Double end power boats?

Discussion in 'Boat Design' started by duluthboats, Jul 7, 2003.

  1. Marko
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    Marko New Member

    Squat boards

    To all,

    How many of you remember the use of squat boards on traditional Chesapeake Bay workboats. Chapelle mentions them (I have forgotten where) and there are also some illustrations in Harry Sucher's books on Simplified Boatbuilding. This idea should be given some thought. Since they could be employed like trim tabs, they would be most effective as speed increases, dynamically eliminating settling of the stern as planing speeds are approached.

    Comments?
     
  2. gonzo
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    gonzo Senior Member

    They call them "hobbles" locally. They developed to correct the squatting on sailboat hulls converted to power.
     
  3. Tom Lathrop
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    Tom Lathrop Junior Member

    I guess that I'm the outcast here since I like the look of properly proportioned transom sterned boats. I do see some "double enders" that appeal but many seem to look a bit forced. Tad is certainly right in that the shape of the stern above the water has nothing to do with the boats performance, displacement or planing. It's all in the shape under water. The traditional double ended pangas of Latin America grew the under water wings, whatever they are called, in order to take the large outboards that they now use. Calkin's Bartender is often fitted with these also in an attempt to keep the stern from squating so much when planing.

    If a boat is to plane and be efficient doing it, it must lift the forward hull out of the water to decrease wetted surface. This requires that the stern be depressed to take an efficient trim angle to develop adequate dynamic lift to support the weight of the boat. A true double ender is not going to like this since there is insufficient lifting surface back there. Planing double enders do so in spite of, not because of, the pointy stern.

    Long narrow boats with double end bottoms like Weston Farmer's Coyote are designed to make reasonably high speed in the upper teens and are very efficient doing it. I doubt that anyone could be a success at selling such a boat though. Martin's Energy 48, built during the 70's fuel crunch, was a good example and like the Memory, it did not sell.
     
  4. Willallison
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    Willallison Senior Member

    ...nope - or if you are, we can cast out together! I hate powerboats with pointy bums - except for a very few heavy displacement passagemaker types
     
  5. gonzo
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    gonzo Senior Member

    Flat bottom double enders with no rocker plane well. However, you got to withstand the pounding. It is not as bad as on a skiff.
     
  6. waterman
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    waterman Boat Geek

    Double enders do plane

    I saw that statement and was surprised. Has every one forgotten the designs of George Crouch? Baby Bootlegger and Typhoon were both double enders! (Although I'm not sure if they have stepped bottoms or not....(which might be considered cheating)).
     
  7. djwkd
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    djwkd Senior Member

    Hi-my friend would like to build this boat so i need to ask the specifications and if you could give me free plans!!!!!!!I Also hope that this post will bring the thread to life.PS:sorry if this is a double post!
     
  8. SC1
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    SC1 Senior Member

    What do you think about this Miss?
     

    Attached Files:

  9. FAST FRED
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    FAST FRED Senior Member

    Tad And Tom are right , boats are sold by the LOA /visable internal room equation.

    Efficient long slim boats are out of style as slip space is sold by the LOA , not sq ft of boat.

    So the 40loa by 22 beam is a winner in the market place. To move it requires massive power , so "mine is bigger than yours" power rating , is a plus for the dockbound boat owners.

    Actually the boats "owner" is a bankster some place that allows the purchaser to operate the boat between payments.

    How much it "Costs" is never the question , "how much per MONTH " is.

    This probably wont change very much during our lifetimes.

    If you want to see efficient boats , look on a mooring , not dockside, as a knowledgable owner has no need for the power hose, and its expenses.

    A mooring can run 1/20 to 1/50 the expense of a slip, or less, and LOA is no problem.

    FF
     
  10. Guillermo
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    Guillermo Ingeniero Naval

    Big and sad truth!
     
  11. djwkd
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    djwkd Senior Member

    Does anyone KNOW the specs???(sorry about caps-im on quick post and can't do italic)and does anyone actually HAVE the plans????
     
  12. tom28571
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    tom28571 Senior Member

    It might help if it was known what you are asking about.
     
  13. Willallison
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    Willallison Senior Member

    Ok - so not [Iall[/I] double-enders are butt-ugly (pun intended, sorry...), SC1 has proved that.

    FF - I beg to differ. Just because you can afford the convenience of a marina berth, doesn't mean you aren't a knowledgeable owner
     
  14. kerosene
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    kerosene Senior Member

    old thread however I'll drop in

    you can find lots of photos from google searches with merilainen + vene (boat in finnish) (meriläinen is correct) or fiskari + vene or retkivene

    This type of boats are fairly common family boats in Finnish coast and lakes. I think they are still being manufactured and they do have pretty strong following.

    example:
    http://www.mikavanhala.fi/venesivut/veneet/kiiski01/
     

  15. Pericles
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    Pericles Senior Member

    Tom,

    Re your post of 27th May

    djwkd is the tyke on Tyneside who wants to drift on a raft.

    http://www.freewebs.com/raftbuilders/

    He last posted on 20th July leading me to think he set off on his adventure, with predictable results. :(

    Let's hope he sees this post.

    Pericles
     
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