Free!Ship Waterline/Displacement query

Discussion in 'Software' started by kaymaran, Dec 8, 2015.

  1. kaymaran

    kaymaran Previous Member

    Apologies if I am being hopless this is my first attempt at using Free!Ship. I have previously built a CLC Sport Tandem kayak and converted it into a trimaran using the Mk3 sailrig with some interesting results (I also added an RS200 jib and a mizzen mast cut down from a windsurfer resulting in quite sprightly performance) and now want to make a more focused pure trimaran without the compromises.

    I've looked at various plans out there and although some are close to what I am looking for there are various things that don't quite stack up to what I want so do something from scratch appears to be the answer.

    I have an outline of the main hull and outrigger shapes but am trying to work out how I can add the estimated total weight to the design and then see how deep the main hull will be sitting in the water whilst still.

    I want the outriggers to be just out of the water or lightly touching so knowing where the main hull will sit I can then get the hieght of the outriggers and the angle of the cross beams sorted.

    I will will be using an ISO dinghy rig as the basis for the project and it will be 4.5m long with the same length outriggers all with a good amount of forward volume to reduce any pitchpoling tendencies as the rig should be quite powerful.

    Both hull and outriggers to hopefully have planing qualities resulting in a sort of Weta alternative.

    The plan is to make a small scale model shortly and crack into the initial build february time.

    I can see about setting the weight of the layers and have effectively bulked them up to the 100kg target weight plus the combined crew weight of 130kg but I don't how to find where the water level will be. I assume Free!Ship can do this?

    The design draft appears to be just an arbitrary figure as far as I can see?

    Any help appreciated - I am likely missing something obvious.
  2. jarmo.hakkinen
    Joined: Jun 2007
    Posts: 66
    Likes: 3, Points: 8, Legacy Rep: 25
    Location: Kerkonkoski

    jarmo.hakkinen Junior Member

    It will be in the Calculations->Hydrostatics. Enter the start and end draft and draft step, then hit calculate. With 0.001m step you'll get close enough. Then in the project settings, change the draft to your just calculated value.
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