deadweight

Discussion in 'Propulsion' started by janzero, Mar 8, 2011.

  1. janzero
    Joined: Feb 2011
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    janzero New Member

    hi guys!

    new member here..just want to know how do you get the particulars given the deadweight or the gross tonnage? i found several ways but i dont know exactly what to use.. is giving range of ratio L/B, B/d, d/D ok to use? have their any fix ratio for every types of vessel?
     
  2. gonzo
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    gonzo Senior Member

    Tonnage formulas are different depending on the country. The same vessel would not measure the same under the diverse rules.
     
  3. Ad Hoc
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    Ad Hoc Naval Architect

    Incorrect.

    Janzero

    It is a simple formulae, viz:

    Tonnage Rules.jpg
     
  4. gonzo
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    gonzo Senior Member

    The tonnage is a measure to calculate taxation. It is different depending on the rules of the country.
     
  5. Ad Hoc
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    Ad Hoc Naval Architect

    The amount of tax, for each country may be different. But the question is about tonnage how to calculate the tonnage, not taxation.

    The tonnage caculation is an international standard and has been inforced since 1982; "Merchnat Shipping (tonnage) Regulation 1982". It is the same formula no matter where in the world one is, nowt to do with what tax you pay.
     
  6. RAraujo
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    RAraujo Senior Member - Naval Architect

    In fact there are several rules for tonnage measurement...

    The most widely used, and applicable to ships on international voyages whose government is signatory of the Convention, is the International Convention on Tonnage Measurement of Ships (ITC69).

    This was a major effort to harmonize the tonnage rules for ships on international trade (before each had to comply with own flag rules which could result in similar ships having quite different tonnages).

    This Convention, expressely, is not applicable to ships of war, ships under 24 metres and ships navigating some inland waters.

    Some countries have extended their application, by internal legislation, to other vessels. EU, for instance, has adapted it to vessels under 24 metres.

    Other Administrations have their own rules for ships not engaged on international voyages or for specific purposes (Suez Canal tonnage for instance) and others have adapted theirs to the ITC type (UTM for Panama Canal).

    There are still cases when different tonnage rules are applied and ships have two tonnage values assigned.

    Now back to the question: if you know the ship type, and eventually mode/place of operation, you can have an idea of the particulars by the tonnage and/or deadweight but nothing very precise (which particulars are you looking for?).

    Note that the type/place of operation may have a strong influence on the particulars for the same type of ship (e.g. a ro-ro pax operating in the Baltic will be very different from a ro-ro pax operating from Spain to Cannary Islands).

    Rodrigo
     

  7. janzero
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    janzero New Member

    thanks..

    but i think i'll just use the formulas given by C.B Barass.. assume deadweight coefficient for a specific type of ship( for example bulk carrier) and then i'll jsut use the ratios L/B, B/D given in ABS since im using ABS as my class...thanks for ur help! really appreciate it..:)
     
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