Curve of Floodable Length with Maxsurf Stability

Discussion in 'Software' started by Rabah, Jun 9, 2016.

  1. Rabah
    Joined: Mar 2014
    Posts: 247
    Likes: 7, Points: 18, Legacy Rep: 50
    Location: Bulgaria

    Rabah Senior Member

    For providing unsinkability, whether it is necessary to test distance between transversal watertight bulkheads of the projected vessel responds requests chapter "Subdivision” on the Classification rules.
    It is possible to test with the function „Floodable Length” of the program Maxsurf Stability:
    1. In the List „What to do” we must select „Floodable Length” – see Fig 1.
    2. In Trim Setup for Load case Full Displacement we select Initial Trim = - 0,097m and VCG = 3,928m – see Fig 2, how it is received in Specified Condition.
    3. We calculate Floodable Length only for Full Displacement – see Fig 3.
    4. We select Permeability factor = 95% for all compartments in the ship – see Fig 4.
    5. We select wave profile – see Fig 5.
    6. Must select Floodable Length Criteria – see Fig 6.
    7. Margin Line Points are visible automatically in the program – see Fig 7.
    8. In the table for transverse bulkheads we point Name and Location – see fig 8.
    9. After Start Analysis the Results for Floodable Length we can see in the Table – see Fig 9.
    10. The Curve of Floodable Length we can see on Fig 10.
    _______________________
    NA Razmik Baharyan
     

    Attached Files:

  2. Rabah
    Joined: Mar 2014
    Posts: 247
    Likes: 7, Points: 18, Legacy Rep: 50
    Location: Bulgaria

    Rabah Senior Member

    Hi everybody,
    Never the ER of the ship at accident it is impossible to fill with water 95 % from theoretical volume of the compartment. For that the Rules of the Classification organizations indicate 85 % Permeability for ER.
    How to apply it in the calculation Floodable Length with program Maxsurf Stability?
    For this purpose in the Table for the Permeability must to add one more - 85 %.
    The Results we can see in the jpeg file.
    Endways from the program it is possible to make Export dxf file.
    After correction in dwg file we shall receive the final output - on length ER Floodable Length it is shown for Permeability 85 %, for all remaining compartments- 95 % - see dxf file.
    ______________________
    NA Razmik Baharyan
     

    Attached Files:

  3. TANSL
    Joined: Sep 2011
    Posts: 5,898
    Likes: 232, Points: 73, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    Some questions :
    • Why you can not apply a permeability of 95%?
    • A permeability of 85% seems too low for some compartments.
    • There are compartments that have not a permeability of 85% neither 95%. What can we do then?.
    • The compartments may have different permeabilities not the same for all of them.
    • Why the .dxf file does not match the one on the screen MaxSurf ?.
    • What happens in the case of two damaged compartments?
    Thanks for your clarification.
     
  4. vkstratis
    Joined: Feb 2015
    Posts: 61
    Likes: 2, Points: 8, Legacy Rep: 14
    Location: Athens, Greece

    vkstratis Marine Designer

    TANSL,

    Maxsurf allows the user to enter whatever permeability he/she likes and plots the floodable length curve for any of those permeabilities on the same graph. It does this with the option of ploting the actual compartments on the background for the user to check against. There is no limit from the software's point of view. Dependes on the class/flag requirements you can use for example 85% for engine room and 95% for other compartments or anything else you like. Plots can be for one, two, etc compartment hulls depending on your requirements.
     

  5. TANSL
    Joined: Sep 2011
    Posts: 5,898
    Likes: 232, Points: 73, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    Vkstratis, thank you for your explanations. I use MaxSurf from about 10 years ago and I know what this program does. For me Maxsurf is a great program.
    I do not understand what Rabah wants to show us with his posts and either I understand him wrong or he does not expressed it well. The result is that I think what he says is wrong or, at least, would have to explain it. I know the answer to questions I do, but I doubt Rabah know them, because, in my opinion, the only thing he knows of naval architecture is MaxSurf User Guide. He is a good user of this software but I doubt that is able to interpret the results obtained with it.
     
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