ISO 12215-6:2008 references to the old 12215-5:2008

Discussion in 'Class Societies' started by Midja, May 1, 2023.

  1. Midja
    Joined: Oct 2022
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    Location: Norway

    Midja Junior Member

    Hello,

    I have a doubt regarding references in ISO 12215-6:2008. It was bought in 2018, and as I can see, document was just reviewed this year, there is not any new version. I am willing to buy new reviewed version only if references in document have been updated to the new 12215-5:2019 rules, but ISO customer service can not confirm that.

    So, as I already wrote, I am using ISO 12215-6:2008, but references inside the document are referring to old ISO rules 12215-5:2008. I would like to check with you if the newer, reviewed version of ISO 12215-6:2008 has references to the new ISO 12215-5:2019.

    I can give you an example where you can check that relevant information; chapter 7 Specific structural details for FRP construction; subchapter 7.1.2.4 Reinforcement of protected zones, I quote:
    "For the protective keel, stem and chine, the minimum dry glass weight of reinforcement for bottom, wmin, as
    defined in ISO 12215-5:2008, Equation (47), is:"
    So my question is, part of text where ISO 12215-5:2008 is mentioned, is it replaced with ISO 12215-5:2019 or some other term? If not, which equation should I use?

    upload_2023-5-1_11-28-28.png
     
  2. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    From what I see on the official website of the ISO organization, there is no new ISO 12215-6 to replace the one from 2008. Some countries, such as Spain, have published ISO 12215-6:2018, which is exactly the same as the from 2008.
    In relation to your question about chapter 7.1.2.4, what I understand is that the Wmin that must be considered is the value obtained in accordance with ISO 12215-5:2019, multiplied by the corresponding factor depending on whether it is the keel (2.2), stem (2.0) or chine (1.7).
     
  3. Midja
    Joined: Oct 2022
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    Midja Junior Member

    Yes, I agree with you, but Wmin is referenced in old document (12215-5:2008) which is out of the use.
    In new version of 12215-5:2019, Wmin is mentioned in Annex I, I would like to confirm that it is ok to use that formulae from Annex I, because there are few differences between Wmin formulae in 12215-5:2008 and 12215-5:2019.

    Thanks!
     
  4. TANSL
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    TANSL Senior Member

    What I apply, of course, is the value of Wmin that is deduced from 12215-5:2019. The calculations of 2008 are no longer valid, they have been replaced by those of 2019.
    You are right, there are quite a few differences between the two standards and it is difficult to know what they are due to. No one explains the reason for the changes. Some have reported errors in the 2019 standard, but the fact is that the entities in charge of verifying the projects follow the standard to the letter, even if it has errors and they know it. Best to forget that 2008 ever existed and use 2019 instead.
     
  5. rxcomposite
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    rxcomposite Senior Member

    That is the weight. What about the width? It says 40 Bh with Bh being the beam of hull in meters. Is it 40 x Bh or 0.04x Bh or 40 x Bh/1000?
     
    Last edited: May 2, 2023
  6. Midja
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    Midja Junior Member

    Thank you, all clear :)
     
  7. Midja
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    Midja Junior Member

    Here is the answer:
    upload_2023-5-2_18-32-10.png
     
  8. rxcomposite
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    rxcomposite Senior Member

    Seemed superfluous that dry fiber weight equation 47. I did worked some numbers and came up with a ridiculously low Wmin for a bottom plate. Combined with a factor for increased fiber weight for keel, chine, stem, it is still low.

    Eq 35 Tmin, (min thickness) seems to take more precedence and more reasonable but then that increased dry fiber weight will not work since it is based on weight.

    Something wrong?
     
    Last edited: May 4, 2023

  9. Midja
    Joined: Oct 2022
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    Midja Junior Member

    I agree with you, I get same low numbers for Wmin; aprox 6 times lower dry fiber weight per panel than calculated through ply by ply method.
    I don`t believe something is wrong since ISO gives you several parameters, as Wmin and tmin to use them in conjunction and have minimum reference point.
    Wmin regarding increased fiber weight for critical areas (keel,...) is in my opinion good reference. It gives additional aprox. 5-6 plies, everything above would be too much.
     
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