Limiting Kg Problem

Discussion in 'Stability' started by rasel02232129, Dec 14, 2020.

  1. rasel02232129
    Joined: Apr 2013
    Posts: 13
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: Bangladesh

    rasel02232129 Junior Member

    Dear All,

    Hope you are well. I'm trying to find the Limiting Kg report by using Maxsurf. But Limiting Kg & VCG values are showing with a minus sign. Though It should be always a plus sign.

    Your help will be highly appreciated regarding this.

    Sincerely Yours,
    Rasel
     

    Attached Files:

  2. TANSL
    Joined: Sep 2011
    Posts: 6,725
    Likes: 491, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    The VCG, which is not calculated by Maxsurf but you have to give it when defining the load conditions, is negative, which is impossible. You must correct the current value and give correct value.
     
  3. rasel02232129
    Joined: Apr 2013
    Posts: 13
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: Bangladesh

    rasel02232129 Junior Member

    Thanks. But currently, I have applied this specific value with a displacement ranage. As the Baseline shows incorrect position how it can be -VCG?
     

    Attached Files:

  4. TANSL
    Joined: Sep 2011
    Posts: 6,725
    Likes: 491, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    The base line position is correct. Is you who need to position correctly the CoG.
     
    Last edited: Dec 17, 2020
  5. Don92
    Joined: Feb 2015
    Posts: 28
    Likes: 5, Points: 3, Legacy Rep: 10
    Location: Glasgow

    Don92 Principal Naval Architect

    Dear Rasel,
    The results you have shown here are surprising. As TANSL mentioned, the KGs that you have defined are clearly incorrect, with values of approximately -1800mm. However, with that being said, the determination of limiting KG and GM is independent of the actual vessel KG and is instead a property of the design. The limiting KG is the maximum vertical centre of gravity your ship design can support whilst meeting the requirements of pertinent regulations and is, therefore, independent from any “true” loading conditions. It is possible though, that the algorithm within maxsurf may struggle to find a reasonable limiting KG value resulting from the fact that the starting point you have defined is so far from the true limiting value. Furthermore, this could be a consequence of the criteria you have applied, could I enquire as to which criteria you have considered?
     
  6. rasel02232129
    Joined: Apr 2013
    Posts: 13
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: Bangladesh

    rasel02232129 Junior Member

    Dear TANSL & Don92,

    Thank you for your valuable comments. FYKI; The Stability Criteria recommended by the European Union (EU)-Classification for Passenger Vessels have been considered.

    Regards,
    Badrul
     
  7. TANSL
    Joined: Sep 2011
    Posts: 6,725
    Likes: 491, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    I don't know those criteria. Perhaps you should consider the IMO criteria for passenger ships.
     

  8. rasel02232129
    Joined: Apr 2013
    Posts: 13
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: Bangladesh

    rasel02232129 Junior Member

    Dear Don92,

    Yes, I tried to do the limiting KG calculation based on the starting point as per true loading conditions limiting value. Now I have got my problem solved (attached herewith). Cordially thanks for your suggestion.

    Regards,
    Badrul
     

    Attached Files:

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.