Iso 12215-7

Discussion in 'Class Societies' started by glynfricker, Feb 4, 2016.

  1. glynfricker
    Joined: May 2012
    Posts: 2
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: California USA

    glynfricker New Member

    Does any one know of any current developments on ISO 12215-7 Structural design for multi hulls, it is not available for purchase on the ISO site (or any other) and no statement of status.

    I found a ICOMIA article, 2004.1, stating that it had reverted to a preliminary item status but nothing else, even ISO says nothing on their site, unless i am missing something?

    I am designing 14 ft recreational power cat, for sale in the USA and Europe . I believe ABS refers to the ISO 12215-7 in my question, for structural loads. DNV HSLS code covers catamarans but not very small pleasure vessels, DNV 2.21 has min loads and moments for small craft but does not cover any structural design considerations for for multi hulls.

    If anyone has any ideas as to which code applies to small recreational catamarans advise would be appreciated.
     
  2. Ad Hoc
    Joined: Oct 2008
    Posts: 6,712
    Likes: 691, Points: 113, Legacy Rep: 2488
    Location: Japan

    Ad Hoc Naval Architect

    Welcome to the forum glynfricker.

    For small recreational boats ISO would be the obvious choice. However, it is a tedious set of rules.

    If you don't mind the scantlings perhaps being a tad heavier in some places, then DNV rules are so much simpler to navigate. I dont follow what you mean by

    Once you have established the global loads/moments from the rules you then follow:

    http://rules.dnvgl.com/docs/pdf/DNV/ruleshslc/2012-07/hs303.pdf

    Part 3. Ch.3 noted in the link.
     
  3. Alik
    Joined: Jul 2003
    Posts: 2,913
    Likes: 247, Points: 73, Legacy Rep: 1306
    Location: Thailand

    Alik Senior Member

    For 14' power catamaran, You do not need structural assessment, under RCD.

    From experience of calculations of (mostly) composite cats, we found that for power cats below 10-15m global strength is not an issue at all.

    Few months ago I saw preliminary version for 12215-7 and it is much inspired by DNV Rules. It was not the final version but the updated is going to be released soon. So, as AdHoc said, You might use DNV Rules. Though I found GL HSC2012 rules much easier to use for small craft.
     
  4. glynfricker
    Joined: May 2012
    Posts: 2
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: California USA

    glynfricker New Member

    glynfricker

    Thanks for the replies Ad Hoc and Alik.
    I see, on full reading, that I can use DNV 2.21 , they do look heavy on first impressions. Lots of reference to bigger structures.

    I will check out the GL rules
    thanks
     
  5. TANSL
    Joined: Sep 2011
    Posts: 6,317
    Likes: 318, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    Check out the Special Service Craft Rules by Lloyd's. It has its own software, very comfortable and easy to use, with a friendly interface for the user.
     
  6. taniwha
    Joined: Sep 2003
    Posts: 205
    Likes: 9, Points: 18, Legacy Rep: 150
    Location: Pattaya, Thailand

    taniwha Senior Member

    No it is not yet ready so for the time being any classification rule such as ABS or ISO 12215-5 is acceptable.
     
  7. TANSL
    Joined: Sep 2011
    Posts: 6,317
    Likes: 318, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    ISO 12215-5 does not study the specific problems of catamarans, interaction between the hulls, additional pressure on the bow, wet deck, twisting in the deck transversal beams, etc. Therefore, although you could use this rule for some parts of the hull, specific areas of a catamaran would have to be done by direct calculation, imo.
     
  8. taniwha
    Joined: Sep 2003
    Posts: 205
    Likes: 9, Points: 18, Legacy Rep: 150
    Location: Pattaya, Thailand

    taniwha Senior Member

    yes that is correct at the moment ISO 12215-5 can only be use as a base of calculations for multihulls
     
  9. taniwha
    Joined: Sep 2003
    Posts: 205
    Likes: 9, Points: 18, Legacy Rep: 150
    Location: Pattaya, Thailand

    taniwha Senior Member

    Sorry Albert, this is a bit a misunderstanding, you do not need to have it verified by a notified body and you can do so called self-certification but you still have to certify it to all essential requirements of the directive including scantlings. Until 6 m there is a possibility to do a drop test if that is what you are referring to.


     

  10. TANSL
    Joined: Sep 2011
    Posts: 6,317
    Likes: 318, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

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.