new Great lakes heavy weather cruising houseboat!

Discussion in 'Boat Design' started by assycat, Jan 14, 2013.

  1. assycat

    assycat Previous Member

    new Great lakes capable cruiser!

    Hi again- this is my version of a one-off, Bolger influenced, flat bottomed great lakes capable cruiser- with more room than most boats over 38 ft.


    displacement- 9000 lbs
    loa- 32 ft (not incuding the swim platform at stern)
    beam- 10 ft
    draft-(not incuding keel) .9 ft
    depth of hull -4 ft
    material- taped seam construction.

    The boat is built in much the same way as the micro trawler by Phil Bolger-

    The 26 ft keel is the key to the boats performance in all weather.
    This long keel acts as a stabilizer which theoretically makes the boat quite stiff in rough weather.

    Ballast can be added to the keel to increase this effect.

    The long keel also keeps a good track, even though the cabins height creates more windage.

    This boat has no more windage than any grand banks 38 or similar trawler.
    The keel also acts to help manouverability in docking and in the tactical diameter.

    A further benefit of this type of keel is that it splits the waves rather than glides over them. This helps keep stiff motion in a rougher seaway.

    Furthermore the keel also acts as a full length, longitudinal stiffener and makes the flat bottomed boat, have little flex. Since normally, flat bottomed boats have a tendency to hog and sag more than v-hulls- this keel strengthens the bottom and resists hogging and sagging forces.

    The boat is also designed to be incredibly fast to build- It utilizes the familiar bolger method which is a taped seam style, but adds the concept of using the plywood as a core and is laminated on both sides to create a very stiff hull.
    Little stiffening will be required, however, bulkheads, floors, engine beds etc. serve to stiffen the hull further.

    Optional core materials can also be used, but ply is recommended since
    it is cheap and easy to use. some kerf cutting may be required to form the sides and bottom using 5/8ths, but with optional 1/2 inch ply, the bottom and topsides are easily formed to the curvature.

    Both sides of the hull are epoxy glassed with one layer of 18 ox biaxial or triaxial cloth with a layer of mat underneath. This should provide plenty of protection and stiffness as a core laminate shcedule-however thicker laminates would be appropriate as well.

    There is a total of 196 sq ft of living space on the boat. The engine is situated near center of bouyancy and the one drawback of the boat is the engine will be situated in the center of the living space, requiring a long shaft, which can be standard mild steel, once the shaft penetrates the hull, since it it not exposed to the elements - a flex coupling and two bearings will be required for the long shaft. However due to its length, this aids in decreasing shaft angle. The angle is no more than 7 degrees of offset.

    The accomodations are accessed through a ladder, via an overhead hatch in the cabin trunk, which leads to the wheelhouse/stateroom, above deck.

    Ease of sight is another feature of the main cabin atop the cabin trunk, giving a height of eye at around 8-9 ft.

    There is plenty of room on this vessel to make it potentially a good liveaboard.

    The length of the vessel should keep costs down when moorage fees are due, compared to a comparable larger vessel with the same amount of living space.

    A small diesel in the 25- 50 hp range is sufficient to propel the boat to 8.5 knots and cruise comfortably at 6 knots using very little fuel.

    The vessel could be built with an alternative propulsion system such as a twin screw or hydraulic drive.

    hope you like it...its my most functional design yet.

    Attached Files:

    1 person likes this.
  2. SamSam
    Joined: Feb 2005
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    SamSam Senior Member

    Bolger influenced.... I can believe that. Cheap and fast trumped looks every time.

    I can't believe windage wouldn't be an issue, and since you're already making apologies for it, I think you have your doubts also.

    You aren't asking questions, but you make a lot of statements about the handling abilities and seaworthiness of this craft intended for heavy weather Great Lakes cruising. Do you have the experience and knowledge to stand behind your statements? Are you sure this design would handle Great Lakes heavy weather? Would you bet your life on it?
  3. afteryou
    Joined: May 2012
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    Location: Southeast Alaska

    afteryou Junior Member

    Yah, I'm not seein' it. looks a little tall.:)
  4. peterAustralia
    Joined: Mar 2006
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    peterAustralia Senior Member

    Its awful

    sorry, but had to say it.

    Hullshape is poor, windage is high, topweight looks an issue too.
    I am sure you can find a plan off the shelf or buy a second hand boat

    I have no problem with you building in quick and simple hard chine plywood, but please not this.
  5. peterAustralia
    Joined: Mar 2006
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    Location: Melbourne Australia

    peterAustralia Senior Member

  6. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    A 3 ton 38' heavy weather cruising houseboat? Are you kidding? Whats the water plane on that puppy, maybe immersed volume too? Give us a hint of your "taped seam" scantlings would you, as I find this, much like most everyone else has. Lastly, what is the logic behind that box keel, as it's going to cause more harm than good in the current configuration (good luck with steering). Any resistance predictions available on this "heavy weather" craft?
  7. El_Guero

    El_Guero Previous Member

    The 'house' looks better than some house boats.

    But, the 'boat' looks like a rollover waiting to happen.
  8. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Without some real figures, I'm not going to guess as to it's stability, but I will note that Bolger's seemingly simple shapes, weren't simple, in fact well thought out in regard to flow and function. This one doesn't appear to incorporate any of the typical logic, Bolger employed in his hull forms. The drawings presented here don't have any real information in them - they're just pictures. If stations, buttocks and waterlines were represented, then a better image of what the hull is shaped like, might offer a clue as to it's abilities (or lack of them).

    Assycat, post the hydro figures for this design, that you may have developed. I have to assume you've done a weight study and stability curve, can you post the pertinent figures for these too?
  9. assycat

    assycat Previous Member

    :eek: Ouch...I guess its back to the drawing board...

    I figured if bolger did this and it worked good...

    Nothing to back up my statements..but appreciate the input.

  10. hoytedow
    Joined: Sep 2009
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    hoytedow Carbon Based Life Form

    You won't be the only one heading back to the drawing board, so take some comfort in that.
  11. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    assycat: Bolger did not "did this and it worked good". He had years of study and practice. His designs were the result of all that experience. Bolger didn't start by designing and building a 38' power cruiser but with small boats where experimenting is cheap and not dangerous. Capsizing a dinghy close to shore is not usually a problem. I don't like Bolger's designs aesthetically, but think he was a genius otherwise.
    1 person likes this.
  12. michigangeorge
    Joined: Dec 2003
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    michigangeorge Junior Member

    The poster has most assuredly never cruised The Great Lakes :-(
  13. peterAustralia
    Joined: Mar 2006
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    Location: Melbourne Australia

    peterAustralia Senior Member

    If you want to do your own thing (and thats OK.. possibly not ideal, but your call)
    I would start my modifying something like this

    seems to have the interior space you want, notice only a single deck (less topweight)
    24,000 pounds, 40ft x 14ft. Seems a nice liveaboard boat. Cost a lot of money to make though,, not cheap.
    maybe you want something a bit smaller?

    maybe you can convert an old fishing boat, put a bigger cabin on it?
  14. peterAustralia
    Joined: Mar 2006
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    Location: Melbourne Australia

    peterAustralia Senior Member

  15. assycat

    assycat Previous Member

    with all due respect-- Thats the reason to designed a boat for them...I grew up on them.

    I love the great lakes..especially superior and huron. altho- the water levels are very very worrying right now.
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