Necessary drawings to be submitted to class for Modified vessel to get approval

Discussion in 'Class Societies' started by navalarchaj, Apr 4, 2014.

  1. navalarchaj
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    navalarchaj Junior Member

    I want the list of drawings to be submitted to class society for the modification of the vessel.

    Modifications:

    1) Inclusion of two longitudinal bulkheads from mid ship towards port side and starboard side

    and also I want all the necessary or minimum drawings need to be submitted to class society if the vessel is not holding previous Class certificate and safety construction certificate??

    Hope you guys respond and get me through this.....
     
  2. Ad Hoc
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    Ad Hoc Naval Architect

    The dwgs/structure you have modified, you submit to Class. It is that simple!

    If the lightship displacement and the LCG vary by more than 1% after modification, you need to re-incline too.
     
  3. TANSL
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    TANSL Senior Member

    The best thing to do is read the rules of the CS which is going to classify the boat. In the first chapters of these rules documents must be submitted for approval / review of the CS are related.
     
  4. rxcomposite
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    rxcomposite Senior Member

    It is listed in the requirements of whatever Class Society you are going to use. "List of drawings to be submitted". Following that, you have to ASSES if the present vessel can pass the requirements of the society. Don't rush as you may find you have to change a lot of things to satisfy Class requirements.
     
  5. navalarchaj
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    navalarchaj Junior Member

    Thank you all for your views......

    I have some doubts which may be small but cannot be neglected, where in ABS rules Part-3 Section 4 (Hull construction and equipment,Bottom structures) for vessels below 90m length .

    What is the unsupporetd span (l) we have to take while doing the calculaions??? -- Pg 56,59,62,63,67,68,71,72,



    Could you provide me some examples of these calculations when you have done before,so that it will be understandable to start the section moduli check of individual members.
     
  6. rxcomposite
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    rxcomposite Senior Member

    You need to have mastery of the rules of the class you are going to use. Failing that, ask for a class surveyor of your choice to do prequal survey. Expensive maybe but that will prevent expensive renovation if you jump in first and find out that this thing and that thing cannot be approve by class.
     
  7. TANSL
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    TANSL Senior Member

    navarchaj, you have no choice but to study a little the rules you want to use. It clearly defines what is reinforcement span, reinforcement spacing, the associated plate, and other many things. Read it and you will see that there is much information contained therein.
     
  8. faradiana2
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    faradiana2 fara

    Arjun,


    Generally, the drawings need to be submit once the modification completed is depend certain question below

    After the modification,

    I) does either new lightship increase or less than 2% from the existing?

    II) does either new LCG increase or less than 1 % from the existing?

    If yes both or either 1 as per above. So in standard practice for the class requirement, the ship/vessel need to do inclining experiment again.

    so, the inclining experiment need to do by class surveyor witness.

    the inclining report shall be submitted for approval.Once it approve..the

    New submission

    i) stability report for approval.

    ii) Bhd contruction drawing to be submit for the structural scantling

    iii)Midship section drawing.
     
  9. TANSL
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    TANSL Senior Member

    faradiana2, I think there is some confusion in your answers. In my opinion, the plans to be submitted no way depend on the variation of the lightship weight, total value or position of its center of gravity. They depend just on the modification suffered by the ship.
    The criteria you explain, justify the need for a new inclining test, which leads to introduce a new stability booklet with all the information it requires.
    In many boats should not submit such information to the Classification Society but directly but to local autorities or delegated entity to these issues.
    I do not remember right now if class requirement talk about when to make a new experience stability. It does talk a bout the rules that each country applies to its boats.
    Inspectors Classification Society do not conduct the inclining test, unless, that task is hired them apart from the class. Experience is performed by a qualified technician, under the builder, who is responsible and who should show if the boat meets or does not meet the applicable regulations.
    Drawings of the structure are to be presented, or not, as you have changed the structure. In general there is no need to submit Bhd construction drawing.
     
  10. faradiana2
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    faradiana2 fara

    ooo...sorry for the confusion,this practice applied to big vessel ...somehow ..in generally for boat less than 24m , class will refer to small vessel less than 24 m regulation. therefore there is no issue on the stability taken into consideration under requirement..only re-incline to have lightship reading and draftmarks reading.

    1.so in this case most of the class societies will issue only for the 'hull compliance cert' if they willing to class the boat .....however each class societies have theirs own enforcement and depend type of boats... .
    2. As the boat never holding any class cert, if enough to submit
    1. General arrangement
    2.structural midship
    3.Bottom structure

    and one thing about 'Inspectors Classification Society do not conduct the inclining test, unless, that task is hired them apart from the class'. They do not conduct..but a witness which is refer to surveyor class attendance and verified during experiment..if the boat holding any class certificate or owner hired class for new building consultancy.
     
  11. TANSL
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    TANSL Senior Member

    I'm sure you're right but, after 43 years working as a naval architec, I've never seen an CS inspector inspecting inclining test that makes other technical.
    My experience covers only boats between 6 m and 150 m in length; from pleasure boats to vessels over 1000 passengers. Maybe that's why I have not seen, as you say, "... which is witness to refer to class attendance and verified surveyor during experiment ..."
    As I said before, I'm sure you're right, but ...
     
  12. faradiana2
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    faradiana2 fara

    ooo...I'm not sure about others class society...but as working as newbuilding surveyor and plan approval engineer one of local class society..that was standard procedure and enforcement ..I also experienced myself by attending number of inclining experiment as a witness..and also refer to my previous explanation that was also standard procedures to our existing customers for existing vessels which are holding our class certificate or any class entry.
     
  13. Ad Hoc
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    Ad Hoc Naval Architect

    I think you're all getting confused with the role of Classification and Statutory regulations.

    Inclining experiments, are part of statutory regulations and are enforced/witnessed and approved by the local Flag state. Some Flag states delegate this role, by agreement, to the Classification society, for all manner of reasons (not worth going into).

    Thus you may well have Class surveyor witness and approving the inclining experiment. But that can only occur, if the Flag state has agreed this beforehand.

    I have had many Class surveyors witness inclining experiments that I have conducted. Reason being the Flag sate didn't really have enough manpower to cover the whole country nor the experience of such vessels. Thus Class performed a duel role.
     

  14. faradiana2
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    faradiana2 fara

    thanks for the well explanation by ad-hoc...yep your are correct..before class society can fully involve all any job ...the owner should 1st request 'authorization letter' from flag state before hired them...once it agreed by flag state..the all jobs ...from beginning till end can be monitor by class without asking permission by flag state time by time...the vessel is already under the class matters if they start to holding class cert or not..depending what owner requirement from the class ...unless dealing will still be continue with flag state for the exemption letters issuance.
     
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