    Dear boatbuilding colleagues, I am a “soon will be boatbuilder” living in the Canary Islands – Spain who will soon start the adventure of building my own 32 X 9,5 beam feet sportfisher, it should be powered with two Suzukis 300, after designing and refining my design for a couple of years now, design, which is styled 80% American 20% European ( from my humble point of view) I would like to hear your opinions about it, as I am a firm believer on hearing others ideas for my design to enjoy the widest consensus possible. In fact I would like this thread to become an exposition of the most objective criticisms in order to refine further more the design and make a “democratic boat”.
    The boat and parts will be made with vinylester resin in female moulds and infusion as much as possible.
    I would like to hear your expert advise which will be much appreciated in the fields of:
    -Design
    -Fiberglass reinforcement recommendations advising on weigh and number of layers of reinforcement
    I can send the 3D design with all measurements to anyone who uses rhinoceros, or I can send the file converted to any format which rhino can make to anyone willing to give some help.
    Here are some pics to take a look.

    Thanks in advance, Jose from the Canaries
     

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  2. BWD
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    BWD Senior Member

    Looks nice. To this american it looks more than 20% euro, not that that is bad.
    But
    Why not an inboard?
    There are a lot of advantages to inboards when you go for big fish....
    I am just an amateur but I might want it to be more like this picture, with or without the skeg...:
     

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  3. jiggerpro
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    jiggerpro Senior Member

    Hello BWD, everyone is an amateur in some moment, so you should not feel ashamed of it, i also regard myself as an amateur at the present time, but decided to make the transition.
    About inboards, they use a lot of space, are heavier, and nowdays i would say are not as reliable and efficient as a modern top of the line outboard, not to mention they are slower. on the other hand inboards offer a cleaner cockpit and transom which is good, but i feel this is their only advantage which can not compensate their other drawbacks.
    Your modification looks better than my original, due to the cleanness of the transom but my opinion is that outboards offer a good pack of advantages when compared to inboards that go far beyond beauty.

    I would consider the use of outboards, as an American feature ( in Europe many peple prefer inboards ) and the large console should be considered an "Euro" feature since here people do not accept that a 32" boat only has enclosed space for a toilet and not much more like is often the case in American center consoles, I would say the general feeling here among boaters is that the available space in a boat should be more evenly distributed, in order to have a more polifacetic boat. and so a large enclosed volume in the console allowing sleeping or resting for two is considered an absolute neccessity here, having in the bow a mega lot of space ( much more than neccessary for fishing) at the price of not having enough for resting is not generally accepted. take a look at the pic I include now so you can see the enormous size of the console compared with American general taste.
    I appreciate very much your comment.
     
  4. jiggerpro
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    jiggerpro Senior Member

    Maybe this pic will be more ilustrative of the concept
     

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  5. jiggerpro
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    jiggerpro Senior Member

    or better still making use of the fabulous 3D tools thst rhinoceros offers ...
     

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  6. Pericles
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    Pericles Senior Member

  7. jiggerpro
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    jiggerpro Senior Member

    Hello Pericles, truly good looking boats both, the Jarrets and the Carolinas plus quite informative links ... Still, no one has given any advise, not even an approximate one in regards to the weight and number of layers fo fiberglass for the hull ...
     
  8. rwatson
    Joined: Aug 2007
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    rwatson Senior Member

    Anyone who can afford two 300 hp engines can spend a few thou with a naval architect to do the scantlings and bouyancy calcs.
    You are no-where near the start! you have a looooong way to go before you even order the materials, and you have no idea how much or what yet, do you.
    Dripfeed hints and guesses on this forum will only agravate you and the forum members who try to convince you that assembling the whole picture can only be done by a dedicated, qualified paid team - democracy is ok for decisions, but lousy for definitative, well thought out and well engineered ideas.
     
  9. Willallison
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    Willallison Senior Member

    Yep.... what rwatson said....
    What you have is preliminary - if pretty - model. Given the cost of setting for series production, the cost of using a proffessional designer to take what you have and refine and complete the process, will not only be a very small proportion of your total outlay, in the long run, it may well save you a great deal.
     
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  10. jiggerpro
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    jiggerpro Senior Member

    I suppose Mr rwatson asumes, I am not going to hire the service of the professionals at my reach ....something I do not know where he got from. not to mention his prophetic ability to know what other members of the forum may feel like aggravation. Off course that if twin 300 can be aforded, a profesional team will be paid it is only (like already said) that I believe in hearing diverse opinions ....... just like when going to the doctor despite him being a good profesional .. you better get ready to hear diverse opinions if you do not want to put your health just into one person opinion. and of course, we know there is a long way to go, in fact the building which will hold the workshop will not be finished in less than 8 months ( already started by the way) . On the other hand where I live there are no boatbuilders ( naval architechts yes) at all, so what could be wrong in trying to hear what much admired American boatbuilding colleagues have to say ?
    I thought that this was forums where great for, to share ideas, learn and teach when possible. Naturally those not inclined to do so can simply ignore the posts, no reason to feel aggravated.
     
  11. jiggerpro
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    jiggerpro Senior Member

    About what Mr Willallison said, in a much friendlier tone by the way, I only have to completely agree, we will hire the service of a naval architect, among other reasons, because the law makes this obligatory if you are to legalize the boat ........ so simply put, you can not do without a naval architect even if you wanted to, which is not the case, I am a civil engineer myself and fully understand the benefits and convenience of relying in to the knowledge of professionals in the diferent fields of knowledge.
     
  12. Pericles
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    Pericles Senior Member

  13. kmorin
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    kmorin Senior Member

    Remarks on lines of preliminary model

    jiggerpro,

    I don't know anything about GRP- infusion or otherwise- boats' construction; but I would like to remark about the design overall.

    First, I like the split sheer line, I always think of the Rybovich Yachts in the SE US when I see that 'leap' in the forward sheer. Its a very bold line in my opinion and the rest of the boat is pretty boldly shaped in accordance with this line. Not sure if this is Euro or Ami lines but they're bold and proud.

    I would like to see you experiment with a slightly concave curve to the after sheer; which is just a little straight to my eye. It's not homely as drawn, but that little cup seems to me to enhance the beauty of the forward line's strength. In addition to that, I'd like to see some convex camber across the transom even it will have a cutout for the outboards. The hollow of the sheer aft of the intersection of the bow line departure coupled with a rise amidships in the transom makes these lines more appealing to me, especially from a 1/4 view on the beam forward or aft the hull.

    As a sport fisherman that might be trolling or working fish over the stern in a follow sea I wonder if just bit more transom would make her more dry? I find that if they can be curved, in plan, and even raked aft a few degrees, transoms seem to have less vertical slop in a short sea against the stern than the more flat plane shown.

    In the plan view shot I like the forward 'deck' or sheer clamp and it would be more attractive if it were slightly more narrow in overall proportion. If the inboard curve is already vertically above the deck-to-topsides intersection line, then moving the inner coaming of that deck outboard may be unsound. On the other hand, I'm only remarking on a very small proportional change that I think would give the look a bit more sleekness -and perhaps only in my view.

    I like the T top treatment and the way it complements the console structure. I'd would enjoy seeing this shape with a convex camber echoing the console's top surface; not as deeply curved, perhaps, but still other than flat.

    The leading edge of the T-top might be swept to recall the leaping sheer and the nicely curved foredeck especially if the two curves were similar in plan. Combining a plan view curve for the T-top's leading edge with a camber, transversely, it would seem you might have a line that would relate that curve to the bow's line at the sheer.

    If I were building a boat this large I'd research the idea of cantilevering the outboards on a bracket to get the most push for the hp. Moving the engines aft will give more deck too, but it may be more work to fish over the outboard the farther aft they hang. This move, though, could allow some more shapeliness in the stern in both directions of that plane. Curves in plan and a rake in profile make following sea handling a bit less work, especially backing down in a swell on game fish. I don't see either shape change as harming her very fine looks.

    All of my remarks are about small possible adjustments to her lines. The resulting looks are what would make her a bit MORE sweet- and only to my eye, it's already a nice design with exciting looks.

    Cheers,
    kmorin
     
  14. jiggerpro
    Joined: Sep 2007
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    jiggerpro Senior Member

    hello kmorin, thanks for your altruism, time and objective approach, your input is exactly what I was looking for, hear what "other boatdesigner brains" have to say about styling, beauty and practicality of my design in order to modify in the direction of improvement whatever necccessary.

    About the straightness of the rear section of the sheerline, I tried ( in earlier versions of the design) keeping it curved, but not concave, I think that keeping it concave as you suggest will inevitably lead to having some portions of the rear section of the sheer lower than the transom which maybe will llook awkward, I also believe, that the straightness of this line section gives the design a "mix of ruggedness and clasic lines" which are reminiscent of the much admired SE US designs.
    About the transom is raked aft 6º in order to allow the power trim of the outboards to allow to push from under in order to give some stern lift if neccessary. about rising the transom, this will make a need to lift the height of the rear section of the sheer making stand up fishing less comfy than with a mid thigh height, about making the transom curved instead of flat you are very probaly very right, It will certainly look better, I just though that with the outboards in place a slight curvature would pass unnoticed, but there are the small details what makes a good design a better one so I will implement your suggestion into the design and soon post the modifications draws.
    About the "forward deck" it also seems to wide to my eye, but the bow flare under it forces it to be this wide or the line between your toes and thigh will be inclined outwards of the boat making the anglers balance more critical and causing a less ergonomic position ( humble points of view ) but I will strill try to move it a bit outwards the thickness of the coaming ( and let you see it soon)

    About the T-top I completely agree with you it wil look so much more graceful and nice to implement some curve .... but my reason to do it straight are that curved lines are much more prone to "catching" wind unless the boat is travelling along the wind direction causing aerodinamic drag, the reason of its flatnessis is also because the center area of the T.top is made of canvas and removable in order to avoid unnecessary drag when making long travels at speed ( at the price of not having a lot of shade ) and tensioned canvas, only knows straight lines but not only are we trying to make a beautiful boat, we are trying to make it efficient as well so its a compromise.
    The reason of this intent to make T-top surfaces as small as possible is to avoid the drag that a large T-top invitable causes when the boat travels slightly tilted upwards as is almost always the case. Again what you suggest, could improve the looks quite a bit so I will see what I can do.

    Engines on brackets are not aesthetically accepted by euro minds, proof of that is that I do not know of even one euro builder that uses them, most of the people here think ( when they see some of those boats in American magazines for example ) that this engine installation way looks extremely awkward and bizarre ( I do not completely agree but yes to a certain extent) despite the fact it might bring some advantages in efficiency.

    I never though I could be discussing boat design with an Alaskan man but have to say it has been very interesting. If you can use rhinoceros I can e-mail you the original drawings so you can tweak the design yourself if so let me know. meanwhile I will try to implement your slight refining touches and soon post them. for a reevaluation.

    thanks from the other side of the pond, Jose
     

  15. jiggerpro
    Joined: Sep 2007
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    jiggerpro Senior Member

    About mr rwatson´s assumtion of me not knowing where to start about materials thickness etc, once again his "glass ball" needs some adjusments, we plan on starting by using specialized reinforcements made specifically for infusion for example those made by Vectorply Inc, they also have Vectorlam a free software downloadable from their web page to help in the calculations of scantlings, not to mention there are also scantling rules and methodology in Dave Gerrs "The elements of boat strenght" quite easy to follow or Macnaugthon´s small booklet on scantlings for fiberglass. Not to mention that many well stablished vendors of reinforcement will gladly through their technical consultancy services give you the scantlings or suggestions based on many boatbuiders experience ... so once again, mr rwatson is wrong in his assumptions of others knowledge or ignorance.
     
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