Bow thruster for shallow waters?

Discussion in 'Boat Design' started by ted655, Dec 18, 2007.

  1. ted655
    Joined: May 2003
    Posts: 640
    Likes: 14, Points: 0, Legacy Rep: 122
    Location: Butte La Rose, LA.

    ted655 Senior Member

    Anyone have an idea on a design or turnkey bow thruster for large houseboat that lives in both deep & shallow waters?
    A permanent thru hull won't work. I've thought of one mounted onto a hyd. jack plate, but the range is only 6". Not enough.
    ????:confused:
     
  2. Scott Carter
    Joined: Oct 2006
    Posts: 130
    Likes: 11, Points: 0, Legacy Rep: 143
    Location: Annapolis

    Scott Carter Senior Member

    Ted,
    I'm unclear about your reference to the boat living in both deep and shallow waters and the connection with a need for its bow thruster to have variable positioning (vertically I assume). Perhaps my idea of shallow is not what this boat's idea of shallow is. How shallow (relative to water beneath the keel)?
    Can you elaborate on this requirement?
    Scott
     
  3. kach22i
    Joined: Feb 2005
    Posts: 2,414
    Likes: 111, Points: 63, Legacy Rep: 1222
    Location: Michigan

    kach22i Architect

    There was a thread on this a while back, but I forget in which section of the forum. There were some nice posts including links to videos. Please use the "SEARCH" function.

    I had posted this in the Random Picture thread, I hope it helps you.

    http://www.willdo.nl/
    [​IMG]
    [​IMG]
     
  4. ted655
    Joined: May 2003
    Posts: 640
    Likes: 14, Points: 0, Legacy Rep: 122
    Location: Butte La Rose, LA.

    ted655 Senior Member

    Louisiana is swamp country. The rivers & canals may be up to `10 meters deep, but out of the channels we often encounter less than a meter. Something "fixed" would soon be stuck in the mud/sand or torn off. We use either sterndrives or outboards on jackplates to deal with these conditions. The bow thruster must be equally versatile.
    .
    In this case, we just now realize a bow thruster is needed. It is a retrofit & needs to be easily installed without major modifications to existing hull or cabin.
    .
    I am wondering about water jet thrusters. I might add, the displacement of this boat is 80,000 lbs.. 23' wide X 50" long.
    See picture.
     

    Attached Files:

  5. ted655
    Joined: May 2003
    Posts: 640
    Likes: 14, Points: 0, Legacy Rep: 122
    Location: Butte La Rose, LA.

    ted655 Senior Member

    Kach22i, thanks! This one IS a possible solution.:D
     
  6. FAST FRED
    Joined: Oct 2002
    Posts: 4,519
    Likes: 110, Points: 63, Legacy Rep: 1009
    Location: Conn in summers , Ortona FL in winter , with big d

    FAST FRED Senior Member

    An electric start outboard , rigged athwartships as bowthruster , could be used easily.

    Instead of shifting fwd and reverse a lever instead of a wheel would turn the engine , so if (when) you hit the nus , the outboard could pivot up as usual.

    15hp is a HECK of a thruster,but whatever you have in the garage will do.

    Send Boudain,

    FF
     
  7. ted655
    Joined: May 2003
    Posts: 640
    Likes: 14, Points: 0, Legacy Rep: 122
    Location: Butte La Rose, LA.

    ted655 Senior Member

    At what HP do they give an option of remotes? higher than 5hp? We had thought of doing that but OBs will only turn a limited arc. This would require one on each side & still not give true side thrust in tight docking. BUT... it probably is the cheapest.
    .
    Here is a "hammerhead boat, set up as you describe. This boat had 4, 70hp Mercs. 2 in aft motor wells & 1, each side, where the rail gates are. Also no anchor! It used spud poles instead. It has a few other inovations also, if anyone is interested.
     

    Attached Files:

  8. kengrome
    Joined: Jul 2006
    Posts: 718
    Likes: 25, Points: 0, Legacy Rep: 305
    Location: Gulf Coast USA

    kengrome Senior Member

    So is a 9.9 HP high thrust outboard with remote controls, isn't it.
     
  9. Pericles
    Joined: Sep 2006
    Posts: 2,009
    Likes: 135, Points: 63, Legacy Rep: 1307
    Location: Heights of High Wycombe, not far from River Thames

    Pericles Senior Member

  10. ted655
    Joined: May 2003
    Posts: 640
    Likes: 14, Points: 0, Legacy Rep: 122
    Location: Butte La Rose, LA.

    ted655 Senior Member

  11. Village_Idiot
    Joined: Oct 2007
    Posts: 382
    Likes: 14, Points: 18, Legacy Rep: 138
    Location: USA

    Village_Idiot Senior Member

    Here's an idea...
    In its most simplistic form, how about a pipe mounted transverse to the square bow of the houseboat? Run a jet from elsewhere on the boat and pipe the outflow to this bow pipe, say, in the form of a T-arrangement. Simply switching (via remote) a valve in the pipe would give you max lateral thrust in either direction. You will never have thrust fore or aft, and you shouldn't need it, as it would be wasted energy for a "bow" thruster.

    :idea: Now, a more efficient design would be curved pipes in a Y-formation with a switching valve at the junction of the Y-pipe.:idea: Jet motor would be sized to whatever you require and could be placed anywhere on the boat (as long as you have adequate water feed). Maybe even a small jet would be sufficient, something like the powertrain from this contraption: http://www.mokai.com/the-mokai.html

    As an alternate, you may be able to design a propeller into the pipe itself and rig a reversible drive for the prop. Key here would be to have a prop with equal thrust in both directions. This design would eliminate excess piping.

    For out-of-the-box thinking, I would like to see "walking" spud bars, something that could pull the boat around in shallow water using hydraulics or even rope (in a block & tackle with pully reduction) to pull the bar around an elevated pivot point. This is what some of the old steamwheelers used on the untamed rivers of yore to slowly but surely pull themselves off/over sandbars. Would be a slow system and take up some valuable space, but would also be a real conversation piece and add character to the boat. :D

    To carry the terrestrial concept further, perhaps you could use a transverse paddlewheel (of sorts) mounted on the bow. The wheel can then paddle through the deeper water and walk through the shallow water. You might still want a way to raise and lower it. Again, a very non-elegant contraption, but a real conversation piece. :p
     
  12. ted655
    Joined: May 2003
    Posts: 640
    Likes: 14, Points: 0, Legacy Rep: 122
    Location: Butte La Rose, LA.

    ted655 Senior Member

    VI, thanks. Kach22i's link is as exactly as you describe, we are checking on the $$ to see if it is in the budget. We think side jets are the solution,
    I have a couple duck hunter friends who are interested in your link.
    I'm afraid the spuds require to much retrofit & weight.:)
     

  13. FAST FRED
    Joined: Oct 2002
    Posts: 4,519
    Likes: 110, Points: 63, Legacy Rep: 1009
    Location: Conn in summers , Ortona FL in winter , with big d

    FAST FRED Senior Member

    We had thought of doing that but OBs will only turn a limited arc. This would require one on each side & still not give true side thrust in tight docking. BUT

    To me it would seem easier to design a mount that DOES swivel 180 deg , to mount an outboard on . than any other building project.

    FF
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.