cutting a keel down?

Discussion in 'Boat Design' started by KenCo, Oct 27, 2005.

  1. KenCo
    Joined: Oct 2005
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    Location: Warwick Rhode Island

    KenCo Junior Member

    I have a super cheap (almost free) mooring avail. at a friends place but the water is only 4' deep at low tide.

    I plan to live aboard, probably cruise the east coast and want a semi-roomy 32'+ boat that will still be stable.

    can a boat w/ a 5'-6'2" draft be cut so the draft is down to 3.5'-4'?

    I'm also thinking of cutting it down then probably adding a wing for stability.

    pros/cons?

    I can do all the work myself including cutting/fabbing a wing for it.
    (25+ yrs. yellow iron, hvy. equip., diesel mech., mech./struct. eng.)

    comments? ;)

    if the above is too crazy any suggestions on boats w/ a shallow draft?
     
  2. RThompson
    Joined: Nov 2004
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    Location: New Zealand

    RThompson Senior Member

    Hi KenCo,

    Your problem is not a new one.
    Assuming you don't already have a boat:

    There are more efficient ways of acheiving shoal draft than cutting down a keel.

    In the first instance there are multihull's, centreboarder's, and bilge keelers.

    Although what you say can be done. Note various production boats available as a deep or shoal draft keelboat.
    In short the cost is performance. (take a boat and for the same displacement give it a shorter keel = less righting moment = smaller rig etc etc. Also less efficient planform for the keel)

    As you will be live aboard and cruising you probably cannot afford to increase the ballast in the keel as you have probably increased the overall displ. of the vessel already with all your extra "living aboard" stuff.

    There are certainly shoal draft cruising 32 footers available, you just have to find them. There's other's who know much more about that than I :)

    Rob
     
  3. cyclops
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    cyclops Senior Member

    The money you put into chopping up a boat of the size you need would better be spent on dredging the slip out if no EPA or solid rock will stop you. Then a real live aboard is great!
     
  4. KenCo
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    Location: Warwick Rhode Island

    KenCo Junior Member

    thanks for the replys,

    The EPA/DEM is nasty here and dredging the sandbar type area isn't an option, it's at the Conimicut Point Lighthouse area in Rhode Island and 2 moorings are allowed at ea. house.


    My labor and free help to do it isn't an issue since cutting a keel is easy as I have recip. and chop saw's that can be jigged easily to cut it down. I'm also used to cutting thick tempered steel's so the cast iron will be like cutting butter.



    The only Cat I can find in my price range is a 30' Long x 13'6" beam Sailcraft Iroquois MKII w/ 1'3" draft (perfect), but it's a scrunch down/low headroom in center type and stand-up on sides layout. The low center headroom is the only drawback since the layout is livable for what I need. Anyone have one of these Cats or similar and is the headroom part easy to get used to?
     
  5. cyclops
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    cyclops Senior Member

    HEEEEYY. I thought you could easily raise the center to the height that you need?? Whats on top is the next project.
     
  6. KenCo
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    Location: Warwick Rhode Island

    KenCo Junior Member

    I already thought of that and did my research on that boat.

    unfortunatly the "mast support" is integrated into the "roof", BUT! that would probably be a nifty project and much easier to do.....

    hmm, a Coach roof Cat??? damm, now that could be a great plan!
     
  7. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    You will have a number of other issues to contend with, besides taking a reciprocating saw to the keel. What about the ballast that will likely live inside or is bolted to this appendage? Maintaining the structural integrity during and after the deed is done. Balance, rig loading, sufficient lateral area, frankly more then you may realize.

    A 32' foot cruiser doesn't need 5 to 6 feet of draft, most don't. There are plenty of shoal craft available in a price range that may suit you. Finding a boat that fits your needs is a wiser method then spending untold or factored effort, time and materials on a keel sorting project that will likely ruin the original qualities of the yacht.

    I've just finished a redesign keel and rudder for a fellow's 27'er and this project required a new rig to make things work right. My opinion is that, this is a bit much in output and outlay just to park the boat on your new found bobber.
     
  8. cyclops
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    cyclops Senior Member

    I think more shopping around and a new post asking everyone here what boat they have would easily maneuver into the size slip you have. Give the lowest depths and widths as a worst case. Also, can their boat "be bottomed out", if needed. And has it, with no damage. These a some of the things that would narrow the selection list for you.
     
  9. KenCo
    Joined: Oct 2005
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    KenCo Junior Member

    thanks to all,

    I've been shopping around and have time to do this and have found some w/ <4' draft but the ideal type layouts are all over 5' draft. The MKII Cat would work except for the headroom but I may overlook that issue.


    the going rate around here is $3k for the season for a slip/ 1500k+ for a mooring so the free mooring very close to shore (<75') w/ power avail. (only actual cost) is the reason for the orig. question.


    I don't favor the "bottom out" idea since not many civilian craft would really be designed for that.
     
  10. chandler
    Joined: Mar 2004
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    Location: U.s. Maine

    chandler Senior Member

    I think cutting an iron ballast keel to get shoal draft is crazy. I don't think it would be as easy as you think. Besides you would have to totally redue all the calculations to balance the boat, if that's even possible with the radical change you propose.
    Have you ever cut cast iron with a reciprocating saw? I'd suggest a torch.
     

  11. KenCo
    Joined: Oct 2005
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    Location: Warwick Rhode Island

    KenCo Junior Member


    1) I would re-add the weight via the wing to readjust it, adding about 30%? lbs. to re-compensate for the 12-15" lost.

    i.e. if 200 lb piece is removed = 260 lbs added back on.
    any calcs. for this?

    2a) I have probably cut every metal known to man.

    2b) no, not a torch, there is always air pockets in lg. castings, they hurt (it basicly explodes) when you hit them. I would do that w/ the chop saw powerhead jigged onto a cutting track. (basicly looks like a mini train track section that is used for long perfect cuts w/ a torch, plasma or abrasive wheel).
     
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