water pump jets on dual hull boats?

Discussion in 'Jet Drives' started by Freddie_220, Dec 16, 2008.

  1. Freddie_220
    Joined: Dec 2008
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    Freddie_220 Junior Member

    My question is that i was wondering about a new M/Y design for a comp.
    Would It be possible to have a tri hull boat, with a slim main hull and two hulls, one on each side of the main hull, with water pump jets installed as propulsion and steering because of the available vectored thrust?
     
  2. marshmat
    Joined: Apr 2005
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    marshmat Senior Member

    Possible? Yup.

    Is it the right solution for the situation? Very hard to say, without knowing anything about how big, how fast, what capabilities, etc.
     
  3. Freddie_220
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    Freddie_220 Junior Member

    The boat would be approx 35m from the front of the main hull to the back, the boat should be as light as possible and also as efficient, this is why it should have a slim main hull which reduces drag and increases efficiency, although there is then the extra drag of the stabilizers with pump-jets inside, the stabilizer size depends on the size of the engine, gearbox and so on.
    __________________
    Frederick de Rohan Willner- 14
     
  4. jim lee
    Joined: Feb 2007
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    jim lee Senior Member

    Why not just one jet in the center hull?

    -jim lee
     
  5. Ilan Voyager
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    Ilan Voyager Senior Member

    Jim is right; why 2 engines? If the tri is slim and light, the outriggers will be very slim and it seems hard to put engine, waterjet, tanks in the outrigger. That could lead to a design of fat and heavy outriggers not very efficient.
    More you may have problems of rolling as the polar inertia of these weights placed far from the center of buoyancy of the main hull. That could be a nice rolling machine...0r a catamaran disguised in trimaran at the end.

    For a light boat you have to shave any non essential weight, and many times a mono engine is more efficient; look at all the cargo ships with one engine. War ships have several engines because requisites of survival. On a lot of medium speed yachts, it would be more efficient to take out one of the engines and all the weight, and if necessary have a small auxiliairy engine. The power needed to move at 9-10 knots a slim trimaran is ridiculously low.

    Another source of problems is the waterjet. These beasts are difficult to tune, are voluminous and heavy (full of water...), and the efficiency is not famous. Placed in the outriggers they will suck air, as the outriggers won't have enough draft if you want to have a good design.

    If the hull is slim, you'll have to cut it brutally at the transom to put the waterjet, and worst you'll have to enlarge the transom to withstand the weight of waterjet. Add you may have a problem of putting the weights of the engine and waterjet at the right place. Surely you'll have to put the engine forward and make a long shaft to couple the engine and the waterjet...complicated, source of noise, vibrations and unreliability.

    Make it simple. Il y a beaucoup plus simple que les jets; quel va etre l'usage du bateau? Je suis tres interesse de savoir plus sur le projet, s'il n'y a pas de probleme de confidentialite. Vous devriez consulter Irens, qui est le plus qualifie en matiere de trimarans ultra legers. Desole, un clavier espagnol n'aide pas pour les accents.

    Look at Ilan Voyager by Nigel Iren...One engine, simple and fast. 21 meters, 6 metric tons, 28 knots with 240 HP, 22 knots cruising with 140 HP. With ocean traveling capabilities.
     
  6. Freddie_220
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    Freddie_220 Junior Member

    my design is based on the ilan voyager,,, where is the bowthruster on the ilan?
     

  7. Freddie_220
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    Freddie_220 Junior Member

    or dont they have one because it is designed to be light?
     
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