O'Day Mariner 19 Conversion Prospects

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  • 06 Nov 2015 14:58
    Reply # 3620171 on 3619414
    Deleted user
    ueli lüthi wrote:
    Timothy Rumbinas wrote:

    …There are various open-source CAD programs that can be had free.

    you're right – my replacement for cardboard clipping is inkscape. it's free, available for the usual operating systems, and capable to calculate the center and the area of any shape.

    here is an example of my planning with inkscape

    ueli


    Lovely work. We have vastly better tools to design with now than we had only a short time ago, and open-source software has really come into its own. In many cases, it can be better than commercial offerings.
  • 06 Nov 2015 14:53
    Reply # 3620154 on 3604852
    Deleted user

    I don't pretend to be an expert by a long shot, by the way. I began studying yacht design a little more than a year ago after leaving my motorcycle in Newfoundland before it came to a complete stop. Facing the dark of winter with a shattered shoulder, I needed something to occupy my mind.

    The Mariner 19 is closely based on the Rhodes 19 -- it's the same hull with slightly plusher accommodations. Philip Rhodes had a heck of a lot more experience in yacht design than I can ever hope to have. However, he also had a racing bias where the 19 was concerned.

     Racers like to have a lot of sails. So far as I can determine, there were at least 4 different sizes of main (at least I have 4, all of which are completely unadorned by reef points), a 155% and 135% Genoa, standard and storm jibs, and various spinnakers. It make's one's head spin!

    My boat is a "2+2," or capable in theory of sleeping four people. I suspect that's a subterfuge. We all know that a V-berth is not intended for sleeping, but sail storage. The crew is supposed to wedge themselves in the coffin-like quarter berths. Luckily, in my example, there is a lazerette over the foot of each quarter berth. My size 12 feet would never fit otherwise.



    Last modified: 06 Nov 2015 15:01 | Deleted user
  • 06 Nov 2015 08:12
    Reply # 3619414 on 3619010
    Timothy Rumbinas wrote:

    …There are various open-source CAD programs that can be had free.

    you're right – my replacement for cardboard clipping is inkscape. it's free, available for the usual operating systems, and capable to calculate the center and the area of any shape.

    here is an example of my planning with inkscape

    ueli


  • 06 Nov 2015 07:52
    Reply # 3619400 on 3604852
    Anonymous

    Hi Tim

    Your link didn't work - I've edited it to have the right link.

    Chris

  • 06 Nov 2015 03:14
    Reply # 3619010 on 3604852
    Deleted user

    Modern software makes braining out a sail plan a lot easier. Rather than cutting out outlines and balancing them on a head of a pin as suggested by writers like Van Loan, one can simply make a tracing of the hull and have the software determine an "area centroid." I have Rhino CAD, which is a very powerful and costly package. Thank goodness for student discounts! Such a powerful program really isn't necessary. For most purposes, a 2-D program will generate enough data to get by with. There are various open-source CAD programs that can be had free. While cup racers will argue that the results are subjective at best, they certainly can be no worse than clipping up tea cartons. So I started with a tracing of the hull below the waterline and ended up with this initial datum  for the CLR.

    Last modified: 06 Nov 2015 07:53 | Anonymous
  • 05 Nov 2015 19:05
    Reply # 3618463 on 3604852
    Deleted user

    So despite how elegant a high-aspect rig may appear, this one will need to be designed for torque, not speed. Stowing spars on the canals is a burning pain in the arse. A few weeks ago, some boats came down from Canada. They were big sexy Beneteaus, the like of which my sort will never be able to afford. After they had their masts and booms stowed for the canal passage on a bunch of lumber that may have been better used to make a hog pen, they didn't look so racy. I hate moving about on a boat with stowed spars. There's always something to hit your head on or trip over.


    Last modified: 05 Nov 2015 19:05 | Deleted user
  • 05 Nov 2015 18:44
    Reply # 3618426 on 3604852
    Deleted user

    With the original sail plan, there is approximately 2.5% of lead with jib and main from CLP. With the smallest main I have and the only jib I have information for, it increases to about 18", which is about 13%. This may be fine for racers, but designer Ted Brewer (for whom I have great respect) suggests that lead may have to to be over 20% for comfortable cruising.

    Last modified: 05 Nov 2015 18:47 | Deleted user
  • 05 Nov 2015 18:33
    Reply # 3618404 on 3604852
    Deleted user

    The junk rig may be on hold for a bit. I drew up what I feel is a pretty good balanced lug configuration as a cat yawl last night in a fit of insomnia. I'm pretty sure the numbers are right, and this rig allows for short spars. I'm on Lake Champlain in the US. To get off the lake requires dismasting and remasting to the south to clear bridges for anything much over 13', and there's a 26' clearance to the north to access the St. Lawrence. My design brief for this one was to keep the timber under 12', which can be quite a challenge. First, here's the conventional rig for this boat, which has quite a lot of air draft for a 19' vessel. It would need to be dismasted, and there's a lot of spaghetti to that, as well as a $3/foot charge on either end, as well as the inconvenience. I shattered my shoulder in a motorcycle "off" in the wilds of Newfoundland, and can't do the job single-handed.

    http://i782.photobucket.com/albums/yy102/canuman/Mariner%2019%20Original%20Sailplan_zpsshubaati.jpg

    Last modified: 05 Nov 2015 18:50 | Deleted user
  • 28 Oct 2015 23:51
    Reply # 3605042 on 3604852
    Deleted user

    Chris,

    Thanks for trimming things up. I found the overrun distressing too -- I'm a former printer and pre-press operator.


    Cheers,

    Tim

  • 28 Oct 2015 22:47
    Reply # 3604966 on 3604852
    Anonymous

    Hi Timothy, and welcome.

    Sounds like you have a lot of fun in prospect.

    I have taken the liberty of reducing the size of your image somewhat - if they are too wide, they cause the text to spill over the right hand side of the frame and become unreadable.

    Good luck with your projects!

    Chris

    Last modified: 28 Oct 2015 22:47 | Anonymous
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