Banka-style boat

Discussion in 'Boat Design' started by muckdiver, Jan 18, 2013.

  1. muckdiver
    Joined: Jan 2013
    Posts: 7
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    Location: Philippines

    muckdiver Junior Member

    Thanks for the info. Next time I am on the boat I will look for other levers/switches on the transmission. The captain does use the clutch.

  2. Keith Gardiner
    Joined: Jul 2019
    Posts: 1
    Likes: 0, Points: 1
    Location: Tablas, Philippines

    Keith Gardiner New Member

    I appreciate that this is a very old thread but I bought a locally built Banka last year. She is a 53 ft composite marine-ply/fibreglass vessel and has a Mitsu 4DR5 engine and gearbox (4 speed) in her belly. This is bolted down in the hull without any mountings but at the tail of the gearbox, there is a steel thrust-plate (also bolted to the hull) through which the prop-shaft is mounted and I imagine that the objective is to avoid the prop pushing thrust onto the gearbox/engine. If this were not there, one can imagine the huge lateral pressure placed upon the gearbox drive-shaft. My experience with automotive gearboxes reveals that these are usually simple thrust washers or small circumferential roller-bearings. I haven't removed the thrust-plate assembly but I'm pretty sure that there is a conical bearing or thrust plate device in there which diverts the prop-shaft thrust into the hull through the thrust-plate and onto the hull.....there must be a nautical term for these somewhere?
    Regarding the exhaust system, this runs through the length of the hull but on the down-pipe from the header, a small pipe is inserted and which feeds in sea-water from a duct below the water-line and which cools and silences the system. A ball-cock is used to shut-off the water ingress once the engine is stopped.
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