Progressive Flooding

Discussion in 'Stability' started by Leopard, Nov 22, 2021 at 6:12 AM.

  1. Leopard
    Joined: Monday
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    Leopard Junior Member

    How to prevent progressive flooding in ship using marine valves? Could you please share any piping arrangement with valves that prevent progressive flooding? I was thinking about adding two valves one near the manifold and one near the each tank. However, what type of valve will be suitable in such a case. Please share your suggestion. Thank you.
     
    marufuddin0 likes this.
  2. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    If there is water flowing through a valve that is flooding a ship, simply closing it will prevent flooding. Are you asking about a broken pipe or hose that is attached to a through-hull fitting below the waterline?
     
  3. jehardiman
    Joined: Aug 2004
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    jehardiman Senior Member

    IIRC, the location of the hull and backup valves is specified in the class rules. Generally, the larger the pipe, the closer the backup valve must be to the hull valve and the closer the hull valve must be to the sea chest.
     
  4. Leopard
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    Location: Belgium

    Leopard Junior Member

    To avoid progressive flooding, I need to add valves near the tanks in bilge,ballast piping system. However, If I add valves under the double bottom, it won't be accessible unless the are remotely operable. So, my thoughts are using remotely operable, most preferably mechanical valve. I was thinking about common practice in such a case. What types of mechanical valves are used for preventing progressive flooding usually? Or alternative methods are adopted to avoid progressive flooding? It will be easier for you to understand me if you have the experience of damage stability booklet for a passenger vessel under class.
     
  5. Leopard
    Joined: Monday
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    Likes: 2, Points: 3
    Location: Belgium

    Leopard Junior Member

    To avoid progressive flooding, I need to add valves near the tanks in bilge,ballast piping system. However, If I add valves under the double bottom, it won't be accessible unless the are remotely operable. So, my thoughts are using remotely operable, most preferably mechanical valve. I was thinking about common practice in such a case. What types of mechanical valves are used for preventing progressive flooding usually? Or alternative methods are adopted to avoid progressive flooding? It will be easier for you to understand me if you have the experience of damage stability booklet for a passenger vessel under class.
     
  6. Leopard
    Joined: Monday
    Posts: 14
    Likes: 2, Points: 3
    Location: Belgium

    Leopard Junior Member

    To avoid progressive flooding, I need to add valves near the tanks in bilge,ballast piping system. However, If I add valves under the double bottom, it won't be accessible unless the are remotely operable. So, my thoughts are using remotely operable, most preferably mechanical valve. I was thinking about common practice in such a case. What types of mechanical valves are used for preventing progressive flooding usually? Or alternative methods are adopted to avoid progressive flooding? It will be easier for you to understand me if you have the experience of damage stability booklet for a passenger vessel under class.
     
  7. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    Like in other of your posts it looks like you want someone to do your homework.
     
  8. Leopard
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    Leopard Junior Member

    It looks like you don't know the answers. Do you have the experience of doing stability booklet for a passenger vessel under class?
     
  9. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    I've 30 years of doing stability books for passengers vessels - as I am sure JEH and others have too.

    And thus, as Gonzo notes, it does seem you wish others to do your work for you.

    Because if you are a naval architect (as your previous thread implies), you would know, it is NOT Class that require the stability book, it is statutory.
    The flags state require the stability book. Some Flag states differ to Class, for a multitude of reasons, but it is STILL a Statuary requirement, not Class.
    Seems this simple differentiation between Class and Flag has eluded you in your studies ....
     
    RAraujo likes this.
  10. Leopard
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    Leopard Junior Member

    Do you mean class will give certificate to a ship even if a ship does not comply damage stability requirement of the class?
     
  11. Ad Hoc
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    Ad Hoc Naval Architect

    Do you understand the role of Class and Flag?
     
  12. Leopard
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    Leopard Junior Member

    No I don't understand. Could you please answer " Do you mean class will give certificate to a ship even if a ship does not comply damage stability requirement of the class?" this question? We are facing a big difficulty since one of our vessels did not comply the damage stability and consequently we are not getting certificate from class.
     
  13. gonzo
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    gonzo Senior Member

    If that is the problem, you need to hire a Naval Architect and maybe also a lawyer. Your vessel appears to have serious issues that may be inherent to the design or construction. This link will explain some of the basics: https://www.mitags.org/certificates-for-ships/
     
  14. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    How and why are the criteria for after damage stability not met?
     

  15. Ad Hoc
    Joined: Oct 2008
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    Location: Japan

    Ad Hoc Naval Architect

    In very broad simple terms:

    Class – consider the safety of the vessel
    Statutory/Flag – consider the safety of those on board.

    Class is independent and you can pick and choose who you want.
    Statutory – is global and controlled by IMO, and is applicable to every vessel built.

    Class – you can have just the hull structure as “Classed”. That’s it. You, as the client are paying for a service. If all you require is just the hull structure, than that is all you pay for and that is all that is shown on the Class certificate – hull structure only.
    Or
    You can go full Class certified, which of course costs considerably more and the hull structure, the mechanical and electrical systems are all inspected and designed to satisfy their rules. Where every item on the boat must be certified by that Class authority, and each item comes with its own certified stamp of approval. Whether it is the main engine, or stainless steel bolts or electrical glands or wiring and steel/aluminium used etc. All come with a Class cert.

    Stability is not a Class requirement, they do not set rules for such. .

    So, there is a very wide range of Class certified approvals – take your pick. So, look at your Class notation and the contract between the yard and the Class society, that’ll tell you what you must comply with to be “classed approved”.

    You can, but very foolish/risky depending on the type of boat, even have your vessel not even Classed, as it is not a requirement. However, it will be very difficult to get insurance for such a vessel, thus, one tends to default to getting a Class cert of sorts.

    Statutory/Flag, in the specification of the vessel, it will state the Class being used that it is being built too (see above) and also, the rules/regulations for stability and passengers that it complies with. For example, is it a HSC Code boat, or an Oil Tanker, or Passenger vessel, tug etc etc. Each vessel type has a set of rules it must comply with – see SOLAS for more details. Some countries have their own interpretations and amendments to the statutory rules too, which differ slightly to those in IMO. But have safety for those on-board at the heart of their philosophy.
    These rules are mandatory for every vessel.

    Thus, you have Flag and Class rules to satisfy.

    Some Flag-state countries do not have the in-house ability or staff available, to perform the Statutory rule checks, such as stability books, inspecting life rafts, or evacuation routes or Loadline compliance etc etc . Basically anything that influence the safety of any person on-board. In this case, Flag will defer their role and responsibility to Class. In this case Class will perform the role of both Class and Flag state, then you must do what Class says – you have no choice in their ole of doing both.

    The advantage of going separate, that is submitting plans/dwgs etc to the Flag state directly rather than via Class, is that where a rule seems onerous, you can appeal against it via a dispensation and provide mitigation as to why. Sometimes, not all the time, they accept. Whereas, if Class are doing the role of both, then Class will not accept any deviation or mitigation – they just apply the rule as written.

    That’s it in a nut shell.
     
    Sam C, Leopard and Rumars like this.
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