small, long-range boat design

Discussion in 'Boat Design' started by allwet, Jun 5, 2014.

  1. Rurudyne
    Joined: Mar 2014
    Posts: 1,170
    Likes: 40, Points: 48, Legacy Rep: 155
    Location: North Texas

    Rurudyne Senior Member

    Boats are kinda like beer: you should have/drink the best your wife thinks you can afford. ;)
     
  2. erik818
    Joined: Feb 2007
    Posts: 237
    Likes: 20, Points: 0, Legacy Rep: 310
    Location: Sweden

    erik818 Senior Member

    I agree with wavepropulsion that a traditional 7 m lapstrake double-ender isn't optimal for a speed of 6 knots or greater. Based on the performance of my boat, and calcuations I made on an improved hull form, I believe that it's possible to meet allwets erquirements in post #33, except that I doubt that 1800 kg displacement can be met (or maybe shouldn't be met) with 150 gallons of diesel + personnel, consumables and equipment on board. Also, the interpretation of "safe and cozy in such storms as one would encounter" has to be very liberal.

    I calculated with a LWL of 7 m and a BWL of 1.4 m and a maximum displacement of 2.5 tonnes. The boat needs to be fully decked-over and self rightening both with and without all the fuel. Designing it to be self-rightening with and without fuel is a challenge, made easier if you intentionally design with extra weight at the bottom, e.g. a sturdy steel-reinforced skeg.
    Erik
     
  3. SVO
    Joined: Nov 2011
    Posts: 8
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Germany

    SVO Junior Member

  4. wavepropulsion
    Joined: May 2010
    Posts: 91
    Likes: 5, Points: 8, Legacy Rep: 29
    Location: Uruguay

    wavepropulsion Pirate Member

    Looks as a very smart design. 10 miles per litre at 5 knots is exactly what I suggest as rational for a boat this size. More fuel is more weight and more boat. And if the boat is slimmer and longer will be the same drag but longer wave, faster, with less headroom but less windage. Don't know if better, just what I have in mind.
    A small jib can help in balance and also as auxiliary propulsion, or for motorsailing; the mast helps if turn turtle.
     
  5. Yobarnacle
    Joined: Nov 2011
    Posts: 1,747
    Likes: 130, Points: 63, Legacy Rep: 851
    Location: Mexico, Florida

    Yobarnacle Senior Member holding true course

    Anybody besides me notice a resemblance between these two boats?

    The second picture is one of my Albin 25s (a free boat, only bought the trailer) as I first saw her. The Albin is bigger, 25 ft X 8.5 ft beam and 6'1" headroom in main cabin. And designed for North Sea, very stable. And has an AFT sleeping cabin as bonus.

    The 3rd illustration is the Albins fuel consumption and range ect with the 20+ HP original diesel. With no alteration in hull and zero ballast, a sailing rig is available for the Albin 25. Weight without liquids, crew or provisions, 3800 lbs. You don't have to build it. Buy one used! :p
     

    Attached Files:

  6. wavepropulsion
    Joined: May 2010
    Posts: 91
    Likes: 5, Points: 8, Legacy Rep: 29
    Location: Uruguay

    wavepropulsion Pirate Member

    Yes, quite similar, but the Albin looks a bit better also. I copyed the table of consumption, is amazingly efficient in a wide spectrum of speeds. Also 10 miles per liter at 5 knots. This boat can do the job.
    I read now is a swedish classic. You know of something similar to build?
     
  7. Yobarnacle
    Joined: Nov 2011
    Posts: 1,747
    Likes: 130, Points: 63, Legacy Rep: 851
    Location: Mexico, Florida

    Yobarnacle Senior Member holding true course

    The Albin 25 also made it on Motorboating and Sailing's list of 100 best ever built fiberglass boats. So I picked up two Albin 25s. One with sailing rig for $1000 and the other Albin free to haul away, but had to buy the trailer for $500 and another $500 for tires. Didn't have any. So, worked out it cost me $1000 each and a new tired trailer in the bargain.

    So I don't know of any similar construction plans.
    I'll post the lines and other documentation if you want?
    I know. I was lucky. Thank you Lord!


    Search Albin 25 on Craigslist
     
  8. Yobarnacle
    Joined: Nov 2011
    Posts: 1,747
    Likes: 130, Points: 63, Legacy Rep: 851
    Location: Mexico, Florida

    Yobarnacle Senior Member holding true course

  9. Rurudyne
    Joined: Mar 2014
    Posts: 1,170
    Likes: 40, Points: 48, Legacy Rep: 155
    Location: North Texas

    Rurudyne Senior Member

  10. wavepropulsion
    Joined: May 2010
    Posts: 91
    Likes: 5, Points: 8, Legacy Rep: 29
    Location: Uruguay

    wavepropulsion Pirate Member

    Thanks Yobarnacle, I was searching about and the most interesting material I found was that one you posted in another thread in this site. But you can post it again here cause the Albin compliment this thread, specially in:
    1) A powerboat this size is seaworthy and able for long passages in relative confort.
    2) Fuel consumption must be calculated based in hp per ton and Froud numbers in combination. Extra hp as reserve.
    3) Is not a new idea, but with new engines and new construction methods are a margin to improvement, specially in weight.
    4) Motoring can be cheaper than sailing in long distances also and is another realistic choice to consider.
    Where I live I can't buy an Albin, may be a wooden dory, but can be a good solution for allewet.
     
  11. Yobarnacle
    Joined: Nov 2011
    Posts: 1,747
    Likes: 130, Points: 63, Legacy Rep: 851
    Location: Mexico, Florida

    Yobarnacle Senior Member holding true course

    some for sale in texas too.
     
  12. Yobarnacle
    Joined: Nov 2011
    Posts: 1,747
    Likes: 130, Points: 63, Legacy Rep: 851
    Location: Mexico, Florida

    Yobarnacle Senior Member holding true course

    here are the lines, I enhanced definition for clarity.
    You might be able to take a wooden dory of near 25 ft, and a little less beam than the Albin 25, add on some external wood frames and fair with foam, outside the dory hull. If it's final form was like the Albin, it should perform like the original Albin. Of course glass it over.
    You wouldn't need to copy the Albin entirely, but if you copied the submersed areas, including heeled submerged areas, it should have the hydrodynamics like the original.
    if it turned out a little bit heavier, the stability of the Albin 25 according to the designer Pers brohall, uncapsizable. That's why she can sail without internal ballast. all that foam would probably make her unsinkable and super well insulated as well. :)
    Just food for thought! :)
    Bueno suerte!
     

    Attached Files:

  13. wavepropulsion
    Joined: May 2010
    Posts: 91
    Likes: 5, Points: 8, Legacy Rep: 29
    Location: Uruguay

    wavepropulsion Pirate Member

    Good idea, but I mentioned dorys cause a better boat shape is unavailable at budget here, and I mean I will do a build (my english is not very academic, can confuse sometimes). Still in a project for a sampan with the carachteristics mentioned in this thread from one year ago and cause this I engaged in the discussion. If you see post #34 will see what I suggested, the FAO boats are scandinavian design also and very similar or same to the Albin, just narrower 1.8 to 2.1 meters beam. Seaworthy boats and probably more economic to run, just less yacht and more working boat confort.
    My former boat was a smaller multichine sampan like shape and I was amazed about characteristics and economy too. Much choices can be done, also a classic dory as the Cape Ann is not a very bad option, the most important is displacement lenght ratio and then the hull shape.
    I will save your drawings in my computer for my studyes, thanks again.
     
  14. Yobarnacle
    Joined: Nov 2011
    Posts: 1,747
    Likes: 130, Points: 63, Legacy Rep: 851
    Location: Mexico, Florida

    Yobarnacle Senior Member holding true course

    my pleasure
     

  15. SVO
    Joined: Nov 2011
    Posts: 8
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Germany

    SVO Junior Member

    Guude,

    Pazappa ist ein Aluminium Boot konstruktuiert und gebaut von D.Jackman Australien
    Knickspant mit gerundetem Achterschiff,schau Duckworks.
    Albin 25 Rundspant in GFK Schau hier http://www.albin-25.nl/

    Viele Grüße SVO
    aus Deutschland
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.