The Mighty Mekong expedition boat

Discussion in 'Boat Design' started by greginlaos, Nov 14, 2010.

  1. greginlaos
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    greginlaos GreginLaos

    Well actually timber is more expensive than steel here, if you are not part of the timber mafia. But I get the point about no redesign. What about the increase in beam ?
     
  2. Bijit Sarkar
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    Bijit Sarkar Naval Architect

    Greg,
    WIth catamaran, you can practically turn the boat around on its own axis.

    After reading thru all the posts, my suggestions are as follows:

    Catamaran steel hull, each side hull of length 7m , breadth 1.5 m. spaced with 2.5 m clearence, giving a total deck space of 5.5m. Each side hull is flat bottom.

    pilot cabin forward for good visibility. Mechanical steering. Twin engine of 14 hp each. This will give you a speed of 7 knots approx. You may not run both engines on full power but twin engines guard against one engine conking out fifteen miles north of nowhere and you left adrift with 10 passenger screaming at you .

    Open deck with canopy. A small enclosed space on both side at aft - for basic toilet on stbd and galley/pantry on port side.

    If you think its workable - i will make some sketches and send it in.
     
  3. hoytedow
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    hoytedow Carbon Based Life Form

    If one engine conks out due to bad fuel both probably will, so multiple independant fuel tanks may save the day.
     
  4. Bijit Sarkar
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    Bijit Sarkar Naval Architect

    Normally with two engines, what I would do is keep two f.o tanks , normally interconnected with a valve feeding one service tank . This connection helps to act as a passive stabilizer.

    In case f.o in one tank is suspicious, one can close the valve and isolate that tank.

    The return oil from engine goes back to the service tank, which is easier to clean and maintain.

    However ,with a cat, it may be better to have two service tanks.
     
  5. hoytedow
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    hoytedow Carbon Based Life Form

    Thanks for that valuable tip.
     
  6. apex1

    apex1 Guest

    You already mentioned it, Gulbrandsson has no problem with 20%.

    I would NOT build a CAT btw., and especially not in steel, but you know already how tricky it can become to maneuvre a wide boat on your rivers.

    Regards
    Richard

    ?and Mae´s Restaurant??
     
  7. Bijit Sarkar
    Joined: Sep 2005
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    Bijit Sarkar Naval Architect

    Greg,
    With only 300 draught, you props will be very inefficient. There will be two ways to circumvent this problem.
    One : design a surface piercing prop and house it inside a tunnel stern. Not advisable on a river with floatsum. I am on Ganges,a river very similar in nature with Mekong.

    two : Mount the engine and shaft at an angle so that prop can be bigger and go deeper. It should be sitting on a stool with a swivel mount so that it can be raised when at very low draft of 300. This is assuming for most of the times you will have a larger draft but for some stretches it may be 300. I vote for this.

    by the way, the link u gave for the engine does not work.
     
  8. greginlaos
    Joined: Nov 2010
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    greginlaos GreginLaos

    Howdy, am going for a short trip up the Man Ou with some friends..back in a couple of days..will consider options on the way

    see ya and thanks
     
  9. Alik
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    Alik Senior Member

    7m cat in steel will be damned heavy. I would suggest FRP hulls in sinkle-skin FRP or plywood, joined with transwerse beams. We have designed 7m garbage collector cat recently with simplified hull shape - joined by aluminum pipes, add cabin on top. That cat is powered by jet outboard; I belive for Mekong motor oar is better.
     
  10. kach22i
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    kach22i Architect

  11. Alik
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    Alik Senior Member

    I doubt if there are any steel boat builders in upper Mekong area. I might be wrong...
     
  12. Milan
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    Milan Senior Member

    Economical fuel consumption was on the top of the priorities list for this project. Heavy catamaran with wide hulls and little space between them will not be a low resistance boat.
     
  13. apex1

    apex1 Guest

    The OP asked for building in steel Albert! But I do not recommend a cat for his purpose, the boat has to be transported on land occasionally!

    A long mono would fit the demand.

    Regards
    Richard
     
  14. Alik
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    Alik Senior Member

    Agreed, mono in steel could work. But better to buy local boat and make some modifications.

    Cat in steel with such proportions would be a monster, at least from my understanding.
     

  15. apex1

    apex1 Guest

    Concur on the latter.

    But the OP wants to build, not buy, and he lives there.

    Regards
    Richard
     
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