Question regarding Ocean Rowing Boats...

Discussion in 'Boat Design' started by Oarswoman1, Apr 5, 2012.

  1. Skyak
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    Skyak Senior Member

    Seattle to Australia human powered, WOW! That's an exciting commission.

    I am wondering about the length vs wetted surface area. My thought is that optimal length is set by the thrust and would be several feet shorter for a single rower. What am I missing? Seakeeping? Human factors? Room for 5 cubic meters of ramen noodles?
     
  2. Eric Sponberg
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    Eric Sponberg Senior Member

    All of the above. Ocean rowing boats go really S-L-O-W, so wetted area is really of secondary concern. Whether you are long or short on wetted area, you would not be able to tell the difference, much, even over the long term, of the difference in friction or thrust force required to propel the boat. Length to beam ratio may play a more important part than wetted area. In fact, our new design has a deep keel on it for good directional and transverse stability.

    Many other factors will determine the overall average speed. Seakeeping and stability are huge factors, as are human factors, and yes you do need to have space to hold nearly a year's worth of supplies. At 28', this boat is not the longest--there are a number of others in the history or rowing that knock on the door of 30' and above. By the same token, the modern history of ocean rowboat development reveals boat lengths of 24' to 26'. So the desired range for a new boat, based on a parametric study of existing designs, points us toward 28' LOA. A length of 26' may be marginal and too light in displacement, and a length of 30' will be too great and too heavy in displacement. My thinking brings me to 28'. I hope to be able to show more soon.

    Eric
     
  3. RHP
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    RHP Senior Member

    Fascinating Eric, you will have a large audience. I've had a long held dream to single handed row an ocean. Long and light would be my preference rather than short and squat and your deep keel ticks my boxes for directional stability and self righting. I also like the ability to pump additional ballast weight when the wind picks up, conversely allowing a reduction in weight in smooth seas. I realize carbon is all the rage these days however in terms of value for money, is there any chance the design kit could be CAD cut in plywood for example for us paupers?
     
  4. Eric Sponberg
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    Eric Sponberg Senior Member

    Thanks, RHP. At the moment we are concentrating on shape and volume in the hull form, which necessarily is being developed with a round bottom (and round top). We're really early in the design phase. Construction is anticipated to be epoxy-glass-core composite, although carbon fiber is on the table because there are a number of builders available in the northeast US who are particularly specialized in carbon fiber boat and component construction. I think that for ease of construction in plywood, a new developable-surfaces hull form would have to be developed, and that would require a different design effort. So no, this particular design will not be available for plywood construction. The overall design parameters, however, may lend themselves to plywood construction should someone want to pursue that effort.

    Eric
     
  5. gonzo
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    gonzo Senior Member

    You have to take into consideration that most of the "rowing" is simply drifting downwind on the trades. Those boats are pigs to row, but they have enough windage to make them move downwind fairly fast. One, which won the race, had such an extreme design that was called a "spinnaker cabin" .
     
  6. RHP
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    RHP Senior Member

  7. SukiSolo
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    SukiSolo Senior Member

    However, for east to west Atlantic crossings it (the 'Spinnaker boat) might not be quite so useful!. Latitude dependent, but certainly from the UK or France....;)
    Maybe the start for the main race (Canaries to Antigua) should be moved a thousand + miles north....;) the sort of challenge Mr Blyth would really like to see!. After all if you sail the 'wrong' way round the world, how about rowing the 'wrong' way?

    Good luck with your work on this one Eric, an interesting adventure in it's own right.
     

  8. gnioco
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    gnioco Junior Member

    Hi,

    Thank you for answers. Basically I am searching a design for a 1 man ocean rowing boat. The boat has to be self-righting, lightweight, .... The plan is to build a purpose boat to cross the Atlantic ocean (Canaries -> Caribbean). No commercializing ambitions, and race winnings...only fulfilling personal dreams and desires. Of course someone will say - buy a used boat. But I want to build one, since I have skills and time. Boat will be build in foam / fiberglass sandwich method. I dont have any problem with the big, catching wind cabin (Open class design), at most, I would prefer that design.

    Basically I dont have the idea how much would cost the design. I am open for offers.

    Thank you in advance,
    Kind regards,
    Nejc
     
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