why two motors on cats?

Discussion in 'Boat Design' started by berney, Jul 5, 2010.

  1. berney
    Joined: Dec 2009
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    berney New Member

    couldn't a cat be designed with one motor and have efficiency and most of the qualities of a cat? I see pontoon boats with one motor. What is themajor problem that requires two motors?
  2. patiras
    Joined: Jan 2007
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    Location: France

    patiras Junior Member

    No problem that requires two motors, however there are advantages to two.
    Redundancy; if your motor fails 10 miles out, you have another one.
    Manoeuverability; spin it on the spot with one forward one reverse.
    Possibly a cleaner flow onto the prop off the back of the hulls than hung in the middle.
    No right or wrong answer really.
  3. Frosty

    Frosty Previous Member

    All of the above and then some, like prop leaving the water engine noise, engine getting swamped etc etc
  4. boybland
    Joined: Jun 2010
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    Location: New Zealand

    boybland Junior Member

    Redundancy by itself should be reason enough, well unless your talking a sailboat in which case the motor is not essential. A lot of sailing cats only have one motor slung from a central pod and retracted during sailing.
  5. Frosty

    Frosty Previous Member

    Wharram type minimalistic crap with single engine longshaft does not appeal to all.

    But-- they do exist!! You'lle not be the first to build one or the last.

    welcome to the forum.

  6. Village_Idiot
    Joined: Oct 2007
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    Village_Idiot Senior Member

    As others have said, many folks prefer the security of having an extra motor, although that is not such a big deal anymore given modern reliable engines and communications devices.

    The biggest issue performance-wise is getting the prop(s) to run in clean water, which is why they are mounted aft of the hull(s) and not between the hulls. The mid-mounts work on pontoons and smaller performance cats (like Texas' flats boats) because they are meant for calmer waters. If you have a true cat and are running in seas greater than 2-3 feet, then you want the props at the end of the hulls, not between where the props may be sucking air every time you go over a wave.

    With that being said, there are single-engine true cats out there, but they typically have their engine mounted on ONE of the hulls, not between the hulls. With two engines, you also have the opportunity for better maneuverability and better overall balance of the craft.
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