Fast Displacment Hull, Plywood, Tunnels and Hull Speed!

Discussion in 'Boat Design' started by Dhutch, Oct 11, 2012.

  1. Dhutch
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    Dhutch Junior Member

  2. michael pierzga
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    michael pierzga Senior Member

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  3. Dhutch
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    Dhutch Junior Member

    I Like that a lot. That is the boat I want to build.

    http://www.elektramarine.com/gallery.html
    http://www.pattersonboatworks.co.uk/New_Boats/Fast_Electric.html

    Happy to cruise at 5 to 15 knotts, with 90kw giving speeds of up to 30 knots. Sold!
    Swap the electrics for a suitably mounted and silenced petrol engine. Very nice.

    I just need someone to tell me I can make it from 'tortured' plywood and hand me some plans...
    http://www.ukhbbr.plus.com/forum.html#nabble-td3287031


    Daniel
     
  4. michael pierzga
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    michael pierzga Senior Member

    Nigel Irens designs beautiful boats.

    Those boats have alot of shape and are strip planked ,then glassed inside and out. This type of construction is simple, fast, light and not overly expensive. Like a modern canoe.

    Unless you have a big pile of plywood outback that you must use , you might further investigate strip plank.

    I'm sure you could contact a Naval Architect and have a similar concept designed for ply. Shapely plywood boats are complex to build.

    For more inspiration You might "Google " German, Swiss , Italian or Austrian lake boats. Some very beautiful low power boats up there.
     
  5. tom28571
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    tom28571 Senior Member

    Actually not, Daniel,

    The so-called planing or transition hump can be minimized or even made unnoticeable with the right design. It is possible to run a small planing boat with it's comfort zone extending down to 10mph or even lower. In addition to a good bottom design, the major criteria is attention to balance and weight. The measure to watch is bottom loading in pounds unit of bottom area in contact with the water. With many current planing boats having bottom loading of 60 to 100 lbs/sq ft, it is no wonder that they have poor performance between 8 and 20 mph. Bow high, strain to plane and huge wake, plus fuel hogging. Its a compromise of course, too much bottom area, which helps low speed planing performance, also reduces top end speed because of high friction drag.
     
  6. Dhutch
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    Dhutch Junior Member

    I found two videos of Elektra last night on youtube, cant confirm the link as youtube is blocked here at work, but I think these may be the two videos.
    http://www.youtube.com/watch?v=ybrVAI7AwwU
    http://www.youtube.com/watch?v=Ntl0c3YYleE
    http://www.youtube.com/watch?v=iuwIkszJr1s

    I also had a call back from Bates Marine about an enquiry for information I had made. It was clear there main interest was to sell me a boat, which is understandable, but there where also keen to dissuade me from buying a boat with real wood on it, because it takes maintenance, and I'm not retired, so cant, apparently. So they recommending a 'pre-owned' Cooper 745 "Dutch Sloop" which while very functional looking is I have to say, one of the most ugly boats ive seen for a long time, although i have seen similar around so they clearly sell well. The slightly larger cooper 800 is no more a dutch or a sloop but looks far nicer, but both appear to be heavy displacement boats, bigger than what I want to be trailing, and generally not really what im after.

    I do however find the videos of the Elektra very nice to watch, and make me even more interested to know more about the hull shape. As well as finding it interesting what a broker would suggest if I was looking to buy new boat.


    Daniel
     
    Last edited: Nov 25, 2012
  7. Ingolf
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    Ingolf Junior Member

  8. Dhutch
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    Dhutch Junior Member

    The plan is to self-build, yes.

    Thats and interesting boat, but appears to be really very simple in hull shape, comprising of just two sides and a base, would it give the low-wake cross-speed performance?

    I have been looking into strip-plank construction, and although I would like to know more about it, assuming you could get a decent number of planks on an hour it seems it should be a fairly quikc build. Sheathed in glass both sides, as I would be planning with the plywood, it becomes a composite boat with semi-structural core.


    Daniel
     
  9. michael pierzga
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    michael pierzga Senior Member

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  10. tunnels

    tunnels Previous Member

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