Which bow thruster?

Discussion in 'Surface Drives' started by rfleet1066, Jul 29, 2012.

  1. rfleet1066
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    rfleet1066 rfleet1066

    I am coming along with the river boat project. About ready for the deck. Now looking for thru-hull bow and stern thrusters I see several manufacturers offer them.

    Any pros and cons? Lewmar and Vetus are the ones that stand out.

    Ideas?

    Ryland
     
  2. PAR
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    PAR Yacht Designer/Builder

    Bow thrusters require some depth to the fore foot to be effective. If you're shallow in the eyes, a drop down thruster is the way to go. What boat is this going on?
     
  3. rfleet1066
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    rfleet1066 rfleet1066

    bow thruster

    This vessel is a pontoon type landing craft, 60" diameter hulls. Waterlline will be less than 28"

    Ryland
     
  4. PAR
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    PAR Yacht Designer/Builder

  5. rfleet1066
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    rfleet1066 rfleet1066


    Yep, here it is.

    Ryland
     

    Attached Files:

  6. PAR
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    PAR Yacht Designer/Builder

    The Vetus will likely be the one that fits your needs best, just from the size of the tube.
     
  7. FAST FRED
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    FAST FRED Senior Member

    I would investigate the possibility of using an 18 to 30HP outboard in a bracket.

    Mounted far fwd facing athwartship with shift cable operation.

    Electric units like the Vetus have very severe time limits and at best are a couple of HP.

    With a remote start OB real power could be had inexpensively.

    With some thought , might even work as get home engine ?

    FF
     
  8. powerabout
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    powerabout Senior Member

    one outboard at each end
    turn them sideways and it will go sideways especially if they are facing each other so you will need to lift the front one when travelling a long distance
     
  9. Red Dwarf
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    Red Dwarf Senior Member

    That is exactly what I am considering. Both are retractable and electric. Basically big trolling motors.
     
  10. BMcF
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    BMcF Senior Member

    Along the lines of previously offered advice, I've run a Sidepower 24V thruster for a number of years on a trimaran hull and:

    1. The power drain is tremendous; even with the multiple large batteries in the bank, too much thruster use quickly draws things down and creates problems for other electronics.

    2. You cannot have too much immersion. At an average of only about a foot of depth above the TOP of my tunnel, it sucks a ton of air and that really kills its effectiveness. 2' or so of immersion above the tunnel top seems to be about the minimum, as we found by having crew run forward to trim down by the bow when the thruster was urgently required. I cannot see any way you would ever achieve anything close to 2' of immersion to top of the tunnel on those pontoon hulls.
     

  11. PAR
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    PAR Yacht Designer/Builder

    A twin main engine setup will eliminate much if not all of the need for a thruster, which on a multi hull is a difficult proposition anyway. Since a twin setup is reasonable and logical on your big pontoon boat, this is the route I'd strongly recommend.
     
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