Structural design - some brief on approaches

Discussion in 'Boat Design' started by Alik, May 10, 2020.

  1. Ad Hoc
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    Ad Hoc Naval Architect

    That's very interesting - thanks for that David.

    Do you think the US will start to go down the route the UK/EU did by slowly introducing more and more prescriptive rules for such vessels - based upon accidents/injuries etc of such vessel, and lead to the slow introduction and compliance of ISO rules in UK/EU?
     
  2. Eric ruttan
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    Eric ruttan Senior Member

    Nope. What would make you think we care about people dieing?

    But seriously, it will never happen in the US. Regulation in the US favour descriptive over proscriptive rules.
     
  3. Alik
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    Alik Senior Member

    As usual, AdHoc turns any technical discussion into his demagogic exercise. Old man's games with words, instead of sense and help to reader. He is blatantly attacking the colleagues presenting their experience, just to emphasize that he is the only naval architect on this forum. Any other designer, especially non-native English speakers, would be bullied by this unhinged person.

    Just as side note, the same happens when this arrogant person is reviewing the papers for publication... The editor had to apologize to me for such a 'reviewer', who evidently did not know the subject, but his critical comments were longer than the paper...

    This is first time in few years I started a new topic, and it was immediately hijacked by AdHoc, with his misleading comments, not to the subject of the topic.

    I am seriously thinking if I should continue to contribute to this forum? Look, most of colleagues designers are only posting pictures, because they don't want to be pulled into discussion with this person...

    So lets turn it into 'AdHoc's zoo', continue as public forum? Choice is yours.
     
    Last edited: May 14, 2020
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  4. Eric ruttan
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    Eric ruttan Senior Member

    I think one must always punch NAZI's.
    As far as one is able, rebuke evil and praise good, i think.

    Perhaps you should stay. At the very least, sharpen some skills.
     
  5. Boat Design Net Moderator
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    Boat Design Net Moderator Moderator

    With the pandemic it seems everyone's nerves are getting a bit short. As the replies in the last page seem to be starting to get out of hand it's probably a good time to insert a request to please keep posts kind to one another on the forum here, and focused on the topic at hand and away from jabs at other members. Stay safe everyone, and let's please keep the threads here enjoyable and productive for a little respite at least.
     
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  6. DCockey
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    DCockey Senior Member

    The US Federal capacity, stability and floatation regulations for recreational vessels, which apply to monohull vessels under 20 feet which are not sailboats, inflatables, canoes or kayaks or similar, were developed in the early 1970's following the introduction of the first national safety regulations for automobiles. The boat builder or importer is required to certify that the boats meet all aplicable regulations. The scope of the US Federal capacity, stability and floatation regulations has not been expanded since they were first adopted. The only significant change I'm aware has been revisions to the specified weight allowance for outboard motors based on motor power.

    ABYC (American Boat and Yacht Council) which is a non-profit trade association has a set of standards which are voluntary. Non-members can view the list of ABYC standards but not the text of the standards at Standards List - American Boat and Yacht Council https://abycinc.org/page/StandardsSupp58 There are no ABYC standards relating to hull structure, strength, etc. ABYC cooperates with ISO and attempts to harmonize the ABYC standards with the ISO ruls where possible. ABYC publishes the standard but does not certify compliance to the standards. My impression is most production and semi-production boat builders in the US follow the ABYC standards. ABYC standards have been added, modified and expanded in response to accidents and injuries.

    Some US builders are now adhearing to ISO requirements. The most common reason is to be able to export to markets such as the EU which require the ISO standards. A few boats have been advertised in the US as meeting ISO standards, particularly the stability standards.

    The major change in US Federal regulation of boats in the last decade or so have been ones relating to air pollution, both exhaust emmisions from engines and evaporative emmissions from gasoline fuel systems.

    I don't know much about the US commercial fishing vessel requirements. A law was enacted in 2010 which added stability regulations for some vessels. I believe that law was in response to the capsizing of several fishing vessels.
     
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  7. Ad Hoc
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    Ad Hoc Naval Architect

    Many thanks DC.
    Just hope you're not accused of hijacking a thread simply by answering a question!

    That's interesting. I wonder whether this will be revised at some point in the future? The leisure crafts of yesterday are very different from those of today... it would suggest it requires an update of sorts.
    Although I do know the weight allocated per passenger for stability/displacement allowances has changed to account for the average weight person increasing.

    I am aware of this aspect, as it becoming an issue for many commercial vessels.
    Compliance with Tier III is becoming mandatory globally soon and the US requires Tier IV now too.

    Adds a lot of weight and requires considerable space/volume to fit the scrubber units in to small hulls.
     
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  8. Alik
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    Alik Senior Member

    Yes, but no one in the thread has asked question about global strength - see the first page.
    AdHoc just came here and started 'answering' about global strengh (in post #10), distracting completely from the subject ;)
    This is why in post #11 I was confused what was happening... Pure hijacking...
     
  9. DCockey
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    DCockey Senior Member

    I am not aware of any moves to revise the US recreational boat capacity, stability and floatation regulations. I should mention that the regulation involving intact stability only applies to very small boats. I've heard of suggestions that conformance to ISO standards should be acceptable in place of conformance to the USCG regulations but I don't think that has gone forward.
    The US Coast Guard changed the standard passenger weight used for calculations involving "inspected" vessels several years ago. However the formula for under 20 feet recreational vessels was not changed.
     
  10. Ad Hoc
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    Ad Hoc Naval Architect

    But it was you, that first raised the issue of global loads, no one else in post #5.

    My reply was to the 24m enquiry by Eric - that's all, and clearly stated as such.

    It then drifted (as all threads do) from replies by posters including yourself.

    But if you see that differently - that's your prerogative!
     
  11. Ad Hoc
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    Ad Hoc Naval Architect

    So if there are no rules for structure etc as you note above. How does a designer/builder sell their products with confidence that it meets "some standard" or some measure of compliance? Who says what is or is not acceptable?
    Since I assume for insurance purposes some paper of such would be required?
     
  12. Alik
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    Alik Senior Member

    I did not ask any question! I stated that global strength is secondary for small craft, this is statement, this is not a question! This is from my experience!
    Do You see question mark, Mr.Word Twister??
    I don't see any one asking question about global strength. So why man You jumped in?? Whom are You answering in post #10 (without quoting the question)??
     
  13. Ad Hoc
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    Ad Hoc Naval Architect

    It seems your reading is clearly different from mine then. The poster in question posing the question was Eric.

    Thus I replied accordingly.
    But clearly you see answering a posters question as hijacking.
     
  14. Alik
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    Alik Senior Member

    Quote question about global strength! There was no such question...
     

  15. Ad Hoc
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    Ad Hoc Naval Architect

    As i stated above, you clearly read the question posed by Eric, very differently from me.
    That's your prerogative not to read it that way.
     
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