boat weight estimates

Discussion in 'Boat Design' started by Mik the stick, Oct 15, 2015.

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

    PAR Yacht Designer/Builder

    Good designers tend to "miss" their weights on the light side, so come launch day, the end result is slightly high and just needs some trimming ballast. Novice designers tend to discount the tedium of the center of masses calculations, so their net results float below their DWL and owners are moving boot stripes the follow day. I show the "boot stripe" at maximum load, so it's always above the actual LWL. On hulls that I build I use a magic marker, under the last coat of epoxy, to show the bottom of the boot stripe. I do this so at some later date, if the bottom paint is stripped off, they'll see the line, assume it's the LWL and end the bottom paint in this area.

    My first industry job was in a spar building shop. After learning the in's and out's of sweeping the shop floor, for some time, I double checked the centers on sail templates. Amazingly enough, after the simple geometry was performed, the last test was the cardboard cutout and pin method on the wall. All centers of all sails were checked this way, before being sent to the loft. Hey, it was the 60's and the Apollo space program was in full swing and it worked for them, so who where we to argue.
     
  2. Ike
    Joined: Apr 2006
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    Location: Washington

    Ike Senior Member

    And I thought this wasn't rocket science!
     
  3. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 473, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    No kidding, every "fin" designed by NASA engineers, in spite of their best (slide rule and 2,000 sq ft., footprint main frame) math, was given the pin on the wall test.
     

  4. rxcomposite
    Joined: Jan 2005
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    Location: Philippines

    rxcomposite Senior Member

    That will make you an indispensable employee. Someoneone with the mind of a rocket scientist but can still sweep the floor.:D
     
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