Results 1 to 15 of 89


Threaded View

  1. #11
    Join Date
    Nov 2005
    Narragansett Bay, R.I.

    Red face


    just a voice of caution: I recommend you take a look at Brian Toss' book on rigging or a couple of web sites...


    (there are others)

    from the sponberg site a rule of thumb is:

    (mast_compression) = ((weight of boat) * (righting moment from CM to CB)) / (distance mast to chain plates)

    rough numbers (eye-balling the boat at 30 degrees of heel)....

    mast_compression = ((5200 lbs) * (1.0 to 1.5 feet)) / (4 feet) = (1300 to 1950) lbs

    This number is higher than some other more detailed models. doubtlessly, Moderator Bill has some better numbers for weights & moments, but the point is there will be a large point load under the mast and you are looking at a large span.

    before you commit to a radical change, you may want to build a full size model and load it with a jack or hydraulic press.

    Maybe I have misread the article.. I'm just a software guy.

    Last edited by bill@ariel231; 08-29-2006 at 08:48 AM.

Similar Threads

  1. All those wires inside my mast gotta go!
    By Scott Galloway in forum Technical
    Replies: 26
    Last Post: 07-04-2007, 07:40 AM
  2. Commander- replace mast support with cross beam
    By beugenides in forum Technical
    Replies: 2
    Last Post: 01-11-2005, 12:04 PM
  3. Tabernacle Operation
    By Scott Galloway in forum Technical
    Replies: 17
    Last Post: 09-04-2003, 08:56 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts