displacement calculation help!

Discussion in 'Boat Design' started by schnaarf, May 31, 2008.

  1. schnaarf
    Joined: Nov 2007
    Posts: 5
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: perth

    schnaarf Junior Member

    Hi, I'm having a bit of trouble with a couple of questions and was wandering if anyone here could help!

    I've got these figures:
    LWL - 15m
    BWL - 4m
    Sail Area - 120m2
    keel weight - 2.5 tonnes
    ballast ratio - 0.25
    SG (salt water) - 1.025

    and need to find:
    Displacement Length or Dimensional Slenderness ratio
    Non dimensional SA/(Vol of Displacement) ratio
    Length/Bredth ratio
    Ballast ratio

    If anyone could help me get started I'd be grateful!

    thanks
    Steven
     
  2. Guillermo
    Joined: Mar 2005
    Posts: 3,644
    Likes: 189, Points: 63, Legacy Rep: 2247
    Location: Pontevedra, Spain

    Guillermo Ingeniero Naval

  3. sharpii2
    Joined: May 2004
    Posts: 2,246
    Likes: 329, Points: 83, Legacy Rep: 611
    Location: Michigan, USA

    sharpii2 Senior Member

    Hi, Schnaarf.

    Here's what I came up with:

    1.) Displacement/Length---= 84.7*
    2.) Sail Area/Displacement = 25.9
    3.) Length/Breadth------- = 3.7 (LWL/0.85)/(WL Beam/0.85)

    * (2.5 mt Ballast)/(0.25 Ballast Ratio)=10 mt Displacement

    Length = 17.5 m
    Beam --= 4.7 m

    These are all really good guesses based on fairly typical contemporary design practices. The actual boat may be longer or shorter and the Beam might be greater.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.