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Thread: ballast keel location

  1. #1

    Default ballast keel location

    I understand some plans come more detailed than others. However, is it unusual to have the ballast keel location and weight omitted from the plans? If so how would you determine these two pieces of information?

  2. #2
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    Default Re: ballast keel location

    Could you tell us any less? <-- JOKE

    To answer the question as asked: I wouldn't -- I'd use complete plans by a known and preferably living designer.
    "The enemies of reason have a certain blind look."
    Doctor Jacquin to Lieutenant D'Hubert, in Ridley Scott's first major film _The Duellists_.

  3. #3
    Join Date
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    Default Re: ballast keel location

    "Study plans" may have views of some of the lines, a picture of the rig, outline accomodation plan, but not detail. Some NA's sell study plans for nominal amounts, some have web sites with evocotive and informative illustrations, like below, but not the detail.

    Real full plans are quite detailed.


  4. #4

    Default Re: ballast keel location

    I guess I could have been more specific. I was referring to Luke Powell's plans that he sells now. I was told that they are what he builds off but the ballast keel location as well as a ballast weight are not included. No table of offsets or construction plans are included either but that is a separate issue.

  5. #5
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    Default Re: ballast keel location

    For an earlier discussion on his boats: http://forum.woodenboat.com/showthre...-Cutters-Video

    I've not gone into detail on these designs but it could be that the boats were meant to have inside ballast.

  6. #6
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    Default Re: ballast keel location

    Well I think I know which bit is ballast if it is external


    And it would be easy enough to estimate its mass.
    It really is quite difficult to build an ugly wooden boat.

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  7. #7
    Join Date
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    Default Re: ballast keel location

    Ballast is shifted about until trim is good. Build her, put it in, go sailing and observe.

  8. #8

    Default Re: ballast keel location

    That picture is the construction plan for the 44’. Unfortunately, there is not a construction plan for the 38’ or 42’. I was told that the construction plan was made purely for pleasure and not building purposes.

  9. #9

    Default Re: ballast keel location

    Just an update in case someone else has these questions down the road...and a couple more questions in case anyone has any insight on the matter:

    42’:
    The only information I can find regarding lead ballast on/in this boat is a website on which Lizzie May was posted for sale. Internal ballast was listed as 1.5 tons and external 3.5 tons. Total displacement was 16 tons putting it at about 31%. I have combed through the pages of Luke’s book ‘Working Sail’ and have noticed several photographs of the ballast keel seemingly being added as a last step after the completion of the boat. It looks to me as though it runs the entire length of the keel. Based on the keel width and length on the plans (height unknown) and indeed if the external ballast runs the entire length of the keel the ‘estimated’ math is as follows:

    width 6” x length 360” x approximate height based on pictures 8” = 17,280 cu inches x weight of lead .409 lbs/ cu inch
    =7,067 lbs or 3.53 tons

    That is pretty close to the numbers that I found online for Lizzie May. I still have yet to confirm if the external lead ballast does indeed run the entire keel. I have seen several pictures of his boats with the ballast keel added as a first step during the construction process and not running the entire length and other photos of it missing until after the build is complete but an entire keel length strip is added as I have described above. I haven’t been able to get confirmation or information from the designer yet, but I have tried.

    Hope my math is right

  10. #10
    Join Date
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    Default Re: ballast keel location

    Luke is a bit of an artist, and some of those "plans" are literally lines plans for framing. Yes, he did build from such drawings as i have seen the originals he built from. If there is a scale on the drawing, it is possible if you know what you are doing.
    The ballast keels varied on his builds, and more often than not, how much cash was availiable at the time to have a keel poured; often more important to get the rest of the boat almost complete and a perspective buyer seeing an almost complete boat is more likely to buy into it, hence the keel was often a late addition.

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