Help regarding GRP catamaran construction

Discussion in 'Fiberglass and Composite Boat Building' started by souravsandesh, Aug 17, 2014.

  1. souravsandesh
    Joined: Aug 2014
    Posts: 8
    Likes: 1, Points: 0, Legacy Rep: 33
    Location: INDIA

    souravsandesh Junior Member

    I am doing my project on design of a 20 seater Glass fiber reinforced plastic catamaran. I have developed the model in RHINO and calculated the hydrostatics through a plugin called ORCA 3D supported by RHINO itself. Now my guide has asked me to find out the total weight estimation of the ship for stability calculations. Am stuk here because am not able to find the densities of the materials no matter how much I search on net. Actually its more like am not able to understand how the process is done. I could ask my guide about all these, but he would complain and shout about being immature and a spoon feeder.

    And he also asked me to calculate the scantlings .Everything was fine until I started looking into DNV rules.And I am not getting how many stiffeners and girders i have to use and also exactly where the stifferners are placed like whether they just lie on the bottom of the hull or they extend up to the hull sides. I am also confused with frames. Like how many frames does my boat. And also no idea about frames and plates and where the girders are places. I just want to know after constructing an empty hull, how these scantlings are placed.Could you please,in brief, explain the construction process as to how it is done?. Please help me with this. If nothing works out I ll ask my guide myself. But before that I should know something.

    please kindly explain the step by step process
    Am attaching some important documents

    The pdf and the word document are given by my guide..the rest all are what I did in rhino and orca 3d.nd autoCAD...in the excel sheet the "sheet27" is my geometrical parameters of my hull for the designed draft.
     

    Attached Files:

  2. TANSL
    Joined: Sep 2011
    Posts: 7,008
    Likes: 563, Points: 123, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    You should not hesitate to ask your teacher because there are questions that neither you nor anyone can know. For example, the weight of the laminates, if you do not define the composition of the layers, mats, fabrics, etc., it is impossible to know.
    Another issue: it seems that the genral layout you've copied from some other project without understanding what you were drawing. In the drawing in pdf format, there are several small lines, numbered from 0 to 60. These are the frames that you yourself have said to have the boat. Therefore it is not logical that you wonder now how many frames are there and where they go.
    There are aspects that should reconsider before you start calculating scantlings with DNV or whatever you want:
    1. Fuel tanks so aftward is not a good solution because it will vary greatly trimming the boat as the fuel is consumed.
    2. Neither is it the shaft line crossing the fuel tanks.
    3. Hulls seem not to be completely symmetrical in the bow. That cosntructivamente speaking, should be avoided.
    4. Etc.
    In short, what I want to convey here is that your teacher should teach or guide you in several aspects before starting weight studies, loading conditions, etc. By the way, be careful with the results appearing in Excel spreadsheets. Analyze them before giving them as good. And note something very important, you can not calculate loading conditions without previously determine lightship weight.
    There are many things that your teacher should have taught you and apparently it has not.
     
  3. Mr Efficiency
    Joined: Oct 2010
    Posts: 10,401
    Likes: 1,035, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    "I could ask my guide about all these, but he would complain and shout about being immature and a spoon feeder."

    What would make him think something like that ! :eek: :D
     
Loading...
Similar Threads
  1. fallguy
    Replies:
    5
    Views:
    177
  2. Carlazzomark
    Replies:
    17
    Views:
    682
  3. fallguy
    Replies:
    19
    Views:
    620
  4. fallguy
    Replies:
    41
    Views:
    1,547
  5. Manuel R Alonso
    Replies:
    9
    Views:
    739
  6. WalleyeSniper
    Replies:
    8
    Views:
    956
  7. First Boat
    Replies:
    8
    Views:
    1,081
  8. Scuff
    Replies:
    24
    Views:
    1,939
  9. Daniel Duprez
    Replies:
    1
    Views:
    537
  10. alyons05
    Replies:
    20
    Views:
    2,494
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.