Affordable seaworthy cruiser

Discussion in 'Boat Design' started by goodwilltoall, Jul 31, 2010.

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  1. wardd
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    wardd Senior Member

    simple solution, always sail so the wind is from starboard
     
  2. BATAAN
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    BATAAN Senior Member

    Oh, so that's what 'great circle course' means.
     
  3. Pierre R
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    Pierre R Senior Member

    He says this in his last post
    You double what he shows in the drawing and its pretty close. He has the symetry drawn in to make that possible. He is not totally off in his line of thinking. His conclusions are what is off the mark.
     
  4. peterAustralia
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    peterAustralia Senior Member

    hi

    the square grid is one foot units yes? seems a quite large craft, costing a lot to build

    You seem to have increased the draught to about 3ft, which is OK, but you loose your original intention of shoal draught. Such is life as they say.

    More seriously, if you move the wheelhouse aft so that it is above the engine, you will greaty increase interior space. A vee bottom will allow for engine to be lower, between the vee bottom and the flat floor is the logical place to put fuel tanks and water tanks, in that as low as possible.

    Your wheelhouse seems 8ft high from the floor, 6.5ft would seem better, smaller windows would be much safer

    move wheelhouse aft, smaller windows, a vee bottom with a small amout of deadrise, and increase beam to 10ft and you are should have something that will work.

    have you ever thought about a multihull, for low cost, low draught, low weight, it might be better. There is one called about face a 50ft atlantic proa that is of similar size and weight, seems a cost effective alternative, it is seaworthy, fast, simple and easy to build
     
  5. goodwilltoall
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    goodwilltoall Senior Member

    Greetings,

    Fuel tanks are symetrical, 85 gallons each side in engine room, 175 gallons each side under berths, and 30 gallons under steps, all below the waterline.

    Whether wheelhouse is moved aft or not, to get more room in berth area there would need to be a raised deck house. As is, the engine room uses complete height of the hull, which after scantlings its about 4.5'. That height is also the right measurement for sitting in berths and helm.

    Full keel increases draft but is needed for engine power as the hull rides flat compared to sail design.

    Scantlings are whats needed for intended purposes, you can go thinner but savings are minimal. Total costs for timber are$2,000.00. Do the math as see for yourself.

    Considering forefoot (Bolger calls it "cutwater"), if going this route would upsweep some more to bring bottom 1" above waterline. The bow has about 5" more to be within 5' height restriction, this would aid with better turning as the boat will travel like a bullet train with hard chines, full keel, balanced shape, and long length (very easy on helm and autopilot), adding bouyancy forward cant hurt either.
     
  6. goodwilltoall
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    goodwilltoall Senior Member

    Another thought: In this part of hemispere, winter is beginning to set in therefore, epoxy construction is out of the question (no shelter or indoor building ideas) so steel construction is being considered.

    Rough idea of scantlings and construction:
    1) Bulkeads laid upside down and welded with temp. crossbraces.
    2) 3/8" x 2" stringers set into bulkheads and frames.
    3) 3/8" plate for sheathing.
    4) Hull flipped.
    5) Radius for deck cut out of bulkheads.
    6) Stringers for deck and 3/16 plate on top.
    7) Deckhouse and wheel house welded up.

    Basic idea with 9,000lbs steel, if buying today in Cleveland - $.70 a lb for $6,300.00 total.

    Apply polymer cement or coal tar epoxy inside. How much would sandblasting help?

    Small angle brackets in stringers welded to screw in 3/4" x 3.5" wood athwarts then 1/2" paneling. This allows circulatiing air convection in living areas to keep dry and small amount of insulation in living areas, thus eliminating foaming.

    Follow Swain methodology for balance.

    Little more expensive and heavier but it has merit. Hear the laughter already and so what, idiot responses get voided and good reasoning is taken in.

    Peace.
     
  7. erik818
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    erik818 Senior Member

    Goodwill,
    Don't give up wood/epoxy just because it's cold. I've used the coldest part of the winters for manufacturing frames and to do other preparations indoors in my garage. As soon as spring approaches and the outdoor temperature rise a few degrees above 0 deg C it's possible to work with wood/epoxy outdoors. You will need a tent or a shed to work in anyway, and if you apply lots of heating when needed the temperature will be OK for epoxy. I've used West System epoxy with the fastest possible hardener for low temperature work. In the middle of the summer I use another, slower, hardener.

    Erik
     
  8. MatthewDS
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    MatthewDS Senior Member

    I guess it depends. How badly do you want your coating to stick. If you don't mind the paint falling off after you coat it, then by all means skip blasting.
     
  9. peterAustralia
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    peterAustralia Senior Member

    3/8" for sheathing in steel!

    you have got to be kidding, if you look here, these heavily built barges are using 6mm steel plate

    http://www.dutch-barge.co.uk/anglodutch/design.php
    I am pretty sure from memory, that steel sailing yachts use 3mm steel plate.

    The dutch barge is not designed to be fast, but rather strong, robust and spacious, thus it uses thicker steel for plating as opposed to a yacht

    My cousins yacht is made of 3mm steel, is 26ft long, and about 10ft wide. It has a 1m draught by way of twin bilge keels. His yacht has a steel hull but wooden topsides, it seems to work well,

    Going wooden topsides for your craft would be a good way of reducing topweight.

    Have you noticed the similarity between your craft and these dutch barges? Both around the same length with long narrow hullforms. Notice the beam on these craft? Also if you go for a narrower hull and with the height you have you will have stability issues. So you need to add a lot more weight down low in terms of ballast.

    So the extra ballast you add, more that degrades and fuel efficiency gains from the finer hullform.

    Apart from the dutch barges seen here, from memory there were some smaller ones too.

    Also, notice that according to the website, just the steel work delivered to the UK is fifty thousand pounds, which is what, approx $100,000

    A completed vessel is 200 thousand pounds, or about $400,000 US

    So steel is strong, not always cheap... and 3/8" is going to cost more that 3mm.

    Go to Indonesia...
    If you cant afford to have it built there.. then you cant afford it at all

    You also have the option once there, when it starts to tip over, to add an outrigger to make it a multihull, as it almost certainly will with your present configuration
     
  10. pdwiley
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    pdwiley Senior Member

    There is no way that you are going to build a 50' boat in steel for $12,000. Go and read the threads in the steel boat building forum. I am not going to bother posting all the reasons why this isn't possible as it's all been said before.

    PDW
     
  11. Pierre R
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    Pierre R Senior Member

    I am in sheer utter amazement. What a thread! Goodwill I think you need some more study on scantlings.
     
  12. breschau
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    breschau Junior Member

    I am a comfort loving landlubber and that is a glorious bathtub.
    Still, I fell off my chair more than once trying to read all the 46 pages in one go. More power to you mr. goodwilltoall.
     
  13. TeddyDiver
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    TeddyDiver Gollywobbler

    :D Concur..
     
  14. BATAAN
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    BATAAN Senior Member

    N.G. Herreshoff's 1909 WESTWARD, at 135 feet overall and setting 12,000 sq ft of sail, had 1/4" hull plating, or 6.4mm. Typical small steel yacht built in Holland has 3mm hull plate, or less than 1/8".
    3/8" is what a big work barge would be skinned with, and the scarred, burnt workers would be using a fork lift and boom truck to do the job. Having spent 30 years as a yard worker, I can speak with authority on the matter.
    Absolutely the cheapest way to build a one-off yacht is plank on frame, nailed, and you can work in the winter outside. Ask the guys in this photo. They'll skid their nice little schooner to the water over the snow when they're done. No epoxy or other fancy stuff and it should last at least 30 years of commercial use.
    Why oh why invent the square wheel? 50,000 years of boat use has taught us a bit about how to build one.
    Boards and nails, how complicated can that be? For some reason we seem to have a need for greater and greater complexity in our lives, and building a simple sharpie-yacht doesn't have to go there. Look around and see there are many small sawmills that can cut planking and frames for a reasonable price and Tremont nail company still sells galvanized boat nails.
     

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  15. goodwilltoall
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    goodwilltoall Senior Member

    Greetings,

    Peter: Big mistake on my part. It is not 3/8" but instead 3/16" (4.5mm). Figures were 1,200SF total at 7.5lbs per SF equalling 9,000lbs. 1/4" (6mm and 10.0lbs per SF) would be to heavy and 1/8" (3mm) to light as well as harder to weld. When the full keel is also added and miscellaneous pieces it would actually be about 11,000lbs needed.

    Thought about it more, and would foam seal as only the living areas would need it. Going with steel would be fine for this boat since it has five watertight compartments but would not do it on sailboat.

    The dutch barges are not similar; 4-1 LB ratios, hull height much higher than 60% of beam (they are really top heavy), and besides the bluff bows.

    No reason to goto Indonesia, 11,000lbs steel delivered to your door for $7,700.00, doubt if you can get cheaper there let alone trying to do business in a foreign country. By the time you got over jet lag, paid your airfare, and lodging, a crew would have it built and for less.

    Wood topsides are prone to problems, might work for cousin maybe he deals with it on an ongoing basis. BTW, mention was made it would be heavier and cost a little bit more. Lets say $20,000.00. You guys keep throwings numbers around ($200,000.00 - $400,000.00), with no basis. Factual costs are given for particular materials so you cant keep arguing about that, you can believe otherwise buts it just an opinion.
     
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